Get rid of unnecessary pointer casts.
[ffmpeg.git] / libavcodec / cinepak.c
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 /**
24  * @file cinepak.c
25  * Cinepak video decoder
26  * by Ewald Snel <ewald@rambo.its.tudelft.nl>
27  * For more information on the Cinepak algorithm, visit:
28  *   http://www.csse.monash.edu.au/~timf/
29  * 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
33 #include <stdio.h>
34 #include <stdlib.h>
35 #include <string.h>
36 #include <unistd.h>
37
38 #include "common.h"
39 #include "avcodec.h"
40 #include "dsputil.h"
41
42
43 typedef struct {
44     uint8_t  y0, y1, y2, y3;
45     uint8_t  u, v;
46 } cvid_codebook_t;
47
48 #define MAX_STRIPS      32
49
50 typedef struct {
51     uint16_t          id;
52     uint16_t          x1, y1;
53     uint16_t          x2, y2;
54     cvid_codebook_t   v4_codebook[256];
55     cvid_codebook_t   v1_codebook[256];
56 } cvid_strip_t;
57
58 typedef struct CinepakContext {
59
60     AVCodecContext *avctx;
61     DSPContext dsp;
62     AVFrame frame;
63
64     unsigned char *data;
65     int size;
66
67     int width, height;
68
69     int palette_video;
70     cvid_strip_t strips[MAX_STRIPS];
71
72     int sega_film_skip_bytes;
73
74 } CinepakContext;
75
76 static void cinepak_decode_codebook (cvid_codebook_t *codebook,
77                                      int chunk_id, int size, uint8_t *data)
78 {
79     uint8_t *eod = (data + size);
80     uint32_t flag, mask;
81     int      i, n;
82
83     /* check if this chunk contains 4- or 6-element vectors */
84     n    = (chunk_id & 0x0400) ? 4 : 6;
85     flag = 0;
86     mask = 0;
87
88     for (i=0; i < 256; i++) {
89         if ((chunk_id & 0x0100) && !(mask >>= 1)) {
90             if ((data + 4) > eod)
91                 break;
92
93             flag  = AV_RB32 (data);
94             data += 4;
95             mask  = 0x80000000;
96         }
97
98         if (!(chunk_id & 0x0100) || (flag & mask)) {
99             if ((data + n) > eod)
100                 break;
101
102             if (n == 6) {
103                 codebook[i].y0 = *data++;
104                 codebook[i].y1 = *data++;
105                 codebook[i].y2 = *data++;
106                 codebook[i].y3 = *data++;
107                 codebook[i].u  = 128 + *data++;
108                 codebook[i].v  = 128 + *data++;
109             } else {
110                 /* this codebook type indicates either greyscale or
111                  * palettized video; if palettized, U & V components will
112                  * not be used so it is safe to set them to 128 for the
113                  * benefit of greyscale rendering in YUV420P */
114                 codebook[i].y0 = *data++;
115                 codebook[i].y1 = *data++;
116                 codebook[i].y2 = *data++;
117                 codebook[i].y3 = *data++;
118                 codebook[i].u  = 128;
119                 codebook[i].v  = 128;
120             }
121         }
122     }
123 }
124
125 static int cinepak_decode_vectors (CinepakContext *s, cvid_strip_t *strip,
126                                    int chunk_id, int size, uint8_t *data)
127 {
128     uint8_t         *eod = (data + size);
129     uint32_t         flag, mask;
130     cvid_codebook_t *codebook;
131     unsigned int     x, y;
132     uint32_t         iy[4];
133     uint32_t         iu[2];
134     uint32_t         iv[2];
135
136     flag = 0;
137     mask = 0;
138
139     for (y=strip->y1; y < strip->y2; y+=4) {
140
141         iy[0] = strip->x1 + (y * s->frame.linesize[0]);
142         iy[1] = iy[0] + s->frame.linesize[0];
143         iy[2] = iy[1] + s->frame.linesize[0];
144         iy[3] = iy[2] + s->frame.linesize[0];
145         iu[0] = (strip->x1/2) + ((y/2) * s->frame.linesize[1]);
146         iu[1] = iu[0] + s->frame.linesize[1];
147         iv[0] = (strip->x1/2) + ((y/2) * s->frame.linesize[2]);
148         iv[1] = iv[0] + s->frame.linesize[2];
