1 /*
2  * MPEG-4 decoder
3  * Copyright (c) 2000,2001 Fabrice Bellard
4  * Copyright (c) 2002-2010 Michael Niedermayer <michaelni@gmx.at>
5  *
6  * This file is part of FFmpeg.
7  *
8  * FFmpeg is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU Lesser General Public
10  * License as published by the Free Software Foundation; either
11  * version 2.1 of the License, or (at your option) any later version.
12  *
13  * FFmpeg is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16  * Lesser General Public License for more details.
17  *
18  * You should have received a copy of the GNU Lesser General Public
19  * License along with FFmpeg; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21  */
22 
23 #define UNCHECKED_BITSTREAM_READER 1
24 
25 #include "libavutil/internal.h"
26 #include "libavutil/opt.h"
27 #include "libavutil/pixdesc.h"
28 #include "error_resilience.h"
29 #include "hwaccel.h"
30 #include "idctdsp.h"
31 #include "internal.h"
32 #include "mpegutils.h"
33 #include "mpegvideo.h"
34 #include "mpegvideodata.h"
35 #include "mpeg4video.h"
36 #include "h263.h"
37 #include "profiles.h"
38 #include "thread.h"
39 #include "xvididct.h"
40 #include "unary.h"
41 
42 /* The defines below define the number of bits that are read at once for
43  * reading vlc values. Changing these may improve speed and data cache needs
44  * be aware though that decreasing them may need the number of stages that is
45  * passed to get_vlc* to be increased. */
46 #define SPRITE_TRAJ_VLC_BITS 6
47 #define DC_VLC_BITS 9
48 #define MB_TYPE_B_VLC_BITS 4
49 #define STUDIO_INTRA_BITS 9
50 
51 static int decode_studio_vol_header(Mpeg4DecContext *ctx, GetBitContext *gb);
52 
53 static VLC dc_lum, dc_chrom;
54 static VLC sprite_trajectory;
55 static VLC mb_type_b_vlc;
56 
57 static const int mb_type_b_map[4] = {
58     MB_TYPE_DIRECT2 | MB_TYPE_L0L1,
59     MB_TYPE_L0L1    | MB_TYPE_16x16,
60     MB_TYPE_L1      | MB_TYPE_16x16,
61     MB_TYPE_L0      | MB_TYPE_16x16,
62 };
63 
64 /**
65  * Predict the ac.
66  * @param n block index (0-3 are luma, 4-5 are chroma)
67  * @param dir the ac prediction direction
68  */
ff_mpeg4_pred_ac(MpegEncContext * s,int16_t * block,int n,int dir)69 void ff_mpeg4_pred_ac(MpegEncContext *s, int16_t *block, int n, int dir)
70 {
71     int i;
72     int16_t *ac_val, *ac_val1;
73     int8_t *const qscale_table = s->current_picture.qscale_table;
74 
75     /* find prediction */
76     ac_val  = &s->ac_val[0][0][0] + s->block_index[n] * 16;
77     ac_val1 = ac_val;
78     if (s->ac_pred) {
79         if (dir == 0) {
80             const int xy = s->mb_x - 1 + s->mb_y * s->mb_stride;
81             /* left prediction */
82             ac_val -= 16;
83 
84             if (s->mb_x == 0 || s->qscale == qscale_table[xy] ||
85                 n == 1 || n == 3) {
86                 /* same qscale */
87                 for (i = 1; i < 8; i++)
88                     block[s->idsp.idct_permutation[i << 3]] += ac_val[i];
89             } else {
90                 /* different qscale, we must rescale */
91                 for (i = 1; i < 8; i++)
92                     block[s->idsp.idct_permutation[i << 3]] += ROUNDED_DIV(ac_val[i] * qscale_table[xy], s->qscale);
93             }
94         } else {
95             const int xy = s->mb_x + s->mb_y * s->mb_stride - s->mb_stride;
96             /* top prediction */
97             ac_val -= 16 * s->block_wrap[n];
98 
99             if (s->mb_y == 0 || s->qscale == qscale_table[xy] ||
100                 n == 2 || n == 3) {
101                 /* same qscale */
102                 for (i = 1; i < 8; i++)
103                     block[s->idsp.idct_permutation[i]] += ac_val[i + 8];
104             } else {
105                 /* different qscale, we must rescale */
106                 for (i = 1; i < 8; i++)
107                     block[s->idsp.idct_permutation[i]] += ROUNDED_DIV(ac_val[i + 8] * qscale_table[xy], s->qscale);
108             }
109         }
110     }
111     /* left copy */
112     for (i = 1; i < 8; i++)
113         ac_val1[i] = block[s->idsp.idct_permutation[i << 3]];
114 
115     /* top copy */
116     for (i = 1; i < 8; i++)
117         ac_val1[8 + i] = block[s->idsp.idct_permutation[i]];
118 }
119 
120 /**
121  * check if the next stuff is a resync marker or the end.
122  * @return 0 if not
123  */
mpeg4_is_resync(Mpeg4DecContext * ctx)124 static inline int mpeg4_is_resync(Mpeg4DecContext *ctx)
125 {
126     MpegEncContext *s = &ctx->m;
127     int bits_count = get_bits_count(&s->gb);
128     int v          = show_bits(&s->gb, 16);
129 
130     if (s->workaround_bugs & FF_BUG_NO_PADDING && !ctx->resync_marker)
131         return 0;
132 
133     while (v <= 0xFF) {
134         if (s->pict_type == AV_PICTURE_TYPE_B ||
135             (v >> (8 - s->pict_type) != 1) || s->partitioned_frame)
136             break;
137         skip_bits(&s->gb, 8 + s->pict_type);
138         bits_count += 8 + s->pict_type;
139         v = show_bits(&s->gb, 16);
140     }
141 
142     if (bits_count + 8 >= s->gb.size_in_bits) {
143         v >>= 8;
144         v  |= 0x7F >> (7 - (bits_count & 7));
145 
146         if (v == 0x7F)
147             return s->mb_num;
148     } else {
149         if (v == ff_mpeg4_resync_prefix[bits_count & 7]) {
150             int len, mb_num;
151             int mb_num_bits = av_log2(s->mb_num - 1) + 1;
152             GetBitContext gb = s->gb;
153 
154             skip_bits(&s->gb, 1);
155             align_get_bits(&s->gb);
156 
157             for (len = 0; len < 32; len++)
158                 if (get_bits1(&s->gb))
159                     break;
160 
161             mb_num = get_bits(&s->gb, mb_num_bits);
162             if (!mb_num || mb_num > s->mb_num || get_bits_count(&s->gb)+6 > s->gb.size_in_bits)
163                 mb_num= -1;
164 
165             s->gb = gb;
166 
167             if (len >= ff_mpeg4_get_video_packet_prefix_length(s))
168                 return mb_num;
169         }
170     }
171     return 0;
172 }
173 
mpeg4_decode_sprite_trajectory(Mpeg4DecContext * ctx,GetBitContext * gb)174 static int mpeg4_decode_sprite_trajectory(Mpeg4DecContext *ctx, GetBitContext *gb)
175 {
176     MpegEncContext *s = &ctx->m;
177     int a     = 2 << s->sprite_warping_accuracy;
178     int rho   = 3  - s->sprite_warping_accuracy;
179     int r     = 16 / a;
180     int alpha = 1;
181     int beta  = 0;
182     int w     = s->width;
183     int h     = s->height;
184     int min_ab, i, w2, h2, w3, h3;
185     int sprite_ref[4][2];
186     int virtual_ref[2][2];
187     int64_t sprite_offset[2][2];
188     int64_t sprite_delta[2][2];
189 
190     // only true for rectangle shapes
191     const int vop_ref[4][2] = { { 0, 0 },         { s->width, 0 },
192                                 { 0, s->height }, { s->width, s->height } };
193     int d[4][2]             = { { 0, 0 }, { 0, 0 }, { 0, 0 }, { 0, 0 } };
194 
195     if (w <= 0 || h <= 0)
196         return AVERROR_INVALIDDATA;
197 
198     /* the decoder was not properly initialized and we cannot continue */
199     if (sprite_trajectory.table == NULL)
200         return AVERROR_INVALIDDATA;
201 
202     for (i = 0; i < ctx->num_sprite_warping_points; i++) {
203         int length;
204         int x = 0, y = 0;
205 
206         length = get_vlc2(gb, sprite_trajectory.table, SPRITE_TRAJ_VLC_BITS, 3);
207         if (length > 0)
208             x = get_xbits(gb, length);
209 
210         if (!(ctx->divx_version == 500 && ctx->divx_build == 413))
211             check_marker(s->avctx, gb, "before sprite_trajectory");
212 
213         length = get_vlc2(gb, sprite_trajectory.table, SPRITE_TRAJ_VLC_BITS, 3);
214         if (length > 0)
215             y = get_xbits(gb, length);
216 
217         check_marker(s->avctx, gb, "after sprite_trajectory");
218         ctx->sprite_traj[i][0] = d[i][0] = x;
219         ctx->sprite_traj[i][1] = d[i][1] = y;
220     }
221     for (; i < 4; i++)
222         ctx->sprite_traj[i][0] = ctx->sprite_traj[i][1] = 0;
223 
224     while ((1 << alpha) < w)
225         alpha++;
226     while ((1 << beta) < h)
227         beta++;  /* typo in the MPEG-4 std for the definition of w' and h' */
228     w2 = 1 << alpha;
229     h2 = 1 << beta;
230 
231     // Note, the 4th point isn't used for GMC
232     if (ctx->divx_version == 500 && ctx->divx_build == 413) {
233         sprite_ref[0][0] = a * vop_ref[0][0] + d[0][0];
234         sprite_ref[0][1] = a * vop_ref[0][1] + d[0][1];
235         sprite_ref[1][0] = a * vop_ref[1][0] + d[0][0] + d[1][0];
236         sprite_ref[1][1] = a * vop_ref[1][1] + d[0][1] + d[1][1];
237         sprite_ref[2][0] = a * vop_ref[2][0] + d[0][0] + d[2][0];
238         sprite_ref[2][1] = a * vop_ref[2][1] + d[0][1] + d[2][1];
239     } else {
240         sprite_ref[0][0] = (a >> 1) * (2 * vop_ref[0][0] + d[0][0]);
241         sprite_ref[0][1] = (a >> 1) * (2 * vop_ref[0][1] + d[0][1]);
242         sprite_ref[1][0] = (a >> 1) * (2 * vop_ref[1][0] + d[0][0] + d[1][0]);
243         sprite_ref[1][1] = (a >> 1) * (2 * vop_ref[1][1] + d[0][1] + d[1][1]);
244         sprite_ref[2][0] = (a >> 1) * (2 * vop_ref[2][0] + d[0][0] + d[2][0]);
245         sprite_ref[2][1] = (a >> 1) * (2 * vop_ref[2][1] + d[0][1] + d[2][1]);
246     }
247     /* sprite_ref[3][0] = (a >> 1) * (2 * vop_ref[3][0] + d[0][0] + d[1][0] + d[2][0] + d[3][0]);
248      * sprite_ref[3][1] = (a >> 1) * (2 * vop_ref[3][1] + d[0][1] + d[1][1] + d[2][1] + d[3][1]); */
249 
250     /* This is mostly identical to the MPEG-4 std (and is totally unreadable
251      * because of that...). Perhaps it should be reordered to be more readable.
252      * The idea behind this virtual_ref mess is to be able to use shifts later
253      * per pixel instead of divides so the distance between points is converted
254      * from w&h based to w2&h2 based which are of the 2^x form. */
255     virtual_ref[0][0] = 16 * (vop_ref[0][0] + w2) +
256                          ROUNDED_DIV(((w - w2) *
257                                            (r * sprite_ref[0][0] - 16LL * vop_ref[0][0]) +
258                                       w2 * (r * sprite_ref[1][0] - 16LL * vop_ref[1][0])), w);
259     virtual_ref[0][1] = 16 * vop_ref[0][1] +
260                         ROUNDED_DIV(((w - w2) *
261                                           (r * sprite_ref[0][1] - 16LL * vop_ref[0][1]) +
262                                      w2 * (r * sprite_ref[1][1] - 16LL * vop_ref[1][1])), w);
263     virtual_ref[1][0] = 16 * vop_ref[0][0] +
264                         ROUNDED_DIV(((h - h2) * (r * sprite_ref[0][0] - 16LL * vop_ref[0][0]) +
265                                            h2 * (r * sprite_ref[2][0] - 16LL * vop_ref[2][0])), h);
266     virtual_ref[1][1] = 16 * (vop_ref[0][1] + h2) +
267                         ROUNDED_DIV(((h - h2) * (r * sprite_ref[0][1] - 16LL * vop_ref[0][1]) +
268                                            h2 * (r * sprite_ref[2][1] - 16LL * vop_ref[2][1])), h);
269 
270     switch (ctx->num_sprite_warping_points) {
271     case 0:
272         sprite_offset[0][0]    =
273         sprite_offset[0][1]    =
274         sprite_offset[1][0]    =
275         sprite_offset[1][1]    = 0;
276         sprite_delta[0][0]     = a;
277         sprite_delta[0][1]     =
278         sprite_delta[1][0]     = 0;
279         sprite_delta[1][1]     = a;
280         ctx->sprite_shift[0]   =
281         ctx->sprite_shift[1]   = 0;
282         break;
283     case 1:     // GMC only
284         sprite_offset[0][0]    = sprite_ref[0][0] - a * vop_ref[0][0];
285         sprite_offset[0][1]    = sprite_ref[0][1] - a * vop_ref[0][1];
286         sprite_offset[1][0]    = ((sprite_ref[0][0] >> 1) | (sprite_ref[0][0] & 1)) -
287                                  a * (vop_ref[0][0] / 2);
288         sprite_offset[1][1]    = ((sprite_ref[0][1] >> 1) | (sprite_ref[0][1] & 1)) -
289                                  a * (vop_ref[0][1] / 2);
290         sprite_delta[0][0]     = a;
291         sprite_delta[0][1]     =
292         sprite_delta[1][0]     = 0;
293         sprite_delta[1][1]     = a;
294         ctx->sprite_shift[0]   =
295         ctx->sprite_shift[1]   = 0;
296         break;
297     case 2:
298         sprite_offset[0][0]    = ((int64_t)      sprite_ref[0][0] * (1 << alpha + rho)) +
299                                  ((int64_t) -r * sprite_ref[0][0] + virtual_ref[0][0]) *
300                                  ((int64_t)        -vop_ref[0][0]) +
301                                  ((int64_t)  r * sprite_ref[0][1] - virtual_ref[0][1]) *
302                                  ((int64_t)        -vop_ref[0][1]) + (1 << (alpha + rho - 1));
303         sprite_offset[0][1]    = ((int64_t)      sprite_ref[0][1] * (1 << alpha + rho)) +
304                                  ((int64_t) -r * sprite_ref[0][1] + virtual_ref[0][1]) *
305                                  ((int64_t)        -vop_ref[0][0]) +
306                                  ((int64_t) -r * sprite_ref[0][0] + virtual_ref[0][0]) *
307                                  ((int64_t)        -vop_ref[0][1]) + (1 << (alpha + rho - 1));
308         sprite_offset[1][0]    = (((int64_t)-r * sprite_ref[0][0] + virtual_ref[0][0]) *
309                                   ((int64_t)-2 *    vop_ref[0][0] + 1) +
310                                   ((int64_t) r * sprite_ref[0][1] - virtual_ref[0][1]) *
311                                   ((int64_t)-2 *    vop_ref[0][1] + 1) + 2 * w2 * r *
312                                    (int64_t)     sprite_ref[0][0] - 16 * w2 + (1 << (alpha + rho + 1)));
313         sprite_offset[1][1]    = (((int64_t)-r * sprite_ref[0][1] + virtual_ref[0][1]) *
314                                   ((int64_t)-2 *    vop_ref[0][0] + 1) +
315                                   ((int64_t)-r * sprite_ref[0][0] + virtual_ref[0][0]) *
316                                   ((int64_t)-2 *    vop_ref[0][1] + 1) + 2 * w2 * r *
317                                   (int64_t)      sprite_ref[0][1] - 16 * w2 + (1 << (alpha + rho + 1)));
318         sprite_delta[0][0] = (-r * sprite_ref[0][0] + virtual_ref[0][0]);
319         sprite_delta[0][1] = (+r * sprite_ref[0][1] - virtual_ref[0][1]);
320         sprite_delta[1][0] = (-r * sprite_ref[0][1] + virtual_ref[0][1]);
321         sprite_delta[1][1] = (-r * sprite_ref[0][0] + virtual_ref[0][0]);
322 
323         ctx->sprite_shift[0]  = alpha + rho;
324         ctx->sprite_shift[1]  = alpha + rho + 2;
325         break;
326     case 3:
327         min_ab = FFMIN(alpha, beta);
328         w3     = w2 >> min_ab;
329         h3     = h2 >> min_ab;
330         sprite_offset[0][0]    = ((int64_t)sprite_ref[0][0] * (1 << (alpha + beta + rho - min_ab))) +
331                                  ((int64_t)-r * sprite_ref[0][0] + virtual_ref[0][0]) * h3 * (-vop_ref[0][0]) +
332                                  ((int64_t)-r * sprite_ref[0][0] + virtual_ref[1][0]) * w3 * (-vop_ref[0][1]) +
333                                  ((int64_t)1 << (alpha + beta + rho - min_ab - 1));
334         sprite_offset[0][1]    = ((int64_t)sprite_ref[0][1] * (1 << (alpha + beta + rho - min_ab))) +
335                                  ((int64_t)-r * sprite_ref[0][1] + virtual_ref[0][1]) * h3 * (-vop_ref[0][0]) +
336                                  ((int64_t)-r * sprite_ref[0][1] + virtual_ref[1][1]) * w3 * (-vop_ref[0][1]) +
337                                  ((int64_t)1 << (alpha + beta + rho - min_ab - 1));
338         sprite_offset[1][0]    = ((int64_t)-r * sprite_ref[0][0] + virtual_ref[0][0]) * h3 * (-2 * vop_ref[0][0] + 1) +
339                                  ((int64_t)-r * sprite_ref[0][0] + virtual_ref[1][0]) * w3 * (-2 * vop_ref[0][1] + 1) +
340                                   (int64_t)2 * w2 * h3 * r * sprite_ref[0][0] - 16 * w2 * h3 +
341                                  ((int64_t)1 << (alpha + beta + rho - min_ab + 1));
342         sprite_offset[1][1]    = ((int64_t)-r * sprite_ref[0][1] + virtual_ref[0][1]) * h3 * (-2 * vop_ref[0][0] + 1) +
343                                  ((int64_t)-r * sprite_ref[0][1] + virtual_ref[1][1]) * w3 * (-2 * vop_ref[0][1] + 1) +
344                                   (int64_t)2 * w2 * h3 * r * sprite_ref[0][1] - 16 * w2 * h3 +
345                                  ((int64_t)1 << (alpha + beta + rho - min_ab + 1));
346         sprite_delta[0][0] = (-r * (int64_t)sprite_ref[0][0] + virtual_ref[0][0]) * h3;
347         sprite_delta[0][1] = (-r * (int64_t)sprite_ref[0][0] + virtual_ref[1][0]) * w3;
348         sprite_delta[1][0] = (-r * (int64_t)sprite_ref[0][1] + virtual_ref[0][1]) * h3;
349         sprite_delta[1][1] = (-r * (int64_t)sprite_ref[0][1] + virtual_ref[1][1]) * w3;
350 
351         ctx->sprite_shift[0]  = alpha + beta + rho - min_ab;
352         ctx->sprite_shift[1]  = alpha + beta + rho - min_ab + 2;
353         break;
354     }
355     /* try to simplify the situation */
356     if (sprite_delta[0][0] == a << ctx->sprite_shift[0] &&
357         sprite_delta[0][1] == 0 &&
358         sprite_delta[1][0] == 0 &&
359         sprite_delta[1][1] == a << ctx->sprite_shift[0]) {
360         sprite_offset[0][0] >>= ctx->sprite_shift[0];
361         sprite_offset[0][1] >>= ctx->sprite_shift[0];
362         sprite_offset[1][0] >>= ctx->sprite_shift[1];
363         sprite_offset[1][1] >>= ctx->sprite_shift[1];
364         sprite_delta[0][0] = a;
365         sprite_delta[0][1] = 0;
366         sprite_delta[1][0] = 0;
367         sprite_delta[1][1] = a;
368         ctx->sprite_shift[0] = 0;
369         ctx->sprite_shift[1] = 0;
370         s->real_sprite_warping_points = 1;
371     } else {
372         int shift_y = 16 - ctx->sprite_shift[0];
373         int shift_c = 16 - ctx->sprite_shift[1];
374 
375         for (i = 0; i < 2; i++) {
376             if (shift_c < 0 || shift_y < 0 ||
377                 FFABS(  sprite_offset[0][i]) >= INT_MAX >> shift_y  ||
378                 FFABS(  sprite_offset[1][i]) >= INT_MAX >> shift_c  ||
379                 FFABS(   sprite_delta[0][i]) >= INT_MAX >> shift_y  ||
380                 FFABS(   sprite_delta[1][i]) >= INT_MAX >> shift_y
381             ) {
382                 avpriv_request_sample(s->avctx, "Too large sprite shift, delta or offset");
383                 goto overflow;
384             }
385         }
386 
387         for (i = 0; i < 2; i++) {
388             sprite_offset[0][i]    *= 1 << shift_y;
389             sprite_offset[1][i]    *= 1 << shift_c;
390             sprite_delta[0][i]     *= 1 << shift_y;
391             sprite_delta[1][i]     *= 1 << shift_y;
392             ctx->sprite_shift[i]     = 16;
393 
394         }
395         for (i = 0; i < 2; i++) {
396             int64_t sd[2] = {
397                 sprite_delta[i][0] - a * (1LL<<16),
398                 sprite_delta[i][1] - a * (1LL<<16)
399             };
400 
401             if (llabs(sprite_offset[0][i] + sprite_delta[i][0] * (w+16LL)) >= INT_MAX ||
402                 llabs(sprite_offset[0][i] + sprite_delta[i][1] * (h+16LL)) >= INT_MAX ||
403                 llabs(sprite_offset[0][i] + sprite_delta[i][0] * (w+16LL) + sprite_delta[i][1] * (h+16LL)) >= INT_MAX ||
404                 llabs(sprite_delta[i][0] * (w+16LL)) >= INT_MAX ||
405                 llabs(sprite_delta[i][1] * (h+16LL)) >= INT_MAX ||
406                 llabs(sd[0]) >= INT_MAX ||
407                 llabs(sd[1]) >= INT_MAX ||
408                 llabs(sprite_offset[0][i] + sd[0] * (w+16LL)) >= INT_MAX ||
409                 llabs(sprite_offset[0][i] + sd[1] * (h+16LL)) >= INT_MAX ||
410                 llabs(sprite_offset[0][i] + sd[0] * (w+16LL) + sd[1] * (h+16LL)) >= INT_MAX
411             ) {
412                 avpriv_request_sample(s->avctx, "Overflow on sprite points");
413                 goto overflow;
414             }
415         }
416         s->real_sprite_warping_points = ctx->num_sprite_warping_points;
417     }
418 
419     for (i = 0; i < 4; i++) {
420         s->sprite_offset[i&1][i>>1] = sprite_offset[i&1][i>>1];
421         s->sprite_delta [i&1][i>>1] = sprite_delta [i&1][i>>1];
422     }
423 
424     return 0;
425 overflow:
426     memset(s->sprite_offset, 0, sizeof(s->sprite_offset));
427     memset(s->sprite_delta, 0, sizeof(s->sprite_delta));
428     return AVERROR_PATCHWELCOME;
429 }
430 
decode_new_pred(Mpeg4DecContext * ctx,GetBitContext * gb)431 static int decode_new_pred(Mpeg4DecContext *ctx, GetBitContext *gb) {
432     MpegEncContext *s = &ctx->m;
433     int len = FFMIN(ctx->time_increment_bits + 3, 15);
434 
435     get_bits(gb, len);
436     if (get_bits1(gb))
437         get_bits(gb, len);
438     check_marker(s->avctx, gb, "after new_pred");
439 
440     return 0;
441 }
442 
443 /**
444  * Decode the next video packet.
