1 /*
2  * Cinepak Video Decoder
3  * Copyright (C) 2003 The FFmpeg project
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 /**
23  * @file
24  * Cinepak video decoder
25  * @author Ewald Snel <ewald@rambo.its.tudelft.nl>
26  *
27  * @see For more information on the Cinepak algorithm, visit:
28  *   http://www.csse.monash.edu.au/~timf/
29  * @see For more information on the quirky data inside Sega FILM/CPK files, visit:
30  *   http://wiki.multimedia.cx/index.php?title=Sega_FILM
31  *
32  * Cinepak colorspace support (c) 2013 Rl, Aetey Global Technologies AB
33  * @author Cinepak colorspace, Rl, Aetey Global Technologies AB
34  */
35 
36 #include <stdio.h>
37 #include <stdlib.h>
38 #include <string.h>
39 
40 #include "libavutil/common.h"
41 #include "libavutil/intreadwrite.h"
42 #include "avcodec.h"
43 #include "internal.h"
44 
45 
46 typedef uint8_t cvid_codebook[12];
47 
48 #define MAX_STRIPS      32
49 
50 typedef struct cvid_strip {
51     uint16_t          id;
52     uint16_t          x1, y1;
53     uint16_t          x2, y2;
54     cvid_codebook     v4_codebook[256];
55     cvid_codebook     v1_codebook[256];
56 } cvid_strip;
57 
58 typedef struct CinepakContext {
59 
60     AVCodecContext *avctx;
61     AVFrame *frame;
62 
63     const unsigned char *data;
64     int size;
65 
66     int width, height;
67 
68     int palette_video;
69     cvid_strip strips[MAX_STRIPS];
70 
71     int sega_film_skip_bytes;
72 
73     uint32_t pal[256];
74 } CinepakContext;
75 
cinepak_decode_codebook(cvid_codebook * codebook,int chunk_id,int size,const uint8_t * data)76 static void cinepak_decode_codebook (cvid_codebook *codebook,
77                                      int chunk_id, int size, const uint8_t *data)
78 {
79     const uint8_t *eod = (data + size);
80     uint32_t flag, mask;
81     int      i, n;
82     uint8_t *p;
83 
84     /* check if this chunk contains 4- or 6-element vectors */
85     n    = (chunk_id & 0x04) ? 4 : 6;
86     flag = 0;
87     mask = 0;
88 
89     p = codebook[0];
90     for (i=0; i < 256; i++) {
91         if ((chunk_id & 0x01) && !(mask >>= 1)) {
92             if ((data + 4) > eod)
93                 break;
94 
95             flag  = AV_RB32 (data);
96             data += 4;
97             mask  = 0x80000000;
98         }
99 
100         if (!(chunk_id & 0x01) || (flag & mask)) {
101             int k, kk;
102 
103             if ((data + n) > eod)
104                 break;
105 
106             for (k = 0; k < 4; ++k) {
107                 int r = *data++;
108                 for (kk = 0; kk < 3; ++kk)
109                     *p++ = r;
110             }
111             if (n == 6) {
112                 int r, g, b, u, v;
113                 u = *(int8_t *)data++;
114                 v = *(int8_t *)data++;
115                 p -= 12;
116                 for(k=0; k<4; ++k) {
117                     r = *p++ + v*2;
118                     g = *p++ - (u/2) - v;
119                     b = *p   + u*2;
120                     p -= 2;
121                     *p++ = av_clip_uint8(r);
122                     *p++ = av_clip_uint8(g);
123                     *p++ = av_clip_uint8(b);
124                 }
125             }
126         } else {
127             p += 12;
128         }
129     }
130 }
131 
cinepak_decode_vectors(CinepakContext * s,cvid_strip * strip,int chunk_id,int size,const uint8_t * data)132 static int cinepak_decode_vectors (CinepakContext *s, cvid_strip *strip,
133                                    int chunk_id, int size, const uint8_t *data)
134 {
135     const uint8_t   *eod = (data + size);
136     uint32_t         flag, mask;
137     uint8_t         *cb0, *cb1, *cb2, *cb3;
138     int             x, y;
139     char            *ip0, *ip1, *ip2, *ip3;
140 
141     flag = 0;
142     mask = 0;
143 
144     for (y=strip->y1; y < strip->y2; y+=4) {
145 
