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
24 * Sierra VMD audio & video decoders
25 * by Vladimir "VAG" Gneushev (vagsoft at mail.ru)
26 * for more information on the Sierra VMD format, visit:
27 * http://www.pcisys.net/~melanson/codecs/
29 * The video decoder outputs PAL8 colorspace data. The decoder expects
30 * a 0x330-byte VMD file header to be transmitted via extradata during
31 * codec initialization. Each encoded frame that is sent to this decoder
32 * is expected to be prepended with the appropriate 16-byte frame
33 * information record from the VMD file.
35 * The audio decoder, like the video decoder, expects each encoded data
36 * chunk to be prepended with the appropriate 16-byte frame information
37 * record from the VMD file. It does not require the 0x330-byte VMD file
38 * header, but it does need the audio setup parameters passed in through
39 * normal libavcodec API means.
46 #include "libavutil/intreadwrite.h"
49 #define VMD_HEADER_SIZE 0x330
50 #define PALETTE_COUNT 256
56 typedef struct VmdVideoContext {
58 AVCodecContext *avctx;
62 const unsigned char *buf;
65 unsigned char palette[PALETTE_COUNT * 4];
66 unsigned char *unpack_buffer;
67 int unpack_buffer_size;
72 #define QUEUE_SIZE 0x1000
73 #define QUEUE_MASK 0x0FFF
75 static void lz_unpack(const unsigned char *src, int src_len,
76 unsigned char *dest, int dest_len)
78 const unsigned char *s;
79 const unsigned char *s_end;
82 unsigned char queue[QUEUE_SIZE];
84 unsigned int dataleft;
85 unsigned int chainofs;
86 unsigned int chainlen;
92 s_end = src + src_len;
98 dataleft = AV_RL32(s);
100 memset(queue, 0x20, QUEUE_SIZE);
101 if (AV_RL32(s) == 0x56781234) {
107 speclen = 100; /* no speclen */
110 while (s_end - s > 0 && dataleft > 0) {
112 if ((tag == 0xFF) && (dataleft > 8)) {
113 if (d_end - d < 8 || s_end - s < 8)
115 for (i = 0; i < 8; i++) {
116 queue[qpos++] = *d++ = *s++;
121 for (i = 0; i < 8; i++) {
125 if (d_end - d < 1 || s_end - s < 1)
127 queue[qpos++] = *d++ = *s++;
134 chainofs |= ((*s & 0xF0) << 4);
135 chainlen = (*s++ & 0x0F) + 3;
136 if (chainlen == speclen) {
139 chainlen = *s++ + 0xF + 3;
141 if (d_end - d < chainlen)
143 for (j = 0; j < chainlen; j++) {
144 *d = queue[chainofs++ & QUEUE_MASK];
145 queue[qpos++] = *d++;
148 dataleft -= chainlen;
156 static int rle_unpack(const unsigned char *src, int src_len, int src_count,
157 unsigned char *dest, int dest_len)
159 const unsigned char *ps;
160 const unsigned char *ps_end;
163 unsigned char *dest_end = dest + dest_len;
166 ps_end = src + src_len;
182 if (dest_end - pd < l || ps_end - ps < l)
188 if (dest_end - pd < i || ps_end - ps < 2)
190 for (i = 0; i < l; i++) {
197 } while (i < src_count);
202 static void vmd_decode(VmdVideoContext *s)
205 unsigned int *palette32;
206 unsigned char r, g, b;
208 /* point to the start of the encoded data */
209 const unsigned char *p = s->buf + 16;
210 const unsigned char *p_end = s->buf + s->size;
212 const unsigned char *pb;
213 const unsigned char *pb_end;
215 unsigned char *dp; /* pointer to current frame */
216 unsigned char *pp; /* pointer to previous frame */
220 int frame_x, frame_y;
221 int frame_width, frame_height;
223 frame_x = AV_RL16(&s->buf[6]);
224 frame_y = AV_RL16(&s->buf[8]);
225 frame_width = AV_RL16(&s->buf[10]) - frame_x + 1;