445  * @return <0 if something went wrong
446  */
ff_mpeg4_decode_video_packet_header(Mpeg4DecContext * ctx)447 int ff_mpeg4_decode_video_packet_header(Mpeg4DecContext *ctx)
448 {
449     MpegEncContext *s = &ctx->m;
450 
451     int mb_num_bits      = av_log2(s->mb_num - 1) + 1;
452     int header_extension = 0, mb_num, len;
453 
454     /* is there enough space left for a video packet + header */
455     if (get_bits_count(&s->gb) > s->gb.size_in_bits - 20)
456         return AVERROR_INVALIDDATA;
457 
458     for (len = 0; len < 32; len++)
459         if (get_bits1(&s->gb))
460             break;
461 
462     if (len != ff_mpeg4_get_video_packet_prefix_length(s)) {
463         av_log(s->avctx, AV_LOG_ERROR, "marker does not match f_code\n");
464         return AVERROR_INVALIDDATA;
465     }
466 
467     if (ctx->shape != RECT_SHAPE) {
468         header_extension = get_bits1(&s->gb);
469         // FIXME more stuff here
470     }
471 
472     mb_num = get_bits(&s->gb, mb_num_bits);
473     if (mb_num >= s->mb_num || !mb_num) {
474         av_log(s->avctx, AV_LOG_ERROR,
475                "illegal mb_num in video packet (%d %d) \n", mb_num, s->mb_num);
476         return AVERROR_INVALIDDATA;
477     }
478 
479     s->mb_x = mb_num % s->mb_width;
480     s->mb_y = mb_num / s->mb_width;
481 
482     if (ctx->shape != BIN_ONLY_SHAPE) {
483         int qscale = get_bits(&s->gb, s->quant_precision);
484         if (qscale)
485             s->chroma_qscale = s->qscale = qscale;
486     }
487 
488     if (ctx->shape == RECT_SHAPE)
489         header_extension = get_bits1(&s->gb);
490 
491     if (header_extension) {
492         int time_incr = 0;
493 
494         while (get_bits1(&s->gb) != 0)
495             time_incr++;
496 
497         check_marker(s->avctx, &s->gb, "before time_increment in video packed header");
498         skip_bits(&s->gb, ctx->time_increment_bits);      /* time_increment */
499         check_marker(s->avctx, &s->gb, "before vop_coding_type in video packed header");
500 
501         skip_bits(&s->gb, 2); /* vop coding type */
502         // FIXME not rect stuff here
503 
504         if (ctx->shape != BIN_ONLY_SHAPE) {
505             skip_bits(&s->gb, 3); /* intra dc vlc threshold */
506             // FIXME don't just ignore everything
507             if (s->pict_type == AV_PICTURE_TYPE_S &&
508                 ctx->vol_sprite_usage == GMC_SPRITE) {
509                 if (mpeg4_decode_sprite_trajectory(ctx, &s->gb) < 0)
510                     return AVERROR_INVALIDDATA;
511                 av_log(s->avctx, AV_LOG_ERROR, "untested\n");
512             }
513 
514             // FIXME reduced res stuff here
515 
516             if (s->pict_type != AV_PICTURE_TYPE_I) {
517                 int f_code = get_bits(&s->gb, 3);       /* fcode_for */
518                 if (f_code == 0)
519                     av_log(s->avctx, AV_LOG_ERROR,
520                            "Error, video packet header damaged (f_code=0)\n");
521             }
522             if (s->pict_type == AV_PICTURE_TYPE_B) {
523                 int b_code = get_bits(&s->gb, 3);
524                 if (b_code == 0)
525                     av_log(s->avctx, AV_LOG_ERROR,
526                            "Error, video packet header damaged (b_code=0)\n");
527             }
528         }
529     }
530     if (ctx->new_pred)
531         decode_new_pred(ctx, &s->gb);
532 
533     return 0;
534 }
535 
reset_studio_dc_predictors(MpegEncContext * s)536 static void reset_studio_dc_predictors(MpegEncContext *s)
537 {
538     /* Reset DC Predictors */
539     s->last_dc[0] =
540     s->last_dc[1] =
541     s->last_dc[2] = 1 << (s->avctx->bits_per_raw_sample + s->dct_precision + s->intra_dc_precision - 1);
542 }
543 
544 /**
545  * Decode the next video packet.
546  * @return <0 if something went wrong
547  */
ff_mpeg4_decode_studio_slice_header(Mpeg4DecContext * ctx)548 int ff_mpeg4_decode_studio_slice_header(Mpeg4DecContext *ctx)
549 {
550     MpegEncContext *s = &ctx->m;
551     GetBitContext *gb = &s->gb;
552     unsigned vlc_len;
553     uint16_t mb_num;
554 
555     if (get_bits_left(gb) >= 32 && get_bits_long(gb, 32) == SLICE_START_CODE) {
556         vlc_len = av_log2(s->mb_width * s->mb_height) + 1;
557         mb_num = get_bits(gb, vlc_len);
558 
559         if (mb_num >= s->mb_num)
560             return AVERROR_INVALIDDATA;
561 
562         s->mb_x = mb_num % s->mb_width;
563         s->mb_y = mb_num / s->mb_width;
564 
565         if (ctx->shape != BIN_ONLY_SHAPE)
566             s->qscale = mpeg_get_qscale(s);
567 
568         if (get_bits1(gb)) {  /* slice_extension_flag */
569             skip_bits1(gb);   /* intra_slice */
570             skip_bits1(gb);   /* slice_VOP_id_enable */
571             skip_bits(gb, 6); /* slice_VOP_id */
572             while (get_bits1(gb)) /* extra_bit_slice */
573                 skip_bits(gb, 8); /* extra_information_slice */
574         }
575 
576         reset_studio_dc_predictors(s);
577     }
578     else {
579         return AVERROR_INVALIDDATA;
580     }
581 
582     return 0;
583 }
584 
585 /**
586  * Get the average motion vector for a GMC MB.
587  * @param n either 0 for the x component or 1 for y
588  * @return the average MV for a GMC MB
589  */
get_amv(Mpeg4DecContext * ctx,int n)590 static inline int get_amv(Mpeg4DecContext *ctx, int n)
591 {
592     MpegEncContext *s = &ctx->m;
593     int x, y, mb_v, sum, dx, dy, shift;
594     int len     = 1 << (s->f_code + 4);
595     const int a = s->sprite_warping_accuracy;
596 
597     if (s->workaround_bugs & FF_BUG_AMV)
598         len >>= s->quarter_sample;
599 
600     if (s->real_sprite_warping_points == 1) {
601         if (ctx->divx_version == 500 && ctx->divx_build == 413 && a >= s->quarter_sample)
602             sum = s->sprite_offset[0][n] / (1 << (a - s->quarter_sample));
603         else
604             sum = RSHIFT(s->sprite_offset[0][n] * (1 << s->quarter_sample), a);
605     } else {
606         dx    = s->sprite_delta[n][0];
607         dy    = s->sprite_delta[n][1];
608         shift = ctx->sprite_shift[0];
609         if (n)
610             dy -= 1 << (shift + a + 1);
611         else
612             dx -= 1 << (shift + a + 1);
613         mb_v = s->sprite_offset[0][n] + dx * s->mb_x * 16 + dy * s->mb_y * 16;
614 
615         sum = 0;
616         for (y = 0; y < 16; y++) {
617             int v;
618 
619             v = mb_v + dy * y;
620             // FIXME optimize
621             for (x = 0; x < 16; x++) {
622                 sum += v >> shift;
623                 v   += dx;
624             }
625         }
626         sum = RSHIFT(sum, a + 8 - s->quarter_sample);
627     }
628 
629     if (sum < -len)
630         sum = -len;
631     else if (sum >= len)
632         sum = len - 1;
633 
634     return sum;
635 }
636 
637 /**
638  * Decode the dc value.
639  * @param n block index (0-3 are luma, 4-5 are chroma)
640  * @param dir_ptr the prediction direction will be stored here
641  * @return the quantized dc
642  */
mpeg4_decode_dc(MpegEncContext * s,int n,int * dir_ptr)643 static inline int mpeg4_decode_dc(MpegEncContext *s, int n, int *dir_ptr)
644 {
645     int level, code;
646 
647     if (n < 4)
648         code = get_vlc2(&s->gb, dc_lum.table, DC_VLC_BITS, 1);
649     else
650         code = get_vlc2(&s->gb, dc_chrom.table, DC_VLC_BITS, 1);
651 
652     if (code < 0 || code > 9 /* && s->nbit < 9 */) {
653         av_log(s->avctx, AV_LOG_ERROR, "illegal dc vlc\n");
654         return AVERROR_INVALIDDATA;
655     }
656 
657     if (code == 0) {
658         level = 0;
659     } else {
660         if (IS_3IV1) {
661             if (code == 1)
662                 level = 2 * get_bits1(&s->gb) - 1;
663             else {
664                 if (get_bits1(&s->gb))
665                     level = get_bits(&s->gb, code - 1) + (1 << (code - 1));
666                 else
667                     level = -get_bits(&s->gb, code - 1) - (1 << (code - 1));
668             }
669         } else {
670             level = get_xbits(&s->gb, code);
671         }
672 
673         if (code > 8) {
674             if (get_bits1(&s->gb) == 0) { /* marker */
675                 if (s->avctx->err_recognition & (AV_EF_BITSTREAM|AV_EF_COMPLIANT)) {
676                     av_log(s->avctx, AV_LOG_ERROR, "dc marker bit missing\n");
677                     return AVERROR_INVALIDDATA;
678                 }
679             }
680         }
681     }
682 
683     return ff_mpeg4_pred_dc(s, n, level, dir_ptr, 0);
684 }
685 
686 /**
687  * Decode first partition.
688  * @return number of MBs decoded or <0 if an error occurred
689  */
mpeg4_decode_partition_a(Mpeg4DecContext * ctx)690 static int mpeg4_decode_partition_a(Mpeg4DecContext *ctx)
691 {
692     MpegEncContext *s = &ctx->m;
693     int mb_num = 0;
694     static const int8_t quant_tab[4] = { -1, -2, 1, 2 };
695 
696     /* decode first partition */
697     s->first_slice_line = 1;
698     for (; s->mb_y < s->mb_height; s->mb_y++) {
699         ff_init_block_index(s);
700         for (; s->mb_x < s->mb_width; s->mb_x++) {
701             const int xy = s->mb_x + s->mb_y * s->mb_stride;
702             int cbpc;
703             int dir = 0;
704 
705             mb_num++;
706             ff_update_block_index(s);
707             if (s->mb_x == s->resync_mb_x && s->mb_y == s->resync_mb_y + 1)
708                 s->first_slice_line = 0;
709 
710             if (s->pict_type == AV_PICTURE_TYPE_I) {
711                 int i;
712 
713                 do {
714                     if (show_bits_long(&s->gb, 19) == DC_MARKER)
715                         return mb_num - 1;
716 
717                     cbpc = get_vlc2(&s->gb, ff_h263_intra_MCBPC_vlc.table, INTRA_MCBPC_VLC_BITS, 2);
718                     if (cbpc < 0) {
719                         av_log(s->avctx, AV_LOG_ERROR,
720                                "mcbpc corrupted at %d %d\n", s->mb_x, s->mb_y);
721                         return AVERROR_INVALIDDATA;
722                     }
723                 } while (cbpc == 8);
724 
725                 s->cbp_table[xy]               = cbpc & 3;
726                 s->current_picture.mb_type[xy] = MB_TYPE_INTRA;
727                 s->mb_intra                    = 1;
728 
729                 if (cbpc & 4)
730                     ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
731 
732                 s->current_picture.qscale_table[xy] = s->qscale;
733 
734                 s->mbintra_table[xy] = 1;
735                 for (i = 0; i < 6; i++) {
736                     int dc_pred_dir;
737                     int dc = mpeg4_decode_dc(s, i, &dc_pred_dir);
738                     if (dc < 0) {
739                         av_log(s->avctx, AV_LOG_ERROR,
740                                "DC corrupted at %d %d\n", s->mb_x, s->mb_y);
741                         return dc;
742                     }
743                     dir <<= 1;
744                     if (dc_pred_dir)
745                         dir |= 1;
746                 }
747                 s->pred_dir_table[xy] = dir;
748             } else { /* P/S_TYPE */
749                 int mx, my, pred_x, pred_y, bits;
750                 int16_t *const mot_val = s->current_picture.motion_val[0][s->block_index[0]];
751                 const int stride       = s->b8_stride * 2;
752 
753 try_again:
754                 bits = show_bits(&s->gb, 17);
755                 if (bits == MOTION_MARKER)
756                     return mb_num - 1;
757 
758                 skip_bits1(&s->gb);
759                 if (bits & 0x10000) {
760                     /* skip mb */
761                     if (s->pict_type == AV_PICTURE_TYPE_S &&
762                         ctx->vol_sprite_usage == GMC_SPRITE) {
763                         s->current_picture.mb_type[xy] = MB_TYPE_SKIP  |
764                                                          MB_TYPE_16x16 |
765                                                          MB_TYPE_GMC   |
766                                                          MB_TYPE_L0;
767                         mx = get_amv(ctx, 0);
768                         my = get_amv(ctx, 1);
769                     } else {
770                         s->current_picture.mb_type[xy] = MB_TYPE_SKIP  |
771                                                          MB_TYPE_16x16 |
772                                                          MB_TYPE_L0;
773                         mx = my = 0;
774                     }
775                     mot_val[0]          =
776                     mot_val[2]          =
777                     mot_val[0 + stride] =
778                     mot_val[2 + stride] = mx;
779                     mot_val[1]          =
780                     mot_val[3]          =
781                     mot_val[1 + stride] =
782                     mot_val[3 + stride] = my;
783 
784                     if (s->mbintra_table[xy])
785                         ff_clean_intra_table_entries(s);
786                     continue;
787                 }
788 
789                 cbpc = get_vlc2(&s->gb, ff_h263_inter_MCBPC_vlc.table, INTER_MCBPC_VLC_BITS, 2);
790                 if (cbpc < 0) {
791                     av_log(s->avctx, AV_LOG_ERROR,
792                            "mcbpc corrupted at %d %d\n", s->mb_x, s->mb_y);
793                     return AVERROR_INVALIDDATA;
794                 }
795                 if (cbpc == 20)
796                     goto try_again;
797 
798                 s->cbp_table[xy] = cbpc & (8 + 3);  // 8 is dquant
799 
800                 s->mb_intra = ((cbpc & 4) != 0);
801 
802                 if (s->mb_intra) {
803                     s->current_picture.mb_type[xy] = MB_TYPE_INTRA;
804                     s->mbintra_table[xy] = 1;
805                     mot_val[0]          =
806                     mot_val[2]          =
807                     mot_val[0 + stride] =
808                     mot_val[2 + stride] = 0;
809                     mot_val[1]          =
810                     mot_val[3]          =
811                     mot_val[1 + stride] =
812                     mot_val[3 + stride] = 0;
813                 } else {
814                     if (s->mbintra_table[xy])
815                         ff_clean_intra_table_entries(s);
816 
817                     if (s->pict_type == AV_PICTURE_TYPE_S &&
818                         ctx->vol_sprite_usage == GMC_SPRITE &&
819                         (cbpc & 16) == 0)
820                         s->mcsel = get_bits1(&s->gb);
821                     else
822                         s->mcsel = 0;
823 
824                     if ((cbpc & 16) == 0) {
825                         /* 16x16 motion prediction */
826 
827                         ff_h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
828                         if (!s->mcsel) {
829                             mx = ff_h263_decode_motion(s, pred_x, s->f_code);
830                             if (mx >= 0xffff)
831                                 return AVERROR_INVALIDDATA;
832 
833                             my = ff_h263_decode_motion(s, pred_y, s->f_code);
834                             if (my >= 0xffff)
835                                 return AVERROR_INVALIDDATA;
836                             s->current_picture.mb_type[xy] = MB_TYPE_16x16 |
837                                                              MB_TYPE_L0;
838                         } else {
839                             mx = get_amv(ctx, 0);
840                             my = get_amv(ctx, 1);
841                             s->current_picture.mb_type[xy] = MB_TYPE_16x16 |
842                                                              MB_TYPE_GMC   |
843                                                              MB_TYPE_L0;
844                         }
845 
846                         mot_val[0]          =
847                         mot_val[2]          =
848                         mot_val[0 + stride] =
849                         mot_val[2 + stride] = mx;
850                         mot_val[1]          =
851                         mot_val[3]          =
852                         mot_val[1 + stride] =
853                         mot_val[3 + stride] = my;
854                     } else {
855                         int i;
856                         s->current_picture.mb_type[xy] = MB_TYPE_8x8 |
857                                                          MB_TYPE_L0;
858                         for (i = 0; i < 4; i++) {
859                             int16_t *mot_val = ff_h263_pred_motion(s, i, 0, &pred_x, &pred_y);
860                             mx = ff_h263_decode_motion(s, pred_x, s->f_code);
861                             if (mx >= 0xffff)
862                                 return AVERROR_INVALIDDATA;
863 
864                             my = ff_h263_decode_motion(s, pred_y, s->f_code);
865                             if (my >= 0xffff)
866                                 return AVERROR_INVALIDDATA;
867                             mot_val[0] = mx;
868                             mot_val[1] = my;
869                         }
870                     }
871                 }
872             }
873         }
874         s->mb_x = 0;
875     }
876 
877     return mb_num;
878 }
879 
880 /**
881  * decode second partition.