146 /* take care of y dimension not being multiple of 4, such streams exist */
147         ip0 = ip1 = ip2 = ip3 = s->frame->data[0] +
148           (s->palette_video?strip->x1:strip->x1*3) + (y * s->frame->linesize[0]);
149         if(s->avctx->height - y > 1) {
150             ip1 = ip0 + s->frame->linesize[0];
151             if(s->avctx->height - y > 2) {
152                 ip2 = ip1 + s->frame->linesize[0];
153                 if(s->avctx->height - y > 3) {
154                     ip3 = ip2 + s->frame->linesize[0];
155                 }
156             }
157         }
158 /* to get the correct picture for not-multiple-of-4 cases let us fill each
159  * block from the bottom up, thus possibly overwriting the bottommost line
160  * more than once but ending with the correct data in place
161  * (instead of in-loop checking) */
162 
163         for (x=strip->x1; x < strip->x2; x+=4) {
164             if ((chunk_id & 0x01) && !(mask >>= 1)) {
165                 if ((data + 4) > eod)
166                     return AVERROR_INVALIDDATA;
167 
168                 flag  = AV_RB32 (data);
169                 data += 4;
170                 mask  = 0x80000000;
171             }
172 
173             if (!(chunk_id & 0x01) || (flag & mask)) {
174                 if (!(chunk_id & 0x02) && !(mask >>= 1)) {
175                     if ((data + 4) > eod)
176                         return AVERROR_INVALIDDATA;
177 
178                     flag  = AV_RB32 (data);
179                     data += 4;
180                     mask  = 0x80000000;
181                 }
182 
183                 if ((chunk_id & 0x02) || (~flag & mask)) {
184                     uint8_t *p;
185                     if (data >= eod)
186                         return AVERROR_INVALIDDATA;
187 
188                     p = strip->v1_codebook[*data++];
189                     if (s->palette_video) {
190                         ip3[0] = ip3[1] = ip2[0] = ip2[1] = p[6];
191                         ip3[2] = ip3[3] = ip2[2] = ip2[3] = p[9];
192                         ip1[0] = ip1[1] = ip0[0] = ip0[1] = p[0];
193                         ip1[2] = ip1[3] = ip0[2] = ip0[3] = p[3];
194                     } else {
195                         p += 6;
196                         memcpy(ip3 + 0, p, 3); memcpy(ip3 + 3, p, 3);
197                         memcpy(ip2 + 0, p, 3); memcpy(ip2 + 3, p, 3);
198                         p += 3; /* ... + 9 */
199                         memcpy(ip3 + 6, p, 3); memcpy(ip3 + 9, p, 3);
200                         memcpy(ip2 + 6, p, 3); memcpy(ip2 + 9, p, 3);
201                         p -= 9; /* ... + 0 */
202                         memcpy(ip1 + 0, p, 3); memcpy(ip1 + 3, p, 3);
203                         memcpy(ip0 + 0, p, 3); memcpy(ip0 + 3, p, 3);
204                         p += 3; /* ... + 3 */
205                         memcpy(ip1 + 6, p, 3); memcpy(ip1 + 9, p, 3);
206                         memcpy(ip0 + 6, p, 3); memcpy(ip0 + 9, p, 3);
207                     }
208 
209                 } else if (flag & mask) {
210                     if ((data + 4) > eod)
211                         return AVERROR_INVALIDDATA;
212 
213                     cb0 = strip->v4_codebook[*data++];
214                     cb1 = strip->v4_codebook[*data++];
215                     cb2 = strip->v4_codebook[*data++];
216                     cb3 = strip->v4_codebook[*data++];
217                     if (s->palette_video) {
218                         uint8_t *p;
219                         p = ip3;
220                         *p++ = cb2[6];
221                         *p++ = cb2[9];
222                         *p++ = cb3[6];
223                         *p   = cb3[9];
224                         p = ip2;
225                         *p++ = cb2[0];
226                         *p++ = cb2[3];
227                         *p++ = cb3[0];
228                         *p   = cb3[3];
229                         p = ip1;
