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FFmpeg/libavcodec/vmdav.c
Michael Niedermayer 53db1cae1c data_size = 0 cleanup 
Originally committed as revision 3146 to svn://svn.ffmpeg.org/ffmpeg/trunk
2004-05-21 14:37:16 +00:00

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/*
* Sierra VMD Audio & Video Decoders
* Copyright (C) 2004 the ffmpeg project
*
* This library 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 of the License, or (at your option) any later version.
*
* This library 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 this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
/**
* @file vmdvideo.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 "common.h"
#include "avcodec.h"
#include "dsputil.h"
#define VMD_HEADER_SIZE 0x330
#define PALETTE_COUNT 256
/*
* Video Decoder
*/
typedef struct VmdVideoContext {
AVCodecContext *avctx;
DSPContext dsp;
AVFrame frame;
AVFrame prev_frame;
unsigned char *buf;
int size;
unsigned char palette[PALETTE_COUNT * 4];
unsigned char *unpack_buffer;
} VmdVideoContext;
#define QUEUE_SIZE 0x1000
#define QUEUE_MASK 0x0FFF
static void lz_unpack(unsigned char *src, unsigned char *dest)
{
unsigned char *s;
unsigned char *d;
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;
d = dest;
dataleft = LE_32(s);
s += 4;
memset(queue, QUEUE_SIZE, 0x20);
if (LE_32(s) == 0x56781234) {
s += 4;
qpos = 0x111;
speclen = 0xF + 3;
} else {
qpos = 0xFEE;
speclen = 100; /* no speclen */
}
while (dataleft > 0) {
tag = *s++;
if ((tag == 0xFF) && (dataleft > 8)) {
for (i = 0; i < 8; i++) {
queue[qpos++] = *d++ = *s++;
qpos &= QUEUE_MASK;
}
dataleft -= 8;
} else {
for (i = 0; i < 8; i++) {
if (dataleft == 0)
break;
if (tag & 0x01) {
queue[qpos++] = *d++ = *s++;
qpos &= QUEUE_MASK;
dataleft--;
} else {
chainofs = *s++;
chainofs |= ((*s & 0xF0) << 4);
chainlen = (*s++ & 0x0F) + 3;
if (chainlen == speclen)
chainlen = *s++ + 0xF + 3;
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(unsigned char *src, unsigned char *dest, int len)
{
unsigned char *ps;
unsigned char *pd;
int i, l;
ps = src;
pd = dest;
if (len & 1)
*pd++ = *ps++;
len >>= 1;
i = 0;
do {
l = *ps++;
if (l & 0x80) {
l = (l & 0x7F) * 2;
memcpy(pd, ps, l);
ps += l;
pd += l;
} else {
for (i = 0; i < l; i++) {
*pd++ = ps[0];
*pd++ = ps[1];
}
ps += 2;
}
i += l;
} while (i < len);
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 */
unsigned char *p = s->buf + 16;
unsigned char *pb;
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;
frame_x = LE_16(&s->buf[6]);
frame_y = LE_16(&s->buf[8]);
frame_width = LE_16(&s->buf[10]) - frame_x + 1;
frame_height = LE_16(&s->buf[12]) - frame_y + 1;
/* if only a certain region will be updated, copy the entire previous
* frame before the decode */
if (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;
meth = *pb++;
if (meth & 0x80) {
lz_unpack(pb, s->unpack_buffer);
meth &= 0x7F;
pb = s->unpack_buffer;
}
dp = &s->frame.data[0][frame_y * s->frame.linesize[0] + frame_x];
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 {
len = *pb++;
if (len & 0x80) {
len = (len & 0x7F) + 1;
memcpy(&dp[ofs], pb, len);
pb += len;
ofs += len;
} else {
/* interframe pixel copy */
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++) {
memcpy(dp, pb, frame_width);
pb += 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 {
len = *pb++;
if (len & 0x80) {
len = (len & 0x7F) + 1;
if (*pb++ == 0xFF)
len = rle_unpack(pb, &dp[ofs], len);
else
memcpy(&dp[ofs], pb, len);
pb += len;
ofs += len;
} else {
/* interframe pixel copy */
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 int vmdvideo_decode_init(AVCodecContext *avctx)
{
VmdVideoContext *s = (VmdVideoContext *)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;
avctx->has_b_frames = 0;
dsputil_init(&s->dsp, avctx);
/* 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 = av_malloc(LE_32(&vmd_header[800]));
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,
uint8_t *buf, int buf_size)
{
VmdVideoContext *s = (VmdVideoContext *)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);
if (s->prev_frame.data[0])