882  * @return <0 if an error occurred
883  */
mpeg4_decode_partition_b(MpegEncContext * s,int mb_count)884 static int mpeg4_decode_partition_b(MpegEncContext *s, int mb_count)
885 {
886     int mb_num = 0;
887     static const int8_t quant_tab[4] = { -1, -2, 1, 2 };
888 
889     s->mb_x = s->resync_mb_x;
890     s->first_slice_line = 1;
891     for (s->mb_y = s->resync_mb_y; mb_num < mb_count; s->mb_y++) {
892         ff_init_block_index(s);
893         for (; mb_num < mb_count && s->mb_x < s->mb_width; s->mb_x++) {
894             const int xy = s->mb_x + s->mb_y * s->mb_stride;
895 
896             mb_num++;
897             ff_update_block_index(s);
898             if (s->mb_x == s->resync_mb_x && s->mb_y == s->resync_mb_y + 1)
899                 s->first_slice_line = 0;
900 
901             if (s->pict_type == AV_PICTURE_TYPE_I) {
902                 int ac_pred = get_bits1(&s->gb);
903                 int cbpy    = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
904                 if (cbpy < 0) {
905                     av_log(s->avctx, AV_LOG_ERROR,
906                            "cbpy corrupted at %d %d\n", s->mb_x, s->mb_y);
907                     return AVERROR_INVALIDDATA;
908                 }
909 
910                 s->cbp_table[xy]               |= cbpy << 2;
911                 s->current_picture.mb_type[xy] |= ac_pred * MB_TYPE_ACPRED;
912             } else { /* P || S_TYPE */
913                 if (IS_INTRA(s->current_picture.mb_type[xy])) {
914                     int i;
915                     int dir     = 0;
916                     int ac_pred = get_bits1(&s->gb);
917                     int cbpy    = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
918 
919                     if (cbpy < 0) {
920                         av_log(s->avctx, AV_LOG_ERROR,
921                                "I cbpy corrupted at %d %d\n", s->mb_x, s->mb_y);
922                         return AVERROR_INVALIDDATA;
923                     }
924 
925                     if (s->cbp_table[xy] & 8)
926                         ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
927                     s->current_picture.qscale_table[xy] = s->qscale;
928 
929                     for (i = 0; i < 6; i++) {
930                         int dc_pred_dir;
931                         int dc = mpeg4_decode_dc(s, i, &dc_pred_dir);
932                         if (dc < 0) {
933                             av_log(s->avctx, AV_LOG_ERROR,
934                                    "DC corrupted at %d %d\n", s->mb_x, s->mb_y);
935                             return dc;
936                         }
937                         dir <<= 1;
938                         if (dc_pred_dir)
939                             dir |= 1;
940                     }
941                     s->cbp_table[xy]               &= 3;  // remove dquant
942                     s->cbp_table[xy]               |= cbpy << 2;
943                     s->current_picture.mb_type[xy] |= ac_pred * MB_TYPE_ACPRED;
944                     s->pred_dir_table[xy]           = dir;
945                 } else if (IS_SKIP(s->current_picture.mb_type[xy])) {
946                     s->current_picture.qscale_table[xy] = s->qscale;
947                     s->cbp_table[xy]                    = 0;
948                 } else {
949                     int cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
950 
951                     if (cbpy < 0) {
952                         av_log(s->avctx, AV_LOG_ERROR,
953                                "P cbpy corrupted at %d %d\n", s->mb_x, s->mb_y);
954                         return AVERROR_INVALIDDATA;
955                     }
956 
957                     if (s->cbp_table[xy] & 8)
958                         ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
959                     s->current_picture.qscale_table[xy] = s->qscale;
960 
961                     s->cbp_table[xy] &= 3;  // remove dquant
962                     s->cbp_table[xy] |= (cbpy ^ 0xf) << 2;
963                 }
964             }
965         }
966         if (mb_num >= mb_count)
967             return 0;
968         s->mb_x = 0;
969     }
970     return 0;
971 }
972 
973 /**
974  * Decode the first and second partition.
975  * @return <0 if error (and sets error type in the error_status_table)
976  */
ff_mpeg4_decode_partitions(Mpeg4DecContext * ctx)977 int ff_mpeg4_decode_partitions(Mpeg4DecContext *ctx)
978 {
979     MpegEncContext *s = &ctx->m;
980     int mb_num;
981     int ret;
982     const int part_a_error = s->pict_type == AV_PICTURE_TYPE_I ? (ER_DC_ERROR | ER_MV_ERROR) : ER_MV_ERROR;
983     const int part_a_end   = s->pict_type == AV_PICTURE_TYPE_I ? (ER_DC_END   | ER_MV_END)   : ER_MV_END;
984 
985     mb_num = mpeg4_decode_partition_a(ctx);
986     if (mb_num <= 0) {
987         ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y,
988                         s->mb_x, s->mb_y, part_a_error);
989         return mb_num ? mb_num : AVERROR_INVALIDDATA;
990     }
991 
992     if (s->resync_mb_x + s->resync_mb_y * s->mb_width + mb_num > s->mb_num) {
993         av_log(s->avctx, AV_LOG_ERROR, "slice below monitor ...\n");
994         ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y,
995                         s->mb_x, s->mb_y, part_a_error);
996         return AVERROR_INVALIDDATA;
997     }
998 
999     s->mb_num_left = mb_num;
1000 
1001     if (s->pict_type == AV_PICTURE_TYPE_I) {
1002         while (show_bits(&s->gb, 9) == 1)
1003             skip_bits(&s->gb, 9);
1004         if (get_bits_long(&s->gb, 19) != DC_MARKER) {
1005             av_log(s->avctx, AV_LOG_ERROR,
1006                    "marker missing after first I partition at %d %d\n",
1007                    s->mb_x, s->mb_y);
1008             return AVERROR_INVALIDDATA;
1009         }
1010     } else {
1011         while (show_bits(&s->gb, 10) == 1)
1012             skip_bits(&s->gb, 10);
1013         if (get_bits(&s->gb, 17) != MOTION_MARKER) {
1014             av_log(s->avctx, AV_LOG_ERROR,
1015                    "marker missing after first P partition at %d %d\n",
1016                    s->mb_x, s->mb_y);
1017             return AVERROR_INVALIDDATA;
1018         }
1019     }
1020     ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y,
1021                     s->mb_x - 1, s->mb_y, part_a_end);
1022 
1023     ret = mpeg4_decode_partition_b(s, mb_num);
1024     if (ret < 0) {
1025         if (s->pict_type == AV_PICTURE_TYPE_P)
1026             ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y,
1027                             s->mb_x, s->mb_y, ER_DC_ERROR);
1028         return ret;
1029     } else {
1030         if (s->pict_type == AV_PICTURE_TYPE_P)
1031             ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y,
1032                             s->mb_x - 1, s->mb_y, ER_DC_END);
1033     }
1034 
1035     return 0;
1036 }
1037 
1038 /**
1039  * Decode a block.
1040  * @return <0 if an error occurred
1041  */
mpeg4_decode_block(Mpeg4DecContext * ctx,int16_t * block,int n,int coded,int intra,int rvlc)1042 static inline int mpeg4_decode_block(Mpeg4DecContext *ctx, int16_t *block,
1043                                      int n, int coded, int intra, int rvlc)
1044 {
1045     MpegEncContext *s = &ctx->m;
1046     int level, i, last, run, qmul, qadd;
1047     int av_uninit(dc_pred_dir);
1048     RLTable *rl;
1049     RL_VLC_ELEM *rl_vlc;
1050     const uint8_t *scan_table;
1051 
1052     // Note intra & rvlc should be optimized away if this is inlined
1053 
1054     if (intra) {
1055         if (ctx->use_intra_dc_vlc) {
1056             /* DC coef */
1057             if (s->partitioned_frame) {
1058                 level = s->dc_val[0][s->block_index[n]];
1059                 if (n < 4)
1060                     level = FASTDIV((level + (s->y_dc_scale >> 1)), s->y_dc_scale);
1061                 else
1062                     level = FASTDIV((level + (s->c_dc_scale >> 1)), s->c_dc_scale);
1063                 dc_pred_dir = (s->pred_dir_table[s->mb_x + s->mb_y * s->mb_stride] << n) & 32;
1064             } else {
1065                 level = mpeg4_decode_dc(s, n, &dc_pred_dir);
1066                 if (level < 0)
1067                     return level;
1068             }
1069             block[0] = level;
1070             i        = 0;
1071         } else {
1072             i = -1;
1073             ff_mpeg4_pred_dc(s, n, 0, &dc_pred_dir, 0);
1074         }
1075         if (!coded)
1076             goto not_coded;
1077 
1078         if (rvlc) {
1079             rl     = &ff_rvlc_rl_intra;
1080             rl_vlc = ff_rvlc_rl_intra.rl_vlc[0];
1081         } else {
1082             rl     = &ff_mpeg4_rl_intra;
1083             rl_vlc = ff_mpeg4_rl_intra.rl_vlc[0];
1084         }
1085         if (s->ac_pred) {
1086             if (dc_pred_dir == 0)
1087                 scan_table = s->intra_v_scantable.permutated;  /* left */
1088             else
1089                 scan_table = s->intra_h_scantable.permutated;  /* top */
1090         } else {
1091             scan_table = s->intra_scantable.permutated;
1092         }
1093         qmul = 1;
1094         qadd = 0;
1095     } else {
1096         i = -1;
1097         if (!coded) {
1098             s->block_last_index[n] = i;
1099             return 0;
1100         }
1101         if (rvlc)
1102             rl = &ff_rvlc_rl_inter;
1103         else
1104             rl = &ff_h263_rl_inter;
1105 
1106         scan_table = s->intra_scantable.permutated;
1107 
1108         if (s->mpeg_quant) {
1109             qmul = 1;
1110             qadd = 0;
1111             if (rvlc)
1112                 rl_vlc = ff_rvlc_rl_inter.rl_vlc[0];
1113             else
1114                 rl_vlc = ff_h263_rl_inter.rl_vlc[0];
1115         } else {
1116             qmul = s->qscale << 1;
1117             qadd = (s->qscale - 1) | 1;
1118             if (rvlc)
1119                 rl_vlc = ff_rvlc_rl_inter.rl_vlc[s->qscale];
1120             else
1121                 rl_vlc = ff_h263_rl_inter.rl_vlc[s->qscale];
1122         }
1123     }
1124     {
1125         OPEN_READER(re, &s->gb);
1126         for (;;) {
1127             UPDATE_CACHE(re, &s->gb);
1128             GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2, 0);
1129             if (level == 0) {
1130                 /* escape */
1131                 if (rvlc) {
1132                     if (SHOW_UBITS(re, &s->gb, 1) == 0) {
1133                         av_log(s->avctx, AV_LOG_ERROR,
1134                                "1. marker bit missing in rvlc esc\n");
1135                         return AVERROR_INVALIDDATA;
1136                     }
1137                     SKIP_CACHE(re, &s->gb, 1);
1138 
1139                     last = SHOW_UBITS(re, &s->gb, 1);
1140                     SKIP_CACHE(re, &s->gb, 1);
1141                     run = SHOW_UBITS(re, &s->gb, 6);
1142                     SKIP_COUNTER(re, &s->gb, 1 + 1 + 6);
1143                     UPDATE_CACHE(re, &s->gb);
1144 
1145                     if (SHOW_UBITS(re, &s->gb, 1) == 0) {
1146                         av_log(s->avctx, AV_LOG_ERROR,
1147                                "2. marker bit missing in rvlc esc\n");
1148                         return AVERROR_INVALIDDATA;
1149                     }
1150                     SKIP_CACHE(re, &s->gb, 1);
1151 
1152                     level = SHOW_UBITS(re, &s->gb, 11);
1153                     SKIP_CACHE(re, &s->gb, 11);
1154 
1155                     if (SHOW_UBITS(re, &s->gb, 5) != 0x10) {
1156                         av_log(s->avctx, AV_LOG_ERROR, "reverse esc missing\n");
1157                         return AVERROR_INVALIDDATA;
1158                     }
1159                     SKIP_CACHE(re, &s->gb, 5);
1160 
1161                     level = level * qmul + qadd;
1162                     level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1163                     SKIP_COUNTER(re, &s->gb, 1 + 11 + 5 + 1);
1164 
1165                     i += run + 1;
1166                     if (last)
1167                         i += 192;
1168                 } else {
1169                     int cache;
1170                     cache = GET_CACHE(re, &s->gb);
1171 
1172                     if (IS_3IV1)
1173                         cache ^= 0xC0000000;
1174 
1175                     if (cache & 0x80000000) {
1176                         if (cache & 0x40000000) {
1177                             /* third escape */
1178                             SKIP_CACHE(re, &s->gb, 2);
1179                             last = SHOW_UBITS(re, &s->gb, 1);
1180                             SKIP_CACHE(re, &s->gb, 1);
1181                             run = SHOW_UBITS(re, &s->gb, 6);
1182                             SKIP_COUNTER(re, &s->gb, 2 + 1 + 6);
1183                             UPDATE_CACHE(re, &s->gb);
1184 
1185                             if (IS_3IV1) {
1186                                 level = SHOW_SBITS(re, &s->gb, 12);
1187                                 LAST_SKIP_BITS(re, &s->gb, 12);
1188                             } else {
1189                                 if (SHOW_UBITS(re, &s->gb, 1) == 0) {
1190                                     av_log(s->avctx, AV_LOG_ERROR,
1191                                            "1. marker bit missing in 3. esc\n");
1192                                     if (!(s->avctx->err_recognition & AV_EF_IGNORE_ERR))
1193                                         return AVERROR_INVALIDDATA;
1194                                 }
1195                                 SKIP_CACHE(re, &s->gb, 1);
1196 
1197                                 level = SHOW_SBITS(re, &s->gb, 12);
1198                                 SKIP_CACHE(re, &s->gb, 12);
1199 
1200                                 if (SHOW_UBITS(re, &s->gb, 1) == 0) {
1201                                     av_log(s->avctx, AV_LOG_ERROR,
1202                                            "2. marker bit missing in 3. esc\n");
1203                                     if (!(s->avctx->err_recognition & AV_EF_IGNORE_ERR))
1204                                         return AVERROR_INVALIDDATA;
1205                                 }
1206 
1207                                 SKIP_COUNTER(re, &s->gb, 1 + 12 + 1);
1208                             }
1209 
1210 #if 0
1211                             if (s->error_recognition >= FF_ER_COMPLIANT) {
1212                                 const int abs_level= FFABS(level);
1213                                 if (abs_level<=MAX_LEVEL && run<=MAX_RUN) {
1214                                     const int run1= run - rl->max_run[last][abs_level] - 1;
1215                                     if (abs_level <= rl->max_level[last][run]) {
1216                                         av_log(s->avctx, AV_LOG_ERROR, "illegal 3. esc, vlc encoding possible\n");
1217                                         return AVERROR_INVALIDDATA;
1218                                     }
1219                                     if (s->error_recognition > FF_ER_COMPLIANT) {
1220                                         if (abs_level <= rl->max_level[last][run]*2) {
1221                                             av_log(s->avctx, AV_LOG_ERROR, "illegal 3. esc, esc 1 encoding possible\n");
1222                                             return AVERROR_INVALIDDATA;
1223                                         }
1224                                         if (run1 >= 0 && abs_level <= rl->max_level[last][run1]) {
1225                                             av_log(s->avctx, AV_LOG_ERROR, "illegal 3. esc, esc 2 encoding possible\n");
1226                                             return AVERROR_INVALIDDATA;
1227                                         }
1228                                     }
1229                                 }
1230                             }
1231 #endif
1232                             if (level > 0)
1233                                 level = level * qmul + qadd;
1234                             else
1235                                 level = level * qmul - qadd;
1236 
1237                             if ((unsigned)(level + 2048) > 4095) {
1238                                 if (s->avctx->err_recognition & (AV_EF_BITSTREAM|AV_EF_AGGRESSIVE)) {
1239                                     if (level > 2560 || level < -2560) {
1240                                         av_log(s->avctx, AV_LOG_ERROR,
1241                                                "|level| overflow in 3. esc, qp=%d\n",
1242                                                s->qscale);
1243                                         return AVERROR_INVALIDDATA;
1244                                     }
1245                                 }
1246                                 level = level < 0 ? -2048 : 2047;
1247                             }
1248 
1249                             i += run + 1;
1250                             if (last)
1251                                 i += 192;
1252                         } else {
1253                             /* second escape */
1254                             SKIP_BITS(re, &s->gb, 2);
1255                             GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2, 1);
1256                             i    += run + rl->max_run[run >> 7][level / qmul] + 1;  // FIXME opt indexing
1257                             level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1258                             LAST_SKIP_BITS(re, &s->gb, 1);
1259                         }
1260                     } else {
1261                         /* first escape */
1262                         SKIP_BITS(re, &s->gb, 1);
1263                         GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2, 1);
1264                         i    += run;
1265                         level = level + rl->max_level[run >> 7][(run - 1) & 63] * qmul;  // FIXME opt indexing
1266                         level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1267                         LAST_SKIP_BITS(re, &s->gb, 1);
1268                     }
1269                 }
1270             } else {
1271                 i    += run;
1272                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1273                 LAST_SKIP_BITS(re, &s->gb, 1);
1274             }
1275             ff_tlog(s->avctx, "dct[%d][%d] = %- 4d end?:%d\n", scan_table[i&63]&7, scan_table[i&63] >> 3, level, i>62);
1276             if (i > 62) {
1277                 i -= 192;
1278                 if (i & (~63)) {
1279                     av_log(s->avctx, AV_LOG_ERROR,
1280                            "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
1281                     return AVERROR_INVALIDDATA;
1282                 }
1283 
1284                 block[scan_table[i]] = level;
1285                 break;
1286             }
1287 
1288             block[scan_table[i]] = level;
1289         }
1290         CLOSE_READER(re, &s->gb);
1291     }
1292 
1293 not_coded:
1294     if (intra) {
1295         if (!ctx->use_intra_dc_vlc) {
1296             block[0] = ff_mpeg4_pred_dc(s, n, block[0], &dc_pred_dir, 0);
1297 
1298             i -= i >> 31;  // if (i == -1) i = 0;
1299         }
1300 
1301         ff_mpeg4_pred_ac(s, block, n, dc_pred_dir);
1302         if (s->ac_pred)
1303             i = 63;  // FIXME not optimal
1304     }
1305     s->block_last_index[n] = i;
1306     return 0;
1307 }
1308 
1309 /**
1310  * decode partition C of one MB.
1311  * @return <0 if an error occurred
1312  */
mpeg4_decode_partitioned_mb(MpegEncContext * s,int16_t block[6][64])1313 static int mpeg4_decode_partitioned_mb(MpegEncContext *s, int16_t block[6][64])
1314 {
1315     Mpeg4DecContext *ctx = s->avctx->priv_data;
1316     int cbp, mb_type;
1317     const int xy = s->mb_x + s->mb_y * s->mb_stride;
1318 
1319     av_assert2(s == (void*)ctx);
1320 
1321     mb_type = s->current_picture.mb_type[xy];
1322     cbp     = s->cbp_table[xy];
1323 
1324     ctx->use_intra_dc_vlc = s->qscale < ctx->intra_dc_threshold;
1325 
1326     if (s->current_picture.qscale_table[xy] != s->qscale)
1327         ff_set_qscale(s, s->current_picture.qscale_table[xy]);
1328 
1329     if (s->pict_type == AV_PICTURE_TYPE_P ||
1330         s->pict_type == AV_PICTURE_TYPE_S) {
1331         int i;
1332         for (i = 0; i < 4; i++) {
1333             s->mv[0][i][0] = s->current_picture.motion_val[0][s->block_index[i]][0];
1334             s->mv[0][i][1] = s->current_picture.motion_val[0][s->block_index[i]][1];
1335         }
1336         s->mb_intra = IS_INTRA(mb_type);
1337 
1338         if (IS_SKIP(mb_type)) {
1339             /* skip mb */
1340             for (i = 0; i < 6; i++)
1341                 s->block_last_index[i] = -1;
1342             s->mv_dir  = MV_DIR_FORWARD;
1343             s->mv_type = MV_TYPE_16X16;
1344             if (s->pict_type == AV_PICTURE_TYPE_S
1345                 && ctx->vol_sprite_usage == GMC_SPRITE) {
1346                 s->mcsel      = 1;
1347                 s->mb_skipped = 0;
1348             } else {
1349                 s->mcsel      = 0;
1350                 s->mb_skipped = 1;
1351             }
1352         } else if (s->mb_intra) {
1353             s->ac_pred = IS_ACPRED(s->current_picture.mb_type[xy]);
1354         } else if (!s->mb_intra) {
1355             // s->mcsel = 0;  // FIXME do we need to init that?
