1 /*
2  * RV10/RV20 decoder
3  * Copyright (c) 2000,2001 Fabrice Bellard
4  * Copyright (c) 2002-2004 Michael Niedermayer
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 /**
24  * @file
25  * RV10/RV20 decoder
26  */
27 
28 #include <inttypes.h>
29 
30 #include "libavutil/imgutils.h"
31 #include "libavutil/thread.h"
32 
33 #include "avcodec.h"
34 #include "error_resilience.h"
35 #include "h263.h"
36 #include "h263data.h"
37 #include "internal.h"
38 #include "mpeg_er.h"
39 #include "mpegutils.h"
40 #include "mpegvideo.h"
41 #include "mpeg4video.h"
42 #include "mpegvideodata.h"
43 #include "rv10.h"
44 
45 #define RV_GET_MAJOR_VER(x)  ((x) >> 28)
46 #define RV_GET_MINOR_VER(x) (((x) >> 20) & 0xFF)
47 #define RV_GET_MICRO_VER(x) (((x) >> 12) & 0xFF)
48 
49 #define MAX_VLC_ENTRIES 1023 // Note: Does not include the skip entries.
50 #define DC_VLC_BITS        9
51 
52 typedef struct RVDecContext {
53     MpegEncContext m;
54     int sub_id;
55     int orig_width, orig_height;
56 } RVDecContext;
57 
58 /* (run, length) encoded value for the symbols table. The actual symbols
59  * are run..run - length (mod 256).
60  * The last two entries in the following table apply to luma only.
61  * The skip values are not included in this list. */
62 static const uint8_t rv_sym_run_len[][2] = {
63     {   0,   0 }, {   1,   0 }, { 255,   0 }, {   3,   1 }, { 254,  1 },
64     {   7,   3 }, { 252,   3 }, {  15,   7 }, { 248,   7 }, {  31, 15 },
65     { 240,  15 }, {  63,  31 }, { 224,  31 }, { 127,  63 }, { 192, 63 },
66     { 255, 127 }, { 128, 127 }, { 127, 255 }, { 128, 255 },
67 };
68 
69 /* entry[i] of the following tables gives
70  * the number of VLC codes of length i + 2. */
71 static const uint16_t rv_lum_len_count[15] = {
72     1,  0,  2,  4,  8, 16, 32,  0, 64,  0, 128,  0, 256,  0, 512,
73 };
74 
75 static const uint16_t rv_chrom_len_count[15] = {
76     1,  2,  4,  0,  8,  0, 16,  0, 32,  0,  64,  0, 128,  0, 256,
77 };
78 
79 static VLC rv_dc_lum, rv_dc_chrom;
80 
ff_rv_decode_dc(MpegEncContext * s,int n)81 int ff_rv_decode_dc(MpegEncContext *s, int n)
82 {
83     int code;
84 
85     if (n < 4) {
86         code = get_vlc2(&s->gb, rv_dc_lum.table, DC_VLC_BITS, 2);
87     } else {
88         code = get_vlc2(&s->gb, rv_dc_chrom.table, DC_VLC_BITS, 2);
89         if (code < 0) {
90             av_log(s->avctx, AV_LOG_ERROR, "chroma dc error\n");
91             return -1;
92         }
93     }
94     return code;
95 }
96 
97 /* read RV 1.0 compatible frame header */
rv10_decode_picture_header(MpegEncContext * s)98 static int rv10_decode_picture_header(MpegEncContext *s)
99 {
100     int mb_count, pb_frame, marker, mb_xy;
101 
102     marker = get_bits1(&s->gb);
103 
104     if (get_bits1(&s->gb))
105         s->pict_type = AV_PICTURE_TYPE_P;
106     else
107         s->pict_type = AV_PICTURE_TYPE_I;
108 
109     if (!marker)
110         av_log(s->avctx, AV_LOG_ERROR, "marker missing\n");
111 
112     pb_frame = get_bits1(&s->gb);
113 
