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DEFINITIONS
This source file includes following definitions.
- lz_unpack
- rle_unpack
- vmd_decode
- vmdvideo_decode_init
- vmdvideo_decode_frame
- vmdvideo_decode_end
- vmdaudio_decode_init
- vmdaudio_decode_audio
- vmdaudio_loadsound
- vmdaudio_decode_frame
/*
* Sierra VMD Audio & Video Decoders
* Copyright (C) 2004 the ffmpeg project
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file libavcodec/vmdav.c
* Sierra VMD audio & video decoders
* by Vladimir "VAG" Gneushev (vagsoft at mail.ru)
* for more information on the Sierra VMD format, visit:
* http://www.pcisys.net/~melanson/codecs/
*
* The video decoder outputs PAL8 colorspace data. The decoder expects
* a 0x330-byte VMD file header to be transmitted via extradata during
* codec initialization. Each encoded frame that is sent to this decoder
* is expected to be prepended with the appropriate 16-byte frame
* information record from the VMD file.
*
* The audio decoder, like the video decoder, expects each encoded data
* chunk to be prepended with the appropriate 16-byte frame information
* record from the VMD file. It does not require the 0x330-byte VMD file
* header, but it does need the audio setup parameters passed in through
* normal libavcodec API means.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "libavutil/intreadwrite.h"
#include "avcodec.h"
#define VMD_HEADER_SIZE 0x330
#define PALETTE_COUNT 256
/*
* Video Decoder
*/
typedef struct VmdVideoContext {
AVCodecContext *avctx;
AVFrame frame;
AVFrame prev_frame;
const unsigned char *buf;
int size;
unsigned char palette[PALETTE_COUNT * 4];
unsigned char *unpack_buffer;
int unpack_buffer_size;
int x_off, y_off;
} VmdVideoContext;
#define QUEUE_SIZE 0x1000
#define QUEUE_MASK 0x0FFF
static void lz_unpack(const unsigned char *src, int src_len,
unsigned char *dest, int dest_len)
{
const unsigned char *s;
unsigned int s_len;
unsigned char *d;
unsigned char *d_end;
unsigned char queue[QUEUE_SIZE];
unsigned int qpos;
unsigned int dataleft;
unsigned int chainofs;
unsigned int chainlen;
unsigned int speclen;
unsigned char tag;
unsigned int i, j;
s = src;
s_len = src_len;
d = dest;
d_end = d + dest_len;
dataleft = AV_RL32(s);
s += 4; s_len -= 4;
memset(queue, 0x20, QUEUE_SIZE);
if (s_len < 4)
return;
if (AV_RL32(s) == 0x56781234) {
s += 4; s_len -= 4;
qpos = 0x111;
speclen = 0xF + 3;
} else {
qpos = 0xFEE;
speclen = 100; /* no speclen */
}
while (dataleft > 0 && s_len > 0) {
tag = *s++; s_len--;
if ((tag == 0xFF) && (dataleft > 8)) {
if (d + 8 > d_end || s_len < 8)
return;
for (i = 0; i < 8; i++) {
queue[qpos++] = *d++ = *s++;
qpos &= QUEUE_MASK;
}
s_len -= 8;
dataleft -= 8;
} else {
for (i = 0; i < 8; i++) {
if (dataleft == 0)
break;
if (tag & 0x01) {
if (d + 1 > d_end || s_len < 1)
return;
queue[qpos++] = *d++ = *s++;
qpos &= QUEUE_MASK;
dataleft--;
s_len--;