149
150         for (x=strip->x1; x < strip->x2; x+=4) {
151             if ((chunk_id & 0x0100) && !(mask >>= 1)) {
152                 if ((data + 4) > eod)
153                     return -1;
154
155                 flag  = AV_RB32 (data);
156                 data += 4;
157                 mask  = 0x80000000;
158             }
159
160             if (!(chunk_id & 0x0100) || (flag & mask)) {
161                 if (!(chunk_id & 0x0200) && !(mask >>= 1)) {
162                     if ((data + 4) > eod)
163                         return -1;
164
165                     flag  = AV_RB32 (data);
166                     data += 4;
167                     mask  = 0x80000000;
168                 }
169
170                 if ((chunk_id & 0x0200) || (~flag & mask)) {
171                     if (data >= eod)
172                         return -1;
173
174                     codebook = &strip->v1_codebook[*data++];
175                     s->frame.data[0][iy[0] + 0] = codebook->y0;
176                     s->frame.data[0][iy[0] + 1] = codebook->y0;
177                     s->frame.data[0][iy[1] + 0] = codebook->y0;
178                     s->frame.data[0][iy[1] + 1] = codebook->y0;
179                     if (!s->palette_video) {
180                         s->frame.data[1][iu[0]] = codebook->u;
181                         s->frame.data[2][iv[0]] = codebook->v;
182                     }
183
184                     s->frame.data[0][iy[0] + 2] = codebook->y1;
185                     s->frame.data[0][iy[0] + 3] = codebook->y1;
186                     s->frame.data[0][iy[1] + 2] = codebook->y1;
187                     s->frame.data[0][iy[1] + 3] = codebook->y1;
188                     if (!s->palette_video) {
189                         s->frame.data[1][iu[0] + 1] = codebook->u;
190                         s->frame.data[2][iv[0] + 1] = codebook->v;
191                     }
192
193                     s->frame.data[0][iy[2] + 0] = codebook->y2;
194                     s->frame.data[0][iy[2] + 1] = codebook->y2;
195                     s->frame.data[0][iy[3] + 0] = codebook->y2;
196                     s->frame.data[0][iy[3] + 1] = codebook->y2;
197                     if (!s->palette_video) {
198                         s->frame.data[1][iu[1]] = codebook->u;
199                         s->frame.data[2][iv[1]] = codebook->v;
200                     }
201
202                     s->frame.data[0][iy[2] + 2] = codebook->y3;
203                     s->frame.data[0][iy[2] + 3] = codebook->y3;
204                     s->frame.data[0][iy[3] + 2] = codebook->y3;
205                     s->frame.data[0][iy[3] + 3] = codebook->y3;
206                     if (!s->palette_video) {
207                         s->frame.data[1][iu[1] + 1] = codebook->u;
208                         s->frame.data[2][iv[1] + 1] = codebook->v;
209                     }
210
211                 } else if (flag & mask) {
212                     if ((data + 4) > eod)
213                         return -1;
214
215                     codebook = &strip->v4_codebook[*data++];
216                     s->frame.data[0][iy[0] + 0] = codebook->y0;
217                     s->frame.data[0][iy[0] + 1] = codebook->y1;
218                     s->frame.data[0][iy[1] + 0] = codebook->y2;
219                     s->frame.data[0][iy[1] + 1] = codebook->y3;
220                     if (!s->palette_video) {
221                         s->frame.data[1][iu[0]] = codebook->u;
222                         s->frame.data[2][iv[0]] = codebook->v;
223                     }
224
225                     codebook = &strip->v4_codebook[*data++];
226                     s->frame.data[0][iy[0] + 2] = codebook->y0;
227                     s->frame.data[0][iy[0] + 3] = codebook->y1;
228                     s->frame.data[0][iy[1] + 2] = codebook->y2;
229                     s->frame.data[0][iy[1] + 3] = codebook->y3;
230                     if (!s->palette_video) {