avctx->release_buffer(avctx, &s->prev_frame);
/* shuffle frames */
s->prev_frame = s->frame;
*data_size = sizeof(AVFrame);
*(AVFrame*)data = s->frame;
/* report that the buffer was completely consumed */
return buf_size;
}
static int vmdvideo_decode_end(AVCodecContext *avctx)
{
VmdVideoContext *s = (VmdVideoContext *)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;
unsigned char steps8[16];
unsigned short steps16[16];
unsigned short steps128[256];
short predictors[2];
} VmdAudioContext;
static int vmdaudio_decode_init(AVCodecContext *avctx)
{
VmdAudioContext *s = (VmdAudioContext *)avctx->priv_data;
int i;
s->avctx = avctx;
s->channels = avctx->channels;
s->bits = avctx->bits_per_sample;
s->block_align = avctx->block_align;
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);
/* set up the steps8 and steps16 tables */
for (i = 0; i < 8; i++) {
if (i < 4)
s->steps8[i] = i;
else
s->steps8[i] = s->steps8[i - 1] + i - 1;
if (i == 0)
s->steps16[i] = 0;
else if (i == 1)
s->steps16[i] = 4;
else if (i == 2)
s->steps16[i] = 16;
else
s->steps16[i] = 1 << (i + 4);
}
/* set up the step128 table */
s->steps128[0] = 0;
s->steps128[1] = 8;
for (i = 0x02; i <= 0x20; i++)
s->steps128[i] = (i - 1) << 4;
for (i = 0x21; i <= 0x60; i++)
s->steps128[i] = (i + 0x1F) << 3;
for (i = 0x61; i <= 0x70; i++)
s->steps128[i] = (i - 0x51) << 6;
for (i = 0x71; i <= 0x78; i++)
s->steps128[i] = (i - 0x69) << 8;
for (i = 0x79; i <= 0x7D; i++)
s->steps128[i] = (i - 0x75) << 10;
s->steps128[0x7E] = 0x3000;
s->steps128[0x7F] = 0x4000;
/* set up the negative half of each table */
for (i = 0; i < 8; i++) {
s->steps8[i + 8] = -s->steps8[i];
s->steps16[i + 8] = -s->steps16[i];
}
for (i = 0; i < 128; i++)
s->steps128[i + 128] = -s->steps128[i];
return 0;
}
static void vmdaudio_decode_audio(VmdAudioContext *s, unsigned char *data,
uint8_t *buf, int ratio) {
}
static int vmdaudio_loadsound(VmdAudioContext *s, unsigned char *data,
uint8_t *buf, int silence)
{
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 ((s->block_align & 0x01) == 0) {
if (silence)
memset(data, 0, s->block_align * 2);
else
vmdaudio_decode_audio(s, data, buf, 1);
} else {
if (silence)
memset(data, 0, s->block_align * 2);
else
vmdaudio_decode_audio(s, data, buf, 1);
}
} else {
/* mono handling */
if (silence) {
if (s->bits == 16) {
memset(data, 0, s->block_align * 2);
bytes_decoded = s->block_align * 2;
} else {
// memset(data, 0x00, s->block_align);
// bytes_decoded = s->block_align;
memset(data, 0x00, s->block_align * 2);
bytes_decoded = s->block_align * 2;
}
} else {
if (s->bits == 16) {
} else {
/* copy the data but convert it to signed */
for (i = 0; i < s->block_align; i++)
data[i * 2 + 1] = buf[i] + 0x80;
bytes_decoded = s->block_align * 2;
}
}
}
return bytes_decoded;
}
static int vmdaudio_decode_frame(AVCodecContext *avctx,
void *data, int *data_size,
uint8_t *buf, int buf_size)
{
VmdAudioContext *s = (VmdAudioContext *)avctx->priv_data;
unsigned int sound_flags;
unsigned char *output_samples = (unsigned char *)data;
/* point to the start of the encoded data */
unsigned char *p = buf + 16;
unsigned char *p_end = buf + buf_size;
if (buf_size < 16)
return buf_size;
if (buf[6] == 1) {
/* the chunk contains audio */
*data_size = vmdaudio_loadsound(s, output_samples, p, 0);
} else if (buf[6] == 2) {
/* the chunk contains audio and silence mixed together */
sound_flags = LE_32(p);
p += 4;
/* do something with extrabufs here? */
while (p < p_end) {
if (sound_flags & 0x01)
/* silence */
*data_size += vmdaudio_loadsound(s, output_samples, p, 1);
else {
/* audio */
*data_size += vmdaudio_loadsound(s, output_samples, p, 0);
p += s->block_align;
}
output_samples += (s->block_align * s->bits / 8);
sound_flags >>= 1;
}
} else if (buf[6] == 3) {
/* silent chunk */
*data_size = vmdaudio_loadsound(s, output_samples, p, 1);
}
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,
};
AVCodec vmdaudio_decoder = {
"vmdaudio",
CODEC_TYPE_AUDIO,
CODEC_ID_VMDAUDIO,
sizeof(VmdAudioContext),
vmdaudio_decode_init,
NULL,
NULL,
vmdaudio_decode_frame,
};
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