114     ff_dlog(s->avctx, "pict_type=%d pb_frame=%d\n", s->pict_type, pb_frame);
115 
116     if (pb_frame) {
117         avpriv_request_sample(s->avctx, "PB-frame");
118         return AVERROR_PATCHWELCOME;
119     }
120 
121     s->qscale = get_bits(&s->gb, 5);
122     if (s->qscale == 0) {
123         av_log(s->avctx, AV_LOG_ERROR, "Invalid qscale value: 0\n");
124         return AVERROR_INVALIDDATA;
125     }
126 
127     if (s->pict_type == AV_PICTURE_TYPE_I) {
128         if (s->rv10_version == 3) {
129             /* specific MPEG like DC coding not used */
130             s->last_dc[0] = get_bits(&s->gb, 8);
131             s->last_dc[1] = get_bits(&s->gb, 8);
132             s->last_dc[2] = get_bits(&s->gb, 8);
133             ff_dlog(s->avctx, "DC:%d %d %d\n", s->last_dc[0],
134                     s->last_dc[1], s->last_dc[2]);
135         }
136     }
137     /* if multiple packets per frame are sent, the position at which
138      * to display the macroblocks is coded here */
139 
140     mb_xy = s->mb_x + s->mb_y * s->mb_width;
141     if (show_bits(&s->gb, 12) == 0 || (mb_xy && mb_xy < s->mb_num)) {
142         s->mb_x  = get_bits(&s->gb, 6); /* mb_x */
143         s->mb_y  = get_bits(&s->gb, 6); /* mb_y */
144         mb_count = get_bits(&s->gb, 12);
145     } else {
146         s->mb_x  = 0;
147         s->mb_y  = 0;
148         mb_count = s->mb_width * s->mb_height;
149     }
150     skip_bits(&s->gb, 3);   /* ignored */
151     s->f_code          = 1;
152     s->unrestricted_mv = 1;
153 
154     return mb_count;
155 }
156 
rv20_decode_picture_header(RVDecContext * rv)157 static int rv20_decode_picture_header(RVDecContext *rv)
158 {
159     MpegEncContext *s = &rv->m;
160     int seq, mb_pos, i, ret;
161     int rpr_max;
162 
163     i = get_bits(&s->gb, 2);
164     switch (i) {
165     case 0:
166         s->pict_type = AV_PICTURE_TYPE_I;
167         break;
168     case 1:
169         s->pict_type = AV_PICTURE_TYPE_I;
170         break;                                  // hmm ...
171     case 2:
172         s->pict_type = AV_PICTURE_TYPE_P;
173         break;
174     case 3:
175         s->pict_type = AV_PICTURE_TYPE_B;
176         break;
177     default:
178         av_log(s->avctx, AV_LOG_ERROR, "unknown frame type\n");
179         return AVERROR_INVALIDDATA;
180     }
181 
182     if (s->low_delay && s->pict_type == AV_PICTURE_TYPE_B) {
183         av_log(s->avctx, AV_LOG_ERROR, "low delay B\n");
184         return -1;
185     }
186     if (!s->last_picture_ptr && s->pict_type == AV_PICTURE_TYPE_B) {
187         av_log(s->avctx, AV_LOG_ERROR, "early B-frame\n");
188         return AVERROR_INVALIDDATA;
189     }
190 
191     if (get_bits1(&s->gb)) {
192         av_log(s->avctx, AV_LOG_ERROR, "reserved bit set\n");
193         return AVERROR_INVALIDDATA;
194     }
195 
196     s->qscale = get_bits(&s->gb, 5);
197     if (s->qscale == 0) {
198         av_log(s->avctx, AV_LOG_ERROR, "Invalid qscale value: 0\n");
199         return AVERROR_INVALIDDATA;
