aboutsummaryrefslogtreecommitdiffstats
path: root/libavcodec/cinepak.c
blob: 4bda2a74eb3e00c00e4578566614b53f608c5114 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
/*
 * Cinepak Video Decoder
 * Copyright (C) 2003 the ffmpeg project
 *
 * This file is part of Libav.
 *
 * Libav is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * Libav is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with Libav; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

/**
 * @file
 * Cinepak video decoder
 * by Ewald Snel <ewald@rambo.its.tudelft.nl>
 * For more information on the Cinepak algorithm, visit:
 *   http://www.csse.monash.edu.au/~timf/
 * For more information on the quirky data inside Sega FILM/CPK files, visit:
 *   http://wiki.multimedia.cx/index.php?title=Sega_FILM
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "libavutil/intreadwrite.h"
#include "avcodec.h"


typedef struct {
    uint8_t  y0, y1, y2, y3;
    uint8_t  u, v;
} cvid_codebook;

#define MAX_STRIPS      32

typedef struct {
    uint16_t          id;
    uint16_t          x1, y1;
    uint16_t          x2, y2;
    cvid_codebook     v4_codebook[256];
    cvid_codebook     v1_codebook[256];
} cvid_strip;

typedef struct CinepakContext {

    AVCodecContext *avctx;
    AVFrame frame;

    const unsigned char *data;
    int size;

    int width, height;

    int palette_video;
    cvid_strip strips[MAX_STRIPS];

    int sega_film_skip_bytes;

    uint32_t pal[256];
} CinepakContext;

static void cinepak_decode_codebook (cvid_codebook *codebook,
                                     int chunk_id, int size, const uint8_t *data)
{
    const uint8_t *eod = (data + size);
    uint32_t flag, mask;
    int      i, n;

    /* check if this chunk contains 4- or 6-element vectors */
    n    = (chunk_id & 0x04) ? 4 : 6;
    flag = 0;
    mask = 0;

    for (i=0; i < 256; i++) {
        if ((chunk_id & 0x01) && !(mask >>= 1)) {
            if ((data + 4) > eod)
                break;

            flag  = AV_RB32 (data);
            data += 4;
            mask  = 0x80000000;
        }

        if (!(chunk_id & 0x01) || (flag & mask)) {
            if ((data + n) > eod)
                break;

            if (n == 6) {
                codebook[i].y0 = *data++;
                codebook[i].y1 = *data++;
                codebook[i].y2 = *data++;
                codebook[i].y3 = *data++;
                codebook[i].u  = 128 + *data++;
                codebook[i].v  = 128 + *data++;
            } else {
                /* this codebook type indicates either greyscale or
                 * palettized video; if palettized, U & V components will
                 * not be used so it is safe to set them to 128 for the
                 * benefit of greyscale rendering in YUV420P */
                codebook[i].y0 = *data++;
                codebook[i].y1 = *data++;
                codebook[i].y2 = *data++;
                codebook[i].y3 = *data++;
                codebook[i].u  = 128;
                codebook[i].v  = 128;
            }
        }
    }
}

static int cinepak_decode_vectors (CinepakContext *s, cvid_strip *strip,
                                   int chunk_id, int size, const uint8_t *data)
{
    const uint8_t   *eod = (data + size);
    uint32_t         flag, mask;
    cvid_codebook   *codebook;
    unsigned int     x, y;
    uint32_t         iy[4];
    uint32_t         iu[2];
    uint32_t         iv[2];

    flag = 0;
    mask = 0;

    for (y=strip->y1; y < strip->y2; y+=4) {

        iy[0] = strip->x1 + (y * s->frame.linesize[0]);
        iy[1] = iy[0] + s->frame.linesize[0];
        iy[2] = iy[1] + s->frame.linesize[0];
        iy[3] = iy[2] + s->frame.linesize[0];
        iu[0] = (strip->x1/2) + ((y/2) * s->frame.linesize[1]);
        iu[1] = iu[0] + s->frame.linesize[1];
        iv[0] = (strip->x1/2) + ((y/2) * s->frame.linesize[2]);
        iv[1] = iv[0] + s->frame.linesize[2];