226 frame_height = AV_RL16(&s->buf[12]) - frame_y + 1;
227 if (frame_x < 0 || frame_width < 0 ||
228 frame_x >= s->avctx->width ||
229 frame_width > s->avctx->width ||
230 frame_x + frame_width > s->avctx->width)
232 if (frame_y < 0 || frame_height < 0 ||
233 frame_y >= s->avctx->height ||
234 frame_height > s->avctx->height ||
235 frame_y + frame_height > s->avctx->height)
238 if ((frame_width == s->avctx->width && frame_height == s->avctx->height) &&
239 (frame_x || frame_y)) {
247 /* if only a certain region will be updated, copy the entire previous
248 * frame before the decode */
249 if (s->prev_frame.data[0] &&
250 (frame_x || frame_y || (frame_width != s->avctx->width) ||
251 (frame_height != s->avctx->height))) {
253 memcpy(s->frame.data[0], s->prev_frame.data[0],
254 s->avctx->height * s->frame.linesize[0]);
257 /* check if there is a new palette */
258 if (s->buf[15] & 0x02) {
259 if (p_end - p < 2 + 3 * PALETTE_COUNT)
262 palette32 = (unsigned int *)s->palette;
263 for (i = 0; i < PALETTE_COUNT; i++) {
267 palette32[i] = 0xFF << 24 | r << 16 | g << 8 | b;
268 palette32[i] |= palette32[i] >> 6 & 0x30303;
272 /* originally UnpackFrame in VAG's code */
277 lz_unpack(pb, p_end - pb, s->unpack_buffer, s->unpack_buffer_size);
279 pb = s->unpack_buffer;
280 pb_end = s->unpack_buffer + s->unpack_buffer_size;
283 dp = &s->frame.data[0][frame_y * s->frame.linesize[0] + frame_x];
284 pp = &s->prev_frame.data[0][frame_y * s->prev_frame.linesize[0] + frame_x];
287 for (i = 0; i < frame_height; i++) {
294 len = (len & 0x7F) + 1;
295 if (ofs + len > frame_width || pb_end - pb < len)
297 memcpy(&dp[ofs], pb, len);
301 /* interframe pixel copy */
302 if (ofs + len + 1 > frame_width || !s->prev_frame.data[0])
304 memcpy(&dp[ofs], &pp[ofs], len + 1);
307 } while (ofs < frame_width);
308 if (ofs > frame_width) {
309 av_log(s->avctx, AV_LOG_ERROR, "VMD video: offset > width (%d > %d)\n",
313 dp += s->frame.linesize[0];
314 pp += s->prev_frame.linesize[0];
319 for (i = 0; i < frame_height; i++) {
320 if (pb_end -pb < frame_width)
322 memcpy(dp, pb, frame_width);
324 dp += s->frame.linesize[0];
325 pp += s->prev_frame.linesize[0];
330 for (i = 0; i < frame_height; i++) {
337 len = (len & 0x7F) + 1;
341 len = rle_unpack(pb, pb_end - pb, len, &dp[ofs], frame_width - ofs);
343 if (pb_end - pb < len)
345 memcpy(&dp[ofs], pb, len);
350 /* interframe pixel copy */
351 if (ofs + len + 1 > frame_width || !s->prev_frame.data[0])
353 memcpy(&dp[ofs], &pp[ofs], len + 1);
356 } while (ofs < frame_width);
357 if (ofs > frame_width) {
358 av_log(s->avctx, AV_LOG_ERROR, "VMD video: offset > width (%d > %d)\n",
361 dp += s->frame.linesize[0];
362 pp += s->prev_frame.linesize[0];
369 static av_cold int vmdvideo_decode_init(AVCodecContext *avctx)
371 VmdVideoContext *s = avctx->priv_data;
373 unsigned int *palette32;
374 int palette_index = 0;
375 unsigned char r, g, b;
376 unsigned char *vmd_header;
377 unsigned char *raw_palette;
380 avctx->pix_fmt = PIX_FMT_PAL8;
382 /* make sure the VMD header made it */
383 if (s->avctx->extradata_size != VMD_HEADER_SIZE) {
384 av_log(s->avctx, AV_LOG_ERROR, "VMD video: expected extradata size of %d\n",
388 vmd_header = (unsigned char *)avctx->extradata;
390 s->unpack_buffer_size = AV_RL32(&vmd_header[800]);