200     }
201 
202     if (RV_GET_MINOR_VER(rv->sub_id) >= 2)
203         s->loop_filter = get_bits1(&s->gb) && !s->avctx->lowres;
204 
205     if (RV_GET_MINOR_VER(rv->sub_id) <= 1)
206         seq = get_bits(&s->gb, 8) << 7;
207     else
208         seq = get_bits(&s->gb, 13) << 2;
209 
210     rpr_max = s->avctx->extradata[1] & 7;
211     if (rpr_max) {
212         int f, new_w, new_h;
213         int rpr_bits = av_log2(rpr_max) + 1;
214 
215         f = get_bits(&s->gb, rpr_bits);
216 
217         if (f) {
218             if (s->avctx->extradata_size < 8 + 2 * f) {
219                 av_log(s->avctx, AV_LOG_ERROR, "Extradata too small.\n");
220                 return AVERROR_INVALIDDATA;
221             }
222 
223             new_w = 4 * ((uint8_t *) s->avctx->extradata)[6 + 2 * f];
224             new_h = 4 * ((uint8_t *) s->avctx->extradata)[7 + 2 * f];
225         } else {
226             new_w = rv->orig_width;
227             new_h = rv->orig_height;
228         }
229         if (new_w != s->width || new_h != s->height || !s->context_initialized) {
230             AVRational old_aspect = s->avctx->sample_aspect_ratio;
231             av_log(s->avctx, AV_LOG_DEBUG,
232                    "attempting to change resolution to %dx%d\n", new_w, new_h);
233             if (av_image_check_size(new_w, new_h, 0, s->avctx) < 0)
234                 return AVERROR_INVALIDDATA;
235             ff_mpv_common_end(s);
236 
237             // attempt to keep aspect during typical resolution switches
238             if (!old_aspect.num)
239                 old_aspect = (AVRational){1, 1};
240             if (2 * (int64_t)new_w * s->height == (int64_t)new_h * s->width)
241                 s->avctx->sample_aspect_ratio = av_mul_q(old_aspect, (AVRational){2, 1});
242             if ((int64_t)new_w * s->height == 2 * (int64_t)new_h * s->width)
243                 s->avctx->sample_aspect_ratio = av_mul_q(old_aspect, (AVRational){1, 2});
244 
245             ret = ff_set_dimensions(s->avctx, new_w, new_h);
246             if (ret < 0)
247                 return ret;
248 
249             s->width  = new_w;
250             s->height = new_h;
251             if ((ret = ff_mpv_common_init(s)) < 0)
252                 return ret;
253         }
254 
255         if (s->avctx->debug & FF_DEBUG_PICT_INFO) {
256             av_log(s->avctx, AV_LOG_DEBUG, "F %d/%d/%d\n", f, rpr_bits, rpr_max);
257         }
258     }
259     if (av_image_check_size(s->width, s->height, 0, s->avctx) < 0)
260         return AVERROR_INVALIDDATA;
261 
262     mb_pos = ff_h263_decode_mba(s);
263 
264     seq |= s->time & ~0x7FFF;
265     if (seq - s->time >  0x4000)
266         seq -= 0x8000;
267     if (seq - s->time < -0x4000)
268         seq += 0x8000;
269 
270     if (seq != s->time) {
271         if (s->pict_type != AV_PICTURE_TYPE_B) {
272             s->time            = seq;
273             s->pp_time         = s->time - s->last_non_b_time;
274             s->last_non_b_time = s->time;
