2 * Cinepak Video Decoder
3 * Copyright (C) 2003 the ffmpeg project
5 * This file is part of FFmpeg.
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.
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.
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
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/
42 uint8_t y0, y1, y2, y3;
52 cvid_codebook_t v4_codebook[256];
53 cvid_codebook_t v1_codebook[256];
56 typedef struct CinepakContext {
58 AVCodecContext *avctx;
68 cvid_strip_t strips[MAX_STRIPS];
72 static void cinepak_decode_codebook (cvid_codebook_t *codebook,
73 int chunk_id, int size, uint8_t *data)
75 uint8_t *eod = (data + size);
79 /* check if this chunk contains 4- or 6-element vectors */
80 n = (chunk_id & 0x0400) ? 4 : 6;
84 for (i=0; i < 256; i++) {
85 if ((chunk_id & 0x0100) && !(mask >>= 1)) {
94 if (!(chunk_id & 0x0100) || (flag & mask)) {
99 codebook[i].y0 = *data++;
100 codebook[i].y1 = *data++;
101 codebook[i].y2 = *data++;
102 codebook[i].y3 = *data++;
103 codebook[i].u = 128 + *data++;
104 codebook[i].v = 128 + *data++;
106 /* this codebook type indicates either greyscale or
107 * palettized video; if palettized, U & V components will
108 * not be used so it is safe to set them to 128 for the
109 * benefit of greyscale rendering in YUV420P */
110 codebook[i].y0 = *data++;
111 codebook[i].y1 = *data++;
112 codebook[i].y2 = *data++;
113 codebook[i].y3 = *data++;
121 static int cinepak_decode_vectors (CinepakContext *s, cvid_strip_t *strip,
122 int chunk_id, int size, uint8_t *data)
124 uint8_t *eod = (data + size);
126 cvid_codebook_t *codebook;
135 for (y=strip->y1; y < strip->y2; y+=4) {
137 iy[0] = strip->x1 + (y * s->frame.linesize[0]);
138 iy[1] = iy[0] + s->frame.linesize[0];
139 iy[2] = iy[1] + s->frame.linesize[0];
140 iy[3] = iy[2] + s->frame.linesize[0];
141 iu[0] = (strip->x1/2) + ((y/2) * s->frame.linesize[1]);
142 iu[1] = iu[0] + s->frame.linesize[1];
143 iv[0] = (strip->x1/2) + ((y/2) * s->frame.linesize[2]);
144 iv[1] = iv[0] + s->frame.linesize[2];
146 for (x=strip->x1; x < strip->x2; x+=4) {
147 if ((chunk_id & 0x0100) && !(mask >>= 1)) {
148 if ((data + 4) > eod)
156 if (!(chunk_id & 0x0100) || (flag & mask)) {
157 if (!(chunk_id & 0x0200) && !(mask >>= 1)) {
158 if ((data + 4) > eod)
166 if ((chunk_id & 0x0200) || (~flag & mask)) {
170 codebook = &strip->v1_codebook[*data++];
171 s->frame.data[0][iy[0] + 0] = codebook->y0;
172 s->frame.data[0][iy[0] + 1] = codebook->y0;
173 s->frame.data[0][iy[1] + 0] = codebook->y0;
174 s->frame.data[0][iy[1] + 1] = codebook->y0;
175 if (!s->palette_video) {
176 s->frame.data[1][iu[0]] = codebook->u;
177 s->frame.data[2][iv[0]] = codebook->v;
180 s->frame.data[0][iy[0] + 2] = codebook->y1;
181 s->frame.data[0][iy[0] + 3] = codebook->y1;
182 s->frame.data[0][iy[1] + 2] = codebook->y1;
183 s->frame.data[0][iy[1] + 3] = codebook->y1;
184 if (!s->palette_video) {
