2 * Sierra VMD Audio & Video Decoders
3 * Copyright (C) 2004 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 * Sierra VMD audio & video decoders
26 * by Vladimir "VAG" Gneushev (vagsoft at mail.ru)
27 * for more information on the Sierra VMD format, visit:
28 * http://www.pcisys.net/~melanson/codecs/
30 * The video decoder outputs PAL8 colorspace data. The decoder expects
31 * a 0x330-byte VMD file header to be transmitted via extradata during
32 * codec initialization. Each encoded frame that is sent to this decoder
33 * is expected to be prepended with the appropriate 16-byte frame
34 * information record from the VMD file.
36 * The audio decoder, like the video decoder, expects each encoded data
37 * chunk to be prepended with the appropriate 16-byte frame information
38 * record from the VMD file. It does not require the 0x330-byte VMD file
39 * header, but it does need the audio setup parameters passed in through
40 * normal libavcodec API means.
52 #define VMD_HEADER_SIZE 0x330
53 #define PALETTE_COUNT 256
59 typedef struct VmdVideoContext {
61 AVCodecContext *avctx;
69 unsigned char palette[PALETTE_COUNT * 4];
70 unsigned char *unpack_buffer;
71 int unpack_buffer_size;
75 #define QUEUE_SIZE 0x1000
76 #define QUEUE_MASK 0x0FFF
78 static void lz_unpack(unsigned char *src, unsigned char *dest, int dest_len)
83 unsigned char queue[QUEUE_SIZE];
85 unsigned int dataleft;
86 unsigned int chainofs;
87 unsigned int chainlen;
95 dataleft = AV_RL32(s);
97 memset(queue, 0x20, QUEUE_SIZE);
98 if (AV_RL32(s) == 0x56781234) {
104 speclen = 100; /* no speclen */
107 while (dataleft > 0) {
109 if ((tag == 0xFF) && (dataleft > 8)) {
112 for (i = 0; i < 8; i++) {
113 queue[qpos++] = *d++ = *s++;
118 for (i = 0; i < 8; i++) {
124 queue[qpos++] = *d++ = *s++;
129 chainofs |= ((*s & 0xF0) << 4);
130 chainlen = (*s++ & 0x0F) + 3;
131 if (chainlen == speclen)
132 chainlen = *s++ + 0xF + 3;
133 if (d + chainlen > d_end)
135 for (j = 0; j < chainlen; j++) {
136 *d = queue[chainofs++ & QUEUE_MASK];
137 queue[qpos++] = *d++;
140 dataleft -= chainlen;
148 static int rle_unpack(unsigned char *src, unsigned char *dest,
149 int src_len, int dest_len)
154 unsigned char *dest_end = dest + dest_len;
167 if (pd + l > dest_end)
173 if (pd + i > dest_end)
175 for (i = 0; i < l; i++) {
182 } while (i < src_len);
187 static void vmd_decode(VmdVideoContext *s)
190 unsigned int *palette32;
191 unsigned char r, g, b;
193 /* point to the start of the encoded data */
194 unsigned char *p = s->buf + 16;
198 unsigned char *dp; /* pointer to current frame */
199 unsigned char *pp; /* pointer to previous frame */
203 int frame_x, frame_y;
204 int frame_width, frame_height;
207 frame_x = AV_RL16(&s->buf[6]);
208 frame_y = AV_RL16(&s->buf[8]);
209 frame_width = AV_RL16(&s->buf[10]) - frame_x + 1;
210 frame_height = AV_RL16(&s->buf[12]) - frame_y + 1;
212 /* if only a certain region will be updated, copy the entire previous
213 * frame before the decode */
214 if (frame_x || frame_y || (frame_width != s->avctx->width) ||
215 (frame_height != s->avctx->height)) {
217 memcpy(s->frame.data[0], s->prev_frame.data[0],
218 s->avctx->height * s->frame.linesize[0]);
221 /* check if there is a new palette */
222 if (s->buf[15] & 0x02) {
224 palette32 = (unsigned int *)s->palette;
225 for (i = 0; i < PALETTE_COUNT; i++) {
229 palette32[i] = (r << 16) | (g << 8) | (b);
231 s->size -= (256 * 3 + 2);
234 /* originally UnpackFrame in VAG's code */