        for (x=strip->x1; x < strip->x2; x+=4) {
            if ((chunk_id & 0x01) && !(mask >>= 1)) {
                if ((data + 4) > eod)
                    return -1;

                flag  = AV_RB32 (data);
                data += 4;
                mask  = 0x80000000;
            }

            if (!(chunk_id & 0x01) || (flag & mask)) {
                if (!(chunk_id & 0x02) && !(mask >>= 1)) {
                    if ((data + 4) > eod)
                        return -1;

                    flag  = AV_RB32 (data);
                    data += 4;
                    mask  = 0x80000000;
                }

                if ((chunk_id & 0x02) || (~flag & mask)) {
                    if (data >= eod)
                        return -1;

                    codebook = &strip->v1_codebook[*data++];
                    s->frame.data[0][iy[0] + 0] = codebook->y0;
                    s->frame.data[0][iy[0] + 1] = codebook->y0;
                    s->frame.data[0][iy[1] + 0] = codebook->y0;
                    s->frame.data[0][iy[1] + 1] = codebook->y0;
                    if (!s->palette_video) {
                        s->frame.data[1][iu[0]] = codebook->u;
                        s->frame.data[2][iv[0]] = codebook->v;
                    }

                    s->frame.data[0][iy[0] + 2] = codebook->y1;
                    s->frame.data[0][iy[0] + 3] = codebook->y1;
                    s->frame.data[0][iy[1] + 2] = codebook->y1;
                    s->frame.data[0][iy[1] + 3] = codebook->y1;
                    if (!s->palette_video) {
                        s->frame.data[1][iu[0] + 1] = codebook->u;
                        s->frame.data[2][iv[0] + 1] = codebook->v;
                    }

                    s->frame.data[0][iy[2] + 0] = codebook->y2;
                    s->frame.data[0][iy[2] + 1] = codebook->y2;
                    s->frame.data[0][iy[3] + 0] = codebook->y2;
                    s->frame.data[0][iy[3] + 1] = codebook->y2;
                    if (!s->palette_video) {
                        s->frame.data[1][iu[1]] = codebook->u;
                        s->frame.data[2][iv[1]] = codebook->v;
                    }

                    s->frame.data[0][iy[2] + 2] = codebook->y3;
                    s->frame.data[0][iy[2] + 3] = codebook->y3;
                    s->frame.data[0][iy[3] + 2] = codebook->y3;
                    s->frame.data[0][iy[3] + 3] = codebook->y3;
                    if (!s->palette_video) {
                        s->frame.data[1][iu[1] + 1] = codebook->u;
                        s->frame.data[2][iv[1] + 1] = codebook->v;
                    }

                } else if (flag & mask) {
                    if ((data + 4) > eod)
                        return -1;

                    codebook = &strip->v4_codebook[*data++];
                    s->frame.data[0][iy[0] + 0] = codebook->y0;
                    s->frame.data[0][iy[0] + 1] = codebook->y1;
                    s->frame.data[0][iy[1] + 0] = codebook->y2;
                    s->frame.data[0][iy[1] + 1] = codebook->y3;
                    if (!s->palette_video) {
                        s->frame.data[1][iu[0]] = codebook->u;
                        s->frame.data[2][iv[0]] = codebook->v;
                    }

                    codebook = &strip->v4_codebook[*data++];
                    s->frame.data[0][iy[0] + 2] = codebook->y0;
                    s->frame.data[0][iy[0] + 3] = codebook->y1;
                    s->frame.data[0][iy[1] + 2] = codebook->y2;
                    s->frame.data[0][iy[1] + 3] = codebook->y3;
                    if (!s->palette_video) {
                        s->frame.data[1][iu[0] + 1] = codebook->u;
                        s->frame.data[2][iv[0] + 1] = codebook->v;
                    }

