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ffmpeg/libavformat/sierravmd.c

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/*
* Sierra VMD Format Demuxer
* 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 sierravmd.c
* Sierra VMD file demuxer
* by Vladimir "VAG" Gneushev (vagsoft at mail.ru)
* for more information on the Sierra VMD file format, visit:
* http://www.pcisys.net/~melanson/codecs/
*/
#include "avformat.h"
#define VMD_HEADER_SIZE 0x0330
#define BYTES_PER_FRAME_RECORD 16
typedef struct {
int stream_index;
offset_t frame_offset;
unsigned int frame_size;
int64_t pts;
int keyframe;
unsigned char frame_record[BYTES_PER_FRAME_RECORD];
} vmd_frame_t;
typedef struct VmdDemuxContext {
int video_stream_index;
int audio_stream_index;
unsigned int frame_count;
unsigned int frames_per_block;
vmd_frame_t *frame_table;
unsigned int current_frame;
int sample_rate;
int64_t audio_sample_counter;
int skiphdr;
unsigned char vmd_header[VMD_HEADER_SIZE];
} VmdDemuxContext;
static int vmd_probe(AVProbeData *p)
{
/* check if the first 2 bytes of the file contain the appropriate size
* of a VMD header chunk */
if (AV_RL16(&p->buf[0]) != VMD_HEADER_SIZE - 2)
return 0;
/* only return half certainty since this check is a bit sketchy */
return AVPROBE_SCORE_MAX / 2;
}
static int vmd_read_header(AVFormatContext *s,
AVFormatParameters *ap)
{
VmdDemuxContext *vmd = s->priv_data;
ByteIOContext *pb = &s->pb;
AVStream *st, *vst;
unsigned int toc_offset;
unsigned char *raw_frame_table;
int raw_frame_table_size;
offset_t current_offset;
int i, j;
unsigned int total_frames;
int64_t pts_inc = 1;
int64_t current_video_pts = 0, current_audio_pts = 0;
unsigned char chunk[BYTES_PER_FRAME_RECORD];
int num, den;
int sound_buffers;
/* fetch the main header, including the 2 header length bytes */
url_fseek(pb, 0, SEEK_SET);
if (get_buffer(pb, vmd->vmd_header, VMD_HEADER_SIZE) != VMD_HEADER_SIZE)
return AVERROR(EIO);
/* start up the decoders */
vst = av_new_stream(s, 0);
if (!vst)
return AVERROR(ENOMEM);
av_set_pts_info(vst, 33, 1, 10);
vmd->video_stream_index = vst->index;
vst->codec->codec_type = CODEC_TYPE_VIDEO;
vst->codec->codec_id = CODEC_ID_VMDVIDEO;
vst->codec->codec_tag = 0; /* no fourcc */
vst->codec->width = AV_RL16(&vmd->vmd_header[12]);
vst->codec->height = AV_RL16(&vmd->vmd_header[14]);
vst->codec->extradata_size = VMD_HEADER_SIZE;
vst->codec->extradata = av_mallocz(VMD_HEADER_SIZE + FF_INPUT_BUFFER_PADDING_SIZE);
memcpy(vst->codec->extradata, vmd->vmd_header, VMD_HEADER_SIZE);
/* if sample rate is 0, assume no audio */
vmd->sample_rate = AV_RL16(&vmd->vmd_header[804]);
if (vmd->sample_rate) {
st = av_new_stream(s, 0);
if (!st)
return AVERROR(ENOMEM);
vmd->audio_stream_index = st->index;
st->codec->codec_type = CODEC_TYPE_AUDIO;
st->codec->codec_id = CODEC_ID_VMDAUDIO;
st->codec->codec_tag = 0; /* no fourcc */
st->codec->channels = (vmd->vmd_header[811] & 0x80) ? 2 : 1;
st->codec->sample_rate = vmd->sample_rate;
st->codec->block_align = AV_RL16(&vmd->vmd_header[806]);
if (st->codec->block_align & 0x8000) {
st->codec->bits_per_sample = 16;
st->codec->block_align = -(st->codec->block_align - 0x10000);
} else {
st->codec->bits_per_sample = 8;
}
st->codec->bit_rate = st->codec->sample_rate *
st->codec->bits_per_sample * st->codec->channels;
/* calculate pts */
num = st->codec->block_align;
den = st->codec->sample_rate * st->codec->channels;
av_reduce(&den, &num, den, num, (1UL<<31)-1);
av_set_pts_info(vst, 33, num, den);
av_set_pts_info(st, 33, num, den);
pts_inc = num;
}
toc_offset = AV_RL32(&vmd->vmd_header[812]);
vmd->frame_count = AV_RL16(&vmd->vmd_header[6]);
vmd->frames_per_block = AV_RL16(&vmd->vmd_header[18]);
url_fseek(pb, toc_offset, SEEK_SET);
raw_frame_table = NULL;
vmd->frame_table = NULL;
sound_buffers = AV_RL16(&vmd->vmd_header[808]);
raw_frame_table_size = vmd->frame_count * 6;
raw_frame_table = av_malloc(raw_frame_table_size);
if(vmd->frame_count * vmd->frames_per_block >= UINT_MAX / sizeof(vmd_frame_t)){