} else {
if (s_len < 2)
return;
chainofs = *s++;
chainofs |= ((*s & 0xF0) << 4);
chainlen = (*s++ & 0x0F) + 3;
s_len -= 2;
if (chainlen == speclen) {
if (s_len < 1)
return;
chainlen = *s++ + 0xF + 3;
s_len--;
}
if (d + chainlen > d_end)
return;
for (j = 0; j < chainlen; j++) {
*d = queue[chainofs++ & QUEUE_MASK];
queue[qpos++] = *d++;
qpos &= QUEUE_MASK;
}
dataleft -= chainlen;
}
tag >>= 1;
}
}
}
}
static int rle_unpack(const unsigned char *src, unsigned char *dest,
int src_count, int src_size, int dest_len)
{
const unsigned char *ps;
unsigned char *pd;
int i, l;
unsigned char *dest_end = dest + dest_len;
ps = src;
pd = dest;
if (src_count & 1) {
if (src_size < 1)
return 0;
*pd++ = *ps++;
src_size--;
}
src_count >>= 1;
i = 0;
do {
if (src_size < 1)
break;
l = *ps++;
src_size--;
if (l & 0x80) {
l = (l & 0x7F) * 2;
if (pd + l > dest_end || src_size < l)
return ps - src;
memcpy(pd, ps, l);
ps += l;
src_size -= l;
pd += l;
} else {
if (pd + i > dest_end || src_size < 2)
return ps - src;
for (i = 0; i < l; i++) {
*pd++ = ps[0];
*pd++ = ps[1];
}
ps += 2;
src_size -= 2;
}
i += l;
} while (i < src_count);
return ps - src;
}
static void vmd_decode(VmdVideoContext *s)
{
int i;
unsigned int *palette32;
unsigned char r, g, b;
/* point to the start of the encoded data */
const unsigned char *p = s->buf + 16;
const unsigned char *pb;
unsigned int pb_size;
unsigned char meth;
unsigned char *dp; /* pointer to current frame */
unsigned char *pp; /* pointer to previous frame */
unsigned char len;
int ofs;
int frame_x, frame_y;
int frame_width, frame_height;
int dp_size;
frame_x = AV_RL16(&s->buf[6]);
frame_y = AV_RL16(&s->buf[8]);
frame_width = AV_RL16(&s->buf[10]) - frame_x + 1;
frame_height = AV_RL16(&s->buf[12]) - frame_y + 1;
if (frame_x < 0 || frame_width < 0 ||
frame_x >= s->avctx->width ||
frame_width > s->avctx->width ||
frame_x + frame_width > s->avctx->width)
return;
if (frame_y < 0 || frame_height < 0 ||
frame_y >= s->avctx->height ||
frame_height > s->avctx->height ||
frame_y + frame_height > s->avctx->height)
return;
if ((frame_width == s->avctx->width && frame_height == s->avctx->height) &&
(frame_x || frame_y)) {
s->x_off = frame_x;
s->y_off = frame_y;
}
frame_x -= s->x_off;
frame_y -= s->y_off;
/* if only a certain region will be updated, copy the entire previous
* frame before the decode */
if (s->prev_frame.data[0] &&
(frame_x || frame_y || (frame_width != s->avctx->width) ||
(frame_height != s->avctx->height))) {
memcpy(s->frame.data[0], s->prev_frame.data[0],
s->avctx->height * s->frame.linesize[0]);
}
/* check if there is a new palette */
if (s->buf[15] & 0x02) {
p += 2;
palette32 = (unsigned int *)s->palette;
for (i = 0; i < PALETTE_COUNT; i++) {
r = *p++ * 4;
g = *p++ * 4;
b = *p++ * 4;
palette32[i] = (r << 16) | (g << 8) | (b);
}
s->size -= (256 * 3 + 2);
}
if (s->size > 0) {
/* originally UnpackFrame in VAG's code */