275         } else {
276             s->time    = seq;
277             s->pb_time = s->pp_time - (s->last_non_b_time - s->time);
278         }
279     }
280     if (s->pict_type == AV_PICTURE_TYPE_B) {
281         if (s->pp_time <=s->pb_time || s->pp_time <= s->pp_time - s->pb_time || s->pp_time<=0) {
282             av_log(s->avctx, AV_LOG_DEBUG,
283                    "messed up order, possible from seeking? skipping current B-frame\n");
284 #define ERROR_SKIP_FRAME -123
285             return ERROR_SKIP_FRAME;
286         }
287         ff_mpeg4_init_direct_mv(s);
288     }
289 
290     s->no_rounding = get_bits1(&s->gb);
291 
292     if (RV_GET_MINOR_VER(rv->sub_id) <= 1 && s->pict_type == AV_PICTURE_TYPE_B)
293         // binary decoder reads 3+2 bits here but they don't seem to be used
294         skip_bits(&s->gb, 5);
295 
296     s->f_code          = 1;
297     s->unrestricted_mv = 1;
298     s->h263_aic        = s->pict_type == AV_PICTURE_TYPE_I;
299     s->modified_quant  = 1;
300     if (!s->avctx->lowres)
301         s->loop_filter = 1;
302 
303     if (s->avctx->debug & FF_DEBUG_PICT_INFO) {
304         av_log(s->avctx, AV_LOG_INFO,
305                "num:%5d x:%2d y:%2d type:%d qscale:%2d rnd:%d\n",
306                seq, s->mb_x, s->mb_y, s->pict_type, s->qscale,
307                s->no_rounding);
308     }
309 
310     av_assert0(s->pict_type != AV_PICTURE_TYPE_B || !s->low_delay);
311 
312     return s->mb_width * s->mb_height - mb_pos;
313 }
314 
rv10_build_vlc(VLC * vlc,const uint16_t len_count[15],const uint8_t sym_rl[][2],int sym_rl_elems)315 static av_cold void rv10_build_vlc(VLC *vlc, const uint16_t len_count[15],
316                                    const uint8_t sym_rl[][2], int sym_rl_elems)
317 {
318     uint16_t syms[MAX_VLC_ENTRIES];
319     uint8_t  lens[MAX_VLC_ENTRIES];
320     unsigned nb_syms = 0, nb_lens = 0;
321 
322     for (unsigned i = 0; i < sym_rl_elems; i++) {
323         unsigned cur_sym = sym_rl[i][0];
324         for (unsigned tmp = nb_syms + sym_rl[i][1]; nb_syms <= tmp; nb_syms++)
325             syms[nb_syms] = 0xFF & cur_sym--;
326     }
327 
328     for (unsigned i = 0; i < 15; i++)
329         for (unsigned tmp = nb_lens + len_count[i]; nb_lens < tmp; nb_lens++)
330             lens[nb_lens] = i + 2;
331     av_assert1(nb_lens == nb_syms);
332     ff_init_vlc_from_lengths(vlc, DC_VLC_BITS, nb_lens, lens, 1,
333                              syms, 2, 2, 0, INIT_VLC_STATIC_OVERLONG, NULL);
334 }
335 
rv10_init_static(void)336 static av_cold void rv10_init_static(void)
337 {
338     static VLC_TYPE table[1472 + 992][2];
339 
340     rv_dc_lum.table             = table;
341     rv_dc_lum.table_allocated   = 1472;
342     rv10_build_vlc(&rv_dc_lum, rv_lum_len_count,
343                    rv_sym_run_len, FF_ARRAY_ELEMS(rv_sym_run_len));
344     for (int i = 0; i < 1 << (DC_VLC_BITS - 7 /* Length of skip prefix */); i++) {
345         /* All codes beginning with 0x7F have the same length and value.