                    codebook = &strip->v4_codebook[*data++];
                    s->frame.data[0][iy[2] + 0] = codebook->y0;
                    s->frame.data[0][iy[2] + 1] = codebook->y1;
                    s->frame.data[0][iy[3] + 0] = codebook->y2;
                    s->frame.data[0][iy[3] + 1] = codebook->y3;
                    if (!s->palette_video) {
                        s->frame.data[1][iu[1]] = codebook->u;
                        s->frame.data[2][iv[1]] = codebook->v;
                    }

                    codebook = &strip->v4_codebook[*data++];
                    s->frame.data[0][iy[2] + 2] = codebook->y0;
                    s->frame.data[0][iy[2] + 3] = codebook->y1;
                    s->frame.data[0][iy[3] + 2] = codebook->y2;
                    s->frame.data[0][iy[3] + 3] = codebook->y3;
                    if (!s->palette_video) {
                        s->frame.data[1][iu[1] + 1] = codebook->u;
                        s->frame.data[2][iv[1] + 1] = codebook->v;
                    }

                }
            }

            iy[0] += 4;  iy[1] += 4;
            iy[2] += 4;  iy[3] += 4;
            iu[0] += 2;  iu[1] += 2;
            iv[0] += 2;  iv[1] += 2;
        }
    }

    return 0;
}

static int cinepak_decode_strip (CinepakContext *s,
                                 cvid_strip *strip, const uint8_t *data, int size)
{
    const uint8_t *eod = (data + size);
    int      chunk_id, chunk_size;

    /* coordinate sanity checks */
    if (strip->x1 >= s->width  || strip->x2 > s->width  ||
        strip->y1 >= s->height || strip->y2 > s->height ||
        strip->x1 >= strip->x2 || strip->y1 >= strip->y2)
        return -1;

    while ((data + 4) <= eod) {
        chunk_id   = data[0];
        chunk_size = AV_RB24 (&data[1]) - 4;
        if(chunk_size < 0)
            return -1;

        data      += 4;
        chunk_size = ((data + chunk_size) > eod) ? (eod - data) : chunk_size;

        switch (chunk_id) {

        case 0x20:
        case 0x21:
        case 0x24:
        case 0x25:
            cinepak_decode_codebook (strip->v4_codebook, chunk_id,
                chunk_size, data);
            break;

        case 0x22:
        case 0x23:
        case 0x26:
        case 0x27:
            cinepak_decode_codebook (strip->v1_codebook, chunk_id,
                chunk_size, data);
            break;

        case 0x30:
        case 0x31:
        case 0x32:
            return cinepak_decode_vectors (s, strip, chunk_id,
                chunk_size, data);
        }

        data += chunk_size;
    }

    return -1;
}

static int cinepak_decode (CinepakContext *s)
{
    const uint8_t  *eod = (s->data + s->size);
    int           i, result, strip_size, frame_flags, num_strips;
    int           y0 = 0;
    int           encoded_buf_size;

    if (s->size < 10)
        return -1;

    frame_flags = s->data[0];
    num_strips  = AV_RB16 (&s->data[8]);
    encoded_buf_size = ((s->data[1] << 16) | AV_RB16 (&s->data[2]));

    /* if this is the first frame, check for deviant Sega FILM data */
    if (s->sega_film_skip_bytes == -1) {
        if (encoded_buf_size != s->size) {
            /* If the encoded frame size differs from the frame size as indicated
             * by the container file, this data likely comes from a Sega FILM/CPK file.
             * If the frame header is followed by the bytes FE 00 00 06 00 00 then
             * this is probably one of the two known files that have 6 extra bytes
             * after the frame header. Else, assume 2 extra bytes. */
            if ((s->data[10] == 0xFE) &&
                (s->data[11] == 0x00) &&
                (s->data[12] == 0x00) &&
                (s->data[13] == 0x06) &&
                (s->data[14] == 0x00) &&
                (s->data[15] == 0x00))
                s->sega_film_skip_bytes = 6;
            else
                s->sega_film_skip_bytes = 2;
        } else
            s->sega_film_skip_bytes = 0;
    }