238 lz_unpack(pb, s->unpack_buffer, s->unpack_buffer_size);
240 pb = s->unpack_buffer;
243 dp = &s->frame.data[0][frame_y * s->frame.linesize[0] + frame_x];
244 dp_size = s->frame.linesize[0] * s->avctx->height;
245 pp = &s->prev_frame.data[0][frame_y * s->prev_frame.linesize[0] + frame_x];
248 for (i = 0; i < frame_height; i++) {
253 len = (len & 0x7F) + 1;
254 if (ofs + len > frame_width)
256 memcpy(&dp[ofs], pb, len);
260 /* interframe pixel copy */
261 if (ofs + len + 1 > frame_width)
263 memcpy(&dp[ofs], &pp[ofs], len + 1);
266 } while (ofs < frame_width);
267 if (ofs > frame_width) {
268 av_log(s->avctx, AV_LOG_ERROR, "VMD video: offset > width (%d > %d)\n",
272 dp += s->frame.linesize[0];
273 pp += s->prev_frame.linesize[0];
278 for (i = 0; i < frame_height; i++) {
279 memcpy(dp, pb, frame_width);
281 dp += s->frame.linesize[0];
282 pp += s->prev_frame.linesize[0];
287 for (i = 0; i < frame_height; i++) {
292 len = (len & 0x7F) + 1;
294 len = rle_unpack(pb, &dp[ofs], len, frame_width - ofs);
296 memcpy(&dp[ofs], pb, len);
300 /* interframe pixel copy */
301 if (ofs + len + 1 > frame_width)
303 memcpy(&dp[ofs], &pp[ofs], len + 1);
306 } while (ofs < frame_width);
307 if (ofs > frame_width) {
308 av_log(s->avctx, AV_LOG_ERROR, "VMD video: offset > width (%d > %d)\n",
311 dp += s->frame.linesize[0];
312 pp += s->prev_frame.linesize[0];
319 static int vmdvideo_decode_init(AVCodecContext *avctx)
321 VmdVideoContext *s = avctx->priv_data;
323 unsigned int *palette32;
324 int palette_index = 0;
325 unsigned char r, g, b;
326 unsigned char *vmd_header;
327 unsigned char *raw_palette;
330 avctx->pix_fmt = PIX_FMT_PAL8;
331 dsputil_init(&s->dsp, avctx);
333 /* make sure the VMD header made it */
334 if (s->avctx->extradata_size != VMD_HEADER_SIZE) {
335 av_log(s->avctx, AV_LOG_ERROR, "VMD video: expected extradata size of %d\n",
339 vmd_header = (unsigned char *)avctx->extradata;
341 s->unpack_buffer_size = AV_RL32(&vmd_header[800]);
342 s->unpack_buffer = av_malloc(s->unpack_buffer_size);
343 if (!s->unpack_buffer)
346 /* load up the initial palette */
347 raw_palette = &vmd_header[28];
348 palette32 = (unsigned int *)s->palette;
349 for (i = 0; i < PALETTE_COUNT; i++) {
350 r = raw_palette[palette_index++] * 4;
351 g = raw_palette[palette_index++] * 4;
352 b = raw_palette[palette_index++] * 4;
353 palette32[i] = (r << 16) | (g << 8) | (b);
356 s->frame.data[0] = s->prev_frame.data[0] = NULL;
361 static int vmdvideo_decode_frame(AVCodecContext *avctx,
362 void *data, int *data_size,
363 uint8_t *buf, int buf_size)
365 VmdVideoContext *s = avctx->priv_data;
373 s->frame.reference = 1;
374 if (avctx->get_buffer(avctx, &s->frame)) {
375 av_log(s->avctx, AV_LOG_ERROR, "VMD Video: get_buffer() failed\n");
381 /* make the palette available on the way out */
382 memcpy(s->frame.data[1], s->palette, PALETTE_COUNT * 4);
384 if (s->prev_frame.data[0])
385 avctx->release_buffer(avctx, &s->prev_frame);
388 s->prev_frame = s->frame;
390 *data_size = sizeof(AVFrame);
391 *(AVFrame*)data = s->frame;
393 /* report that the buffer was completely consumed */
397 static int vmdvideo_decode_end(AVCodecContext *avctx)
399 VmdVideoContext *s = avctx->priv_data;
401 if (s->prev_frame.data[0])
402 avctx->release_buffer(avctx, &s->prev_frame);
403 av_free(s->unpack_buffer);
413 typedef struct VmdAudioContext {
414 AVCodecContext *avctx;
421 static uint16_t vmdaudio_table[128] = {
