2 * Sierra VMD Audio & Video Decoders
3 * Copyright (C) 2004 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23 * Sierra VMD audio & video decoders
24 * by Vladimir "VAG" Gneushev (vagsoft at mail.ru)
25 * for more information on the Sierra VMD format, visit:
26 * http://www.pcisys.net/~melanson/codecs/
28 * The video decoder outputs PAL8 colorspace data. The decoder expects
29 * a 0x330-byte VMD file header to be transmitted via extradata during
30 * codec initialization. Each encoded frame that is sent to this decoder
31 * is expected to be prepended with the appropriate 16-byte frame
32 * information record from the VMD file.
34 * The audio decoder, like the video decoder, expects each encoded data
35 * chunk to be prepended with the appropriate 16-byte frame information
36 * record from the VMD file. It does not require the 0x330-byte VMD file
37 * header, but it does need the audio setup parameters passed in through
38 * normal libavcodec API means.
50 #define VMD_HEADER_SIZE 0x330
51 #define PALETTE_COUNT 256
57 typedef struct VmdVideoContext {
59 AVCodecContext *avctx;
67 unsigned char palette[PALETTE_COUNT * 4];
68 unsigned char *unpack_buffer;
69 int unpack_buffer_size;
73 #define QUEUE_SIZE 0x1000
74 #define QUEUE_MASK 0x0FFF
76 static void lz_unpack(unsigned char *src, unsigned char *dest, int dest_len)
81 unsigned char queue[QUEUE_SIZE];
83 unsigned int dataleft;
84 unsigned int chainofs;
85 unsigned int chainlen;
95 memset(queue, QUEUE_SIZE, 0x20);
96 if (LE_32(s) == 0x56781234) {
102 speclen = 100; /* no speclen */
105 while (dataleft > 0) {
107 if ((tag == 0xFF) && (dataleft > 8)) {
110 for (i = 0; i < 8; i++) {
111 queue[qpos++] = *d++ = *s++;
116 for (i = 0; i < 8; i++) {
122 queue[qpos++] = *d++ = *s++;
127 chainofs |= ((*s & 0xF0) << 4);
128 chainlen = (*s++ & 0x0F) + 3;
129 if (chainlen == speclen)
130 chainlen = *s++ + 0xF + 3;
131 if (d + chainlen > d_end)
133 for (j = 0; j < chainlen; j++) {
134 *d = queue[chainofs++ & QUEUE_MASK];
135 queue[qpos++] = *d++;
138 dataleft -= chainlen;
146 static int rle_unpack(unsigned char *src, unsigned char *dest,
147 int src_len, int dest_len)
152 unsigned char *dest_end = dest + dest_len;
165 if (pd + l > dest_end)
171 if (pd + i > dest_end)
173 for (i = 0; i < l; i++) {
180 } while (i < src_len);
185 static void vmd_decode(VmdVideoContext *s)
188 unsigned int *palette32;
189 unsigned char r, g, b;
191 /* point to the start of the encoded data */
192 unsigned char *p = s->buf + 16;
196 unsigned char *dp; /* pointer to current frame */
197 unsigned char *pp; /* pointer to previous frame */
201 int frame_x, frame_y;
202 int frame_width, frame_height;
205 frame_x = LE_16(&s->buf[6]);
206 frame_y = LE_16(&s->buf[8]);
207 frame_width = LE_16(&s->buf[10]) - frame_x + 1;
208 frame_height = LE_16(&s->buf[12]) - frame_y + 1;
210 /* if only a certain region will be updated, copy the entire previous
211 * frame before the decode */
212 if (frame_x || frame_y || (frame_width != s->avctx->width) ||
213 (frame_height != s->avctx->height)) {
215 memcpy(s->frame.data[0], s->prev_frame.data[0],
216 s->avctx->height * s->frame.linesize[0]);
219 /* check if there is a new palette */
220 if (s->buf[15] & 0x02) {
222 palette32 = (unsigned int *)s->palette;
223 for (i = 0; i < PALETTE_COUNT; i++) {
227 palette32[i] = (r << 16) | (g << 8) | (b);
229 s->size -= (256 * 3 + 2);
232 /* originally UnpackFrame in VAG's code */
236 lz_unpack(pb, s->unpack_buffer, s->unpack_buffer_size);