185 s->frame.data[1][iu[0] + 1] = codebook->u;
186 s->frame.data[2][iv[0] + 1] = codebook->v;
189 s->frame.data[0][iy[2] + 0] = codebook->y2;
190 s->frame.data[0][iy[2] + 1] = codebook->y2;
191 s->frame.data[0][iy[3] + 0] = codebook->y2;
192 s->frame.data[0][iy[3] + 1] = codebook->y2;
193 if (!s->palette_video) {
194 s->frame.data[1][iu[1]] = codebook->u;
195 s->frame.data[2][iv[1]] = codebook->v;
198 s->frame.data[0][iy[2] + 2] = codebook->y3;
199 s->frame.data[0][iy[2] + 3] = codebook->y3;
200 s->frame.data[0][iy[3] + 2] = codebook->y3;
201 s->frame.data[0][iy[3] + 3] = codebook->y3;
202 if (!s->palette_video) {
203 s->frame.data[1][iu[1] + 1] = codebook->u;
204 s->frame.data[2][iv[1] + 1] = codebook->v;
207 } else if (flag & mask) {
208 if ((data + 4) > eod)
211 codebook = &strip->v4_codebook[*data++];
212 s->frame.data[0][iy[0] + 0] = codebook->y0;
213 s->frame.data[0][iy[0] + 1] = codebook->y1;
214 s->frame.data[0][iy[1] + 0] = codebook->y2;
215 s->frame.data[0][iy[1] + 1] = codebook->y3;
216 if (!s->palette_video) {
217 s->frame.data[1][iu[0]] = codebook->u;
218 s->frame.data[2][iv[0]] = codebook->v;
221 codebook = &strip->v4_codebook[*data++];
222 s->frame.data[0][iy[0] + 2] = codebook->y0;
223 s->frame.data[0][iy[0] + 3] = codebook->y1;
224 s->frame.data[0][iy[1] + 2] = codebook->y2;
225 s->frame.data[0][iy[1] + 3] = codebook->y3;
226 if (!s->palette_video) {
227 s->frame.data[1][iu[0] + 1] = codebook->u;
228 s->frame.data[2][iv[0] + 1] = codebook->v;
231 codebook = &strip->v4_codebook[*data++];
232 s->frame.data[0][iy[2] + 0] = codebook->y0;
233 s->frame.data[0][iy[2] + 1] = codebook->y1;
234 s->frame.data[0][iy[3] + 0] = codebook->y2;
235 s->frame.data[0][iy[3] + 1] = codebook->y3;
236 if (!s->palette_video) {
237 s->frame.data[1][iu[1]] = codebook->u;
238 s->frame.data[2][iv[1]] = codebook->v;
241 codebook = &strip->v4_codebook[*data++];
242 s->frame.data[0][iy[2] + 2] = codebook->y0;
243 s->frame.data[0][iy[2] + 3] = codebook->y1;
244 s->frame.data[0][iy[3] + 2] = codebook->y2;
245 s->frame.data[0][iy[3] + 3] = codebook->y3;
246 if (!s->palette_video) {
247 s->frame.data[1][iu[1] + 1] = codebook->u;
248 s->frame.data[2][iv[1] + 1] = codebook->v;
254 iy[0] += 4; iy[1] += 4;
255 iy[2] += 4; iy[3] += 4;
256 iu[0] += 2; iu[1] += 2;
257 iv[0] += 2; iv[1] += 2;
264 static int cinepak_decode_strip (CinepakContext *s,
265 cvid_strip_t *strip, uint8_t *data, int size)
267 uint8_t *eod = (data + size);
268 int chunk_id, chunk_size;
270 /* coordinate sanity checks */
271 if (strip->x1 >= s->width || strip->x2 > s->width ||
272 strip->y1 >= s->height || strip->y2 > s->height ||
273 strip->x1 >= strip->x2 || strip->y1 >= strip->y2)
276 while ((data + 4) <= eod) {
277 chunk_id = BE_16 (&data[0]);
278 chunk_size = BE_16 (&data[2]) - 4;
283 chunk_size = ((data + chunk_size) > eod) ? (eod - data) : chunk_size;
291 cinepak_decode_codebook (strip->v4_codebook, chunk_id,