av_log(s, AV_LOG_ERROR, "vmd->frame_count * vmd->frames_per_block too large\n");
return -1;
}
vmd->frame_table = av_malloc((vmd->frame_count * vmd->frames_per_block + sound_buffers) * sizeof(vmd_frame_t));
if (!raw_frame_table || !vmd->frame_table) {
av_free(raw_frame_table);
av_free(vmd->frame_table);
return AVERROR(ENOMEM);
}
if (get_buffer(pb, raw_frame_table, raw_frame_table_size) !=
raw_frame_table_size) {
av_free(raw_frame_table);
av_free(vmd->frame_table);
return AVERROR(EIO);
}
total_frames = 0;
for (i = 0; i < vmd->frame_count; i++) {
current_offset = AV_RL32(&raw_frame_table[6 * i + 2]);
/* handle each entry in index block */
for (j = 0; j < vmd->frames_per_block; j++) {
int type;
uint32_t size;
get_buffer(pb, chunk, BYTES_PER_FRAME_RECORD);
type = chunk[0];
size = AV_RL32(&chunk[2]);
if(!size)
continue;
switch(type) {
case 1: /* Audio Chunk */
/* first audio chunk contains several audio buffers */
if(current_audio_pts){
vmd->frame_table[total_frames].frame_offset = current_offset;
vmd->frame_table[total_frames].stream_index = vmd->audio_stream_index;
vmd->frame_table[total_frames].frame_size = size;
memcpy(vmd->frame_table[total_frames].frame_record, chunk, BYTES_PER_FRAME_RECORD);
vmd->frame_table[total_frames].pts = current_audio_pts;
total_frames++;
current_audio_pts += pts_inc;
}else{
uint32_t flags;
int k;
int noff;
int64_t pos;
pos = url_ftell(pb);
url_fseek(pb, current_offset, SEEK_SET);
flags = get_le32(pb);
noff = 4;
url_fseek(pb, pos, SEEK_SET);
av_log(s, AV_LOG_DEBUG, "Sound mapping = %08X (%i bufs)\n", flags, sound_buffers);
for(k = 0; k < sound_buffers - 1; k++){
if(flags & 1) { /* silent block */
vmd->frame_table[total_frames].frame_size = 0;
}else{
vmd->frame_table[total_frames].frame_size = st->codec->block_align + (st->codec->block_align & 1);
}
noff += vmd->frame_table[total_frames].frame_size;
vmd->frame_table[total_frames].frame_offset = current_offset + noff;
vmd->frame_table[total_frames].stream_index = vmd->audio_stream_index;
memcpy(vmd->frame_table[total_frames].frame_record, chunk, BYTES_PER_FRAME_RECORD);
vmd->frame_table[total_frames].pts = current_audio_pts;
total_frames++;
current_audio_pts += pts_inc;
flags >>= 1;
}
}
break;
case 2: /* Video Chunk */
vmd->frame_table[total_frames].frame_offset = current_offset;
vmd->frame_table[total_frames].stream_index = vmd->video_stream_index;
vmd->frame_table[total_frames].frame_size = size;
memcpy(vmd->frame_table[total_frames].frame_record, chunk, BYTES_PER_FRAME_RECORD);
vmd->frame_table[total_frames].pts = current_video_pts;
total_frames++;
break;
}
current_offset += size;
}
current_video_pts += pts_inc;
}
av_free(raw_frame_table);
vmd->current_frame = 0;
vmd->frame_count = total_frames;
return 0;
}
static int vmd_read_packet(AVFormatContext *s,
AVPacket *pkt)
{
VmdDemuxContext *vmd = s->priv_data;
ByteIOContext *pb = &s->pb;
int ret = 0;
vmd_frame_t *frame;
if (vmd->current_frame >= vmd->frame_count)
return AVERROR(EIO);
frame = &vmd->frame_table[vmd->current_frame];
/* position the stream (will probably be there already) */
url_fseek(pb, frame->frame_offset, SEEK_SET);
if (av_new_packet(pkt, frame->frame_size + BYTES_PER_FRAME_RECORD))
return AVERROR(ENOMEM);
pkt->pos= url_ftell(pb);
memcpy(pkt->data, frame->frame_record, BYTES_PER_FRAME_RECORD);
ret = get_buffer(pb, pkt->data + BYTES_PER_FRAME_RECORD,
frame->frame_size);
if (ret != frame->frame_size) {
av_free_packet(pkt);
ret = AVERROR(EIO);
}
pkt->stream_index = frame->stream_index;
pkt->pts = frame->pts;
av_log(NULL, AV_LOG_INFO, " dispatching %s frame with %d bytes and pts %"PRId64"\n",
(frame->frame_record[0] == 0x02) ? "video" : "audio",
frame->frame_size + BYTES_PER_FRAME_RECORD,
pkt->pts);
vmd->current_frame++;
return ret;
}
static int vmd_read_close(AVFormatContext *s)
{
VmdDemuxContext *vmd = s->priv_data;
av_free(vmd->frame_table);
return 0;
}
AVInputFormat vmd_demuxer = {
"vmd",
"Sierra VMD format",
sizeof(VmdDemuxContext),
vmd_probe,
vmd_read_header,
vmd_read_packet,
vmd_read_close,
};
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