346          * Modifying the table directly saves us the useless subtables. */
347         rv_dc_lum.table[(0x7F << (DC_VLC_BITS - 7)) + i][0] = 255;
348         rv_dc_lum.table[(0x7F << (DC_VLC_BITS - 7)) + i][1] = 18;
349     }
350     rv_dc_chrom.table           = &table[1472];
351     rv_dc_chrom.table_allocated = 992;
352     rv10_build_vlc(&rv_dc_chrom, rv_chrom_len_count,
353                    rv_sym_run_len, FF_ARRAY_ELEMS(rv_sym_run_len) - 2);
354     for (int i = 0; i < 1 << (DC_VLC_BITS - 9 /* Length of skip prefix */); i++) {
355         /* Same as above. */
356         rv_dc_chrom.table[(0x1FE << (DC_VLC_BITS - 9)) + i][0] = 255;
357         rv_dc_chrom.table[(0x1FE << (DC_VLC_BITS - 9)) + i][1] = 18;
358     }
359     ff_h263_decode_init_vlc();
360 }
361 
rv10_decode_init(AVCodecContext * avctx)362 static av_cold int rv10_decode_init(AVCodecContext *avctx)
363 {
364     static AVOnce init_static_once = AV_ONCE_INIT;
365     RVDecContext *rv = avctx->priv_data;
366     MpegEncContext *s = &rv->m;
367     int major_ver, minor_ver, micro_ver, ret;
368 
369     if (avctx->extradata_size < 8) {
370         av_log(avctx, AV_LOG_ERROR, "Extradata is too small.\n");
371         return AVERROR_INVALIDDATA;
372     }
373     if ((ret = av_image_check_size(avctx->coded_width,
374                                    avctx->coded_height, 0, avctx)) < 0)
375         return ret;
376 
377     ff_mpv_decode_init(s, avctx);
378 
379     s->out_format  = FMT_H263;
380 
381     rv->orig_width  =
382     s->width        = avctx->coded_width;
383     rv->orig_height =
384     s->height       = avctx->coded_height;
385 
386     s->h263_long_vectors = ((uint8_t *) avctx->extradata)[3] & 1;
387     rv->sub_id           = AV_RB32((uint8_t *) avctx->extradata + 4);
388 
389     major_ver = RV_GET_MAJOR_VER(rv->sub_id);
390     minor_ver = RV_GET_MINOR_VER(rv->sub_id);
391     micro_ver = RV_GET_MICRO_VER(rv->sub_id);
392 
393     s->low_delay = 1;
394     switch (major_ver) {
395     case 1:
396         s->rv10_version = micro_ver ? 3 : 1;
397         s->obmc         = micro_ver == 2;
398         break;
399     case 2:
400         if (minor_ver >= 2) {
401             s->low_delay           = 0;
402             s->avctx->has_b_frames = 1;
403         }
404         break;
405     default:
406         av_log(s->avctx, AV_LOG_ERROR, "unknown header %X\n", rv->sub_id);
407         avpriv_request_sample(avctx, "RV1/2 version");
408         return AVERROR_PATCHWELCOME;
409     }
410 
411     if (avctx->debug & FF_DEBUG_PICT_INFO) {
412         av_log(avctx, AV_LOG_DEBUG, "ver:%X ver0:%"PRIX32"\n", rv->sub_id,
413                ((uint32_t *) avctx->extradata)[0]);
414     }
415 
416     avctx->pix_fmt = AV_PIX_FMT_YUV420P;
417 
418     ff_mpv_idct_init(s);
419     if ((ret = ff_mpv_common_init(s)) < 0)
420         return ret;
421 
422     ff_h263dsp_init(&s->h263dsp);
423 
424     /* init static VLCs */
425     ff_thread_once(&init_static_once, rv10_init_static);
426 
427     return 0;
428 }
429 
rv10_decode_end(AVCodecContext * avctx)430 static av_cold int rv10_decode_end(AVCodecContext *avctx)
431 {
432     MpegEncContext *s = avctx->priv_data;
433 
434     ff_mpv_common_end(s);
435     return 0;
436 }
437 
rv10_decode_packet(AVCodecContext * avctx,const uint8_t * buf,int buf_size,int buf_size2,int whole_size)438 static int rv10_decode_packet(AVCodecContext *avctx, const uint8_t *buf,