pb = p;
pb_size = s->buf + s->size - pb;
if (pb_size < 1)
return;
meth = *pb++; pb_size--;
if (meth & 0x80) {
lz_unpack(pb, pb_size,
s->unpack_buffer, s->unpack_buffer_size);
meth &= 0x7F;
pb = s->unpack_buffer;
pb_size = s->unpack_buffer_size;
}
dp = &s->frame.data[0][frame_y * s->frame.linesize[0] + frame_x];
dp_size = s->frame.linesize[0] * s->avctx->height;
pp = &s->prev_frame.data[0][frame_y * s->prev_frame.linesize[0] + frame_x];
switch (meth) {
case 1:
for (i = 0; i < frame_height; i++) {
ofs = 0;
do {
if (pb_size < 1)
return;
len = *pb++;
pb_size--;
if (len & 0x80) {
len = (len & 0x7F) + 1;
if (ofs + len > frame_width || pb_size < len)
return;
memcpy(&dp[ofs], pb, len);
pb += len;
pb_size -= len;
ofs += len;
} else {
/* interframe pixel copy */
if (ofs + len + 1 > frame_width || !s->prev_frame.data[0])
return;
memcpy(&dp[ofs], &pp[ofs], len + 1);
ofs += len + 1;
}
} while (ofs < frame_width);
if (ofs > frame_width) {
av_log(s->avctx, AV_LOG_ERROR, "VMD video: offset > width (%d > %d)\n",
ofs, frame_width);
break;
}
dp += s->frame.linesize[0];
pp += s->prev_frame.linesize[0];
}
break;
case 2:
for (i = 0; i < frame_height; i++) {
if (pb_size < frame_width)
return;
memcpy(dp, pb, frame_width);
pb += frame_width;
pb_size -= frame_width;
dp += s->frame.linesize[0];
pp += s->prev_frame.linesize[0];
}
break;
case 3:
for (i = 0; i < frame_height; i++) {
ofs = 0;
do {
if (pb_size < 1)
return;
len = *pb++;
pb_size--;
if (len & 0x80) {
len = (len & 0x7F) + 1;
if (pb_size < 1)
return;
if (*pb++ == 0xFF)
len = rle_unpack(pb, &dp[ofs], len, pb_size, frame_width - ofs);
else {
if (pb_size < len)
return;
memcpy(&dp[ofs], pb, len);
}
pb += len;
pb_size -= 1 + len;
ofs += len;
} else {
/* interframe pixel copy */
if (ofs + len + 1 > frame_width || !s->prev_frame.data[0])
return;
memcpy(&dp[ofs], &pp[ofs], len + 1);
ofs += len + 1;
}
} while (ofs < frame_width);
if (ofs > frame_width) {
av_log(s->avctx, AV_LOG_ERROR, "VMD video: offset > width (%d > %d)\n",
ofs, frame_width);
}
dp += s->frame.linesize[0];
pp += s->prev_frame.linesize[0];
}
break;
}
}
}
static av_cold int vmdvideo_decode_init(AVCodecContext *avctx)
{
VmdVideoContext *s = avctx->priv_data;
int i;
unsigned int *palette32;
int palette_index = 0;
unsigned char r, g, b;
unsigned char *vmd_header;
unsigned char *raw_palette;
s->avctx = avctx;
avctx->pix_fmt = PIX_FMT_PAL8;
/* make sure the VMD header made it */
if (s->avctx->extradata_size != VMD_HEADER_SIZE) {
av_log(s->avctx, AV_LOG_ERROR, "VMD video: expected extradata size of %d\n",
VMD_HEADER_SIZE);
return -1;
}
vmd_header = (unsigned char *)avctx->extradata;
s->unpack_buffer_size = AV_RL32(&vmd_header[800]);
s->unpack_buffer = av_malloc(s->unpack_buffer_size);
if (!s->unpack_buffer)
return -1;
/* load up the initial palette */
raw_palette = &vmd_header[28];
palette32 = (unsigned int *)s->palette;
for (i = 0; i < PALETTE_COUNT; i++) {