391 s->unpack_buffer = av_malloc(s->unpack_buffer_size);
392 if (!s->unpack_buffer)
395 /* load up the initial palette */
396 raw_palette = &vmd_header[28];
397 palette32 = (unsigned int *)s->palette;
398 for (i = 0; i < PALETTE_COUNT; i++) {
399 r = raw_palette[palette_index++] * 4;
400 g = raw_palette[palette_index++] * 4;
401 b = raw_palette[palette_index++] * 4;
402 palette32[i] = (r << 16) | (g << 8) | (b);
405 avcodec_get_frame_defaults(&s->frame);
406 avcodec_get_frame_defaults(&s->prev_frame);
411 static int vmdvideo_decode_frame(AVCodecContext *avctx,
412 void *data, int *data_size,
415 const uint8_t *buf = avpkt->data;
416 int buf_size = avpkt->size;
417 VmdVideoContext *s = avctx->priv_data;
425 s->frame.reference = 3;
426 if (avctx->get_buffer(avctx, &s->frame)) {
427 av_log(s->avctx, AV_LOG_ERROR, "VMD Video: get_buffer() failed\n");
433 /* make the palette available on the way out */
434 memcpy(s->frame.data[1], s->palette, PALETTE_COUNT * 4);
437 FFSWAP(AVFrame, s->frame, s->prev_frame);
438 if (s->frame.data[0])
439 avctx->release_buffer(avctx, &s->frame);
441 *data_size = sizeof(AVFrame);
442 *(AVFrame*)data = s->prev_frame;
444 /* report that the buffer was completely consumed */
448 static av_cold int vmdvideo_decode_end(AVCodecContext *avctx)
450 VmdVideoContext *s = avctx->priv_data;
452 if (s->prev_frame.data[0])
453 avctx->release_buffer(avctx, &s->prev_frame);
454 av_free(s->unpack_buffer);
464 #define BLOCK_TYPE_AUDIO 1
465 #define BLOCK_TYPE_INITIAL 2
466 #define BLOCK_TYPE_SILENCE 3
468 typedef struct VmdAudioContext {
473 static const uint16_t vmdaudio_table[128] = {
474 0x000, 0x008, 0x010, 0x020, 0x030, 0x040, 0x050, 0x060, 0x070, 0x080,
475 0x090, 0x0A0, 0x0B0, 0x0C0, 0x0D0, 0x0E0, 0x0F0, 0x100, 0x110, 0x120,
476 0x130, 0x140, 0x150, 0x160, 0x170, 0x180, 0x190, 0x1A0, 0x1B0, 0x1C0,
477 0x1D0, 0x1E0, 0x1F0, 0x200, 0x208, 0x210, 0x218, 0x220, 0x228, 0x230,
478 0x238, 0x240, 0x248, 0x250, 0x258, 0x260, 0x268, 0x270, 0x278, 0x280,
479 0x288, 0x290, 0x298, 0x2A0, 0x2A8, 0x2B0, 0x2B8, 0x2C0, 0x2C8, 0x2D0,
480 0x2D8, 0x2E0, 0x2E8, 0x2F0, 0x2F8, 0x300, 0x308, 0x310, 0x318, 0x320,
481 0x328, 0x330, 0x338, 0x340, 0x348, 0x350, 0x358, 0x360, 0x368, 0x370,
482 0x378, 0x380, 0x388, 0x390, 0x398, 0x3A0, 0x3A8, 0x3B0, 0x3B8, 0x3C0,
483 0x3C8, 0x3D0, 0x3D8, 0x3E0, 0x3E8, 0x3F0, 0x3F8, 0x400, 0x440, 0x480,
484 0x4C0, 0x500, 0x540, 0x580, 0x5C0, 0x600, 0x640, 0x680, 0x6C0, 0x700,
485 0x740, 0x780, 0x7C0, 0x800, 0x900, 0xA00, 0xB00, 0xC00, 0xD00, 0xE00,
486 0xF00, 0x1000, 0x1400, 0x1800, 0x1C00, 0x2000, 0x3000, 0x4000
489 static av_cold int vmdaudio_decode_init(AVCodecContext *avctx)
491 VmdAudioContext *s = avctx->priv_data;
493 if (avctx->channels < 1 || avctx->channels > 2) {
494 av_log(avctx, AV_LOG_ERROR, "invalid number of channels\n");
495 return AVERROR(EINVAL);
497 if (avctx->block_align < 1) {
498 av_log(avctx, AV_LOG_ERROR, "invalid block align\n");
499 return AVERROR(EINVAL);
502 if (avctx->bits_per_coded_sample == 16)
503 avctx->sample_fmt = AV_SAMPLE_FMT_S16;
505 avctx->sample_fmt = AV_SAMPLE_FMT_U8;
506 s->out_bps = av_get_bytes_per_sample(avctx->sample_fmt);
508 s->chunk_size = avctx->block_align + avctx->channels * (s->out_bps == 2);
510 av_log(avctx, AV_LOG_DEBUG, "%d channels, %d bits/sample, "