1356 
1357             s->mv_dir = MV_DIR_FORWARD;
1358             if (IS_8X8(mb_type)) {
1359                 s->mv_type = MV_TYPE_8X8;
1360             } else {
1361                 s->mv_type = MV_TYPE_16X16;
1362             }
1363         }
1364     } else { /* I-Frame */
1365         s->mb_intra = 1;
1366         s->ac_pred  = IS_ACPRED(s->current_picture.mb_type[xy]);
1367     }
1368 
1369     if (!IS_SKIP(mb_type)) {
1370         int i;
1371         s->bdsp.clear_blocks(s->block[0]);
1372         /* decode each block */
1373         for (i = 0; i < 6; i++) {
1374             if (mpeg4_decode_block(ctx, block[i], i, cbp & 32, s->mb_intra, ctx->rvlc) < 0) {
1375                 av_log(s->avctx, AV_LOG_ERROR,
1376                        "texture corrupted at %d %d %d\n",
1377                        s->mb_x, s->mb_y, s->mb_intra);
1378                 return AVERROR_INVALIDDATA;
1379             }
1380             cbp += cbp;
1381         }
1382     }
1383 
1384     /* per-MB end of slice check */
1385     if (--s->mb_num_left <= 0) {
1386         if (mpeg4_is_resync(ctx))
1387             return SLICE_END;
1388         else
1389             return SLICE_NOEND;
1390     } else {
1391         if (mpeg4_is_resync(ctx)) {
1392             const int delta = s->mb_x + 1 == s->mb_width ? 2 : 1;
1393             if (s->cbp_table[xy + delta])
1394                 return SLICE_END;
1395         }
1396         return SLICE_OK;
1397     }
1398 }
1399 
mpeg4_decode_mb(MpegEncContext * s,int16_t block[6][64])1400 static int mpeg4_decode_mb(MpegEncContext *s, int16_t block[6][64])
1401 {
1402     Mpeg4DecContext *ctx = s->avctx->priv_data;
1403     int cbpc, cbpy, i, cbp, pred_x, pred_y, mx, my, dquant;
1404     int16_t *mot_val;
1405     static const int8_t quant_tab[4] = { -1, -2, 1, 2 };
1406     const int xy = s->mb_x + s->mb_y * s->mb_stride;
1407 
1408     av_assert2(s ==  (void*)ctx);
1409     av_assert2(s->h263_pred);
1410 
1411     if (s->pict_type == AV_PICTURE_TYPE_P ||
1412         s->pict_type == AV_PICTURE_TYPE_S) {
1413         do {
1414             if (get_bits1(&s->gb)) {
1415                 /* skip mb */
1416                 s->mb_intra = 0;
1417                 for (i = 0; i < 6; i++)
1418                     s->block_last_index[i] = -1;
1419                 s->mv_dir  = MV_DIR_FORWARD;
1420                 s->mv_type = MV_TYPE_16X16;
1421                 if (s->pict_type == AV_PICTURE_TYPE_S &&
1422                     ctx->vol_sprite_usage == GMC_SPRITE) {
1423                     s->current_picture.mb_type[xy] = MB_TYPE_SKIP  |
1424                                                      MB_TYPE_GMC   |
1425                                                      MB_TYPE_16x16 |
1426                                                      MB_TYPE_L0;
1427                     s->mcsel       = 1;
1428                     s->mv[0][0][0] = get_amv(ctx, 0);
1429                     s->mv[0][0][1] = get_amv(ctx, 1);
1430                     s->mb_skipped  = 0;
1431                 } else {
1432                     s->current_picture.mb_type[xy] = MB_TYPE_SKIP  |
1433                                                      MB_TYPE_16x16 |
1434                                                      MB_TYPE_L0;
1435                     s->mcsel       = 0;
1436                     s->mv[0][0][0] = 0;
1437                     s->mv[0][0][1] = 0;
1438                     s->mb_skipped  = 1;
1439                 }
1440                 goto end;
1441             }
1442             cbpc = get_vlc2(&s->gb, ff_h263_inter_MCBPC_vlc.table, INTER_MCBPC_VLC_BITS, 2);
1443             if (cbpc < 0) {
1444                 av_log(s->avctx, AV_LOG_ERROR,
1445                        "mcbpc damaged at %d %d\n", s->mb_x, s->mb_y);
1446                 return AVERROR_INVALIDDATA;
1447             }
1448         } while (cbpc == 20);
1449 
1450         s->bdsp.clear_blocks(s->block[0]);
1451         dquant      = cbpc & 8;
1452         s->mb_intra = ((cbpc & 4) != 0);
1453         if (s->mb_intra)
1454             goto intra;
1455 
1456         if (s->pict_type == AV_PICTURE_TYPE_S &&
1457             ctx->vol_sprite_usage == GMC_SPRITE && (cbpc & 16) == 0)
1458             s->mcsel = get_bits1(&s->gb);
1459         else
1460             s->mcsel = 0;
1461         cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1) ^ 0x0F;
1462         if (cbpy < 0) {
1463             av_log(s->avctx, AV_LOG_ERROR,
1464                    "P cbpy damaged at %d %d\n", s->mb_x, s->mb_y);
1465             return AVERROR_INVALIDDATA;
1466         }
1467 
1468         cbp = (cbpc & 3) | (cbpy << 2);
1469         if (dquant)
1470             ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
1471         if ((!s->progressive_sequence) &&
1472             (cbp || (s->workaround_bugs & FF_BUG_XVID_ILACE)))
1473             s->interlaced_dct = get_bits1(&s->gb);
1474 
1475         s->mv_dir = MV_DIR_FORWARD;
1476         if ((cbpc & 16) == 0) {
1477             if (s->mcsel) {
1478                 s->current_picture.mb_type[xy] = MB_TYPE_GMC   |
1479                                                  MB_TYPE_16x16 |
1480                                                  MB_TYPE_L0;
1481                 /* 16x16 global motion prediction */
1482                 s->mv_type     = MV_TYPE_16X16;
1483                 mx             = get_amv(ctx, 0);
1484                 my             = get_amv(ctx, 1);
1485                 s->mv[0][0][0] = mx;
1486                 s->mv[0][0][1] = my;
1487             } else if ((!s->progressive_sequence) && get_bits1(&s->gb)) {
1488                 s->current_picture.mb_type[xy] = MB_TYPE_16x8 |
1489                                                  MB_TYPE_L0   |
1490                                                  MB_TYPE_INTERLACED;
1491                 /* 16x8 field motion prediction */
1492                 s->mv_type = MV_TYPE_FIELD;
1493 
1494                 s->field_select[0][0] = get_bits1(&s->gb);
1495                 s->field_select[0][1] = get_bits1(&s->gb);
1496 
1497                 ff_h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
1498 
1499                 for (i = 0; i < 2; i++) {
1500                     mx = ff_h263_decode_motion(s, pred_x, s->f_code);
1501                     if (mx >= 0xffff)
1502                         return AVERROR_INVALIDDATA;
1503 
1504                     my = ff_h263_decode_motion(s, pred_y / 2, s->f_code);
1505                     if (my >= 0xffff)
1506                         return AVERROR_INVALIDDATA;
1507 
1508                     s->mv[0][i][0] = mx;
1509                     s->mv[0][i][1] = my;
1510                 }
1511             } else {
1512                 s->current_picture.mb_type[xy] = MB_TYPE_16x16 | MB_TYPE_L0;
1513                 /* 16x16 motion prediction */
1514                 s->mv_type = MV_TYPE_16X16;
1515                 ff_h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
1516                 mx = ff_h263_decode_motion(s, pred_x, s->f_code);
1517 
1518                 if (mx >= 0xffff)
1519                     return AVERROR_INVALIDDATA;
1520 
1521                 my = ff_h263_decode_motion(s, pred_y, s->f_code);
1522 
1523                 if (my >= 0xffff)
1524                     return AVERROR_INVALIDDATA;
1525                 s->mv[0][0][0] = mx;
1526                 s->mv[0][0][1] = my;
1527             }
1528         } else {
1529             s->current_picture.mb_type[xy] = MB_TYPE_8x8 | MB_TYPE_L0;
1530             s->mv_type                     = MV_TYPE_8X8;
1531             for (i = 0; i < 4; i++) {
1532                 mot_val = ff_h263_pred_motion(s, i, 0, &pred_x, &pred_y);
1533                 mx      = ff_h263_decode_motion(s, pred_x, s->f_code);
1534                 if (mx >= 0xffff)
1535                     return AVERROR_INVALIDDATA;
1536 
1537                 my = ff_h263_decode_motion(s, pred_y, s->f_code);
1538                 if (my >= 0xffff)
1539                     return AVERROR_INVALIDDATA;
1540                 s->mv[0][i][0] = mx;
1541                 s->mv[0][i][1] = my;
1542                 mot_val[0]     = mx;
1543                 mot_val[1]     = my;
1544             }
1545         }
1546     } else if (s->pict_type == AV_PICTURE_TYPE_B) {
1547         int modb1;   // first bit of modb
1548         int modb2;   // second bit of modb
1549         int mb_type;
1550 
1551         s->mb_intra = 0;  // B-frames never contain intra blocks
1552         s->mcsel    = 0;  //      ...               true gmc blocks
1553 
1554         if (s->mb_x == 0) {
1555             for (i = 0; i < 2; i++) {
1556                 s->last_mv[i][0][0] =
1557                 s->last_mv[i][0][1] =
1558                 s->last_mv[i][1][0] =
1559                 s->last_mv[i][1][1] = 0;
1560             }
1561 
1562             ff_thread_await_progress(&s->next_picture_ptr->tf, s->mb_y, 0);
1563         }
1564 
1565         /* if we skipped it in the future P-frame than skip it now too */
1566         s->mb_skipped = s->next_picture.mbskip_table[s->mb_y * s->mb_stride + s->mb_x];  // Note, skiptab=0 if last was GMC
1567 
1568         if (s->mb_skipped) {
1569             /* skip mb */
1570             for (i = 0; i < 6; i++)
1571                 s->block_last_index[i] = -1;
1572 
1573             s->mv_dir      = MV_DIR_FORWARD;
1574             s->mv_type     = MV_TYPE_16X16;
1575             s->mv[0][0][0] =
1576             s->mv[0][0][1] =
1577             s->mv[1][0][0] =
1578             s->mv[1][0][1] = 0;
1579             s->current_picture.mb_type[xy] = MB_TYPE_SKIP  |
1580                                              MB_TYPE_16x16 |
1581                                              MB_TYPE_L0;
1582             goto end;
1583         }
1584 
1585         modb1 = get_bits1(&s->gb);
1586         if (modb1) {
1587             // like MB_TYPE_B_DIRECT but no vectors coded
1588             mb_type = MB_TYPE_DIRECT2 | MB_TYPE_SKIP | MB_TYPE_L0L1;
1589             cbp     = 0;
1590         } else {
1591             modb2   = get_bits1(&s->gb);
1592             mb_type = get_vlc2(&s->gb, mb_type_b_vlc.table, MB_TYPE_B_VLC_BITS, 1);
1593             if (mb_type < 0) {
1594                 av_log(s->avctx, AV_LOG_ERROR, "illegal MB_type\n");
1595                 return AVERROR_INVALIDDATA;
1596             }
1597             mb_type = mb_type_b_map[mb_type];
1598             if (modb2) {
1599                 cbp = 0;
1600             } else {
1601                 s->bdsp.clear_blocks(s->block[0]);
1602                 cbp = get_bits(&s->gb, 6);
1603             }
1604 
1605             if ((!IS_DIRECT(mb_type)) && cbp) {
1606                 if (get_bits1(&s->gb))
1607                     ff_set_qscale(s, s->qscale + get_bits1(&s->gb) * 4 - 2);
1608             }
1609 
1610             if (!s->progressive_sequence) {
1611                 if (cbp)
1612                     s->interlaced_dct = get_bits1(&s->gb);
1613 
1614                 if (!IS_DIRECT(mb_type) && get_bits1(&s->gb)) {
1615                     mb_type |= MB_TYPE_16x8 | MB_TYPE_INTERLACED;
1616                     mb_type &= ~MB_TYPE_16x16;
1617 
1618                     if (USES_LIST(mb_type, 0)) {
1619                         s->field_select[0][0] = get_bits1(&s->gb);
1620                         s->field_select[0][1] = get_bits1(&s->gb);
1621                     }
1622                     if (USES_LIST(mb_type, 1)) {
1623                         s->field_select[1][0] = get_bits1(&s->gb);
1624                         s->field_select[1][1] = get_bits1(&s->gb);
1625                     }
1626                 }
1627             }
1628 
1629             s->mv_dir = 0;
1630             if ((mb_type & (MB_TYPE_DIRECT2 | MB_TYPE_INTERLACED)) == 0) {
1631                 s->mv_type = MV_TYPE_16X16;
1632 
1633                 if (USES_LIST(mb_type, 0)) {
1634                     s->mv_dir = MV_DIR_FORWARD;
1635 
1636                     mx = ff_h263_decode_motion(s, s->last_mv[0][0][0], s->f_code);
1637                     my = ff_h263_decode_motion(s, s->last_mv[0][0][1], s->f_code);
1638                     s->last_mv[0][1][0] =
1639                     s->last_mv[0][0][0] =
1640                     s->mv[0][0][0]      = mx;
1641                     s->last_mv[0][1][1] =
1642                     s->last_mv[0][0][1] =
1643                     s->mv[0][0][1]      = my;
1644                 }
1645 
1646                 if (USES_LIST(mb_type, 1)) {
1647                     s->mv_dir |= MV_DIR_BACKWARD;
1648 
1649                     mx = ff_h263_decode_motion(s, s->last_mv[1][0][0], s->b_code);
1650                     my = ff_h263_decode_motion(s, s->last_mv[1][0][1], s->b_code);
1651                     s->last_mv[1][1][0] =
1652                     s->last_mv[1][0][0] =
1653                     s->mv[1][0][0]      = mx;
1654                     s->last_mv[1][1][1] =
1655                     s->last_mv[1][0][1] =
1656                     s->mv[1][0][1]      = my;
1657                 }
1658             } else if (!IS_DIRECT(mb_type)) {
1659                 s->mv_type = MV_TYPE_FIELD;
1660 
1661                 if (USES_LIST(mb_type, 0)) {
1662                     s->mv_dir = MV_DIR_FORWARD;
1663 
1664                     for (i = 0; i < 2; i++) {
1665                         mx = ff_h263_decode_motion(s, s->last_mv[0][i][0], s->f_code);
1666                         my = ff_h263_decode_motion(s, s->last_mv[0][i][1] / 2, s->f_code);
1667                         s->last_mv[0][i][0] =
1668                         s->mv[0][i][0]      = mx;
1669                         s->last_mv[0][i][1] = (s->mv[0][i][1] = my) * 2;
1670                     }
1671                 }
1672 
1673                 if (USES_LIST(mb_type, 1)) {
1674                     s->mv_dir |= MV_DIR_BACKWARD;
1675 
1676                     for (i = 0; i < 2; i++) {
1677                         mx = ff_h263_decode_motion(s, s->last_mv[1][i][0], s->b_code);
1678                         my = ff_h263_decode_motion(s, s->last_mv[1][i][1] / 2, s->b_code);
1679                         s->last_mv[1][i][0] =
1680                         s->mv[1][i][0]      = mx;
1681                         s->last_mv[1][i][1] = (s->mv[1][i][1] = my) * 2;
1682                     }
1683                 }
1684             }
1685         }
1686 
1687         if (IS_DIRECT(mb_type)) {
1688             if (IS_SKIP(mb_type)) {
1689                 mx =
1690                 my = 0;
1691             } else {
1692                 mx = ff_h263_decode_motion(s, 0, 1);
1693                 my = ff_h263_decode_motion(s, 0, 1);
1694             }
1695 
1696             s->mv_dir = MV_DIR_FORWARD | MV_DIR_BACKWARD | MV_DIRECT;
1697             mb_type  |= ff_mpeg4_set_direct_mv(s, mx, my);
1698         }
1699         s->current_picture.mb_type[xy] = mb_type;
1700     } else { /* I-Frame */
1701         do {
1702             cbpc = get_vlc2(&s->gb, ff_h263_intra_MCBPC_vlc.table, INTRA_MCBPC_VLC_BITS, 2);
1703             if (cbpc < 0) {
1704                 av_log(s->avctx, AV_LOG_ERROR,
1705                        "I cbpc damaged at %d %d\n", s->mb_x, s->mb_y);
1706                 return AVERROR_INVALIDDATA;
1707             }
1708         } while (cbpc == 8);
1709 
1710         dquant = cbpc & 4;
1711         s->mb_intra = 1;
1712 
1713 intra:
1714         s->ac_pred = get_bits1(&s->gb);
1715         if (s->ac_pred)
1716             s->current_picture.mb_type[xy] = MB_TYPE_INTRA | MB_TYPE_ACPRED;
1717         else
1718             s->current_picture.mb_type[xy] = MB_TYPE_INTRA;
1719 
1720         cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
1721         if (cbpy < 0) {
1722             av_log(s->avctx, AV_LOG_ERROR,
1723                    "I cbpy damaged at %d %d\n", s->mb_x, s->mb_y);
1724             return AVERROR_INVALIDDATA;
1725         }
1726         cbp = (cbpc & 3) | (cbpy << 2);
1727 
1728         ctx->use_intra_dc_vlc = s->qscale < ctx->intra_dc_threshold;
1729 
1730         if (dquant)
1731             ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
1732 
1733         if (!s->progressive_sequence)
1734             s->interlaced_dct = get_bits1(&s->gb);
1735 
1736         s->bdsp.clear_blocks(s->block[0]);
1737         /* decode each block */
1738         for (i = 0; i < 6; i++) {
1739             if (mpeg4_decode_block(ctx, block[i], i, cbp & 32, 1, 0) < 0)
1740                 return AVERROR_INVALIDDATA;
1741             cbp += cbp;
1742         }
1743         goto end;
1744     }
1745 
1746     /* decode each block */
1747     for (i = 0; i < 6; i++) {
1748         if (mpeg4_decode_block(ctx, block[i], i, cbp & 32, 0, 0) < 0)
1749             return AVERROR_INVALIDDATA;
1750         cbp += cbp;
1751     }
1752 
1753 end:
1754     /* per-MB end of slice check */
1755     if (s->codec_id == AV_CODEC_ID_MPEG4) {
1756         int next = mpeg4_is_resync(ctx);
1757         if (next) {
1758             if        (s->mb_x + s->mb_y*s->mb_width + 1 >  next && (s->avctx->err_recognition & AV_EF_AGGRESSIVE)) {
1759                 return AVERROR_INVALIDDATA;
1760             } else if (s->mb_x + s->mb_y*s->mb_width + 1 >= next)