422 0x000, 0x008, 0x010, 0x020, 0x030, 0x040, 0x050, 0x060, 0x070, 0x080,
423 0x090, 0x0A0, 0x0B0, 0x0C0, 0x0D0, 0x0E0, 0x0F0, 0x100, 0x110, 0x120,
424 0x130, 0x140, 0x150, 0x160, 0x170, 0x180, 0x190, 0x1A0, 0x1B0, 0x1C0,
425 0x1D0, 0x1E0, 0x1F0, 0x200, 0x208, 0x210, 0x218, 0x220, 0x228, 0x230,
426 0x238, 0x240, 0x248, 0x250, 0x258, 0x260, 0x268, 0x270, 0x278, 0x280,
427 0x288, 0x290, 0x298, 0x2A0, 0x2A8, 0x2B0, 0x2B8, 0x2C0, 0x2C8, 0x2D0,
428 0x2D8, 0x2E0, 0x2E8, 0x2F0, 0x2F8, 0x300, 0x308, 0x310, 0x318, 0x320,
429 0x328, 0x330, 0x338, 0x340, 0x348, 0x350, 0x358, 0x360, 0x368, 0x370,
430 0x378, 0x380, 0x388, 0x390, 0x398, 0x3A0, 0x3A8, 0x3B0, 0x3B8, 0x3C0,
431 0x3C8, 0x3D0, 0x3D8, 0x3E0, 0x3E8, 0x3F0, 0x3F8, 0x400, 0x440, 0x480,
432 0x4C0, 0x500, 0x540, 0x580, 0x5C0, 0x600, 0x640, 0x680, 0x6C0, 0x700,
433 0x740, 0x780, 0x7C0, 0x800, 0x900, 0xA00, 0xB00, 0xC00, 0xD00, 0xE00,
434 0xF00, 0x1000, 0x1400, 0x1800, 0x1C00, 0x2000, 0x3000, 0x4000
437 static int vmdaudio_decode_init(AVCodecContext *avctx)
439 VmdAudioContext *s = avctx->priv_data;
442 s->channels = avctx->channels;
443 s->bits = avctx->bits_per_sample;
444 s->block_align = avctx->block_align;
446 av_log(s->avctx, AV_LOG_DEBUG, "%d channels, %d bits/sample, block align = %d, sample rate = %d\n",
447 s->channels, s->bits, s->block_align, avctx->sample_rate);
452 static void vmdaudio_decode_audio(VmdAudioContext *s, unsigned char *data,
453 uint8_t *buf, int stereo)
457 int16_t *out = (int16_t*)data;
459 for(i = 0; i < s->block_align; i++) {
461 s->predictors[chan] -= vmdaudio_table[buf[i] & 0x7F];
463 s->predictors[chan] += vmdaudio_table[buf[i]];
464 s->predictors[chan] = av_clip(s->predictors[chan], -32768, 32767);
465 out[i] = s->predictors[chan];
470 static int vmdaudio_loadsound(VmdAudioContext *s, unsigned char *data,
471 uint8_t *buf, int silence)
473 int bytes_decoded = 0;
477 // av_log(s->avctx, AV_LOG_INFO, "silent block!\n");
478 if (s->channels == 2) {
480 /* stereo handling */
482 memset(data, 0, s->block_align * 2);
485 vmdaudio_decode_audio(s, data, buf, 1);
487 /* copy the data but convert it to signed */
488 for (i = 0; i < s->block_align; i++){
489 *data++ = buf[i] + 0x80;
490 *data++ = buf[i] + 0x80;
495 bytes_decoded = s->block_align * 2;
499 memset(data, 0, s->block_align * 2);
502 vmdaudio_decode_audio(s, data, buf, 0);
504 /* copy the data but convert it to signed */
505 for (i = 0; i < s->block_align; i++){
506 *data++ = buf[i] + 0x80;
507 *data++ = buf[i] + 0x80;
513 return s->block_align * 2;
516 static int vmdaudio_decode_frame(AVCodecContext *avctx,
517 void *data, int *data_size,
518 uint8_t *buf, int buf_size)
520 VmdAudioContext *s = avctx->priv_data;
521 unsigned char *output_samples = (unsigned char *)data;
523 /* point to the start of the encoded data */
524 unsigned char *p = buf + 16;
530 /* the chunk contains audio */
531 *data_size = vmdaudio_loadsound(s, output_samples, p, 0);
532 } else if (buf[6] == 2) {
533 /* the chunk may contain audio */
535 *data_size = vmdaudio_loadsound(s, output_samples, p, (buf_size == 16));
536 output_samples += (s->block_align * s->bits / 8);
537 } else if (buf[6] == 3) {
539 *data_size = vmdaudio_loadsound(s, output_samples, p, 1);
547 * Public Data Structures
550 AVCodec vmdvideo_decoder = {
554 sizeof(VmdVideoContext),
555 vmdvideo_decode_init,
558 vmdvideo_decode_frame,
562 AVCodec vmdaudio_decoder = {
566 sizeof(VmdAudioContext),
567 vmdaudio_decode_init,
570 vmdaudio_decode_frame,