231                         s->frame.data[1][iu[0] + 1] = codebook->u;
232                         s->frame.data[2][iv[0] + 1] = codebook->v;
233                     }
234
235                     codebook = &strip->v4_codebook[*data++];
236                     s->frame.data[0][iy[2] + 0] = codebook->y0;
237                     s->frame.data[0][iy[2] + 1] = codebook->y1;
238                     s->frame.data[0][iy[3] + 0] = codebook->y2;
239                     s->frame.data[0][iy[3] + 1] = codebook->y3;
240                     if (!s->palette_video) {
241                         s->frame.data[1][iu[1]] = codebook->u;
242                         s->frame.data[2][iv[1]] = codebook->v;
243                     }
244
245                     codebook = &strip->v4_codebook[*data++];
246                     s->frame.data[0][iy[2] + 2] = codebook->y0;
247                     s->frame.data[0][iy[2] + 3] = codebook->y1;
248                     s->frame.data[0][iy[3] + 2] = codebook->y2;
249                     s->frame.data[0][iy[3] + 3] = codebook->y3;
250                     if (!s->palette_video) {
251                         s->frame.data[1][iu[1] + 1] = codebook->u;
252                         s->frame.data[2][iv[1] + 1] = codebook->v;
253                     }
254
255                 }
256             }
257
258             iy[0] += 4;  iy[1] += 4;
259             iy[2] += 4;  iy[3] += 4;
260             iu[0] += 2;  iu[1] += 2;
261             iv[0] += 2;  iv[1] += 2;
262         }
263     }
264
265     return 0;
266 }
267
268 static int cinepak_decode_strip (CinepakContext *s,
269                                  cvid_strip_t *strip, uint8_t *data, int size)
270 {
271     uint8_t *eod = (data + size);
272     int      chunk_id, chunk_size;
273
274     /* coordinate sanity checks */
275     if (strip->x1 >= s->width  || strip->x2 > s->width  ||
276         strip->y1 >= s->height || strip->y2 > s->height ||
277         strip->x1 >= strip->x2 || strip->y1 >= strip->y2)
278         return -1;
279
280     while ((data + 4) <= eod) {
281         chunk_id   = AV_RB16 (&data[0]);
282         chunk_size = AV_RB16 (&data[2]) - 4;
283         if(chunk_size < 0)
284             return -1;
285
286         data      += 4;
287         chunk_size = ((data + chunk_size) > eod) ? (eod - data) : chunk_size;
288
289         switch (chunk_id) {
290
291         case 0x2000:
292         case 0x2100:
293         case 0x2400:
294         case 0x2500:
295             cinepak_decode_codebook (strip->v4_codebook, chunk_id,
296                 chunk_size, data);
297             break;
298
299         case 0x2200:
300         case 0x2300:
301         case 0x2600:
302         case 0x2700:
303             cinepak_decode_codebook (strip->v1_codebook, chunk_id,
304                 chunk_size, data);
305             break;
306
307         case 0x3000:
308         case 0x3100:
309         case 0x3200:
310             return cinepak_decode_vectors (s, strip, chunk_id,
311                 chunk_size, data);
312         }
313
314         data += chunk_size;
315     }
316
317     return -1;
318 }
319
320 static int cinepak_decode (CinepakContext *s)
321 {
322     uint8_t      *eod = (s->data + s->size);
323     int           i, result, strip_size, frame_flags, num_strips;
324     int           y0 = 0;
325     int           encoded_buf_size;
326
327     if (s->size < 10)
328         return -1;
329
330     frame_flags = s->data[0];
331     num_strips  = AV_RB16 (&s->data[8]);
332     encoded_buf_size = ((s->data[1] << 16) | AV_RB16 (&s->data[2]));
333
334     /* if this is the first frame, check for deviant Sega FILM data */
335     if (s->sega_film_skip_bytes == -1) {
336         if (encoded_buf_size != s->size) {
337             /* If the encoded frame size differs from the frame size as indicated
338              * by the container file, this data likely comes from a Sega FILM/CPK file.