    s->data += 10 + s->sega_film_skip_bytes;

    if (num_strips > MAX_STRIPS)
        num_strips = MAX_STRIPS;

    for (i=0; i < num_strips; i++) {
        if ((s->data + 12) > eod)
            return -1;

        s->strips[i].id = s->data[0];
        s->strips[i].y1 = y0;
        s->strips[i].x1 = 0;
        s->strips[i].y2 = y0 + AV_RB16 (&s->data[8]);
        s->strips[i].x2 = s->avctx->width;

        strip_size = AV_RB24 (&s->data[1]) - 12;
        s->data   += 12;
        strip_size = ((s->data + strip_size) > eod) ? (eod - s->data) : strip_size;

        if ((i > 0) && !(frame_flags & 0x01)) {
            memcpy (s->strips[i].v4_codebook, s->strips[i-1].v4_codebook,
                sizeof(s->strips[i].v4_codebook));
            memcpy (s->strips[i].v1_codebook, s->strips[i-1].v1_codebook,
                sizeof(s->strips[i].v1_codebook));
        }

        result = cinepak_decode_strip (s, &s->strips[i], s->data, strip_size);

        if (result != 0)
            return result;

        s->data += strip_size;
        y0    = s->strips[i].y2;
    }
    return 0;
}

static av_cold int cinepak_decode_init(AVCodecContext *avctx)
{
    CinepakContext *s = avctx->priv_data;

    s->avctx = avctx;
    s->width = (avctx->width + 3) & ~3;
    s->height = (avctx->height + 3) & ~3;
    s->sega_film_skip_bytes = -1;  /* uninitialized state */

    // check for paletted data
    if (avctx->bits_per_coded_sample != 8) {
        s->palette_video = 0;
        avctx->pix_fmt = PIX_FMT_YUV420P;
    } else {
        s->palette_video = 1;
        avctx->pix_fmt = PIX_FMT_PAL8;
    }

    s->frame.data[0] = NULL;

    return 0;
}

static int cinepak_decode_frame(AVCodecContext *avctx,
                                void *data, int *data_size,
                                AVPacket *avpkt)
{
    const uint8_t *buf = avpkt->data;
    int buf_size = avpkt->size;
    CinepakContext *s = avctx->priv_data;

    s->data = buf;
    s->size = buf_size;

    s->frame.reference = 1;
    s->frame.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE |
                            FF_BUFFER_HINTS_REUSABLE;
    if (avctx->reget_buffer(avctx, &s->frame)) {
        av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
        return -1;
    }

    if (s->palette_video) {
        const uint8_t *pal = av_packet_get_side_data(avpkt, AV_PKT_DATA_PALETTE, NULL);
        if (pal) {
            s->frame.palette_has_changed = 1;
            memcpy(s->pal, pal, AVPALETTE_SIZE);
        }
    }

    cinepak_decode(s);

    if (s->palette_video)
        memcpy (s->frame.data[1], s->pal, AVPALETTE_SIZE);

    *data_size = sizeof(AVFrame);
    *(AVFrame*)data = s->frame;

    /* report that the buffer was completely consumed */
    return buf_size;
}

static av_cold int cinepak_decode_end(AVCodecContext *avctx)
{
    CinepakContext *s = avctx->priv_data;

    if (s->frame.data[0])
        avctx->release_buffer(avctx, &s->frame);

    return 0;
}

AVCodec ff_cinepak_decoder = {
    "cinepak",
    AVMEDIA_TYPE_VIDEO,
    CODEC_ID_CINEPAK,
    sizeof(CinepakContext),
    cinepak_decode_init,
    NULL,
    cinepak_decode_end,
    cinepak_decode_frame,
    CODEC_CAP_DR1,
    .long_name = NULL_IF_CONFIG_SMALL("Cinepak"),
};