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