230                         *p++ = cb0[6];
231                         *p++ = cb0[9];
232                         *p++ = cb1[6];
233                         *p   = cb1[9];
234                         p = ip0;
235                         *p++ = cb0[0];
236                         *p++ = cb0[3];
237                         *p++ = cb1[0];
238                         *p   = cb1[3];
239                     } else {
240                         memcpy(ip3 + 0, cb2 + 6, 6);
241                         memcpy(ip3 + 6, cb3 + 6, 6);
242                         memcpy(ip2 + 0, cb2 + 0, 6);
243                         memcpy(ip2 + 6, cb3 + 0, 6);
244                         memcpy(ip1 + 0, cb0 + 6, 6);
245                         memcpy(ip1 + 6, cb1 + 6, 6);
246                         memcpy(ip0 + 0, cb0 + 0, 6);
247                         memcpy(ip0 + 6, cb1 + 0, 6);
248                     }
249 
250                 }
251             }
252 
253             if (s->palette_video) {
254                 ip0 += 4;  ip1 += 4;
255                 ip2 += 4;  ip3 += 4;
256             } else {
257                 ip0 += 12;  ip1 += 12;
258                 ip2 += 12;  ip3 += 12;
259             }
260         }
261     }
262 
263     return 0;
264 }
265 
cinepak_decode_strip(CinepakContext * s,cvid_strip * strip,const uint8_t * data,int size)266 static int cinepak_decode_strip (CinepakContext *s,
267                                  cvid_strip *strip, const uint8_t *data, int size)
268 {
269     const uint8_t *eod = (data + size);
270     int      chunk_id, chunk_size;
271 
272     /* coordinate sanity checks */
273     if (strip->x2 > s->width   ||
274         strip->y2 > s->height  ||
275         strip->x1 >= strip->x2 || strip->y1 >= strip->y2)
276         return AVERROR_INVALIDDATA;
277 
278     while ((data + 4) <= eod) {
279         chunk_id   = data[0];
280         chunk_size = AV_RB24 (&data[1]) - 4;
281         if(chunk_size < 0)
282             return AVERROR_INVALIDDATA;
283 
284         data      += 4;
285         chunk_size = ((data + chunk_size) > eod) ? (eod - data) : chunk_size;
286 
287         switch (chunk_id) {
288 
289         case 0x20:
290         case 0x21:
291         case 0x24:
292         case 0x25:
293             cinepak_decode_codebook (strip->v4_codebook, chunk_id,
294                 chunk_size, data);
295             break;
296 
297         case 0x22:
298         case 0x23:
299         case 0x26:
300         case 0x27:
301             cinepak_decode_codebook (strip->v1_codebook, chunk_id,
302                 chunk_size, data);
303             break;
304 
305         case 0x30:
306         case 0x31:
307         case 0x32:
308             return cinepak_decode_vectors (s, strip, chunk_id,
309                 chunk_size, data);
310         }
311 
312         data += chunk_size;
313     }
314 
315     return AVERROR_INVALIDDATA;
316 }
317 
cinepak_predecode_check(CinepakContext * s)318 static int cinepak_predecode_check (CinepakContext *s)
319 {
320     int           num_strips;
321     int           encoded_buf_size;
322 
323     num_strips  = AV_RB16 (&s->data[8]);
324     encoded_buf_size = AV_RB24(&s->data[1]);
325 
326     if (s->size < encoded_buf_size * (int64_t)(100 - s->avctx->discard_damaged_percentage) / 100)
327         return AVERROR_INVALIDDATA;
328 
329     /* if this is the first frame, check for deviant Sega FILM data */
330     if (s->sega_film_skip_bytes == -1) {
331         if (!encoded_buf_size) {
332             avpriv_request_sample(s->avctx, "encoded_buf_size 0");
333             return AVERROR_PATCHWELCOME;
334         }
335         if (encoded_buf_size != s->size && (s->size % encoded_buf_size) != 0) {
336             /* If the encoded frame size differs from the frame size as indicated
337              * by the container file, this data likely comes from a Sega FILM/CPK file.