238 pb = s->unpack_buffer;
241 dp = &s->frame.data[0][frame_y * s->frame.linesize[0] + frame_x];
242 dp_size = s->frame.linesize[0] * s->avctx->height;
243 pp = &s->prev_frame.data[0][frame_y * s->prev_frame.linesize[0] + frame_x];
246 for (i = 0; i < frame_height; i++) {
251 len = (len & 0x7F) + 1;
252 if (ofs + len > frame_width)
254 memcpy(&dp[ofs], pb, len);
258 /* interframe pixel copy */
259 if (ofs + len + 1 > frame_width)
261 memcpy(&dp[ofs], &pp[ofs], len + 1);
264 } while (ofs < frame_width);
265 if (ofs > frame_width) {
266 av_log(s->avctx, AV_LOG_ERROR, "VMD video: offset > width (%d > %d)\n",
270 dp += s->frame.linesize[0];
271 pp += s->prev_frame.linesize[0];
276 for (i = 0; i < frame_height; i++) {
277 memcpy(dp, pb, frame_width);
279 dp += s->frame.linesize[0];
280 pp += s->prev_frame.linesize[0];
285 for (i = 0; i < frame_height; i++) {
290 len = (len & 0x7F) + 1;
292 len = rle_unpack(pb, &dp[ofs], len, frame_width - ofs);
294 memcpy(&dp[ofs], pb, len);
298 /* interframe pixel copy */
299 if (ofs + len + 1 > frame_width)
301 memcpy(&dp[ofs], &pp[ofs], len + 1);
304 } while (ofs < frame_width);
305 if (ofs > frame_width) {
306 av_log(s->avctx, AV_LOG_ERROR, "VMD video: offset > width (%d > %d)\n",
309 dp += s->frame.linesize[0];
310 pp += s->prev_frame.linesize[0];
317 static int vmdvideo_decode_init(AVCodecContext *avctx)
319 VmdVideoContext *s = (VmdVideoContext *)avctx->priv_data;
321 unsigned int *palette32;
322 int palette_index = 0;
323 unsigned char r, g, b;
324 unsigned char *vmd_header;
325 unsigned char *raw_palette;
328 avctx->pix_fmt = PIX_FMT_PAL8;
329 avctx->has_b_frames = 0;
330 dsputil_init(&s->dsp, avctx);
332 /* make sure the VMD header made it */
333 if (s->avctx->extradata_size != VMD_HEADER_SIZE) {
334 av_log(s->avctx, AV_LOG_ERROR, "VMD video: expected extradata size of %d\n",
338 vmd_header = (unsigned char *)avctx->extradata;
340 s->unpack_buffer_size = LE_32(&vmd_header[800]);
341 s->unpack_buffer = av_malloc(s->unpack_buffer_size);
342 if (!s->unpack_buffer)
345 /* load up the initial palette */
346 raw_palette = &vmd_header[28];
347 palette32 = (unsigned int *)s->palette;
348 for (i = 0; i < PALETTE_COUNT; i++) {
349 r = raw_palette[palette_index++] * 4;
350 g = raw_palette[palette_index++] * 4;
351 b = raw_palette[palette_index++] * 4;
352 palette32[i] = (r << 16) | (g << 8) | (b);
355 s->frame.data[0] = s->prev_frame.data[0] = NULL;
360 static int vmdvideo_decode_frame(AVCodecContext *avctx,
361 void *data, int *data_size,
362 uint8_t *buf, int buf_size)
364 VmdVideoContext *s = (VmdVideoContext *)avctx->priv_data;
372 s->frame.reference = 1;
373 if (avctx->get_buffer(avctx, &s->frame)) {
374 av_log(s->avctx, AV_LOG_ERROR, "VMD Video: get_buffer() failed\n");
380 /* make the palette available on the way out */
381 memcpy(s->frame.data[1], s->palette, PALETTE_COUNT * 4);
383 if (s->prev_frame.data[0])
384 avctx->release_buffer(avctx, &s->prev_frame);
387 s->prev_frame = s->frame;
389 *data_size = sizeof(AVFrame);
390 *(AVFrame*)data = s->frame;
392 /* report that the buffer was completely consumed */
396 static int vmdvideo_decode_end(AVCodecContext *avctx)
398 VmdVideoContext *s = (VmdVideoContext *)avctx->priv_data;
400 if (s->prev_frame.data[0])
401 avctx->release_buffer(avctx, &s->prev_frame);
402 av_free(s->unpack_buffer);
412 typedef struct VmdAudioContext {
413 AVCodecContext *avctx;
417 unsigned char steps8[16];
418 unsigned short steps16[16];
419 unsigned short steps128[256];
