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ffmpeg/libavformat/idroqdec.c

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/*
* id RoQ (.roq) File Demuxer
* Copyright (c) 2003 The ffmpeg Project
*
* This file is part of Libav.
*
* Libav 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.
*
* Libav 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 Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* id RoQ format file demuxer
* by Mike Melanson (melanson@pcisys.net)
* for more information on the .roq file format, visit:
* http://www.csse.monash.edu.au/~timf/
*/
#include "libavutil/intreadwrite.h"
#include "avformat.h"
#define RoQ_MAGIC_NUMBER 0x1084
#define RoQ_CHUNK_PREAMBLE_SIZE 8
#define RoQ_AUDIO_SAMPLE_RATE 22050
#define RoQ_CHUNKS_TO_SCAN 30
#define RoQ_INFO 0x1001
#define RoQ_QUAD_CODEBOOK 0x1002
#define RoQ_QUAD_VQ 0x1011
#define RoQ_SOUND_MONO 0x1020
#define RoQ_SOUND_STEREO 0x1021
typedef struct RoqDemuxContext {
int width;
int height;
int audio_channels;
int video_stream_index;
int audio_stream_index;
int64_t video_pts;
unsigned int audio_frame_count;
} RoqDemuxContext;
static int roq_probe(AVProbeData *p)
{
if ((AV_RL16(&p->buf[0]) != RoQ_MAGIC_NUMBER) ||
(AV_RL32(&p->buf[2]) != 0xFFFFFFFF))
return 0;
return AVPROBE_SCORE_MAX;
}
static int roq_read_header(AVFormatContext *s,
AVFormatParameters *ap)
{
RoqDemuxContext *roq = s->priv_data;
AVIOContext *pb = s->pb;
int framerate;
AVStream *st;
unsigned char preamble[RoQ_CHUNK_PREAMBLE_SIZE];
/* get the main header */
if (avio_read(pb, preamble, RoQ_CHUNK_PREAMBLE_SIZE) !=
RoQ_CHUNK_PREAMBLE_SIZE)
return AVERROR(EIO);
framerate = AV_RL16(&preamble[6]);
/* init private context parameters */
roq->width = roq->height = roq->audio_channels = roq->video_pts =
roq->audio_frame_count = 0;
roq->audio_stream_index = -1;
st = av_new_stream(s, 0);
if (!st)
return AVERROR(ENOMEM);
av_set_pts_info(st, 63, 1, framerate);
roq->video_stream_index = st->index;
st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
st->codec->codec_id = CODEC_ID_ROQ;
st->codec->codec_tag = 0; /* no fourcc */
return 0;
}
static int roq_read_packet(AVFormatContext *s,
AVPacket *pkt)
{
RoqDemuxContext *roq = s->priv_data;
AVIOContext *pb = s->pb;
int ret = 0;
unsigned int chunk_size;
unsigned int chunk_type;
unsigned int codebook_size;
unsigned char preamble[RoQ_CHUNK_PREAMBLE_SIZE];
int packet_read = 0;
int64_t codebook_offset;
while (!packet_read) {
if (s->pb->eof_reached)
return AVERROR(EIO);
/* get the next chunk preamble */
if ((ret = avio_read(pb, preamble, RoQ_CHUNK_PREAMBLE_SIZE)) !=
RoQ_CHUNK_PREAMBLE_SIZE)
return AVERROR(EIO);
chunk_type = AV_RL16(&preamble[0]);
chunk_size = AV_RL32(&preamble[2]);
if(chunk_size > INT_MAX)
return AVERROR_INVALIDDATA;
switch (chunk_type) {
case RoQ_INFO:
if (!roq->width || !roq->height) {
AVStream *st = s->streams[roq->video_stream_index];
if (avio_read(pb, preamble, RoQ_CHUNK_PREAMBLE_SIZE) != RoQ_CHUNK_PREAMBLE_SIZE)
return AVERROR(EIO);
st->codec->width = roq->width = AV_RL16(preamble);
st->codec->height = roq->height = AV_RL16(preamble + 2);
break;
}
/* don't care about this chunk anymore */
avio_skip(pb, RoQ_CHUNK_PREAMBLE_SIZE);
break;
case RoQ_QUAD_CODEBOOK:
/* packet needs to contain both this codebook and next VQ chunk */
codebook_offset = avio_tell(pb) - RoQ_CHUNK_PREAMBLE_SIZE;
codebook_size = chunk_size;
avio_skip(pb, codebook_size);
if (avio_read(pb, preamble, RoQ_CHUNK_PREAMBLE_SIZE) !=
RoQ_CHUNK_PREAMBLE_SIZE)
return AVERROR(EIO);
chunk_size = AV_RL32(&preamble[2]) + RoQ_CHUNK_PREAMBLE_SIZE * 2 +
codebook_size;
/* rewind */
avio_seek(pb, codebook_offset, SEEK_SET);
/* load up the packet */
ret= av_get_packet(pb, pkt, chunk_size);
if (ret != chunk_size)
return AVERROR(EIO);
pkt->stream_index = roq->video_stream_index;
pkt->pts = roq->video_pts++;
packet_read = 1;
break;
case RoQ_SOUND_MONO:
case RoQ_SOUND_STEREO:
if (roq->audio_stream_index == -1) {
AVStream *st = av_new_stream(s, 1);
if (!st)
return AVERROR(ENOMEM);
av_set_pts_info(st, 32, 1, RoQ_AUDIO_SAMPLE_RATE);
roq->audio_stream_index = st->index;
st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
st->codec->codec_id = CODEC_ID_ROQ_DPCM;
st->codec->codec_tag = 0; /* no tag */
st->codec->channels = roq->audio_channels = chunk_type == RoQ_SOUND_STEREO ? 2 : 1;
st->codec->sample_rate = RoQ_AUDIO_SAMPLE_RATE;
st->codec->bits_per_coded_sample = 16;
st->codec->bit_rate = st->codec->channels * st->codec->sample_rate *
st->codec->bits_per_coded_sample;
st->codec->block_align = st->codec->channels * st->codec->bits_per_coded_sample;
}
case RoQ_QUAD_VQ:
/* load up the packet */
if (av_new_packet(pkt, chunk_size + RoQ_CHUNK_PREAMBLE_SIZE))
return AVERROR(EIO);
/* copy over preamble */
memcpy(pkt->data, preamble, RoQ_CHUNK_PREAMBLE_SIZE);
if (chunk_type == RoQ_QUAD_VQ) {
pkt->stream_index = roq->video_stream_index;
pkt->pts = roq->video_pts++;
} else {
pkt->stream_index = roq->audio_stream_index;
pkt->pts = roq->audio_frame_count;
roq->audio_frame_count += (chunk_size / roq->audio_channels);
}
pkt->pos= avio_tell(pb);
ret = avio_read(pb, pkt->data + RoQ_CHUNK_PREAMBLE_SIZE,
chunk_size);
if (ret != chunk_size)
ret = AVERROR(EIO);
packet_read = 1;
break;
default:
av_log(s, AV_LOG_ERROR, " unknown RoQ chunk (%04X)\n", chunk_type);
return AVERROR_INVALIDDATA;
break;
}
}
return ret;
}
AVInputFormat ff_roq_demuxer = {
"RoQ",
NULL_IF_CONFIG_SMALL("id RoQ format"),
sizeof(RoqDemuxContext),
roq_probe,
roq_read_header,
roq_read_packet,
};
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