511 "block align = %d, sample rate = %d\n",
512 avctx->channels, avctx->bits_per_coded_sample, avctx->block_align,
518 static void decode_audio_s16(int16_t *out, const uint8_t *buf, int buf_size,
522 const uint8_t *buf_end = buf + buf_size;
524 int st = channels - 1;
526 /* decode initial raw sample */
527 for (ch = 0; ch < channels; ch++) {
528 predictor[ch] = (int16_t)AV_RL16(buf);
530 *out++ = predictor[ch];
533 /* decode DPCM samples */
535 while (buf < buf_end) {
538 predictor[ch] -= vmdaudio_table[b & 0x7F];
540 predictor[ch] += vmdaudio_table[b];
541 predictor[ch] = av_clip_int16(predictor[ch]);
542 *out++ = predictor[ch];
547 static int vmdaudio_decode_frame(AVCodecContext *avctx,
548 void *data, int *data_size,
551 const uint8_t *buf = avpkt->data;
552 const uint8_t *buf_end;
553 int buf_size = avpkt->size;
554 VmdAudioContext *s = avctx->priv_data;
555 int block_type, silent_chunks, audio_chunks;
556 int nb_samples, out_size;
557 uint8_t *output_samples_u8 = data;
558 int16_t *output_samples_s16 = data;
561 av_log(avctx, AV_LOG_WARNING, "skipping small junk packet\n");
567 if (block_type < BLOCK_TYPE_AUDIO || block_type > BLOCK_TYPE_SILENCE) {
568 av_log(avctx, AV_LOG_ERROR, "unknown block type: %d\n", block_type);
569 return AVERROR(EINVAL);
574 /* get number of silent chunks */
576 if (block_type == BLOCK_TYPE_INITIAL) {
579 av_log(avctx, AV_LOG_ERROR, "packet is too small\n");
580 return AVERROR(EINVAL);
582 flags = AV_RB32(buf);
583 silent_chunks = av_popcount(flags);
586 } else if (block_type == BLOCK_TYPE_SILENCE) {
588 buf_size = 0; // should already be zero but set it just to be sure
591 /* ensure output buffer is large enough */
592 audio_chunks = buf_size / s->chunk_size;
593 nb_samples = ((silent_chunks + audio_chunks) * avctx->block_align) / avctx->channels;
594 out_size = nb_samples * avctx->channels * s->out_bps;
595 if (*data_size < out_size)
598 /* decode silent chunks */
599 if (silent_chunks > 0) {
600 int silent_size = avctx->block_align * silent_chunks;
601 if (s->out_bps == 2) {
602 memset(output_samples_s16, 0x00, silent_size * 2);
603 output_samples_s16 += silent_size;
605 memset(output_samples_u8, 0x80, silent_size);
606 output_samples_u8 += silent_size;
610 /* decode audio chunks */
611 if (audio_chunks > 0) {
612 buf_end = buf + buf_size;
613 while (buf < buf_end) {
614 if (s->out_bps == 2) {
615 decode_audio_s16(output_samples_s16, buf, s->chunk_size,
617 output_samples_s16 += avctx->block_align;
619 memcpy(output_samples_u8, buf, s->chunk_size);
620 output_samples_u8 += avctx->block_align;
622 buf += s->chunk_size;
626 *data_size = out_size;
632 * Public Data Structures
635 AVCodec ff_vmdvideo_decoder = {
637 .type = AVMEDIA_TYPE_VIDEO,
638 .id = CODEC_ID_VMDVIDEO,
639 .priv_data_size = sizeof(VmdVideoContext),
640 .init = vmdvideo_decode_init,
641 .close = vmdvideo_decode_end,
642 .decode = vmdvideo_decode_frame,
643 .capabilities = CODEC_CAP_DR1,
644 .long_name = NULL_IF_CONFIG_SMALL("Sierra VMD video"),
647 AVCodec ff_vmdaudio_decoder = {
649 .type = AVMEDIA_TYPE_AUDIO,
650 .id = CODEC_ID_VMDAUDIO,
651 .priv_data_size = sizeof(VmdAudioContext),
652 .init = vmdaudio_decode_init,
653 .decode = vmdaudio_decode_frame,
654 .long_name = NULL_IF_CONFIG_SMALL("Sierra VMD audio"),