1761                 return SLICE_END;
1762 
1763             if (s->pict_type == AV_PICTURE_TYPE_B) {
1764                 const int delta= s->mb_x + 1 == s->mb_width ? 2 : 1;
1765                 ff_thread_await_progress(&s->next_picture_ptr->tf,
1766                                          (s->mb_x + delta >= s->mb_width)
1767                                          ? FFMIN(s->mb_y + 1, s->mb_height - 1)
1768                                          : s->mb_y, 0);
1769                 if (s->next_picture.mbskip_table[xy + delta])
1770                     return SLICE_OK;
1771             }
1772 
1773             return SLICE_END;
1774         }
1775     }
1776 
1777     return SLICE_OK;
1778 }
1779 
1780 /* As per spec, studio start code search isn't the same as the old type of start code */
next_start_code_studio(GetBitContext * gb)1781 static void next_start_code_studio(GetBitContext *gb)
1782 {
1783     align_get_bits(gb);
1784 
1785     while (get_bits_left(gb) >= 24 && show_bits_long(gb, 24) != 0x1) {
1786         get_bits(gb, 8);
1787     }
1788 }
1789 
1790 /* additional_code, vlc index */
1791 static const uint8_t ac_state_tab[22][2] =
1792 {
1793     {0, 0},
1794     {0, 1},
1795     {1, 1},
1796     {2, 1},
1797     {3, 1},
1798     {4, 1},
1799     {5, 1},
1800     {1, 2},
1801     {2, 2},
1802     {3, 2},
1803     {4, 2},
1804     {5, 2},
1805     {6, 2},
1806     {1, 3},
1807     {2, 4},
1808     {3, 5},
1809     {4, 6},
1810     {5, 7},
1811     {6, 8},
1812     {7, 9},
1813     {8, 10},
1814     {0, 11}
1815 };
1816 
mpeg4_decode_studio_block(MpegEncContext * s,int32_t block[64],int n)1817 static int mpeg4_decode_studio_block(MpegEncContext *s, int32_t block[64], int n)
1818 {
1819     Mpeg4DecContext *ctx = s->avctx->priv_data;
1820 
1821     int cc, dct_dc_size, dct_diff, code, j, idx = 1, group = 0, run = 0,
1822         additional_code_len, sign, mismatch;
1823     VLC *cur_vlc = &ctx->studio_intra_tab[0];
1824     uint8_t *const scantable = s->intra_scantable.permutated;
1825     const uint16_t *quant_matrix;
1826     uint32_t flc;
1827     const int min = -1 *  (1 << (s->avctx->bits_per_raw_sample + 6));
1828     const int max =      ((1 << (s->avctx->bits_per_raw_sample + 6)) - 1);
1829 
1830     mismatch = 1;
1831 
1832     memset(block, 0, 64 * sizeof(int32_t));
1833 
1834     if (n < 4) {
1835         cc = 0;
1836         dct_dc_size = get_vlc2(&s->gb, ctx->studio_luma_dc.table, STUDIO_INTRA_BITS, 2);
1837         quant_matrix = s->intra_matrix;
1838     } else {
1839         cc = (n & 1) + 1;
1840         if (ctx->rgb)
1841             dct_dc_size = get_vlc2(&s->gb, ctx->studio_luma_dc.table, STUDIO_INTRA_BITS, 2);
1842         else
1843             dct_dc_size = get_vlc2(&s->gb, ctx->studio_chroma_dc.table, STUDIO_INTRA_BITS, 2);
1844         quant_matrix = s->chroma_intra_matrix;
1845     }
1846 
1847     if (dct_dc_size < 0) {
1848         av_log(s->avctx, AV_LOG_ERROR, "illegal dct_dc_size vlc\n");
1849         return AVERROR_INVALIDDATA;
1850     } else if (dct_dc_size == 0) {
1851         dct_diff = 0;
1852     } else {
1853         dct_diff = get_xbits(&s->gb, dct_dc_size);
1854 
1855         if (dct_dc_size > 8) {
1856             if(!check_marker(s->avctx, &s->gb, "dct_dc_size > 8"))
1857                 return AVERROR_INVALIDDATA;
1858         }
1859 
1860     }
1861 
1862     s->last_dc[cc] += dct_diff;
1863 
1864     if (s->mpeg_quant)
1865         block[0] = s->last_dc[cc] * (8 >> s->intra_dc_precision);
1866     else
1867         block[0] = s->last_dc[cc] * (8 >> s->intra_dc_precision) * (8 >> s->dct_precision);
1868     /* TODO: support mpeg_quant for AC coefficients */
1869 
1870     block[0] = av_clip(block[0], min, max);
1871     mismatch ^= block[0];
1872 
1873     /* AC Coefficients */
1874     while (1) {
1875         group = get_vlc2(&s->gb, cur_vlc->table, STUDIO_INTRA_BITS, 2);
1876 
1877         if (group < 0) {
1878             av_log(s->avctx, AV_LOG_ERROR, "illegal ac coefficient group vlc\n");
1879             return AVERROR_INVALIDDATA;
1880         }
1881 
1882         additional_code_len = ac_state_tab[group][0];
1883         cur_vlc = &ctx->studio_intra_tab[ac_state_tab[group][1]];
1884 
1885         if (group == 0) {
1886             /* End of Block */
1887             break;
1888         } else if (group >= 1 && group <= 6) {
1889             /* Zero run length (Table B.47) */
1890             run = 1 << additional_code_len;
1891             if (additional_code_len)
1892                 run += get_bits(&s->gb, additional_code_len);
1893             idx += run;
1894             continue;
1895         } else if (group >= 7 && group <= 12) {
1896             /* Zero run length and +/-1 level (Table B.48) */
1897             code = get_bits(&s->gb, additional_code_len);
1898             sign = code & 1;
1899             code >>= 1;
1900             run = (1 << (additional_code_len - 1)) + code;
1901             idx += run;
1902             if (idx > 63)
1903                 return AVERROR_INVALIDDATA;
1904             j = scantable[idx++];
1905             block[j] = sign ? 1 : -1;
1906         } else if (group >= 13 && group <= 20) {
1907             /* Level value (Table B.49) */
1908             if (idx > 63)
1909                 return AVERROR_INVALIDDATA;
1910             j = scantable[idx++];
1911             block[j] = get_xbits(&s->gb, additional_code_len);
1912         } else if (group == 21) {
1913             /* Escape */
1914             if (idx > 63)
1915                 return AVERROR_INVALIDDATA;
1916             j = scantable[idx++];
1917             additional_code_len = s->avctx->bits_per_raw_sample + s->dct_precision + 4;
1918             flc = get_bits(&s->gb, additional_code_len);
1919             if (flc >> (additional_code_len-1))
1920                 block[j] = -1 * (( flc ^ ((1 << additional_code_len) -1)) + 1);
1921             else
1922                 block[j] = flc;
1923         }
1924         block[j] = ((8 * 2 * block[j] * quant_matrix[j] * s->qscale) >> s->dct_precision) / 32;
1925         block[j] = av_clip(block[j], min, max);
1926         mismatch ^= block[j];
1927     }
1928 
1929     block[63] ^= mismatch & 1;
1930 
1931     return 0;
1932 }
1933 
mpeg4_decode_dpcm_macroblock(MpegEncContext * s,int16_t macroblock[256],int n)1934 static int mpeg4_decode_dpcm_macroblock(MpegEncContext *s, int16_t macroblock[256], int n)
1935 {
1936     int i, j, w, h, idx = 0;
1937     int block_mean, rice_parameter, rice_prefix_code, rice_suffix_code,
1938         dpcm_residual, left, top, topleft, min_left_top, max_left_top, p, p2, output;
1939     h = 16 >> (n ? s->chroma_y_shift : 0);
1940     w = 16 >> (n ? s->chroma_x_shift : 0);
1941 
1942     block_mean = get_bits(&s->gb, s->avctx->bits_per_raw_sample);
1943     if (block_mean == 0){
1944         av_log(s->avctx, AV_LOG_ERROR, "Forbidden block_mean\n");
1945         return AVERROR_INVALIDDATA;
1946     }
1947     s->last_dc[n] = block_mean * (1 << (s->dct_precision + s->intra_dc_precision));
1948 
1949     rice_parameter = get_bits(&s->gb, 4);
1950     if (rice_parameter == 0) {
1951         av_log(s->avctx, AV_LOG_ERROR, "Forbidden rice_parameter\n");
1952         return AVERROR_INVALIDDATA;
1953     }
1954 
1955     if (rice_parameter == 15)
1956         rice_parameter = 0;
1957 
1958     if (rice_parameter > 11) {
1959         av_log(s->avctx, AV_LOG_ERROR, "Forbidden rice_parameter\n");
1960         return AVERROR_INVALIDDATA;
1961     }
1962 
1963     for (i = 0; i < h; i++) {
1964         output = 1 << (s->avctx->bits_per_raw_sample - 1);
1965         top = 1 << (s->avctx->bits_per_raw_sample - 1);
1966 
1967         for (j = 0; j < w; j++) {
1968             left = output;
1969             topleft = top;
1970 
1971             rice_prefix_code = get_unary(&s->gb, 1, 12);
1972 
1973             /* Escape */
1974             if (rice_prefix_code == 11)
1975                 dpcm_residual = get_bits(&s->gb, s->avctx->bits_per_raw_sample);
1976             else {
1977                 if (rice_prefix_code == 12) {
1978                     av_log(s->avctx, AV_LOG_ERROR, "Forbidden rice_prefix_code\n");
1979                     return AVERROR_INVALIDDATA;
1980                 }
1981                 rice_suffix_code = get_bitsz(&s->gb, rice_parameter);
1982                 dpcm_residual = (rice_prefix_code << rice_parameter) + rice_suffix_code;
1983             }
1984 
1985             /* Map to a signed residual */
1986             if (dpcm_residual & 1)
1987                 dpcm_residual = (-1 * dpcm_residual) >> 1;
1988             else
1989                 dpcm_residual = (dpcm_residual >> 1);
1990 
1991             if (i != 0)
1992                 top = macroblock[idx-w];
1993 
1994             p = left + top - topleft;
1995             min_left_top = FFMIN(left, top);
1996             if (p < min_left_top)
1997                 p = min_left_top;
1998 
1999             max_left_top = FFMAX(left, top);
2000             if (p > max_left_top)
2001                 p = max_left_top;
2002 
2003             p2 = (FFMIN(min_left_top, topleft) + FFMAX(max_left_top, topleft)) >> 1;
2004             if (p2 == p)
2005                 p2 = block_mean;
2006 
2007             if (p2 > p)
2008                 dpcm_residual *= -1;
2009 
2010             macroblock[idx++] = output = (dpcm_residual + p) & ((1 << s->avctx->bits_per_raw_sample) - 1);
2011         }
2012     }
2013 
2014     return 0;
2015 }
2016 
mpeg4_decode_studio_mb(MpegEncContext * s,int16_t block_[12][64])2017 static int mpeg4_decode_studio_mb(MpegEncContext *s, int16_t block_[12][64])
2018 {
2019     int i;
2020 
2021     s->dpcm_direction = 0;
2022 
2023     /* StudioMacroblock */
2024     /* Assumes I-VOP */
2025     s->mb_intra = 1;
2026     if (get_bits1(&s->gb)) { /* compression_mode */
2027         /* DCT */
2028         /* macroblock_type, 1 or 2-bit VLC */
2029         if (!get_bits1(&s->gb)) {
2030             skip_bits1(&s->gb);
2031             s->qscale = mpeg_get_qscale(s);
2032         }
2033 
2034         for (i = 0; i < mpeg4_block_count[s->chroma_format]; i++) {
2035             if (mpeg4_decode_studio_block(s, (*s->block32)[i], i) < 0)
2036                 return AVERROR_INVALIDDATA;
2037         }
2038     } else {
2039         /* DPCM */
2040         check_marker(s->avctx, &s->gb, "DPCM block start");
2041         s->dpcm_direction = get_bits1(&s->gb) ? -1 : 1;
2042         for (i = 0; i < 3; i++) {
2043             if (mpeg4_decode_dpcm_macroblock(s, (*s->dpcm_macroblock)[i], i) < 0)
2044                 return AVERROR_INVALIDDATA;
2045         }
2046     }
2047 
2048     if (get_bits_left(&s->gb) >= 24 && show_bits(&s->gb, 23) == 0) {
2049         next_start_code_studio(&s->gb);
2050         return SLICE_END;
2051     }
2052 
2053     //vcon-stp9L1.bits (first frame)
2054     if (get_bits_left(&s->gb) == 0)
2055         return SLICE_END;
2056 
2057     //vcon-stp2L1.bits, vcon-stp3L1.bits, vcon-stp6L1.bits, vcon-stp7L1.bits, vcon-stp8L1.bits, vcon-stp10L1.bits (first frame)
2058     if (get_bits_left(&s->gb) < 8U && show_bits(&s->gb, get_bits_left(&s->gb)) == 0)
2059         return SLICE_END;
2060 
2061     return SLICE_OK;
2062 }
2063 
mpeg4_decode_gop_header(MpegEncContext * s,GetBitContext * gb)2064 static int mpeg4_decode_gop_header(MpegEncContext *s, GetBitContext *gb)
2065 {
2066     int hours, minutes, seconds;
2067 
2068     if (!show_bits(gb, 23)) {
2069         av_log(s->avctx, AV_LOG_WARNING, "GOP header invalid\n");
2070         return AVERROR_INVALIDDATA;
2071     }
2072 
2073     hours   = get_bits(gb, 5);
2074     minutes = get_bits(gb, 6);
2075     check_marker(s->avctx, gb, "in gop_header");
2076     seconds = get_bits(gb, 6);
2077 
2078     s->time_base = seconds + 60*(minutes + 60*hours);
2079 
2080     skip_bits1(gb);
2081     skip_bits1(gb);
2082 
2083     return 0;
2084 }
2085 
mpeg4_decode_profile_level(MpegEncContext * s,GetBitContext * gb,int * profile,int * level)2086 static int mpeg4_decode_profile_level(MpegEncContext *s, GetBitContext *gb, int *profile, int *level)
2087 {
2088 
2089     *profile = get_bits(gb, 4);
2090     *level   = get_bits(gb, 4);
2091 
2092     // for Simple profile, level 0
2093     if (*profile == 0 && *level == 8) {
2094         *level = 0;
2095     }
2096 
2097     return 0;
2098 }
2099 
mpeg4_decode_visual_object(MpegEncContext * s,GetBitContext * gb)2100 static int mpeg4_decode_visual_object(MpegEncContext *s, GetBitContext *gb)
2101 {
2102     int visual_object_type;
2103     int is_visual_object_identifier = get_bits1(gb);
2104 
2105     if (is_visual_object_identifier) {
2106         skip_bits(gb, 4+3);
2107     }
2108     visual_object_type = get_bits(gb, 4);
2109 
2110     if (visual_object_type == VOT_VIDEO_ID ||
2111         visual_object_type == VOT_STILL_TEXTURE_ID) {
2112         int video_signal_type = get_bits1(gb);
2113         if (video_signal_type) {
2114             int video_range, color_description;
2115             skip_bits(gb, 3); // video_format
2116             video_range = get_bits1(gb);
2117             color_description = get_bits1(gb);
2118 
2119             s->avctx->color_range = video_range ? AVCOL_RANGE_JPEG : AVCOL_RANGE_MPEG;
2120 
2121             if (color_description) {
2122                 s->avctx->color_primaries = get_bits(gb, 8);
2123                 s->avctx->color_trc       = get_bits(gb, 8);
2124                 s->avctx->colorspace      = get_bits(gb, 8);
2125             }
2126         }
2127     }
2128 
2129     return 0;
2130 }
2131 
mpeg4_load_default_matrices(MpegEncContext * s)2132 static void mpeg4_load_default_matrices(MpegEncContext *s)
2133 {
2134     int i, v;
2135 
2136     /* load default matrices */
2137     for (i = 0; i < 64; i++) {
2138         int j = s->idsp.idct_permutation[i];
2139         v = ff_mpeg4_default_intra_matrix[i];
2140         s->intra_matrix[j]        = v;
2141         s->chroma_intra_matrix[j] = v;
2142 
2143         v = ff_mpeg4_default_non_intra_matrix[i];
2144         s->inter_matrix[j]        = v;
2145         s->chroma_inter_matrix[j] = v;
2146     }
2147 }
2148 
decode_vol_header(Mpeg4DecContext * ctx,GetBitContext * gb)2149 static int decode_vol_header(Mpeg4DecContext *ctx, GetBitContext *gb)
2150 {
2151     MpegEncContext *s = &ctx->m;
2152     int width, height, vo_ver_id;
2153 
2154     /* vol header */
2155     skip_bits(gb, 1);                   /* random access */
2156     s->vo_type = get_bits(gb, 8);
2157 
2158     /* If we are in studio profile (per vo_type), check if its all consistent
2159      * and if so continue pass control to decode_studio_vol_header().
2160      * elIf something is inconsistent, error out
2161      * else continue with (non studio) vol header decpoding.
2162      */
2163     if (s->vo_type == CORE_STUDIO_VO_TYPE ||
2164         s->vo_type == SIMPLE_STUDIO_VO_TYPE) {
2165         if (s->avctx->profile != FF_PROFILE_UNKNOWN && s->avctx->profile != FF_PROFILE_MPEG4_SIMPLE_STUDIO)
2166             return AVERROR_INVALIDDATA;
2167         s->studio_profile = 1;
2168         s->avctx->profile = FF_PROFILE_MPEG4_SIMPLE_STUDIO;
2169         return decode_studio_vol_header(ctx, gb);
2170     } else if (s->studio_profile) {
2171         return AVERROR_PATCHWELCOME;
2172     }
2173 
2174     if (get_bits1(gb) != 0) {           /* is_ol_id */
2175         vo_ver_id = get_bits(gb, 4);    /* vo_ver_id */
2176         skip_bits(gb, 3);               /* vo_priority */
2177     } else {
2178         vo_ver_id = 1;
2179     }
2180     s->aspect_ratio_info = get_bits(gb, 4);
2181     if (s->aspect_ratio_info == FF_ASPECT_EXTENDED) {
2182         s->avctx->sample_aspect_ratio.num = get_bits(gb, 8);  // par_width
2183         s->avctx->sample_aspect_ratio.den = get_bits(gb, 8);  // par_height
2184     } else {
2185         s->avctx->sample_aspect_ratio = ff_h263_pixel_aspect[s->aspect_ratio_info];
2186     }
2187 
2188     if ((ctx->vol_control_parameters = get_bits1(gb))) { /* vol control parameter */
2189         int chroma_format = get_bits(gb, 2);
2190         if (chroma_format != CHROMA_420)
2191             av_log(s->avctx, AV_LOG_ERROR, "illegal chroma format\n");
2192 
2193         s->low_delay = get_bits1(gb);
2194         if (get_bits1(gb)) {    /* vbv parameters */
2195             get_bits(gb, 15);   /* first_half_bitrate */
2196             check_marker(s->avctx, gb, "after first_half_bitrate");
2197             get_bits(gb, 15);   /* latter_half_bitrate */
2198             check_marker(s->avctx, gb, "after latter_half_bitrate");
2199             get_bits(gb, 15);   /* first_half_vbv_buffer_size */
2200             check_marker(s->avctx, gb, "after first_half_vbv_buffer_size");
2201             get_bits(gb, 3);    /* latter_half_vbv_buffer_size */
2202             get_bits(gb, 11);   /* first_half_vbv_occupancy */
2203             check_marker(s->avctx, gb, "after first_half_vbv_occupancy");
2204             get_bits(gb, 15);   /* latter_half_vbv_occupancy */
2205             check_marker(s->avctx, gb, "after latter_half_vbv_occupancy");
2206         }
2207     } else {
2208         /* is setting low delay flag only once the smartest thing to do?