439                               int buf_size, int buf_size2, int whole_size)
440 {
441     RVDecContext *rv = avctx->priv_data;
442     MpegEncContext *s = &rv->m;
443     int mb_count, mb_pos, left, start_mb_x, active_bits_size, ret;
444 
445     active_bits_size = buf_size * 8;
446     init_get_bits(&s->gb, buf, FFMAX(buf_size, buf_size2) * 8);
447     if (s->codec_id == AV_CODEC_ID_RV10)
448         mb_count = rv10_decode_picture_header(s);
449     else
450         mb_count = rv20_decode_picture_header(rv);
451     if (mb_count < 0) {
452         if (mb_count != ERROR_SKIP_FRAME)
453             av_log(s->avctx, AV_LOG_ERROR, "HEADER ERROR\n");
454         return AVERROR_INVALIDDATA;
455     }
456 
457     if (s->mb_x >= s->mb_width ||
458         s->mb_y >= s->mb_height) {
459         av_log(s->avctx, AV_LOG_ERROR, "POS ERROR %d %d\n", s->mb_x, s->mb_y);
460         return AVERROR_INVALIDDATA;
461     }
462     mb_pos = s->mb_y * s->mb_width + s->mb_x;
463     left   = s->mb_width * s->mb_height - mb_pos;
464     if (mb_count > left) {
465         av_log(s->avctx, AV_LOG_ERROR, "COUNT ERROR\n");
466         return AVERROR_INVALIDDATA;
467     }
468 
469     if (whole_size < s->mb_width * s->mb_height / 8)
470         return AVERROR_INVALIDDATA;
471 
472     if ((s->mb_x == 0 && s->mb_y == 0) || !s->current_picture_ptr) {
473         // FIXME write parser so we always have complete frames?
474         if (s->current_picture_ptr) {
475             ff_er_frame_end(&s->er);
476             ff_mpv_frame_end(s);
477             s->mb_x = s->mb_y = s->resync_mb_x = s->resync_mb_y = 0;
478         }
479         if ((ret = ff_mpv_frame_start(s, avctx)) < 0)
480             return ret;
481         ff_mpeg_er_frame_start(s);
482     } else {
483         if (s->current_picture_ptr->f->pict_type != s->pict_type) {
484             av_log(s->avctx, AV_LOG_ERROR, "Slice type mismatch\n");
485             return AVERROR_INVALIDDATA;
486         }
487     }
488 
489 
490     ff_dlog(avctx, "qscale=%d\n", s->qscale);
491 
492     /* default quantization values */
493     if (s->codec_id == AV_CODEC_ID_RV10) {
494         if (s->mb_y == 0)
495             s->first_slice_line = 1;
496     } else {
497         s->first_slice_line = 1;
498         s->resync_mb_x      = s->mb_x;
499     }
500     start_mb_x     = s->mb_x;
501     s->resync_mb_y = s->mb_y;
502     if (s->h263_aic) {
503         s->y_dc_scale_table =
504         s->c_dc_scale_table = ff_aic_dc_scale_table;
505     } else {
506         s->y_dc_scale_table =
507         s->c_dc_scale_table = ff_mpeg1_dc_scale_table;
508     }
509 
510     if (s->modified_quant)
511         s->chroma_qscale_table = ff_h263_chroma_qscale_table;
512 
513     ff_set_qscale(s, s->qscale);
514 
515     s->rv10_first_dc_coded[0] = 0;
516     s->rv10_first_dc_coded[1] = 0;
517     s->rv10_first_dc_coded[2] = 0;
518     s->block_wrap[0] =
519     s->block_wrap[1] =
520     s->block_wrap[2] =
521     s->block_wrap[3] = s->b8_stride;
522     s->block_wrap[4] =
523     s->block_wrap[5] = s->mb_stride;
524     ff_init_block_index(s);
525 
526     /* decode each macroblock */
527     for (s->mb_num_left = mb_count; s->mb_num_left > 0; s->mb_num_left--) {
528         int ret;
529         ff_update_block_index(s);
530         ff_tlog(avctx, "**mb x=%d y=%d\n", s->mb_x, s->mb_y);
