2 * Cinepak Video Decoder
3 * Copyright (C) 2003 the ffmpeg project
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation; either
8 * version 2 of the License, or (at your option) any later version.
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Lesser General Public License for more details.
15 * You should have received a copy of the GNU Lesser General Public
16 * License along with this library; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 * Cinepak video decoder
24 * by Ewald Snel <ewald@rambo.its.tudelft.nl>
25 * For more information on the Cinepak algorithm, visit:
26 * http://www.csse.monash.edu.au/~timf/
40 uint8_t y0, y1, y2, y3;
50 cvid_codebook_t v4_codebook[256];
51 cvid_codebook_t v1_codebook[256];
54 typedef struct CinepakContext {
56 AVCodecContext *avctx;
66 cvid_strip_t strips[MAX_STRIPS];
70 static void cinepak_decode_codebook (cvid_codebook_t *codebook,
71 int chunk_id, int size, uint8_t *data)
73 uint8_t *eod = (data + size);
77 /* check if this chunk contains 4- or 6-element vectors */
78 n = (chunk_id & 0x0400) ? 4 : 6;
82 for (i=0; i < 256; i++) {
83 if ((chunk_id & 0x0100) && !(mask >>= 1)) {
92 if (!(chunk_id & 0x0100) || (flag & mask)) {
97 codebook[i].y0 = *data++;
98 codebook[i].y1 = *data++;
99 codebook[i].y2 = *data++;
100 codebook[i].y3 = *data++;
101 codebook[i].u = 128 + *data++;
102 codebook[i].v = 128 + *data++;
104 /* this codebook type indicates either greyscale or
105 * palettized video; if palettized, U & V components will
106 * not be used so it is safe to set them to 128 for the
107 * benefit of greyscale rendering in YUV420P */
108 codebook[i].y0 = *data++;
109 codebook[i].y1 = *data++;
110 codebook[i].y2 = *data++;
111 codebook[i].y3 = *data++;
119 static int cinepak_decode_vectors (CinepakContext *s, cvid_strip_t *strip,
120 int chunk_id, int size, uint8_t *data)
122 uint8_t *eod = (data + size);
124 cvid_codebook_t *codebook;
133 for (y=strip->y1; y < strip->y2; y+=4) {
135 iy[0] = strip->x1 + (y * s->frame.linesize[0]);
136 iy[1] = iy[0] + s->frame.linesize[0];
137 iy[2] = iy[1] + s->frame.linesize[0];
138 iy[3] = iy[2] + s->frame.linesize[0];
139 iu[0] = (strip->x1/2) + ((y/2) * s->frame.linesize[1]);
140 iu[1] = iu[0] + s->frame.linesize[1];
141 iv[0] = (strip->x1/2) + ((y/2) * s->frame.linesize[2]);
142 iv[1] = iv[0] + s->frame.linesize[2];
144 for (x=strip->x1; x < strip->x2; x+=4) {
145 if ((chunk_id & 0x0100) && !(mask >>= 1)) {
146 if ((data + 4) > eod)
154 if (!(chunk_id & 0x0100) || (flag & mask)) {
155 if (!(chunk_id & 0x0200) && !(mask >>= 1)) {
156 if ((data + 4) > eod)
164 if ((chunk_id & 0x0200) || (~flag & mask)) {
168 codebook = &strip->v1_codebook[*data++];
169 s->frame.data[0][iy[0] + 0] = codebook->y0;
170 s->frame.data[0][iy[0] + 1] = codebook->y0;
171 s->frame.data[0][iy[1] + 0] = codebook->y0;
172 s->frame.data[0][iy[1] + 1] = codebook->y0;
173 if (!s->palette_video) {
174 s->frame.data[1][iu[0]] = codebook->u;