2209          * low delay detection will not be overridden. */
2210         if (s->picture_number == 0) {
2211             switch(s->vo_type) {
2212             case SIMPLE_VO_TYPE:
2213             case ADV_SIMPLE_VO_TYPE:
2214                 s->low_delay = 1;
2215                 break;
2216             default:
2217                 s->low_delay = 0;
2218             }
2219         }
2220     }
2221 
2222     ctx->shape = get_bits(gb, 2); /* vol shape */
2223     if (ctx->shape != RECT_SHAPE)
2224         av_log(s->avctx, AV_LOG_ERROR, "only rectangular vol supported\n");
2225     if (ctx->shape == GRAY_SHAPE && vo_ver_id != 1) {
2226         av_log(s->avctx, AV_LOG_ERROR, "Gray shape not supported\n");
2227         skip_bits(gb, 4);  /* video_object_layer_shape_extension */
2228     }
2229 
2230     check_marker(s->avctx, gb, "before time_increment_resolution");
2231 
2232     s->avctx->framerate.num = get_bits(gb, 16);
2233     if (!s->avctx->framerate.num) {
2234         av_log(s->avctx, AV_LOG_ERROR, "framerate==0\n");
2235         return AVERROR_INVALIDDATA;
2236     }
2237 
2238     ctx->time_increment_bits = av_log2(s->avctx->framerate.num - 1) + 1;
2239     if (ctx->time_increment_bits < 1)
2240         ctx->time_increment_bits = 1;
2241 
2242     check_marker(s->avctx, gb, "before fixed_vop_rate");
2243 
2244     if (get_bits1(gb) != 0)     /* fixed_vop_rate  */
2245         s->avctx->framerate.den = get_bits(gb, ctx->time_increment_bits);
2246     else
2247         s->avctx->framerate.den = 1;
2248 
2249     s->avctx->time_base = av_inv_q(av_mul_q(s->avctx->framerate, (AVRational){s->avctx->ticks_per_frame, 1}));
2250 
2251     ctx->t_frame = 0;
2252 
2253     if (ctx->shape != BIN_ONLY_SHAPE) {
2254         if (ctx->shape == RECT_SHAPE) {
2255             check_marker(s->avctx, gb, "before width");
2256             width = get_bits(gb, 13);
2257             check_marker(s->avctx, gb, "before height");
2258             height = get_bits(gb, 13);
2259             check_marker(s->avctx, gb, "after height");
2260             if (width && height &&  /* they should be non zero but who knows */
2261                 !(s->width && s->codec_tag == AV_RL32("MP4S"))) {
2262                 if (s->width && s->height &&
2263                     (s->width != width || s->height != height))
2264                     s->context_reinit = 1;
2265                 s->width  = width;
2266                 s->height = height;
2267             }
2268         }
2269 
2270         s->progressive_sequence  =
2271         s->progressive_frame     = get_bits1(gb) ^ 1;
2272         s->interlaced_dct        = 0;
2273         if (!get_bits1(gb) && (s->avctx->debug & FF_DEBUG_PICT_INFO))
2274             av_log(s->avctx, AV_LOG_INFO,           /* OBMC Disable */
2275                    "MPEG-4 OBMC not supported (very likely buggy encoder)\n");
2276         if (vo_ver_id == 1)
2277             ctx->vol_sprite_usage = get_bits1(gb);    /* vol_sprite_usage */
2278         else
2279             ctx->vol_sprite_usage = get_bits(gb, 2);  /* vol_sprite_usage */
2280 
2281         if (ctx->vol_sprite_usage == STATIC_SPRITE)
2282             av_log(s->avctx, AV_LOG_ERROR, "Static Sprites not supported\n");
2283         if (ctx->vol_sprite_usage == STATIC_SPRITE ||
2284             ctx->vol_sprite_usage == GMC_SPRITE) {
2285             if (ctx->vol_sprite_usage == STATIC_SPRITE) {
2286                 skip_bits(gb, 13); // sprite_width
2287                 check_marker(s->avctx, gb, "after sprite_width");
2288                 skip_bits(gb, 13); // sprite_height
2289                 check_marker(s->avctx, gb, "after sprite_height");
2290                 skip_bits(gb, 13); // sprite_left
2291                 check_marker(s->avctx, gb, "after sprite_left");
2292                 skip_bits(gb, 13); // sprite_top
2293                 check_marker(s->avctx, gb, "after sprite_top");
2294             }
2295             ctx->num_sprite_warping_points = get_bits(gb, 6);
2296             if (ctx->num_sprite_warping_points > 3) {
2297                 av_log(s->avctx, AV_LOG_ERROR,
2298                        "%d sprite_warping_points\n",
2299                        ctx->num_sprite_warping_points);
2300                 ctx->num_sprite_warping_points = 0;
2301                 return AVERROR_INVALIDDATA;
2302             }
2303             s->sprite_warping_accuracy  = get_bits(gb, 2);
2304             ctx->sprite_brightness_change = get_bits1(gb);
2305             if (ctx->vol_sprite_usage == STATIC_SPRITE)
2306                 skip_bits1(gb); // low_latency_sprite
2307         }
2308         // FIXME sadct disable bit if verid!=1 && shape not rect
2309 
2310         if (get_bits1(gb) == 1) {                   /* not_8_bit */
2311             s->quant_precision = get_bits(gb, 4);   /* quant_precision */
2312             if (get_bits(gb, 4) != 8)               /* bits_per_pixel */
2313                 av_log(s->avctx, AV_LOG_ERROR, "N-bit not supported\n");
2314             if (s->quant_precision != 5)
2315                 av_log(s->avctx, AV_LOG_ERROR,
2316                        "quant precision %d\n", s->quant_precision);
2317             if (s->quant_precision<3 || s->quant_precision>9) {
2318                 s->quant_precision = 5;
2319             }
2320         } else {
2321             s->quant_precision = 5;
2322         }
2323 
2324         // FIXME a bunch of grayscale shape things
2325 
2326         if ((s->mpeg_quant = get_bits1(gb))) { /* vol_quant_type */
2327             int i, v;
2328 
2329             mpeg4_load_default_matrices(s);
2330 
2331             /* load custom intra matrix */
2332             if (get_bits1(gb)) {
2333                 int last = 0;
2334                 for (i = 0; i < 64; i++) {
2335                     int j;
2336                     if (get_bits_left(gb) < 8) {
2337                         av_log(s->avctx, AV_LOG_ERROR, "insufficient data for custom matrix\n");
2338                         return AVERROR_INVALIDDATA;
2339                     }
2340                     v = get_bits(gb, 8);
2341                     if (v == 0)
2342                         break;
2343 
2344                     last = v;
2345                     j = s->idsp.idct_permutation[ff_zigzag_direct[i]];
2346                     s->intra_matrix[j]        = last;
2347                     s->chroma_intra_matrix[j] = last;
2348                 }
2349 
2350                 /* replicate last value */
2351                 for (; i < 64; i++) {
2352                     int j = s->idsp.idct_permutation[ff_zigzag_direct[i]];
2353                     s->intra_matrix[j]        = last;
2354                     s->chroma_intra_matrix[j] = last;
2355                 }
2356             }
2357 
2358             /* load custom non intra matrix */
2359             if (get_bits1(gb)) {
2360                 int last = 0;
2361                 for (i = 0; i < 64; i++) {
2362                     int j;
2363                     if (get_bits_left(gb) < 8) {
2364                         av_log(s->avctx, AV_LOG_ERROR, "insufficient data for custom matrix\n");
2365                         return AVERROR_INVALIDDATA;
2366                     }
2367                     v = get_bits(gb, 8);
2368                     if (v == 0)
2369                         break;
2370 
2371                     last = v;
2372                     j = s->idsp.idct_permutation[ff_zigzag_direct[i]];
2373                     s->inter_matrix[j]        = v;
2374                     s->chroma_inter_matrix[j] = v;
2375                 }
2376 
2377                 /* replicate last value */
2378                 for (; i < 64; i++) {
2379                     int j = s->idsp.idct_permutation[ff_zigzag_direct[i]];
2380                     s->inter_matrix[j]        = last;
2381                     s->chroma_inter_matrix[j] = last;
2382                 }
2383             }
2384 
2385             // FIXME a bunch of grayscale shape things
2386         }
2387 
2388         if (vo_ver_id != 1)
2389             s->quarter_sample = get_bits1(gb);
2390         else
2391             s->quarter_sample = 0;
2392 
2393         if (get_bits_left(gb) < 4) {
2394             av_log(s->avctx, AV_LOG_ERROR, "VOL Header truncated\n");
2395             return AVERROR_INVALIDDATA;
2396         }
2397 
2398         if (!get_bits1(gb)) {
2399             int pos               = get_bits_count(gb);
2400             int estimation_method = get_bits(gb, 2);
2401             if (estimation_method < 2) {
2402                 if (!get_bits1(gb)) {
2403                     ctx->cplx_estimation_trash_i += 8 * get_bits1(gb);  /* opaque */
2404                     ctx->cplx_estimation_trash_i += 8 * get_bits1(gb);  /* transparent */
2405                     ctx->cplx_estimation_trash_i += 8 * get_bits1(gb);  /* intra_cae */
2406                     ctx->cplx_estimation_trash_i += 8 * get_bits1(gb);  /* inter_cae */
2407                     ctx->cplx_estimation_trash_i += 8 * get_bits1(gb);  /* no_update */
2408                     ctx->cplx_estimation_trash_i += 8 * get_bits1(gb);  /* upsampling */
2409                 }
2410                 if (!get_bits1(gb)) {
2411                     ctx->cplx_estimation_trash_i += 8 * get_bits1(gb);  /* intra_blocks */
2412                     ctx->cplx_estimation_trash_p += 8 * get_bits1(gb);  /* inter_blocks */
2413                     ctx->cplx_estimation_trash_p += 8 * get_bits1(gb);  /* inter4v_blocks */
2414                     ctx->cplx_estimation_trash_i += 8 * get_bits1(gb);  /* not coded blocks */
2415                 }
2416                 if (!check_marker(s->avctx, gb, "in complexity estimation part 1")) {
2417                     skip_bits_long(gb, pos - get_bits_count(gb));
2418                     goto no_cplx_est;
2419                 }
2420                 if (!get_bits1(gb)) {
2421                     ctx->cplx_estimation_trash_i += 8 * get_bits1(gb);  /* dct_coeffs */
2422                     ctx->cplx_estimation_trash_i += 8 * get_bits1(gb);  /* dct_lines */
2423                     ctx->cplx_estimation_trash_i += 8 * get_bits1(gb);  /* vlc_syms */
2424                     ctx->cplx_estimation_trash_i += 4 * get_bits1(gb);  /* vlc_bits */
2425                 }
2426                 if (!get_bits1(gb)) {
2427                     ctx->cplx_estimation_trash_p += 8 * get_bits1(gb);  /* apm */
2428                     ctx->cplx_estimation_trash_p += 8 * get_bits1(gb);  /* npm */
2429                     ctx->cplx_estimation_trash_b += 8 * get_bits1(gb);  /* interpolate_mc_q */
2430                     ctx->cplx_estimation_trash_p += 8 * get_bits1(gb);  /* forwback_mc_q */
2431                     ctx->cplx_estimation_trash_p += 8 * get_bits1(gb);  /* halfpel2 */
2432                     ctx->cplx_estimation_trash_p += 8 * get_bits1(gb);  /* halfpel4 */
2433                 }
2434                 if (!check_marker(s->avctx, gb, "in complexity estimation part 2")) {
2435                     skip_bits_long(gb, pos - get_bits_count(gb));
2436                     goto no_cplx_est;
2437                 }
2438                 if (estimation_method == 1) {
2439                     ctx->cplx_estimation_trash_i += 8 * get_bits1(gb);  /* sadct */
2440                     ctx->cplx_estimation_trash_p += 8 * get_bits1(gb);  /* qpel */
2441                 }
2442             } else
2443                 av_log(s->avctx, AV_LOG_ERROR,
2444                        "Invalid Complexity estimation method %d\n",
2445                        estimation_method);
2446         } else {
2447 
2448 no_cplx_est:
2449             ctx->cplx_estimation_trash_i =
2450             ctx->cplx_estimation_trash_p =
2451             ctx->cplx_estimation_trash_b = 0;
2452         }
2453 
2454         ctx->resync_marker = !get_bits1(gb); /* resync_marker_disabled */
2455 
2456         s->data_partitioning = get_bits1(gb);
2457         if (s->data_partitioning)
2458             ctx->rvlc = get_bits1(gb);
2459 
2460         if (vo_ver_id != 1) {
2461             ctx->new_pred = get_bits1(gb);
2462             if (ctx->new_pred) {
2463                 av_log(s->avctx, AV_LOG_ERROR, "new pred not supported\n");
2464                 skip_bits(gb, 2); /* requested upstream message type */
2465                 skip_bits1(gb);   /* newpred segment type */
2466             }
2467             if (get_bits1(gb)) // reduced_res_vop
2468                 av_log(s->avctx, AV_LOG_ERROR,
2469                        "reduced resolution VOP not supported\n");
2470         } else {
2471             ctx->new_pred = 0;
2472         }
2473 
2474         ctx->scalability = get_bits1(gb);
2475 
2476         if (ctx->scalability) {
2477             GetBitContext bak = *gb;
2478             int h_sampling_factor_n;
2479             int h_sampling_factor_m;
2480             int v_sampling_factor_n;
2481             int v_sampling_factor_m;
2482 
2483             skip_bits1(gb);    // hierarchy_type
2484             skip_bits(gb, 4);  /* ref_layer_id */
2485             skip_bits1(gb);    /* ref_layer_sampling_dir */
2486             h_sampling_factor_n = get_bits(gb, 5);
2487             h_sampling_factor_m = get_bits(gb, 5);
2488             v_sampling_factor_n = get_bits(gb, 5);
2489             v_sampling_factor_m = get_bits(gb, 5);
2490             ctx->enhancement_type = get_bits1(gb);
2491 
2492             if (h_sampling_factor_n == 0 || h_sampling_factor_m == 0 ||
2493                 v_sampling_factor_n == 0 || v_sampling_factor_m == 0) {
2494                 /* illegal scalability header (VERY broken encoder),
2495                  * trying to workaround */
2496                 ctx->scalability = 0;
2497                 *gb            = bak;
2498             } else
2499                 av_log(s->avctx, AV_LOG_ERROR, "scalability not supported\n");
2500 
2501             // bin shape stuff FIXME
2502         }
2503     }
2504 
2505     if (s->avctx->debug&FF_DEBUG_PICT_INFO) {
2506         av_log(s->avctx, AV_LOG_DEBUG, "tb %d/%d, tincrbits:%d, qp_prec:%d, ps:%d, low_delay:%d  %s%s%s%s\n",
2507                s->avctx->framerate.den, s->avctx->framerate.num,
2508                ctx->time_increment_bits,
2509                s->quant_precision,
2510                s->progressive_sequence,
2511                s->low_delay,
2512                ctx->scalability ? "scalability " :"" , s->quarter_sample ? "qpel " : "",
2513                s->data_partitioning ? "partition " : "", ctx->rvlc ? "rvlc " : ""
2514         );
2515     }
2516 
2517     return 0;
2518 }
2519 
2520 /**
2521  * Decode the user data stuff in the header.
2522  * Also initializes divx/xvid/lavc_version/build.
2523  */
decode_user_data(Mpeg4DecContext * ctx,GetBitContext * gb)2524 static int decode_user_data(Mpeg4DecContext *ctx, GetBitContext *gb)
2525 {
2526     MpegEncContext *s = &ctx->m;
2527     char buf[256];
2528     int i;
2529     int e;
2530     int ver = 0, build = 0, ver2 = 0, ver3 = 0;
2531     char last;
2532 
2533     for (i = 0; i < 255 && get_bits_count(gb) < gb->size_in_bits; i++) {
2534         if (show_bits(gb, 23) == 0)
2535             break;
2536         buf[i] = get_bits(gb, 8);
2537     }
2538     buf[i] = 0;
2539 
2540     /* divx detection */
2541     e = sscanf(buf, "DivX%dBuild%d%c", &ver, &build, &last);
2542     if (e < 2)
2543         e = sscanf(buf, "DivX%db%d%c", &ver, &build, &last);
2544     if (e >= 2) {
2545         ctx->divx_version = ver;
2546         ctx->divx_build   = build;
2547         s->divx_packed  = e == 3 && last == 'p';
2548     }
2549 
2550     /* libavcodec detection */
2551     e = sscanf(buf, "FFmpe%*[^b]b%d", &build) + 3;
2552     if (e != 4)
2553         e = sscanf(buf, "FFmpeg v%d.%d.%d / libavcodec build: %d", &ver, &ver2, &ver3, &build);
2554     if (e != 4) {
2555         e = sscanf(buf, "Lavc%d.%d.%d", &ver, &ver2, &ver3) + 1;
2556         if (e > 1) {
2557             if (ver > 0xFFU || ver2 > 0xFFU || ver3 > 0xFFU) {
2558                 av_log(s->avctx, AV_LOG_WARNING,
2559                      "Unknown Lavc version string encountered, %d.%d.%d; "
2560                      "clamping sub-version values to 8-bits.\n",
2561                      ver, ver2, ver3);
2562             }
2563             build = ((ver & 0xFF) << 16) + ((ver2 & 0xFF) << 8) + (ver3 & 0xFF);
2564         }
2565     }
2566     if (e != 4) {
2567         if (strcmp(buf, "ffmpeg") == 0)
2568             ctx->lavc_build = 4600;
2569     }
2570     if (e == 4)
2571         ctx->lavc_build = build;
2572 
2573     /* Xvid detection */
2574     e = sscanf(buf, "XviD%d", &build);
2575     if (e == 1)
2576         ctx->xvid_build = build;
2577 
2578     return 0;
2579 }
2580 
ff_mpeg4_workaround_bugs(AVCodecContext * avctx)2581 int ff_mpeg4_workaround_bugs(AVCodecContext *avctx)
2582 {
2583     Mpeg4DecContext *ctx = avctx->priv_data;
2584     MpegEncContext *s = &ctx->m;
2585 
2586     if (ctx->xvid_build == -1 && ctx->divx_version == -1 && ctx->lavc_build == -1) {
2587         if (s->codec_tag        == AV_RL32("XVID") ||
2588             s->codec_tag        == AV_RL32("XVIX") ||
2589             s->codec_tag        == AV_RL32("RMP4") ||
2590             s->codec_tag        == AV_RL32("ZMP4") ||
2591             s->codec_tag        == AV_RL32("SIPP"))
2592             ctx->xvid_build = 0;
2593     }
2594 
2595     if (ctx->xvid_build == -1 && ctx->divx_version == -1 && ctx->lavc_build == -1)
2596         if (s->codec_tag == AV_RL32("DIVX") && s->vo_type == 0 &&
2597             ctx->vol_control_parameters == 0)
2598             ctx->divx_version = 400;  // divx 4
2599 
2600     if (ctx->xvid_build >= 0 && ctx->divx_version >= 0) {
2601         ctx->divx_version =
2602         ctx->divx_build   = -1;
2603     }
2604 
2605     if (s->workaround_bugs & FF_BUG_AUTODETECT) {
2606         if (s->codec_tag == AV_RL32("XVIX"))
2607             s->workaround_bugs |= FF_BUG_XVID_ILACE;
2608 
2609         if (s->codec_tag == AV_RL32("UMP4"))
2610             s->workaround_bugs |= FF_BUG_UMP4;
2611 
2612         if (ctx->divx_version >= 500 && ctx->divx_build < 1814)
2613             s->workaround_bugs |= FF_BUG_QPEL_CHROMA;
2614 
2615         if (ctx->divx_version > 502 && ctx->divx_build < 1814)
2616             s->workaround_bugs |= FF_BUG_QPEL_CHROMA2;
2617 
2618         if (ctx->xvid_build <= 3U)
2619             s->padding_bug_score = 256 * 256 * 256 * 64;
2620 
2621         if (ctx->xvid_build <= 1U)
2622             s->workaround_bugs |= FF_BUG_QPEL_CHROMA;
2623 
2624         if (ctx->xvid_build <= 12U)
2625             s->workaround_bugs |= FF_BUG_EDGE;
2626 
2627         if (ctx->xvid_build <= 32U)
2628             s->workaround_bugs |= FF_BUG_DC_CLIP;
2629 
2630 #define SET_QPEL_FUNC(postfix1, postfix2)                           \
2631     s->qdsp.put_        ## postfix1 = ff_put_        ## postfix2;   \
2632     s->qdsp.put_no_rnd_ ## postfix1 = ff_put_no_rnd_ ## postfix2;   \
2633     s->qdsp.avg_        ## postfix1 = ff_avg_        ## postfix2;
2634 
2635         if (ctx->lavc_build < 4653U)
2636             s->workaround_bugs |= FF_BUG_STD_QPEL;
2637 
2638         if (ctx->lavc_build < 4655U)
2639             s->workaround_bugs |= FF_BUG_DIRECT_BLOCKSIZE;
2640 
2641         if (ctx->lavc_build < 4670U)
2642             s->workaround_bugs |= FF_BUG_EDGE;
2643 
2644         if (ctx->lavc_build <= 4712U)
2645             s->workaround_bugs |= FF_BUG_DC_CLIP;
2646 
2647         if ((ctx->lavc_build&0xFF) >= 100) {
2648             if (ctx->lavc_build > 3621476 && ctx->lavc_build < 3752552 &&
2649                (ctx->lavc_build < 3752037 || ctx->lavc_build > 3752191) // 3.2.1+
2650             )
2651                 s->workaround_bugs |= FF_BUG_IEDGE;
2652         }
2653 
2654         if (ctx->divx_version >= 0)
2655             s->workaround_bugs |= FF_BUG_DIRECT_BLOCKSIZE;
2656         if (ctx->divx_version == 501 && ctx->divx_build == 20020416)
2657             s->padding_bug_score = 256 * 256 * 256 * 64;
2658 
2659         if (ctx->divx_version < 500U)
2660             s->workaround_bugs |= FF_BUG_EDGE;
2661 
2662         if (ctx->divx_version >= 0)
2663             s->workaround_bugs |= FF_BUG_HPEL_CHROMA;
2664     }
2665 
2666     if (s->workaround_bugs & FF_BUG_STD_QPEL) {
2667         SET_QPEL_FUNC(qpel_pixels_tab[0][5], qpel16_mc11_old_c)
2668         SET_QPEL_FUNC(qpel_pixels_tab[0][7], qpel16_mc31_old_c)
2669         SET_QPEL_FUNC(qpel_pixels_tab[0][9], qpel16_mc12_old_c)
2670         SET_QPEL_FUNC(qpel_pixels_tab[0][11], qpel16_mc32_old_c)
2671         SET_QPEL_FUNC(qpel_pixels_tab[0][13], qpel16_mc13_old_c)
2672         SET_QPEL_FUNC(qpel_pixels_tab[0][15], qpel16_mc33_old_c)
2673 
2674         SET_QPEL_FUNC(qpel_pixels_tab[1][5], qpel8_mc11_old_c)
2675         SET_QPEL_FUNC(qpel_pixels_tab[1][7], qpel8_mc31_old_c)
2676         SET_QPEL_FUNC(qpel_pixels_tab[1][9], qpel8_mc12_old_c)
2677         SET_QPEL_FUNC(qpel_pixels_tab[1][11], qpel8_mc32_old_c)
2678         SET_QPEL_FUNC(qpel_pixels_tab[1][13], qpel8_mc13_old_c)
2679         SET_QPEL_FUNC(qpel_pixels_tab[1][15], qpel8_mc33_old_c)
2680     }
2681 
2682     if (avctx->debug & FF_DEBUG_BUGS)
2683         av_log(s->avctx, AV_LOG_DEBUG,
2684                "bugs: %X lavc_build:%d xvid_build:%d divx_version:%d divx_build:%d %s\n",
2685                s->workaround_bugs, ctx->lavc_build, ctx->xvid_build,
2686                ctx->divx_version, ctx->divx_build, s->divx_packed ? "p" : "");
2687 
2688     if (CONFIG_MPEG4_DECODER && ctx->xvid_build >= 0 &&
2689         s->codec_id == AV_CODEC_ID_MPEG4 &&
2690         avctx->idct_algo == FF_IDCT_AUTO) {
2691         avctx->idct_algo = FF_IDCT_XVID;
2692         ff_mpv_idct_init(s);
2693         return 1;
2694     }
2695 
2696     return 0;
2697 }
2698 
decode_vop_header(Mpeg4DecContext * ctx,GetBitContext * gb)2699 static int decode_vop_header(Mpeg4DecContext *ctx, GetBitContext *gb)
2700 {
2701     MpegEncContext *s = &ctx->m;
2702     int time_incr, time_increment;
2703     int64_t pts;
2704 
2705     s->mcsel       = 0;
2706     s->pict_type = get_bits(gb, 2) + AV_PICTURE_TYPE_I;        /* pict type: I = 0 , P = 1 */
2707     if (s->pict_type == AV_PICTURE_TYPE_B && s->low_delay &&
2708         ctx->vol_control_parameters == 0 && !(s->avctx->flags & AV_CODEC_FLAG_LOW_DELAY)) {
2709         av_log(s->avctx, AV_LOG_ERROR, "low_delay flag set incorrectly, clearing it\n");
2710         s->low_delay = 0;
2711     }
2712 
2713     s->partitioned_frame = s->data_partitioning && s->pict_type != AV_PICTURE_TYPE_B;
2714     if (s->partitioned_frame)
2715         s->decode_mb = mpeg4_decode_partitioned_mb;
2716     else
2717         s->decode_mb = mpeg4_decode_mb;
2718 
2719     time_incr = 0;
2720     while (get_bits1(gb) != 0)