338              * If the frame header is followed by the bytes FE 00 00 06 00 00 then
339              * this is probably one of the two known files that have 6 extra bytes
340              * after the frame header. Else, assume 2 extra bytes. The container
341              * size also cannot be a multiple of the encoded size. */
342             if (s->size >= 16 &&
343                 (s->data[10] == 0xFE) &&
344                 (s->data[11] == 0x00) &&
345                 (s->data[12] == 0x00) &&
346                 (s->data[13] == 0x06) &&
347                 (s->data[14] == 0x00) &&
348                 (s->data[15] == 0x00))
349                 s->sega_film_skip_bytes = 6;
350             else
351                 s->sega_film_skip_bytes = 2;
352         } else
353             s->sega_film_skip_bytes = 0;
354     }
355 
356     if (s->size < 10 + s->sega_film_skip_bytes + num_strips * 12)
357         return AVERROR_INVALIDDATA;
358 
359     if (num_strips) {
360         const uint8_t *data = s->data + 10 + s->sega_film_skip_bytes;
361         int strip_size = AV_RB24 (data + 1);
362         if (strip_size < 12 || strip_size > encoded_buf_size)
363             return AVERROR_INVALIDDATA;
364     }
365 
366     return 0;
367 }
368 
cinepak_decode(CinepakContext * s)369 static int cinepak_decode (CinepakContext *s)
370 {
371     const uint8_t  *eod = (s->data + s->size);
372     int           i, result, strip_size, frame_flags, num_strips;
373     int           y0 = 0;
374 
375     frame_flags = s->data[0];
376     num_strips  = AV_RB16 (&s->data[8]);
377 
378     s->data += 10 + s->sega_film_skip_bytes;
379 
380     num_strips = FFMIN(num_strips, MAX_STRIPS);
381 
382     s->frame->key_frame = 0;
383 
384     for (i=0; i < num_strips; i++) {
385         if ((s->data + 12) > eod)
386             return AVERROR_INVALIDDATA;
387 
388         s->strips[i].id = s->data[0];
389 /* zero y1 means "relative to the previous stripe" */
390         if (!(s->strips[i].y1 = AV_RB16 (&s->data[4])))
391             s->strips[i].y2 = (s->strips[i].y1 = y0) + AV_RB16 (&s->data[8]);
392         else
393             s->strips[i].y2 = AV_RB16 (&s->data[8]);
394         s->strips[i].x1 = AV_RB16 (&s->data[6]);
395         s->strips[i].x2 = AV_RB16 (&s->data[10]);
396 
397         if (s->strips[i].id == 0x10)
398             s->frame->key_frame = 1;
399 
400         strip_size = AV_RB24 (&s->data[1]) - 12;
401         if (strip_size < 0)
402             return AVERROR_INVALIDDATA;
403         s->data   += 12;
404         strip_size = ((s->data + strip_size) > eod) ? (eod - s->data) : strip_size;
405 
406         if ((i > 0) && !(frame_flags & 0x01)) {
407             memcpy (s->strips[i].v4_codebook, s->strips[i-1].v4_codebook,
408                 sizeof(s->strips[i].v4_codebook));
409             memcpy (s->strips[i].v1_codebook, s->strips[i-1].v1_codebook,
410                 sizeof(s->strips[i].v1_codebook));
411         }
412 
413         result = cinepak_decode_strip (s, &s->strips[i], s->data, strip_size);
414 
415         if (result != 0)
416             return result;
417 
418         s->data += strip_size;
419         y0    = s->strips[i].y2;
420     }
421     return 0;
422 }
423 
cinepak_decode_init(AVCodecContext * avctx)424 static av_cold int cinepak_decode_init(AVCodecContext *avctx)
425 {