339              * If the frame header is followed by the bytes FE 00 00 06 00 00 then
340              * this is probably one of the two known files that have 6 extra bytes
341              * after the frame header. Else, assume 2 extra bytes. */
342             if ((s->data[10] == 0xFE) &&
343                 (s->data[11] == 0x00) &&
344                 (s->data[12] == 0x00) &&
345                 (s->data[13] == 0x06) &&
346                 (s->data[14] == 0x00) &&
347                 (s->data[15] == 0x00))
348                 s->sega_film_skip_bytes = 6;
349             else
350                 s->sega_film_skip_bytes = 2;
351         } else
352             s->sega_film_skip_bytes = 0;
353     }
354
355     s->data += 10 + s->sega_film_skip_bytes;
356
357     if (num_strips > MAX_STRIPS)
358         num_strips = MAX_STRIPS;
359
360     for (i=0; i < num_strips; i++) {
361         if ((s->data + 12) > eod)
362             return -1;
363
364         s->strips[i].id = AV_RB16 (s->data);
365         s->strips[i].y1 = y0;
366         s->strips[i].x1 = 0;
367         s->strips[i].y2 = y0 + AV_RB16 (&s->data[8]);
368         s->strips[i].x2 = s->avctx->width;
369
370         strip_size = AV_RB16 (&s->data[2]) - 12;
371         s->data   += 12;
372         strip_size = ((s->data + strip_size) > eod) ? (eod - s->data) : strip_size;
373
374         if ((i > 0) && !(frame_flags & 0x01)) {
375             memcpy (s->strips[i].v4_codebook, s->strips[i-1].v4_codebook,
376                 sizeof(s->strips[i].v4_codebook));
377             memcpy (s->strips[i].v1_codebook, s->strips[i-1].v1_codebook,
378                 sizeof(s->strips[i].v1_codebook));
379         }
380
381         result = cinepak_decode_strip (s, &s->strips[i], s->data, strip_size);
382
383         if (result != 0)
384             return result;
385
386         s->data += strip_size;
387         y0    = s->strips[i].y2;
388     }
389     return 0;
390 }
391
392 static int cinepak_decode_init(AVCodecContext *avctx)
393 {
394     CinepakContext *s = avctx->priv_data;
395
396     s->avctx = avctx;
397     s->width = (avctx->width + 3) & ~3;
398     s->height = (avctx->height + 3) & ~3;
399     s->sega_film_skip_bytes = -1;  /* uninitialized state */
400
401     // check for paletted data
402     if ((avctx->palctrl == NULL) || (avctx->bits_per_sample == 40)) {
403         s->palette_video = 0;
404         avctx->pix_fmt = PIX_FMT_YUV420P;
405     } else {
406         s->palette_video = 1;
407         avctx->pix_fmt = PIX_FMT_PAL8;
408     }
409
410     dsputil_init(&s->dsp, avctx);
411
412     s->frame.data[0] = NULL;
413
414     return 0;
415 }
416
417 static int cinepak_decode_frame(AVCodecContext *avctx,
418                                 void *data, int *data_size,
419                                 uint8_t *buf, int buf_size)
420 {
421     CinepakContext *s = avctx->priv_data;
422
423     s->data = buf;
424     s->size = buf_size;
425
426     s->frame.reference = 1;
427     s->frame.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE |
428                             FF_BUFFER_HINTS_REUSABLE;
429     if (avctx->reget_buffer(avctx, &s->frame)) {
430         av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
431         return -1;
432     }
433
434     cinepak_decode(s);
435
436     if (s->palette_video) {
437         memcpy (s->frame.data[1], avctx->palctrl->palette, AVPALETTE_SIZE);
438         if (avctx->palctrl->palette_changed) {
439             s->frame.palette_has_changed = 1;
440             avctx->palctrl->palette_changed = 0;
441         } else
442             s->frame.palette_has_changed = 0;
443     }
444
445     *data_size = sizeof(AVFrame);
446     *(AVFrame*)data = s->frame;
447
448     /* report that the buffer was completely consumed */
449     return buf_size;
450 }
451
452 static int cinepak_decode_end(AVCodecContext *avctx)
453 {
454     CinepakContext *s = avctx->priv_data;
455
456     if (s->frame.data[0])
457         avctx->release_buffer(avctx, &s->frame);
458
459     return 0;
460 }
461
462 AVCodec cinepak_decoder = {
463     "cinepak",
464     CODEC_TYPE_VIDEO,
465     CODEC_ID_CINEPAK,
466     sizeof(CinepakContext),
467     cinepak_decode_init,
468     NULL,
469     cinepak_decode_end,
470     cinepak_decode_frame,
471     CODEC_CAP_DR1,
472 };