175 s->frame.data[2][iv[0]] = codebook->v;
178 s->frame.data[0][iy[0] + 2] = codebook->y1;
179 s->frame.data[0][iy[0] + 3] = codebook->y1;
180 s->frame.data[0][iy[1] + 2] = codebook->y1;
181 s->frame.data[0][iy[1] + 3] = codebook->y1;
182 if (!s->palette_video) {
183 s->frame.data[1][iu[0] + 1] = codebook->u;
184 s->frame.data[2][iv[0] + 1] = codebook->v;
187 s->frame.data[0][iy[2] + 0] = codebook->y2;
188 s->frame.data[0][iy[2] + 1] = codebook->y2;
189 s->frame.data[0][iy[3] + 0] = codebook->y2;
190 s->frame.data[0][iy[3] + 1] = codebook->y2;
191 if (!s->palette_video) {
192 s->frame.data[1][iu[1]] = codebook->u;
193 s->frame.data[2][iv[1]] = codebook->v;
196 s->frame.data[0][iy[2] + 2] = codebook->y3;
197 s->frame.data[0][iy[2] + 3] = codebook->y3;
198 s->frame.data[0][iy[3] + 2] = codebook->y3;
199 s->frame.data[0][iy[3] + 3] = codebook->y3;
200 if (!s->palette_video) {
201 s->frame.data[1][iu[1] + 1] = codebook->u;
202 s->frame.data[2][iv[1] + 1] = codebook->v;
205 } else if (flag & mask) {
206 if ((data + 4) > eod)
209 codebook = &strip->v4_codebook[*data++];
210 s->frame.data[0][iy[0] + 0] = codebook->y0;
211 s->frame.data[0][iy[0] + 1] = codebook->y1;
212 s->frame.data[0][iy[1] + 0] = codebook->y2;
213 s->frame.data[0][iy[1] + 1] = codebook->y3;
214 if (!s->palette_video) {
215 s->frame.data[1][iu[0]] = codebook->u;
216 s->frame.data[2][iv[0]] = codebook->v;
219 codebook = &strip->v4_codebook[*data++];
220 s->frame.data[0][iy[0] + 2] = codebook->y0;
221 s->frame.data[0][iy[0] + 3] = codebook->y1;
222 s->frame.data[0][iy[1] + 2] = codebook->y2;
223 s->frame.data[0][iy[1] + 3] = codebook->y3;
224 if (!s->palette_video) {
225 s->frame.data[1][iu[0] + 1] = codebook->u;
226 s->frame.data[2][iv[0] + 1] = codebook->v;
229 codebook = &strip->v4_codebook[*data++];
230 s->frame.data[0][iy[2] + 0] = codebook->y0;
231 s->frame.data[0][iy[2] + 1] = codebook->y1;
232 s->frame.data[0][iy[3] + 0] = codebook->y2;
233 s->frame.data[0][iy[3] + 1] = codebook->y3;
234 if (!s->palette_video) {
235 s->frame.data[1][iu[1]] = codebook->u;
236 s->frame.data[2][iv[1]] = codebook->v;
239 codebook = &strip->v4_codebook[*data++];
240 s->frame.data[0][iy[2] + 2] = codebook->y0;
241 s->frame.data[0][iy[2] + 3] = codebook->y1;
242 s->frame.data[0][iy[3] + 2] = codebook->y2;
243 s->frame.data[0][iy[3] + 3] = codebook->y3;
244 if (!s->palette_video) {
245 s->frame.data[1][iu[1] + 1] = codebook->u;
246 s->frame.data[2][iv[1] + 1] = codebook->v;
252 iy[0] += 4; iy[1] += 4;
253 iy[2] += 4; iy[3] += 4;
254 iu[0] += 2; iu[1] += 2;
255 iv[0] += 2; iv[1] += 2;
262 static int cinepak_decode_strip (CinepakContext *s,
263 cvid_strip_t *strip, uint8_t *data, int size)
265 uint8_t *eod = (data + size);
266 int chunk_id, chunk_size;
268 /* coordinate sanity checks */
269 if (strip->x1 >= s->width || strip->x2 > s->width ||
270 strip->y1 >= s->height || strip->y2 > s->height ||
271 strip->x1 >= strip->x2 || strip->y1 >= strip->y2)