r = raw_palette[palette_index++] * 4;
g = raw_palette[palette_index++] * 4;
b = raw_palette[palette_index++] * 4;
palette32[i] = (r << 16) | (g << 8) | (b);
}
s->frame.data[0] = s->prev_frame.data[0] = NULL;
return 0;
}
static int vmdvideo_decode_frame(AVCodecContext *avctx,
void *data, int *data_size,
const uint8_t *buf, int buf_size)
{
VmdVideoContext *s = avctx->priv_data;
s->buf = buf;
s->size = buf_size;
if (buf_size < 16)
return buf_size;
s->frame.reference = 1;
if (avctx->get_buffer(avctx, &s->frame)) {
av_log(s->avctx, AV_LOG_ERROR, "VMD Video: get_buffer() failed\n");
return -1;
}
vmd_decode(s);
/* make the palette available on the way out */
memcpy(s->frame.data[1], s->palette, PALETTE_COUNT * 4);
/* shuffle frames */
FFSWAP(AVFrame, s->frame, s->prev_frame);
if (s->frame.data[0])
avctx->release_buffer(avctx, &s->frame);
*data_size = sizeof(AVFrame);
*(AVFrame*)data = s->prev_frame;
/* report that the buffer was completely consumed */
return buf_size;
}
static av_cold int vmdvideo_decode_end(AVCodecContext *avctx)
{
VmdVideoContext *s = avctx->priv_data;
if (s->prev_frame.data[0])
avctx->release_buffer(avctx, &s->prev_frame);
av_free(s->unpack_buffer);
return 0;
}
/*
* Audio Decoder
*/
typedef struct VmdAudioContext {
AVCodecContext *avctx;
int channels;
int bits;
int block_align;
int predictors[2];
} VmdAudioContext;
static const uint16_t vmdaudio_table[128] = {
0x000, 0x008, 0x010, 0x020, 0x030, 0x040, 0x050, 0x060, 0x070, 0x080,
0x090, 0x0A0, 0x0B0, 0x0C0, 0x0D0, 0x0E0, 0x0F0, 0x100, 0x110, 0x120,
0x130, 0x140, 0x150, 0x160, 0x170, 0x180, 0x190, 0x1A0, 0x1B0, 0x1C0,
0x1D0, 0x1E0, 0x1F0, 0x200, 0x208, 0x210, 0x218, 0x220, 0x228, 0x230,
0x238, 0x240, 0x248, 0x250, 0x258, 0x260, 0x268, 0x270, 0x278, 0x280,
0x288, 0x290, 0x298, 0x2A0, 0x2A8, 0x2B0, 0x2B8, 0x2C0, 0x2C8, 0x2D0,
0x2D8, 0x2E0, 0x2E8, 0x2F0, 0x2F8, 0x300, 0x308, 0x310, 0x318, 0x320,
0x328, 0x330, 0x338, 0x340, 0x348, 0x350, 0x358, 0x360, 0x368, 0x370,
0x378, 0x380, 0x388, 0x390, 0x398, 0x3A0, 0x3A8, 0x3B0, 0x3B8, 0x3C0,
0x3C8, 0x3D0, 0x3D8, 0x3E0, 0x3E8, 0x3F0, 0x3F8, 0x400, 0x440, 0x480,
0x4C0, 0x500, 0x540, 0x580, 0x5C0, 0x600, 0x640, 0x680, 0x6C0, 0x700,
0x740, 0x780, 0x7C0, 0x800, 0x900, 0xA00, 0xB00, 0xC00, 0xD00, 0xE00,
0xF00, 0x1000, 0x1400, 0x1800, 0x1C00, 0x2000, 0x3000, 0x4000
};
static av_cold int vmdaudio_decode_init(AVCodecContext *avctx)
{
VmdAudioContext *s = avctx->priv_data;
s->avctx = avctx;
s->channels = avctx->channels;
s->bits = avctx->bits_per_coded_sample;
s->block_align = avctx->block_align;
avctx->sample_fmt = SAMPLE_FMT_S16;
av_log(s->avctx, AV_LOG_DEBUG, "%d channels, %d bits/sample, block align = %d, sample rate = %d\n",
s->channels, s->bits, s->block_align, avctx->sample_rate);
return 0;
}
static void vmdaudio_decode_audio(VmdAudioContext *s, unsigned char *data,
const uint8_t *buf, int buf_size, int stereo)