299 cinepak_decode_codebook (strip->v1_codebook, chunk_id,
306 return cinepak_decode_vectors (s, strip, chunk_id,
316 static int cinepak_decode (CinepakContext *s)
318 uint8_t *eod = (s->data + s->size);
319 int i, result, strip_size, frame_flags, num_strips;
321 int encoded_buf_size;
322 /* if true, Cinepak data is from a Sega FILM/CPK file */
323 int sega_film_data = 0;
328 frame_flags = s->data[0];
329 num_strips = BE_16 (&s->data[8]);
330 encoded_buf_size = ((s->data[1] << 16) | BE_16 (&s->data[2]));
331 if (encoded_buf_size != s->size)
338 if (num_strips > MAX_STRIPS)
339 num_strips = MAX_STRIPS;
341 for (i=0; i < num_strips; i++) {
342 if ((s->data + 12) > eod)
345 s->strips[i].id = BE_16 (s->data);
346 s->strips[i].y1 = y0;
348 s->strips[i].y2 = y0 + BE_16 (&s->data[8]);
349 s->strips[i].x2 = s->avctx->width;
351 strip_size = BE_16 (&s->data[2]) - 12;
353 strip_size = ((s->data + strip_size) > eod) ? (eod - s->data) : strip_size;
355 if ((i > 0) && !(frame_flags & 0x01)) {
356 memcpy (s->strips[i].v4_codebook, s->strips[i-1].v4_codebook,
357 sizeof(s->strips[i].v4_codebook));
358 memcpy (s->strips[i].v1_codebook, s->strips[i-1].v1_codebook,
359 sizeof(s->strips[i].v1_codebook));
362 result = cinepak_decode_strip (s, &s->strips[i], s->data, strip_size);
367 s->data += strip_size;
368 y0 = s->strips[i].y2;
373 static int cinepak_decode_init(AVCodecContext *avctx)
375 CinepakContext *s = (CinepakContext *)avctx->priv_data;
378 s->width = (avctx->width + 3) & ~3;
379 s->height = (avctx->height + 3) & ~3;
381 // check for paletted data
382 if ((avctx->palctrl == NULL) || (avctx->bits_per_sample == 40)) {
383 s->palette_video = 0;
384 avctx->pix_fmt = PIX_FMT_YUV420P;
386 s->palette_video = 1;
387 avctx->pix_fmt = PIX_FMT_PAL8;
390 avctx->has_b_frames = 0;
391 dsputil_init(&s->dsp, avctx);
393 s->frame.data[0] = NULL;
398 static int cinepak_decode_frame(AVCodecContext *avctx,
399 void *data, int *data_size,
400 uint8_t *buf, int buf_size)
402 CinepakContext *s = (CinepakContext *)avctx->priv_data;
407 s->frame.reference = 1;
408 s->frame.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE |
409 FF_BUFFER_HINTS_REUSABLE;
410 if (avctx->reget_buffer(avctx, &s->frame)) {
411 av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
417 if (s->palette_video) {
418 memcpy (s->frame.data[1], avctx->palctrl->palette, AVPALETTE_SIZE);
419 if (avctx->palctrl->palette_changed) {
420 s->frame.palette_has_changed = 1;
421 avctx->palctrl->palette_changed = 0;
423 s->frame.palette_has_changed = 0;
426 *data_size = sizeof(AVFrame);
427 *(AVFrame*)data = s->frame;
429 /* report that the buffer was completely consumed */
433 static int cinepak_decode_end(AVCodecContext *avctx)
435 CinepakContext *s = (CinepakContext *)avctx->priv_data;
437 if (s->frame.data[0])
438 avctx->release_buffer(avctx, &s->frame);
443 AVCodec cinepak_decoder = {
447 sizeof(CinepakContext),
451 cinepak_decode_frame,