274 while ((data + 4) <= eod) {
275 chunk_id = BE_16 (&data[0]);
276 chunk_size = BE_16 (&data[2]) - 4;
278 chunk_size = ((data + chunk_size) > eod) ? (eod - data) : chunk_size;
286 cinepak_decode_codebook (strip->v4_codebook, chunk_id,
294 cinepak_decode_codebook (strip->v1_codebook, chunk_id,
301 return cinepak_decode_vectors (s, strip, chunk_id,
311 static int cinepak_decode (CinepakContext *s)
313 uint8_t *eod = (s->data + s->size);
314 int i, result, strip_size, frame_flags, num_strips;
320 frame_flags = s->data[0];
321 num_strips = BE_16 (&s->data[8]);
324 if (num_strips > MAX_STRIPS)
325 num_strips = MAX_STRIPS;
327 for (i=0; i < num_strips; i++) {
328 if ((s->data + 12) > eod)
331 s->strips[i].id = BE_16 (s->data);
332 s->strips[i].y1 = y0;
334 s->strips[i].y2 = y0 + BE_16 (&s->data[8]);
335 s->strips[i].x2 = s->avctx->width;
337 strip_size = BE_16 (&s->data[2]) - 12;
339 strip_size = ((s->data + strip_size) > eod) ? (eod - s->data) : strip_size;
341 if ((i > 0) && !(frame_flags & 0x01)) {
342 memcpy (s->strips[i].v4_codebook, s->strips[i-1].v4_codebook,
343 sizeof(s->strips[i].v4_codebook));
344 memcpy (s->strips[i].v1_codebook, s->strips[i-1].v1_codebook,
345 sizeof(s->strips[i].v1_codebook));
348 result = cinepak_decode_strip (s, &s->strips[i], s->data, strip_size);
353 s->data += strip_size;
354 y0 = s->strips[i].y2;
359 static int cinepak_decode_init(AVCodecContext *avctx)
361 CinepakContext *s = (CinepakContext *)avctx->priv_data;
364 s->width = (avctx->width + 3) & ~3;
365 s->height = (avctx->height + 3) & ~3;
367 // check for paletted data
368 if ((avctx->palctrl == NULL) || (avctx->bits_per_sample == 40)) {
369 s->palette_video = 0;
370 avctx->pix_fmt = PIX_FMT_YUV420P;
372 s->palette_video = 1;
373 avctx->pix_fmt = PIX_FMT_PAL8;
376 avctx->has_b_frames = 0;
377 dsputil_init(&s->dsp, avctx);
379 s->frame.data[0] = NULL;
384 static int cinepak_decode_frame(AVCodecContext *avctx,
385 void *data, int *data_size,
386 uint8_t *buf, int buf_size)
388 CinepakContext *s = (CinepakContext *)avctx->priv_data;
393 s->frame.reference = 1;
394 s->frame.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE |
395 FF_BUFFER_HINTS_REUSABLE;
396 if (avctx->reget_buffer(avctx, &s->frame)) {
397 av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
403 if (s->palette_video) {
404 memcpy (s->frame.data[1], avctx->palctrl->palette, AVPALETTE_SIZE);
405 if (avctx->palctrl->palette_changed) {
406 s->frame.palette_has_changed = 1;
407 avctx->palctrl->palette_changed = 0;
409 s->frame.palette_has_changed = 0;
412 *data_size = sizeof(AVFrame);
413 *(AVFrame*)data = s->frame;
415 /* report that the buffer was completely consumed */
419 static int cinepak_decode_end(AVCodecContext *avctx)
421 CinepakContext *s = (CinepakContext *)avctx->priv_data;
423 if (s->frame.data[0])
424 avctx->release_buffer(avctx, &s->frame);
429 AVCodec cinepak_decoder = {
433 sizeof(CinepakContext),
437 cinepak_decode_frame,