2721         time_incr++;
2722 
2723     check_marker(s->avctx, gb, "before time_increment");
2724 
2725     if (ctx->time_increment_bits == 0 ||
2726         !(show_bits(gb, ctx->time_increment_bits + 1) & 1)) {
2727         av_log(s->avctx, AV_LOG_WARNING,
2728                "time_increment_bits %d is invalid in relation to the current bitstream, this is likely caused by a missing VOL header\n", ctx->time_increment_bits);
2729 
2730         for (ctx->time_increment_bits = 1;
2731              ctx->time_increment_bits < 16;
2732              ctx->time_increment_bits++) {
2733             if (s->pict_type == AV_PICTURE_TYPE_P ||
2734                 (s->pict_type == AV_PICTURE_TYPE_S &&
2735                  ctx->vol_sprite_usage == GMC_SPRITE)) {
2736                 if ((show_bits(gb, ctx->time_increment_bits + 6) & 0x37) == 0x30)
2737                     break;
2738             } else if ((show_bits(gb, ctx->time_increment_bits + 5) & 0x1F) == 0x18)
2739                 break;
2740         }
2741 
2742         av_log(s->avctx, AV_LOG_WARNING,
2743                "time_increment_bits set to %d bits, based on bitstream analysis\n", ctx->time_increment_bits);
2744         if (s->avctx->framerate.num && 4*s->avctx->framerate.num < 1<<ctx->time_increment_bits) {
2745             s->avctx->framerate.num = 1<<ctx->time_increment_bits;
2746             s->avctx->time_base = av_inv_q(av_mul_q(s->avctx->framerate, (AVRational){s->avctx->ticks_per_frame, 1}));
2747         }
2748     }
2749 
2750     if (IS_3IV1)
2751         time_increment = get_bits1(gb);        // FIXME investigate further
2752     else
2753         time_increment = get_bits(gb, ctx->time_increment_bits);
2754 
2755     if (s->pict_type != AV_PICTURE_TYPE_B) {
2756         s->last_time_base = s->time_base;
2757         s->time_base     += time_incr;
2758         s->time = s->time_base * (int64_t)s->avctx->framerate.num + time_increment;
2759         if (s->workaround_bugs & FF_BUG_UMP4) {
2760             if (s->time < s->last_non_b_time) {
2761                 /* header is not mpeg-4-compatible, broken encoder,
2762                  * trying to workaround */
2763                 s->time_base++;
2764                 s->time += s->avctx->framerate.num;
2765             }
2766         }
2767         s->pp_time         = s->time - s->last_non_b_time;
2768         s->last_non_b_time = s->time;
2769     } else {
2770         s->time    = (s->last_time_base + time_incr) * (int64_t)s->avctx->framerate.num + time_increment;
2771         s->pb_time = s->pp_time - (s->last_non_b_time - s->time);
2772         if (s->pp_time <= s->pb_time ||
2773             s->pp_time <= s->pp_time - s->pb_time ||
2774             s->pp_time <= 0) {
2775             /* messed up order, maybe after seeking? skipping current B-frame */
2776             return FRAME_SKIPPED;
2777         }
2778         ff_mpeg4_init_direct_mv(s);
2779 
2780         if (ctx->t_frame == 0)
2781             ctx->t_frame = s->pb_time;
2782         if (ctx->t_frame == 0)
2783             ctx->t_frame = 1;  // 1/0 protection
2784         s->pp_field_time = (ROUNDED_DIV(s->last_non_b_time, ctx->t_frame) -
2785                             ROUNDED_DIV(s->last_non_b_time - s->pp_time, ctx->t_frame)) * 2;
2786         s->pb_field_time = (ROUNDED_DIV(s->time, ctx->t_frame) -
2787                             ROUNDED_DIV(s->last_non_b_time - s->pp_time, ctx->t_frame)) * 2;
2788         if (s->pp_field_time <= s->pb_field_time || s->pb_field_time <= 1) {
2789             s->pb_field_time = 2;
2790             s->pp_field_time = 4;
2791             if (!s->progressive_sequence)
2792                 return FRAME_SKIPPED;
2793         }
2794     }
2795 
2796     if (s->avctx->framerate.den)
2797         pts = ROUNDED_DIV(s->time, s->avctx->framerate.den);
2798     else
2799         pts = AV_NOPTS_VALUE;
2800     ff_dlog(s->avctx, "MPEG4 PTS: %"PRId64"\n", pts);
2801 
2802     check_marker(s->avctx, gb, "before vop_coded");
2803 
2804     /* vop coded */
2805     if (get_bits1(gb) != 1) {
2806         if (s->avctx->debug & FF_DEBUG_PICT_INFO)
2807             av_log(s->avctx, AV_LOG_ERROR, "vop not coded\n");
2808         return FRAME_SKIPPED;
2809     }
2810     if (ctx->new_pred)
2811         decode_new_pred(ctx, gb);
2812 
2813     if (ctx->shape != BIN_ONLY_SHAPE &&
2814                     (s->pict_type == AV_PICTURE_TYPE_P ||
2815                      (s->pict_type == AV_PICTURE_TYPE_S &&
2816                       ctx->vol_sprite_usage == GMC_SPRITE))) {
2817         /* rounding type for motion estimation */
2818         s->no_rounding = get_bits1(gb);
2819     } else {
2820         s->no_rounding = 0;
2821     }
2822     // FIXME reduced res stuff
2823 
2824     if (ctx->shape != RECT_SHAPE) {
2825         if (ctx->vol_sprite_usage != 1 || s->pict_type != AV_PICTURE_TYPE_I) {
2826             skip_bits(gb, 13);  /* width */
2827             check_marker(s->avctx, gb, "after width");
2828             skip_bits(gb, 13);  /* height */
2829             check_marker(s->avctx, gb, "after height");
2830             skip_bits(gb, 13);  /* hor_spat_ref */
2831             check_marker(s->avctx, gb, "after hor_spat_ref");
2832             skip_bits(gb, 13);  /* ver_spat_ref */
2833         }
2834         skip_bits1(gb);         /* change_CR_disable */
2835 
2836         if (get_bits1(gb) != 0)
2837             skip_bits(gb, 8);   /* constant_alpha_value */
2838     }
2839 
2840     // FIXME complexity estimation stuff
2841 
2842     if (ctx->shape != BIN_ONLY_SHAPE) {
2843         skip_bits_long(gb, ctx->cplx_estimation_trash_i);
2844         if (s->pict_type != AV_PICTURE_TYPE_I)
2845             skip_bits_long(gb, ctx->cplx_estimation_trash_p);
2846         if (s->pict_type == AV_PICTURE_TYPE_B)
2847             skip_bits_long(gb, ctx->cplx_estimation_trash_b);
2848 
2849         if (get_bits_left(gb) < 3) {
2850             av_log(s->avctx, AV_LOG_ERROR, "Header truncated\n");
2851             return AVERROR_INVALIDDATA;
2852         }
2853         ctx->intra_dc_threshold = ff_mpeg4_dc_threshold[get_bits(gb, 3)];
2854         if (!s->progressive_sequence) {
2855             s->top_field_first = get_bits1(gb);
2856             s->alternate_scan  = get_bits1(gb);
2857         } else
2858             s->alternate_scan = 0;
2859     }
2860 
2861     if (s->alternate_scan) {
2862         ff_init_scantable(s->idsp.idct_permutation, &s->inter_scantable,   ff_alternate_vertical_scan);
2863         ff_init_scantable(s->idsp.idct_permutation, &s->intra_scantable,   ff_alternate_vertical_scan);
2864         ff_init_scantable(s->idsp.idct_permutation, &s->intra_h_scantable, ff_alternate_vertical_scan);
2865         ff_init_scantable(s->idsp.idct_permutation, &s->intra_v_scantable, ff_alternate_vertical_scan);
2866     } else {
2867         ff_init_scantable(s->idsp.idct_permutation, &s->inter_scantable,   ff_zigzag_direct);
2868         ff_init_scantable(s->idsp.idct_permutation, &s->intra_scantable,   ff_zigzag_direct);
2869         ff_init_scantable(s->idsp.idct_permutation, &s->intra_h_scantable, ff_alternate_horizontal_scan);
2870         ff_init_scantable(s->idsp.idct_permutation, &s->intra_v_scantable, ff_alternate_vertical_scan);
2871     }
2872 
2873     if (s->pict_type == AV_PICTURE_TYPE_S) {
2874         if((ctx->vol_sprite_usage == STATIC_SPRITE ||
2875             ctx->vol_sprite_usage == GMC_SPRITE)) {
2876             if (mpeg4_decode_sprite_trajectory(ctx, gb) < 0)
2877                 return AVERROR_INVALIDDATA;
2878             if (ctx->sprite_brightness_change)
2879                 av_log(s->avctx, AV_LOG_ERROR,
2880                     "sprite_brightness_change not supported\n");
2881             if (ctx->vol_sprite_usage == STATIC_SPRITE)
2882                 av_log(s->avctx, AV_LOG_ERROR, "static sprite not supported\n");
2883         } else {
2884             memset(s->sprite_offset, 0, sizeof(s->sprite_offset));
2885             memset(s->sprite_delta, 0, sizeof(s->sprite_delta));
2886         }
2887     }
2888 
2889     if (ctx->shape != BIN_ONLY_SHAPE) {
2890         s->chroma_qscale = s->qscale = get_bits(gb, s->quant_precision);
2891         if (s->qscale == 0) {
2892             av_log(s->avctx, AV_LOG_ERROR,
2893                    "Error, header damaged or not MPEG-4 header (qscale=0)\n");
2894             return AVERROR_INVALIDDATA;  // makes no sense to continue, as there is nothing left from the image then
2895         }
2896 
2897         if (s->pict_type != AV_PICTURE_TYPE_I) {
2898             s->f_code = get_bits(gb, 3);        /* fcode_for */
2899             if (s->f_code == 0) {
2900                 av_log(s->avctx, AV_LOG_ERROR,
2901                        "Error, header damaged or not MPEG-4 header (f_code=0)\n");
2902                 s->f_code = 1;
2903                 return AVERROR_INVALIDDATA;  // makes no sense to continue, as there is nothing left from the image then
2904             }
2905         } else
2906             s->f_code = 1;
2907 
2908         if (s->pict_type == AV_PICTURE_TYPE_B) {
2909             s->b_code = get_bits(gb, 3);
2910             if (s->b_code == 0) {
2911                 av_log(s->avctx, AV_LOG_ERROR,
2912                        "Error, header damaged or not MPEG4 header (b_code=0)\n");
2913                 s->b_code=1;
2914                 return AVERROR_INVALIDDATA; // makes no sense to continue, as the MV decoding will break very quickly
2915             }
2916         } else
2917             s->b_code = 1;
2918 
2919         if (s->avctx->debug & FF_DEBUG_PICT_INFO) {
2920             av_log(s->avctx, AV_LOG_DEBUG,
2921                    "qp:%d fc:%d,%d %s size:%d pro:%d alt:%d top:%d %spel part:%d resync:%d w:%d a:%d rnd:%d vot:%d%s dc:%d ce:%d/%d/%d time:%"PRId64" tincr:%d\n",
2922                    s->qscale, s->f_code, s->b_code,
2923                    s->pict_type == AV_PICTURE_TYPE_I ? "I" : (s->pict_type == AV_PICTURE_TYPE_P ? "P" : (s->pict_type == AV_PICTURE_TYPE_B ? "B" : "S")),
2924                    gb->size_in_bits,s->progressive_sequence, s->alternate_scan,
2925                    s->top_field_first, s->quarter_sample ? "q" : "h",
2926                    s->data_partitioning, ctx->resync_marker,
2927                    ctx->num_sprite_warping_points, s->sprite_warping_accuracy,
2928                    1 - s->no_rounding, s->vo_type,
2929                    ctx->vol_control_parameters ? " VOLC" : " ", ctx->intra_dc_threshold,
2930                    ctx->cplx_estimation_trash_i, ctx->cplx_estimation_trash_p,
2931                    ctx->cplx_estimation_trash_b,
2932                    s->time,
2933                    time_increment
2934                   );
2935         }
2936 
2937         if (!ctx->scalability) {
2938             if (ctx->shape != RECT_SHAPE && s->pict_type != AV_PICTURE_TYPE_I)
2939                 skip_bits1(gb);  // vop shape coding type
2940         } else {
2941             if (ctx->enhancement_type) {
2942                 int load_backward_shape = get_bits1(gb);
2943                 if (load_backward_shape)
2944                     av_log(s->avctx, AV_LOG_ERROR,
2945                            "load backward shape isn't supported\n");
2946             }
2947             skip_bits(gb, 2);  // ref_select_code
2948         }
2949     }
2950     /* detect buggy encoders which don't set the low_delay flag
2951      * (divx4/xvid/opendivx). Note we cannot detect divx5 without B-frames
2952      * easily (although it's buggy too) */
2953     if (s->vo_type == 0 && ctx->vol_control_parameters == 0 &&
2954         ctx->divx_version == -1 && s->picture_number == 0) {
2955         av_log(s->avctx, AV_LOG_WARNING,
2956                "looks like this file was encoded with (divx4/(old)xvid/opendivx) -> forcing low_delay flag\n");
2957         s->low_delay = 1;
2958     }
2959 
2960     s->picture_number++;  // better than pic number==0 always ;)
2961 
2962     // FIXME add short header support
2963     s->y_dc_scale_table = ff_mpeg4_y_dc_scale_table;
2964     s->c_dc_scale_table = ff_mpeg4_c_dc_scale_table;
2965 
2966     if (s->workaround_bugs & FF_BUG_EDGE) {
2967         s->h_edge_pos = s->width;
2968         s->v_edge_pos = s->height;
2969     }
2970     return 0;
2971 }
2972 
read_quant_matrix_ext(MpegEncContext * s,GetBitContext * gb)2973 static int read_quant_matrix_ext(MpegEncContext *s, GetBitContext *gb)
2974 {
2975     int i, j, v;
2976 
2977     if (get_bits1(gb)) {
2978         if (get_bits_left(gb) < 64*8)
2979             return AVERROR_INVALIDDATA;
2980         /* intra_quantiser_matrix */
2981         for (i = 0; i < 64; i++) {
2982             v = get_bits(gb, 8);
2983             j = s->idsp.idct_permutation[ff_zigzag_direct[i]];
2984             s->intra_matrix[j]        = v;
2985             s->chroma_intra_matrix[j] = v;
2986         }
2987     }
2988 
2989     if (get_bits1(gb)) {
2990         if (get_bits_left(gb) < 64*8)
2991             return AVERROR_INVALIDDATA;
2992         /* non_intra_quantiser_matrix */
2993         for (i = 0; i < 64; i++) {
2994             get_bits(gb, 8);
2995         }
2996     }
2997 
2998     if (get_bits1(gb)) {
2999         if (get_bits_left(gb) < 64*8)
3000             return AVERROR_INVALIDDATA;
3001         /* chroma_intra_quantiser_matrix */
3002         for (i = 0; i < 64; i++) {
3003             v = get_bits(gb, 8);
3004             j = s->idsp.idct_permutation[ff_zigzag_direct[i]];
3005             s->chroma_intra_matrix[j] = v;
3006         }
3007     }
3008 
3009     if (get_bits1(gb)) {
3010         if (get_bits_left(gb) < 64*8)
3011             return AVERROR_INVALIDDATA;
3012         /* chroma_non_intra_quantiser_matrix */
3013         for (i = 0; i < 64; i++) {
3014             get_bits(gb, 8);
3015         }
3016     }
3017 
3018     next_start_code_studio(gb);
3019     return 0;
3020 }
3021 
extension_and_user_data(MpegEncContext * s,GetBitContext * gb,int id)3022 static void extension_and_user_data(MpegEncContext *s, GetBitContext *gb, int id)
3023 {
3024     uint32_t startcode;
3025     uint8_t extension_type;
3026 
3027     startcode = show_bits_long(gb, 32);
3028     if (startcode == USER_DATA_STARTCODE || startcode == EXT_STARTCODE) {
3029 
3030         if ((id == 2 || id == 4) && startcode == EXT_STARTCODE) {
3031             skip_bits_long(gb, 32);
3032             extension_type = get_bits(gb, 4);
3033             if (extension_type == QUANT_MATRIX_EXT_ID)
3034                 read_quant_matrix_ext(s, gb);
3035         }
3036     }
3037 }
3038 
decode_smpte_tc(Mpeg4DecContext * ctx,GetBitContext * gb)3039 static void decode_smpte_tc(Mpeg4DecContext *ctx, GetBitContext *gb)
3040 {
3041     MpegEncContext *s = &ctx->m;
3042 
3043     skip_bits(gb, 16); /* Time_code[63..48] */
3044     check_marker(s->avctx, gb, "after Time_code[63..48]");
3045     skip_bits(gb, 16); /* Time_code[47..32] */
3046     check_marker(s->avctx, gb, "after Time_code[47..32]");
3047     skip_bits(gb, 16); /* Time_code[31..16] */
3048     check_marker(s->avctx, gb, "after Time_code[31..16]");
3049     skip_bits(gb, 16); /* Time_code[15..0] */
3050     check_marker(s->avctx, gb, "after Time_code[15..0]");
3051     skip_bits(gb, 4); /* reserved_bits */
3052 }
3053 
3054 /**
3055  * Decode the next studio vop header.
3056  * @return <0 if something went wrong
3057  */
decode_studio_vop_header(Mpeg4DecContext * ctx,GetBitContext * gb)3058 static int decode_studio_vop_header(Mpeg4DecContext *ctx, GetBitContext *gb)
3059 {
3060     MpegEncContext *s = &ctx->m;
3061 
3062     if (get_bits_left(gb) <= 32)
3063         return 0;
3064 
3065     s->partitioned_frame = 0;
3066     s->interlaced_dct = 0;
3067     s->decode_mb = mpeg4_decode_studio_mb;
3068 
3069     decode_smpte_tc(ctx, gb);
3070 
3071     skip_bits(gb, 10); /* temporal_reference */
3072     skip_bits(gb, 2); /* vop_structure */
3073     s->pict_type = get_bits(gb, 2) + AV_PICTURE_TYPE_I; /* vop_coding_type */
3074     if (get_bits1(gb)) { /* vop_coded */
3075         skip_bits1(gb); /* top_field_first */
3076         skip_bits1(gb); /* repeat_first_field */
3077         s->progressive_frame = get_bits1(gb) ^ 1; /* progressive_frame */
3078     }
3079 
3080     if (s->pict_type == AV_PICTURE_TYPE_I) {
3081         if (get_bits1(gb))
3082             reset_studio_dc_predictors(s);
3083     }
3084 
3085     if (ctx->shape != BIN_ONLY_SHAPE) {
3086         s->alternate_scan = get_bits1(gb);
3087         s->frame_pred_frame_dct = get_bits1(gb);
3088         s->dct_precision = get_bits(gb, 2);
3089         s->intra_dc_precision = get_bits(gb, 2);
3090         s->q_scale_type = get_bits1(gb);
3091     }
3092 
3093     if (s->alternate_scan) {
3094         ff_init_scantable(s->idsp.idct_permutation, &s->inter_scantable,   ff_alternate_vertical_scan);
3095         ff_init_scantable(s->idsp.idct_permutation, &s->intra_scantable,   ff_alternate_vertical_scan);
3096         ff_init_scantable(s->idsp.idct_permutation, &s->intra_h_scantable, ff_alternate_vertical_scan);
3097         ff_init_scantable(s->idsp.idct_permutation, &s->intra_v_scantable, ff_alternate_vertical_scan);
3098     } else {
3099         ff_init_scantable(s->idsp.idct_permutation, &s->inter_scantable,   ff_zigzag_direct);
3100         ff_init_scantable(s->idsp.idct_permutation, &s->intra_scantable,   ff_zigzag_direct);
3101         ff_init_scantable(s->idsp.idct_permutation, &s->intra_h_scantable, ff_alternate_horizontal_scan);
3102         ff_init_scantable(s->idsp.idct_permutation, &s->intra_v_scantable, ff_alternate_vertical_scan);
3103     }
3104 
3105     mpeg4_load_default_matrices(s);
3106 
3107     next_start_code_studio(gb);
3108     extension_and_user_data(s, gb, 4);
3109 
3110     return 0;
3111 }
3112 
decode_studiovisualobject(Mpeg4DecContext * ctx,GetBitContext * gb)3113 static int decode_studiovisualobject(Mpeg4DecContext *ctx, GetBitContext *gb)
3114 {
3115     MpegEncContext *s = &ctx->m;
3116     int visual_object_type;
3117 
3118         skip_bits(gb, 4); /* visual_object_verid */
3119         visual_object_type = get_bits(gb, 4);
3120         if (visual_object_type != VOT_VIDEO_ID) {
3121             avpriv_request_sample(s->avctx, "VO type %u", visual_object_type);
3122             return AVERROR_PATCHWELCOME;
3123         }
3124 
3125         next_start_code_studio(gb);
3126         extension_and_user_data(s, gb, 1);
3127 
3128     return 0;
3129 }
3130 
decode_studio_vol_header(Mpeg4DecContext * ctx,GetBitContext * gb)3131 static int decode_studio_vol_header(Mpeg4DecContext *ctx, GetBitContext *gb)
3132 {
3133     MpegEncContext *s = &ctx->m;
3134     int width, height;
3135     int bits_per_raw_sample;
3136 
3137             // random_accessible_vol and video_object_type_indication have already
3138             // been read by the caller decode_vol_header()
3139             skip_bits(gb, 4); /* video_object_layer_verid */
3140             ctx->shape = get_bits(gb, 2); /* video_object_layer_shape */
3141             skip_bits(gb, 4); /* video_object_layer_shape_extension */
3142             skip_bits1(gb); /* progressive_sequence */
3143             if (ctx->shape != BIN_ONLY_SHAPE) {
3144                 ctx->rgb = get_bits1(gb); /* rgb_components */
3145                 s->chroma_format = get_bits(gb, 2); /* chroma_format */
3146                 if (!s->chroma_format) {
3147                     av_log(s->avctx, AV_LOG_ERROR, "illegal chroma format\n");
3148                     return AVERROR_INVALIDDATA;
3149                 }
3150 
3151                 bits_per_raw_sample = get_bits(gb, 4); /* bit_depth */
3152                 if (bits_per_raw_sample == 10) {
3153                     if (ctx->rgb) {
3154                         s->avctx->pix_fmt = AV_PIX_FMT_GBRP10;
3155                     }
3156                     else {
3157                         s->avctx->pix_fmt = s->chroma_format == CHROMA_422 ? AV_PIX_FMT_YUV422P10 : AV_PIX_FMT_YUV444P10;
3158                     }
3159                 }
3160                 else {
3161                     avpriv_request_sample(s->avctx, "MPEG-4 Studio profile bit-depth %u", bits_per_raw_sample);
3162                     return AVERROR_PATCHWELCOME;
3163                 }
3164                 s->avctx->bits_per_raw_sample = bits_per_raw_sample;
3165             }
3166             if (ctx->shape == RECT_SHAPE) {
3167                 check_marker(s->avctx, gb, "before video_object_layer_width");
3168                 width = get_bits(gb, 14); /* video_object_layer_width */
3169                 check_marker(s->avctx, gb, "before video_object_layer_height");
3170                 height = get_bits(gb, 14); /* video_object_layer_height */
3171                 check_marker(s->avctx, gb, "after video_object_layer_height");
3172 
3173                 /* Do the same check as non-studio profile */
3174                 if (width && height) {
3175                     if (s->width && s->height &&
3176                         (s->width != width || s->height != height))
3177                         s->context_reinit = 1;
3178                     s->width  = width;
3179                     s->height = height;
3180                 }
3181             }
3182             s->aspect_ratio_info = get_bits(gb, 4);
3183             if (s->aspect_ratio_info == FF_ASPECT_EXTENDED) {
3184                 s->avctx->sample_aspect_ratio.num = get_bits(gb, 8);  // par_width
3185                 s->avctx->sample_aspect_ratio.den = get_bits(gb, 8);  // par_height
3186             } else {
3187                 s->avctx->sample_aspect_ratio = ff_h263_pixel_aspect[s->aspect_ratio_info];
3188             }
3189             skip_bits(gb, 4); /* frame_rate_code */
3190             skip_bits(gb, 15); /* first_half_bit_rate */
3191             check_marker(s->avctx, gb, "after first_half_bit_rate");
3192             skip_bits(gb, 15); /* latter_half_bit_rate */
3193             check_marker(s->avctx, gb, "after latter_half_bit_rate");
3194             skip_bits(gb, 15); /* first_half_vbv_buffer_size */
3195             check_marker(s->avctx, gb, "after first_half_vbv_buffer_size");
3196             skip_bits(gb, 3); /* latter_half_vbv_buffer_size */
3197             skip_bits(gb, 11); /* first_half_vbv_buffer_size */
3198             check_marker(s->avctx, gb, "after first_half_vbv_buffer_size");
3199             skip_bits(gb, 15); /* latter_half_vbv_occupancy */
3200             check_marker(s->avctx, gb, "after latter_half_vbv_occupancy");
3201             s->low_delay = get_bits1(gb);
3202             s->mpeg_quant = get_bits1(gb); /* mpeg2_stream */
3203 
3204             next_start_code_studio(gb);
3205             extension_and_user_data(s, gb, 2);
3206 
3207     return 0;
3208 }
3209 
3210 /**
3211  * Decode MPEG-4 headers.