531 
532         s->mv_dir  = MV_DIR_FORWARD;
533         s->mv_type = MV_TYPE_16X16;
534         ret = ff_h263_decode_mb(s, s->block);
535 
536         // Repeat the slice end check from ff_h263_decode_mb with our active
537         // bitstream size
538         if (ret != SLICE_ERROR && active_bits_size >= get_bits_count(&s->gb)) {
539             int v = show_bits(&s->gb, 16);
540 
541             if (get_bits_count(&s->gb) + 16 > active_bits_size)
542                 v >>= get_bits_count(&s->gb) + 16 - active_bits_size;
543 
544             if (!v)
545                 ret = SLICE_END;
546         }
547         if (ret != SLICE_ERROR && active_bits_size < get_bits_count(&s->gb) &&
548             8 * buf_size2 >= get_bits_count(&s->gb)) {
549             active_bits_size = buf_size2 * 8;
550             av_log(avctx, AV_LOG_DEBUG, "update size from %d to %d\n",
551                    8 * buf_size, active_bits_size);
552             ret = SLICE_OK;
553         }
554 
555         if (ret == SLICE_ERROR || active_bits_size < get_bits_count(&s->gb)) {
556             av_log(s->avctx, AV_LOG_ERROR, "ERROR at MB %d %d\n", s->mb_x,
557                    s->mb_y);
558             return AVERROR_INVALIDDATA;
559         }
560         if (s->pict_type != AV_PICTURE_TYPE_B)
561             ff_h263_update_motion_val(s);
562         ff_mpv_reconstruct_mb(s, s->block);
563         if (s->loop_filter)
564             ff_h263_loop_filter(s);
565 
566         if (++s->mb_x == s->mb_width) {
567             s->mb_x = 0;
568             s->mb_y++;
569             ff_init_block_index(s);
570         }
571         if (s->mb_x == s->resync_mb_x)
572             s->first_slice_line = 0;
573         if (ret == SLICE_END)
574             break;
575     }
576 
577     ff_er_add_slice(&s->er, start_mb_x, s->resync_mb_y, s->mb_x - 1, s->mb_y,
578                     ER_MB_END);
579 
580     return active_bits_size;
581 }
582 
get_slice_offset(AVCodecContext * avctx,const uint8_t * buf,int n)583 static int get_slice_offset(AVCodecContext *avctx, const uint8_t *buf, int n)
584 {
585     if (avctx->slice_count)
586         return avctx->slice_offset[n];
587     else
588         return AV_RL32(buf + n * 8);
589 }
590 
rv10_decode_frame(AVCodecContext * avctx,void * data,int * got_frame,AVPacket * avpkt)591 static int rv10_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
592                              AVPacket *avpkt)
593 {
594     const uint8_t *buf = avpkt->data;
595     int buf_size       = avpkt->size;
596     MpegEncContext *s = avctx->priv_data;
597     AVFrame *pict = data;
598     int i, ret;
599     int slice_count;
600     const uint8_t *slices_hdr = NULL;
601 
602     ff_dlog(avctx, "*****frame %d size=%d\n", avctx->frame_number, buf_size);
603 
604     /* no supplementary picture */
605     if (buf_size == 0) {
606         return 0;
607     }
608 
609     if (!avctx->slice_count) {
610         slice_count = (*buf++) + 1;
611         buf_size--;
612 
613         if (!slice_count || buf_size <= 8 * slice_count) {
614             av_log(avctx, AV_LOG_ERROR, "Invalid slice count: %d.\n",
615                    slice_count);
616             return AVERROR_INVALIDDATA;
617         }
618 
619         slices_hdr = buf + 4;
620         buf       += 8 * slice_count;
621         buf_size  -= 8 * slice_count;
622     } else