{
int i;
int chan = 0;
int16_t *out = (int16_t*)data;
for(i = 0; i < buf_size; i++) {
if(buf[i] & 0x80)
s->predictors[chan] -= vmdaudio_table[buf[i] & 0x7F];
else
s->predictors[chan] += vmdaudio_table[buf[i]];
s->predictors[chan] = av_clip_int16(s->predictors[chan]);
out[i] = s->predictors[chan];
chan ^= stereo;
}
}
static int vmdaudio_loadsound(VmdAudioContext *s, unsigned char *data,
const uint8_t *buf, int silence, int data_size)
{
int bytes_decoded = 0;
int i;
// if (silence)
// av_log(s->avctx, AV_LOG_INFO, "silent block!\n");
if (s->channels == 2) {
/* stereo handling */
if (silence) {
memset(data, 0, data_size * 2);
} else {
if (s->bits == 16)
vmdaudio_decode_audio(s, data, buf, data_size, 1);
else {
/* copy the data but convert it to signed */
for (i = 0; i < data_size; i++){
*data++ = buf[i] + 0x80;
*data++ = buf[i] + 0x80;
}
}
}
} else {
bytes_decoded = data_size * 2;
/* mono handling */
if (silence) {
memset(data, 0, data_size * 2);
} else {
if (s->bits == 16) {
vmdaudio_decode_audio(s, data, buf, data_size, 0);
} else {
/* copy the data but convert it to signed */
for (i = 0; i < data_size; i++){
*data++ = buf[i] + 0x80;
*data++ = buf[i] + 0x80;
}
}
}
}
return data_size * 2;
}
static int vmdaudio_decode_frame(AVCodecContext *avctx,
void *data, int *data_size,
const uint8_t *buf, int buf_size)
{
VmdAudioContext *s = avctx->priv_data;
unsigned char *output_samples = (unsigned char *)data;
/* point to the start of the encoded data */
const unsigned char *p = buf + 16;
if (buf_size < 16)
return buf_size;
if (buf[6] == 1) {
/* the chunk contains audio */
*data_size = vmdaudio_loadsound(s, output_samples, p, 0, buf_size - 16);
} else if (buf[6] == 2) {
/* initial chunk, may contain audio and silence */
uint32_t flags = AV_RB32(p);
int raw_block_size = s->block_align * s->bits / 8;
int silent_chunks;
if(flags == 0xFFFFFFFF)
silent_chunks = 32;
else
silent_chunks = av_log2(flags + 1);
if(*data_size < (s->block_align*silent_chunks + buf_size - 20) * 2)
return -1;
*data_size = 0;
memset(output_samples, 0, raw_block_size * silent_chunks);
output_samples += raw_block_size * silent_chunks;
*data_size = raw_block_size * silent_chunks;
*data_size += vmdaudio_loadsound(s, output_samples, p + 4, 0, buf_size - 20);
} else if (buf[6] == 3) {
/* silent chunk */
*data_size = vmdaudio_loadsound(s, output_samples, p, 1, 0);
}
return buf_size;
}
/*
* Public Data Structures
*/
AVCodec vmdvideo_decoder = {
"vmdvideo",
CODEC_TYPE_VIDEO,
CODEC_ID_VMDVIDEO,
sizeof(VmdVideoContext),
vmdvideo_decode_init,
NULL,
vmdvideo_decode_end,
vmdvideo_decode_frame,
CODEC_CAP_DR1,
.long_name = NULL_IF_CONFIG_SMALL("Sierra VMD video"),
};
AVCodec vmdaudio_decoder = {
"vmdaudio",
CODEC_TYPE_AUDIO,
CODEC_ID_VMDAUDIO,
sizeof(VmdAudioContext),
vmdaudio_decode_init,
NULL,
NULL,
vmdaudio_decode_frame,
.long_name = NULL_IF_CONFIG_SMALL("Sierra VMD audio"),
};