3212  * @return <0 if no VOP found (or a damaged one)
3213  *         FRAME_SKIPPED if a not coded VOP is found
3214  *         0 if a VOP is found
3215  */
ff_mpeg4_decode_picture_header(Mpeg4DecContext * ctx,GetBitContext * gb)3216 int ff_mpeg4_decode_picture_header(Mpeg4DecContext *ctx, GetBitContext *gb)
3217 {
3218     MpegEncContext *s = &ctx->m;
3219     unsigned startcode, v;
3220     int ret;
3221     int vol = 0;
3222 
3223     /* search next start code */
3224     align_get_bits(gb);
3225 
3226     // If we have not switched to studio profile than we also did not switch bps
3227     // that means something else (like a previous instance) outside set bps which
3228     // would be inconsistant with the currect state, thus reset it
3229     if (!s->studio_profile && s->avctx->bits_per_raw_sample != 8)
3230         s->avctx->bits_per_raw_sample = 0;
3231 
3232     if (s->codec_tag == AV_RL32("WV1F") && show_bits(gb, 24) == 0x575630) {
3233         skip_bits(gb, 24);
3234         if (get_bits(gb, 8) == 0xF0)
3235             goto end;
3236     }
3237 
3238     startcode = 0xff;
3239     for (;;) {
3240         if (get_bits_count(gb) >= gb->size_in_bits) {
3241             if (gb->size_in_bits == 8 &&
3242                 (ctx->divx_version >= 0 || ctx->xvid_build >= 0) || s->codec_tag == AV_RL32("QMP4")) {
3243                 av_log(s->avctx, AV_LOG_VERBOSE, "frame skip %d\n", gb->size_in_bits);
3244                 return FRAME_SKIPPED;  // divx bug
3245             } else
3246                 return AVERROR_INVALIDDATA;  // end of stream
3247         }
3248 
3249         /* use the bits after the test */
3250         v = get_bits(gb, 8);
3251         startcode = ((startcode << 8) | v) & 0xffffffff;
3252 
3253         if ((startcode & 0xFFFFFF00) != 0x100)
3254             continue;  // no startcode
3255 
3256         if (s->avctx->debug & FF_DEBUG_STARTCODE) {
3257             av_log(s->avctx, AV_LOG_DEBUG, "startcode: %3X ", startcode);
3258             if (startcode <= 0x11F)
3259                 av_log(s->avctx, AV_LOG_DEBUG, "Video Object Start");
3260             else if (startcode <= 0x12F)
3261                 av_log(s->avctx, AV_LOG_DEBUG, "Video Object Layer Start");
3262             else if (startcode <= 0x13F)
3263                 av_log(s->avctx, AV_LOG_DEBUG, "Reserved");
3264             else if (startcode <= 0x15F)
3265                 av_log(s->avctx, AV_LOG_DEBUG, "FGS bp start");
3266             else if (startcode <= 0x1AF)
3267                 av_log(s->avctx, AV_LOG_DEBUG, "Reserved");
3268             else if (startcode == 0x1B0)
3269                 av_log(s->avctx, AV_LOG_DEBUG, "Visual Object Seq Start");
3270             else if (startcode == 0x1B1)
3271                 av_log(s->avctx, AV_LOG_DEBUG, "Visual Object Seq End");
3272             else if (startcode == 0x1B2)
3273                 av_log(s->avctx, AV_LOG_DEBUG, "User Data");
3274             else if (startcode == 0x1B3)
3275                 av_log(s->avctx, AV_LOG_DEBUG, "Group of VOP start");
3276             else if (startcode == 0x1B4)
3277                 av_log(s->avctx, AV_LOG_DEBUG, "Video Session Error");
3278             else if (startcode == 0x1B5)
3279                 av_log(s->avctx, AV_LOG_DEBUG, "Visual Object Start");
3280             else if (startcode == 0x1B6)
3281                 av_log(s->avctx, AV_LOG_DEBUG, "Video Object Plane start");
3282             else if (startcode == 0x1B7)
3283                 av_log(s->avctx, AV_LOG_DEBUG, "slice start");
3284             else if (startcode == 0x1B8)
3285                 av_log(s->avctx, AV_LOG_DEBUG, "extension start");
3286             else if (startcode == 0x1B9)
3287                 av_log(s->avctx, AV_LOG_DEBUG, "fgs start");
3288             else if (startcode == 0x1BA)
3289                 av_log(s->avctx, AV_LOG_DEBUG, "FBA Object start");
3290             else if (startcode == 0x1BB)
3291                 av_log(s->avctx, AV_LOG_DEBUG, "FBA Object Plane start");
3292             else if (startcode == 0x1BC)
3293                 av_log(s->avctx, AV_LOG_DEBUG, "Mesh Object start");
3294             else if (startcode == 0x1BD)
3295                 av_log(s->avctx, AV_LOG_DEBUG, "Mesh Object Plane start");
3296             else if (startcode == 0x1BE)
3297                 av_log(s->avctx, AV_LOG_DEBUG, "Still Texture Object start");
3298             else if (startcode == 0x1BF)
3299                 av_log(s->avctx, AV_LOG_DEBUG, "Texture Spatial Layer start");
3300             else if (startcode == 0x1C0)
3301                 av_log(s->avctx, AV_LOG_DEBUG, "Texture SNR Layer start");
3302             else if (startcode == 0x1C1)
3303                 av_log(s->avctx, AV_LOG_DEBUG, "Texture Tile start");
3304             else if (startcode == 0x1C2)
3305                 av_log(s->avctx, AV_LOG_DEBUG, "Texture Shape Layer start");
3306             else if (startcode == 0x1C3)
3307                 av_log(s->avctx, AV_LOG_DEBUG, "stuffing start");
3308             else if (startcode <= 0x1C5)
3309                 av_log(s->avctx, AV_LOG_DEBUG, "reserved");
3310             else if (startcode <= 0x1FF)
3311                 av_log(s->avctx, AV_LOG_DEBUG, "System start");
3312             av_log(s->avctx, AV_LOG_DEBUG, " at %d\n", get_bits_count(gb));
3313         }
3314 
3315         if (startcode >= 0x120 && startcode <= 0x12F) {
3316             if (vol) {
3317                 av_log(s->avctx, AV_LOG_WARNING, "Ignoring multiple VOL headers\n");
3318                 continue;
3319             }
3320             vol++;
3321             if ((ret = decode_vol_header(ctx, gb)) < 0)
3322                 return ret;
3323         } else if (startcode == USER_DATA_STARTCODE) {
3324             decode_user_data(ctx, gb);
3325         } else if (startcode == GOP_STARTCODE) {
3326             mpeg4_decode_gop_header(s, gb);
3327         } else if (startcode == VOS_STARTCODE) {
3328             int profile, level;
3329             mpeg4_decode_profile_level(s, gb, &profile, &level);
3330             if (profile == FF_PROFILE_MPEG4_SIMPLE_STUDIO &&
3331                 (level > 0 && level < 9)) {
3332                 s->studio_profile = 1;
3333                 next_start_code_studio(gb);
3334                 extension_and_user_data(s, gb, 0);
3335             } else if (s->studio_profile) {
3336                 avpriv_request_sample(s->avctx, "Mixes studio and non studio profile\n");
3337                 return AVERROR_PATCHWELCOME;
3338             }
3339             s->avctx->profile = profile;
3340             s->avctx->level   = level;
3341         } else if (startcode == VISUAL_OBJ_STARTCODE) {
3342             if (s->studio_profile) {
3343                 if ((ret = decode_studiovisualobject(ctx, gb)) < 0)
3344                     return ret;
3345             } else
3346                 mpeg4_decode_visual_object(s, gb);
3347         } else if (startcode == VOP_STARTCODE) {
3348             break;
3349         }
3350 
3351         align_get_bits(gb);
3352         startcode = 0xff;
3353     }
3354 
3355 end:
3356     if (s->avctx->flags & AV_CODEC_FLAG_LOW_DELAY)
3357         s->low_delay = 1;
3358     s->avctx->has_b_frames = !s->low_delay;
3359 
3360     if (s->studio_profile) {
3361         if (!s->avctx->bits_per_raw_sample) {
3362             av_log(s->avctx, AV_LOG_ERROR, "Missing VOL header\n");
3363             return AVERROR_INVALIDDATA;
3364         }
3365         return decode_studio_vop_header(ctx, gb);
3366     } else
3367         return decode_vop_header(ctx, gb);
3368 }
3369 
ff_mpeg4videodec_static_init(void)3370 av_cold void ff_mpeg4videodec_static_init(void) {
3371     static int done = 0;
3372 
3373     if (!done) {
3374         ff_rl_init(&ff_mpeg4_rl_intra, ff_mpeg4_static_rl_table_store[0]);
3375         ff_rl_init(&ff_rvlc_rl_inter, ff_mpeg4_static_rl_table_store[1]);
3376         ff_rl_init(&ff_rvlc_rl_intra, ff_mpeg4_static_rl_table_store[2]);
3377         INIT_VLC_RL(ff_mpeg4_rl_intra, 554);
3378         INIT_VLC_RL(ff_rvlc_rl_inter, 1072);
3379         INIT_VLC_RL(ff_rvlc_rl_intra, 1072);
3380         INIT_VLC_STATIC(&dc_lum, DC_VLC_BITS, 10 /* 13 */,
3381                         &ff_mpeg4_DCtab_lum[0][1], 2, 1,
3382                         &ff_mpeg4_DCtab_lum[0][0], 2, 1, 512);
3383         INIT_VLC_STATIC(&dc_chrom, DC_VLC_BITS, 10 /* 13 */,
3384                         &ff_mpeg4_DCtab_chrom[0][1], 2, 1,
3385                         &ff_mpeg4_DCtab_chrom[0][0], 2, 1, 512);
3386         INIT_VLC_STATIC(&sprite_trajectory, SPRITE_TRAJ_VLC_BITS, 15,
3387                         &ff_sprite_trajectory_tab[0][1], 4, 2,
3388                         &ff_sprite_trajectory_tab[0][0], 4, 2, 128);
3389         INIT_VLC_STATIC(&mb_type_b_vlc, MB_TYPE_B_VLC_BITS, 4,
3390                         &ff_mb_type_b_tab[0][1], 2, 1,
3391                         &ff_mb_type_b_tab[0][0], 2, 1, 16);
3392         done = 1;
3393     }
3394 }
3395 
ff_mpeg4_frame_end(AVCodecContext * avctx,const uint8_t * buf,int buf_size)3396 int ff_mpeg4_frame_end(AVCodecContext *avctx, const uint8_t *buf, int buf_size)
3397 {
3398     Mpeg4DecContext *ctx = avctx->priv_data;
3399     MpegEncContext    *s = &ctx->m;
3400 
3401     /* divx 5.01+ bitstream reorder stuff */
3402     /* Since this clobbers the input buffer and hwaccel codecs still need the
3403      * data during hwaccel->end_frame we should not do this any earlier */
3404     if (s->divx_packed) {
3405         int current_pos     = s->gb.buffer == s->bitstream_buffer ? 0 : (get_bits_count(&s->gb) >> 3);
3406         int startcode_found = 0;
3407 
3408         if (buf_size - current_pos > 7) {
3409 
3410             int i;
3411             for (i = current_pos; i < buf_size - 4; i++)
3412 
3413                 if (buf[i]     == 0 &&
3414                     buf[i + 1] == 0 &&
3415                     buf[i + 2] == 1 &&
3416                     buf[i + 3] == 0xB6) {
3417                     startcode_found = !(buf[i + 4] & 0x40);
3418                     break;
3419                 }
3420         }
3421 
3422         if (startcode_found) {
3423             if (!ctx->showed_packed_warning) {
3424                 av_log(s->avctx, AV_LOG_INFO, "Video uses a non-standard and "
3425                        "wasteful way to store B-frames ('packed B-frames'). "
3426                        "Consider using the mpeg4_unpack_bframes bitstream filter without encoding but stream copy to fix it.\n");
3427                 ctx->showed_packed_warning = 1;
3428             }
3429             av_fast_padded_malloc(&s->bitstream_buffer,
3430                            &s->allocated_bitstream_buffer_size,
3431                            buf_size - current_pos);
3432             if (!s->bitstream_buffer) {
3433                 s->bitstream_buffer_size = 0;
3434                 return AVERROR(ENOMEM);
3435             }
3436             memcpy(s->bitstream_buffer, buf + current_pos,
3437                    buf_size - current_pos);
3438             s->bitstream_buffer_size = buf_size - current_pos;
3439         }
3440     }
3441 
3442     return 0;
3443 }
3444 
3445 #if HAVE_THREADS
mpeg4_update_thread_context(AVCodecContext * dst,const AVCodecContext * src)3446 static int mpeg4_update_thread_context(AVCodecContext *dst,
3447                                        const AVCodecContext *src)
3448 {
3449     Mpeg4DecContext *s = dst->priv_data;
3450     const Mpeg4DecContext *s1 = src->priv_data;
3451     int init = s->m.context_initialized;
3452 
3453     int ret = ff_mpeg_update_thread_context(dst, src);
3454 
3455     if (ret < 0)
3456         return ret;
3457 
3458     memcpy(((uint8_t*)s) + sizeof(MpegEncContext), ((uint8_t*)s1) + sizeof(MpegEncContext), sizeof(Mpeg4DecContext) - sizeof(MpegEncContext));
3459 
3460     if (CONFIG_MPEG4_DECODER && !init && s1->xvid_build >= 0)
3461         ff_xvid_idct_init(&s->m.idsp, dst);
3462 
3463     return 0;
3464 }
3465 #endif
3466 
init_studio_vlcs(Mpeg4DecContext * ctx)3467 static av_cold int init_studio_vlcs(Mpeg4DecContext *ctx)
3468 {
3469     int i, ret;
3470 
3471     for (i = 0; i < 12; i++) {
3472         ret = init_vlc(&ctx->studio_intra_tab[i], STUDIO_INTRA_BITS, 22,
3473                        &ff_mpeg4_studio_intra[i][0][1], 4, 2,
3474                        &ff_mpeg4_studio_intra[i][0][0], 4, 2,
3475                        0);
3476 
3477         if (ret < 0)
3478             return ret;
3479     }
3480 
3481     ret = init_vlc(&ctx->studio_luma_dc, STUDIO_INTRA_BITS, 19,
3482                    &ff_mpeg4_studio_dc_luma[0][1], 4, 2,
3483                    &ff_mpeg4_studio_dc_luma[0][0], 4, 2,
3484                    0);
3485     if (ret < 0)
3486         return ret;
3487 
3488     ret = init_vlc(&ctx->studio_chroma_dc, STUDIO_INTRA_BITS, 19,
3489                    &ff_mpeg4_studio_dc_chroma[0][1], 4, 2,
3490                    &ff_mpeg4_studio_dc_chroma[0][0], 4, 2,
3491                    0);
3492     if (ret < 0)
3493         return ret;
3494 
3495     return 0;
3496 }
3497 
decode_init(AVCodecContext * avctx)3498 static av_cold int decode_init(AVCodecContext *avctx)
3499 {
3500     Mpeg4DecContext *ctx = avctx->priv_data;
3501     MpegEncContext *s = &ctx->m;
3502     int ret;
3503 
3504     ctx->divx_version =
3505     ctx->divx_build   =
3506     ctx->xvid_build   =
3507     ctx->lavc_build   = -1;
3508 
3509     if ((ret = ff_h263_decode_init(avctx)) < 0)
3510         return ret;
3511 
3512     ff_mpeg4videodec_static_init();
3513     if ((ret = init_studio_vlcs(ctx)) < 0)
3514         return ret;
3515 
3516     s->h263_pred = 1;
3517     s->low_delay = 0; /* default, might be overridden in the vol header during header parsing */
3518     s->decode_mb = mpeg4_decode_mb;
3519     ctx->time_increment_bits = 4; /* default value for broken headers */
3520 
3521     avctx->chroma_sample_location = AVCHROMA_LOC_LEFT;
3522     avctx->internal->allocate_progress = 1;
3523 
3524     return 0;
3525 }
3526 
decode_end(AVCodecContext * avctx)3527 static av_cold int decode_end(AVCodecContext *avctx)
3528 {
3529     Mpeg4DecContext *ctx = avctx->priv_data;
3530     int i;
3531 
3532     if (!avctx->internal->is_copy) {
3533         for (i = 0; i < 12; i++)
3534             ff_free_vlc(&ctx->studio_intra_tab[i]);
3535 
3536         ff_free_vlc(&ctx->studio_luma_dc);
3537         ff_free_vlc(&ctx->studio_chroma_dc);
3538     }
3539 
3540     return ff_h263_decode_end(avctx);
3541 }
3542 
3543 static const AVOption mpeg4_options[] = {
3544     {"quarter_sample", "1/4 subpel MC", offsetof(MpegEncContext, quarter_sample), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, 0},
3545     {"divx_packed", "divx style packed b frames", offsetof(MpegEncContext, divx_packed), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, 0},
3546     {NULL}
3547 };
3548 
3549 static const AVClass mpeg4_class = {
3550     .class_name = "MPEG4 Video Decoder",
3551     .item_name  = av_default_item_name,
3552     .option     = mpeg4_options,
3553     .version    = LIBAVUTIL_VERSION_INT,
3554 };
3555 
3556 AVCodec ff_mpeg4_decoder = {
3557     .name                  = "mpeg4",
3558     .long_name             = NULL_IF_CONFIG_SMALL("MPEG-4 part 2"),
3559     .type                  = AVMEDIA_TYPE_VIDEO,
3560     .id                    = AV_CODEC_ID_MPEG4,
3561     .priv_data_size        = sizeof(Mpeg4DecContext),
3562     .init                  = decode_init,
3563     .close                 = decode_end,
3564     .decode                = ff_h263_decode_frame,
3565     .capabilities          = AV_CODEC_CAP_DRAW_HORIZ_BAND | AV_CODEC_CAP_DR1 |
3566                              AV_CODEC_CAP_TRUNCATED | AV_CODEC_CAP_DELAY |
3567                              AV_CODEC_CAP_FRAME_THREADS,
3568     .caps_internal         = FF_CODEC_CAP_SKIP_FRAME_FILL_PARAM,
3569     .flush                 = ff_mpeg_flush,
3570     .max_lowres            = 3,
3571     .pix_fmts              = ff_h263_hwaccel_pixfmt_list_420,
3572     .profiles              = NULL_IF_CONFIG_SMALL(ff_mpeg4_video_profiles),
3573     .update_thread_context = ONLY_IF_THREADS_ENABLED(mpeg4_update_thread_context),
3574     .priv_class = &mpeg4_class,
3575     .hw_configs            = (const AVCodecHWConfigInternal*[]) {
3576 #if CONFIG_MPEG4_NVDEC_HWACCEL
3577                                HWACCEL_NVDEC(mpeg4),
3578 #endif
3579 #if CONFIG_MPEG4_VAAPI_HWACCEL
3580                                HWACCEL_VAAPI(mpeg4),
3581 #endif
3582 #if CONFIG_MPEG4_VDPAU_HWACCEL
3583                                HWACCEL_VDPAU(mpeg4),
3584 #endif
3585 #if CONFIG_MPEG4_VIDEOTOOLBOX_HWACCEL
3586                                HWACCEL_VIDEOTOOLBOX(mpeg4),
3587 #endif
3588                                NULL
3589                            },
3590 };
3591