623         slice_count = avctx->slice_count;
624 
625     for (i = 0; i < slice_count; i++) {
626         unsigned offset = get_slice_offset(avctx, slices_hdr, i);
627         int size, size2;
628 
629         if (offset >= buf_size)
630             return AVERROR_INVALIDDATA;
631 
632         if (i + 1 == slice_count)
633             size = buf_size - offset;
634         else
635             size = get_slice_offset(avctx, slices_hdr, i + 1) - offset;
636 
637         if (i + 2 >= slice_count)
638             size2 = buf_size - offset;
639         else
640             size2 = get_slice_offset(avctx, slices_hdr, i + 2) - offset;
641 
642         if (size <= 0 || size2 <= 0 ||
643             offset + FFMAX(size, size2) > buf_size)
644             return AVERROR_INVALIDDATA;
645 
646         if ((ret = rv10_decode_packet(avctx, buf + offset, size, size2, buf_size)) < 0)
647             return ret;
648 
649         if (ret > 8 * size)
650             i++;
651     }
652 
653     if (s->current_picture_ptr && s->mb_y >= s->mb_height) {
654         ff_er_frame_end(&s->er);
655         ff_mpv_frame_end(s);
656 
657         if (s->pict_type == AV_PICTURE_TYPE_B || s->low_delay) {
658             if ((ret = av_frame_ref(pict, s->current_picture_ptr->f)) < 0)
659                 return ret;
660             ff_print_debug_info(s, s->current_picture_ptr, pict);
661             ff_mpv_export_qp_table(s, pict, s->current_picture_ptr, FF_QSCALE_TYPE_MPEG1);
662         } else if (s->last_picture_ptr) {
663             if ((ret = av_frame_ref(pict, s->last_picture_ptr->f)) < 0)
664                 return ret;
665             ff_print_debug_info(s, s->last_picture_ptr, pict);
666             ff_mpv_export_qp_table(s, pict,s->last_picture_ptr, FF_QSCALE_TYPE_MPEG1);
667         }
668 
669         if (s->last_picture_ptr || s->low_delay) {
670             *got_frame = 1;
671         }
672 
673         // so we can detect if frame_end was not called (find some nicer solution...)
674         s->current_picture_ptr = NULL;
675     }
676 
677     return avpkt->size;
678 }
679 
680 AVCodec ff_rv10_decoder = {
681     .name           = "rv10",
682     .long_name      = NULL_IF_CONFIG_SMALL("RealVideo 1.0"),
683     .type           = AVMEDIA_TYPE_VIDEO,
684     .id             = AV_CODEC_ID_RV10,
685     .priv_data_size = sizeof(RVDecContext),
686     .init           = rv10_decode_init,
687     .close          = rv10_decode_end,
688     .decode         = rv10_decode_frame,
689     .capabilities   = AV_CODEC_CAP_DR1,
690     .max_lowres     = 3,
691     .pix_fmts       = (const enum AVPixelFormat[]) {
692         AV_PIX_FMT_YUV420P,
693         AV_PIX_FMT_NONE
694     },
695 };
696 
697 AVCodec ff_rv20_decoder = {
698     .name           = "rv20",
699     .long_name      = NULL_IF_CONFIG_SMALL("RealVideo 2.0"),
700     .type           = AVMEDIA_TYPE_VIDEO,
701     .id             = AV_CODEC_ID_RV20,
702     .priv_data_size = sizeof(RVDecContext),
703     .init           = rv10_decode_init,
704     .close          = rv10_decode_end,
705     .decode         = rv10_decode_frame,
706     .capabilities   = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_DELAY,
707     .flush          = ff_mpeg_flush,
708     .max_lowres     = 3,
709     .pix_fmts       = (const enum AVPixelFormat[]) {
710         AV_PIX_FMT_YUV420P,
711         AV_PIX_FMT_NONE
712     },
713 };
714