423 static int vmdaudio_decode_init(AVCodecContext *avctx)
425 VmdAudioContext *s = (VmdAudioContext *)avctx->priv_data;
429 s->channels = avctx->channels;
430 s->bits = avctx->bits_per_sample;
431 s->block_align = avctx->block_align;
433 av_log(s->avctx, AV_LOG_DEBUG, "%d channels, %d bits/sample, block align = %d, sample rate = %d\n",
434 s->channels, s->bits, s->block_align, avctx->sample_rate);
436 /* set up the steps8 and steps16 tables */
437 for (i = 0; i < 8; i++) {
441 s->steps8[i] = s->steps8[i - 1] + i - 1;
450 s->steps16[i] = 1 << (i + 4);
453 /* set up the step128 table */
456 for (i = 0x02; i <= 0x20; i++)
457 s->steps128[i] = (i - 1) << 4;
458 for (i = 0x21; i <= 0x60; i++)
459 s->steps128[i] = (i + 0x1F) << 3;
460 for (i = 0x61; i <= 0x70; i++)
461 s->steps128[i] = (i - 0x51) << 6;
462 for (i = 0x71; i <= 0x78; i++)
463 s->steps128[i] = (i - 0x69) << 8;
464 for (i = 0x79; i <= 0x7D; i++)
465 s->steps128[i] = (i - 0x75) << 10;
466 s->steps128[0x7E] = 0x3000;
467 s->steps128[0x7F] = 0x4000;
469 /* set up the negative half of each table */
470 for (i = 0; i < 8; i++) {
471 s->steps8[i + 8] = -s->steps8[i];
472 s->steps16[i + 8] = -s->steps16[i];
474 for (i = 0; i < 128; i++)
475 s->steps128[i + 128] = -s->steps128[i];
480 static void vmdaudio_decode_audio(VmdAudioContext *s, unsigned char *data,
481 uint8_t *buf, int ratio) {
485 static int vmdaudio_loadsound(VmdAudioContext *s, unsigned char *data,
486 uint8_t *buf, int silence)
488 int bytes_decoded = 0;
492 av_log(s->avctx, AV_LOG_INFO, "silent block!\n");
493 if (s->channels == 2) {
495 /* stereo handling */
496 if ((s->block_align & 0x01) == 0) {
498 memset(data, 0, s->block_align * 2);
500 vmdaudio_decode_audio(s, data, buf, 1);
503 memset(data, 0, s->block_align * 2);
505 vmdaudio_decode_audio(s, data, buf, 1);
512 memset(data, 0, s->block_align * 2);
513 bytes_decoded = s->block_align * 2;
515 // memset(data, 0x00, s->block_align);
516 // bytes_decoded = s->block_align;
517 memset(data, 0x00, s->block_align * 2);
518 bytes_decoded = s->block_align * 2;
521 /* copy the data but convert it to signed */
522 for (i = 0; i < s->block_align; i++)
523 data[i * 2 + 1] = buf[i] + 0x80;
524 bytes_decoded = s->block_align * 2;
528 return bytes_decoded;
531 static int vmdaudio_decode_frame(AVCodecContext *avctx,
532 void *data, int *data_size,
533 uint8_t *buf, int buf_size)
535 VmdAudioContext *s = (VmdAudioContext *)avctx->priv_data;
536 unsigned int sound_flags;
537 unsigned char *output_samples = (unsigned char *)data;
539 /* point to the start of the encoded data */
540 unsigned char *p = buf + 16;
541 unsigned char *p_end = buf + buf_size;
547 /* the chunk contains audio */
548 *data_size = vmdaudio_loadsound(s, output_samples, p, 0);
549 } else if (buf[6] == 2) {
550 /* the chunk contains audio and silence mixed together */
551 sound_flags = LE_32(p);
554 /* do something with extrabufs here? */
557 if (sound_flags & 0x01)
559 *data_size += vmdaudio_loadsound(s, output_samples, p, 1);
562 *data_size += vmdaudio_loadsound(s, output_samples, p, 0);
565 output_samples += (s->block_align * s->bits / 8);
568 } else if (buf[6] == 3) {
570 *data_size = vmdaudio_loadsound(s, output_samples, p, 1);
578 * Public Data Structures
581 AVCodec vmdvideo_decoder = {
585 sizeof(VmdVideoContext),
586 vmdvideo_decode_init,
589 vmdvideo_decode_frame,
593 AVCodec vmdaudio_decoder = {
597 sizeof(VmdAudioContext),
598 vmdaudio_decode_init,
601 vmdaudio_decode_frame,