426     CinepakContext *s = avctx->priv_data;
427 
428     s->avctx = avctx;
429     s->width = (avctx->width + 3) & ~3;
430     s->height = (avctx->height + 3) & ~3;
431 
432     s->sega_film_skip_bytes = -1;  /* uninitialized state */
433 
434     // check for paletted data
435     if (avctx->bits_per_coded_sample != 8) {
436         s->palette_video = 0;
437         avctx->pix_fmt = AV_PIX_FMT_RGB24;
438     } else {
439         s->palette_video = 1;
440         avctx->pix_fmt = AV_PIX_FMT_PAL8;
441     }
442 
443     s->frame = av_frame_alloc();
444     if (!s->frame)
445         return AVERROR(ENOMEM);
446 
447     return 0;
448 }
449 
cinepak_decode_frame(AVCodecContext * avctx,void * data,int * got_frame,AVPacket * avpkt)450 static int cinepak_decode_frame(AVCodecContext *avctx,
451                                 void *data, int *got_frame,
452                                 AVPacket *avpkt)
453 {
454     const uint8_t *buf = avpkt->data;
455     int ret = 0, buf_size = avpkt->size;
456     CinepakContext *s = avctx->priv_data;
457     int num_strips;
458 
459     s->data = buf;
460     s->size = buf_size;
461 
462     if (s->size < 10)
463         return AVERROR_INVALIDDATA;
464 
465     num_strips = AV_RB16 (&s->data[8]);
466 
467     //Empty frame, do not waste time
468     if (!num_strips && (!s->palette_video || !av_packet_get_side_data(avpkt, AV_PKT_DATA_PALETTE, NULL)))
469         return buf_size;
470 
471     if ((ret = cinepak_predecode_check(s)) < 0) {
472         av_log(avctx, AV_LOG_ERROR, "cinepak_predecode_check failed\n");
473         return ret;
474     }
475 
476     if ((ret = ff_reget_buffer(avctx, s->frame, 0)) < 0)
477         return ret;
478 
479     if (s->palette_video) {
480         buffer_size_t size;
481         const uint8_t *pal = av_packet_get_side_data(avpkt, AV_PKT_DATA_PALETTE, &size);
482         if (pal && size == AVPALETTE_SIZE) {
483             s->frame->palette_has_changed = 1;
484             memcpy(s->pal, pal, AVPALETTE_SIZE);
485         } else if (pal) {
486             av_log(avctx, AV_LOG_ERROR, "Palette size %d is wrong\n", size);
487         }
488     }
489 
490     if ((ret = cinepak_decode(s)) < 0) {
491         av_log(avctx, AV_LOG_ERROR, "cinepak_decode failed\n");
492     }
493 
494     if (s->palette_video)
495         memcpy (s->frame->data[1], s->pal, AVPALETTE_SIZE);
496 
497     if ((ret = av_frame_ref(data, s->frame)) < 0)
498         return ret;
499 
500     *got_frame = 1;
501 
502     /* report that the buffer was completely consumed */
503     return buf_size;
504 }
505 
cinepak_decode_end(AVCodecContext * avctx)506 static av_cold int cinepak_decode_end(AVCodecContext *avctx)
507 {
508     CinepakContext *s = avctx->priv_data;
509 
510     av_frame_free(&s->frame);
511 
512     return 0;
513 }
514 
515 AVCodec ff_cinepak_decoder = {
516     .name           = "cinepak",
517     .long_name      = NULL_IF_CONFIG_SMALL("Cinepak"),
518     .type           = AVMEDIA_TYPE_VIDEO,
519     .id             = AV_CODEC_ID_CINEPAK,
520     .priv_data_size = sizeof(CinepakContext),
521     .init           = cinepak_decode_init,
522     .close          = cinepak_decode_end,
523     .decode         = cinepak_decode_frame,
524     .capabilities   = AV_CODEC_CAP_DR1,
525     .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE,
526 };
527