ffmpeg/libavformat/idroq.c

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/*
* Id RoQ (.roq) File Demuxer
* Copyright (c) 2003 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 idroq.c
* 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 "avformat.h"
#define LE_16(x) ((((uint8_t*)(x))[1] << 8) | ((uint8_t*)(x))[0])
#define LE_32(x) ((((uint8_t*)(x))[3] << 24) | \
(((uint8_t*)(x))[2] << 16) | \
(((uint8_t*)(x))[1] << 8) | \
((uint8_t*)(x))[0])
#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 framerate;
int frame_pts_inc;
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 ((LE_16(&p->buf[0]) != RoQ_MAGIC_NUMBER) ||
(LE_32(&p->buf[2]) != 0xFFFFFFFF))
return 0;
return AVPROBE_SCORE_MAX;
}
static int roq_read_header(AVFormatContext *s,
AVFormatParameters *ap)
{
RoqDemuxContext *roq = s->priv_data;
ByteIOContext *pb = &s->pb;
AVStream *st;
unsigned char preamble[RoQ_CHUNK_PREAMBLE_SIZE];
int i;
unsigned int chunk_size;
unsigned int chunk_type;
/* get the main header */
if (get_buffer(pb, preamble, RoQ_CHUNK_PREAMBLE_SIZE) !=
RoQ_CHUNK_PREAMBLE_SIZE)
return AVERROR_IO;
roq->framerate = LE_16(&preamble[6]);
roq->frame_pts_inc = 90000 / roq->framerate;
/* set the pts reference (1 pts = 1/90000) */
s->pts_num = 1;
s->pts_den = 90000;
/* init private context parameters */
roq->width = roq->height = roq->audio_channels = roq->video_pts =
roq->audio_frame_count = 0;
/* scan the first n chunks searching for A/V parameters */
for (i = 0; i < RoQ_CHUNKS_TO_SCAN; i++) {
if (get_buffer(pb, preamble, RoQ_CHUNK_PREAMBLE_SIZE) !=
RoQ_CHUNK_PREAMBLE_SIZE)
return AVERROR_IO;
chunk_type = LE_16(&preamble[0]);
chunk_size = LE_32(&preamble[2]);
switch (chunk_type) {
case RoQ_INFO:
/* fetch the width and height; reuse the preamble bytes */
if (get_buffer(pb, preamble, RoQ_CHUNK_PREAMBLE_SIZE) !=
RoQ_CHUNK_PREAMBLE_SIZE)
return AVERROR_IO;
roq->width = LE_16(&preamble[0]);
roq->height = LE_16(&preamble[2]);
break;
case RoQ_QUAD_CODEBOOK:
case RoQ_QUAD_VQ:
/* ignore during this scan */
url_fseek(pb, chunk_size, SEEK_CUR);
break;
case RoQ_SOUND_MONO:
roq->audio_channels = 1;
url_fseek(pb, chunk_size, SEEK_CUR);
break;
case RoQ_SOUND_STEREO:
roq->audio_channels = 2;
url_fseek(pb, chunk_size, SEEK_CUR);
break;
default:
printf (" unknown RoQ chunk type (%04X)\n", LE_16(&preamble[0]));
return AVERROR_INVALIDDATA;
break;
}
/* if all necessary parameters have been gathered, exit early */
if ((roq->width && roq->height) && roq->audio_channels)
break;
}
/* seek back to the first chunk */
url_fseek(pb, RoQ_CHUNK_PREAMBLE_SIZE, SEEK_SET);
/* initialize the decoders */
st = av_new_stream(s, 0);
if (!st)
return AVERROR_NOMEM;
roq->video_stream_index = st->index;
st->codec.codec_type = CODEC_TYPE_VIDEO;
st->codec.codec_id = CODEC_ID_ROQ;
st->codec.codec_tag = 0; /* no fourcc */
st->codec.width = roq->width;
st->codec.height = roq->height;
if (roq->audio_channels) {
st = av_new_stream(s, 0);
if (!st)
return AVERROR_NOMEM;
roq->audio_stream_index = st->index;
st->codec.codec_type = CODEC_TYPE_AUDIO;
st->codec.codec_id = CODEC_ID_ROQ_DPCM;
st->codec.codec_tag = 0; /* no tag */
st->codec.channels = roq->audio_channels;
st->codec.sample_rate = RoQ_AUDIO_SAMPLE_RATE;
st->codec.bits_per_sample = 16;
st->codec.bit_rate = st->codec.channels * st->codec.sample_rate *
st->codec.bits_per_sample;
st->codec.block_align = st->codec.channels * st->codec.bits_per_sample;
}
printf (" video is %d x %d, audio is %d channels\n",
roq->width, roq->height, roq->audio_channels);
return 0;
}
static int roq_read_packet(AVFormatContext *s,
AVPacket *pkt)
{
RoqDemuxContext *roq = s->priv_data;
ByteIOContext *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;
offset_t codebook_offset;
while (!packet_read) {
if (url_feof(&s->pb))
return -EIO;
/* get the next chunk preamble */
if ((ret = get_buffer(pb, preamble, RoQ_CHUNK_PREAMBLE_SIZE)) !=
RoQ_CHUNK_PREAMBLE_SIZE)
return -EIO;
chunk_type = LE_16(&preamble[0]);
chunk_size = LE_32(&preamble[2]);
switch (chunk_type) {
case RoQ_INFO:
/* don't care about this chunk anymore */
url_fseek(pb, RoQ_CHUNK_PREAMBLE_SIZE, SEEK_CUR);
break;
case RoQ_QUAD_CODEBOOK:
/* packet needs to contain both this codebook and next VQ chunk */
codebook_offset = url_ftell(pb) - RoQ_CHUNK_PREAMBLE_SIZE;
codebook_size = chunk_size;
url_fseek(pb, codebook_size, SEEK_CUR);
if (get_buffer(pb, preamble, RoQ_CHUNK_PREAMBLE_SIZE) !=
RoQ_CHUNK_PREAMBLE_SIZE)
return -EIO;
chunk_size = LE_32(&preamble[2]) + RoQ_CHUNK_PREAMBLE_SIZE * 2 +
codebook_size;
/* rewind */
url_fseek(pb, codebook_offset, SEEK_SET);
/* load up the packet */
if (av_new_packet(pkt, chunk_size))
return -EIO;
pkt->stream_index = roq->video_stream_index;
pkt->pts = roq->video_pts;
ret = get_buffer(pb, pkt->data, chunk_size);
if (ret != chunk_size)
ret = -EIO;
roq->video_pts += roq->frame_pts_inc;
packet_read = 1;
break;
case RoQ_SOUND_MONO:
case RoQ_SOUND_STEREO:
case RoQ_QUAD_VQ:
/* load up the packet */
if (av_new_packet(pkt, chunk_size + RoQ_CHUNK_PREAMBLE_SIZE))
return -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;
roq->video_pts += roq->frame_pts_inc;
} else {
pkt->stream_index = roq->audio_stream_index;
pkt->pts = roq->audio_frame_count;
pkt->pts *= 90000;
pkt->pts /= RoQ_AUDIO_SAMPLE_RATE;
roq->audio_frame_count += (chunk_size / roq->audio_channels);
}
ret = get_buffer(pb, pkt->data, chunk_size);
if (ret != chunk_size)
ret = -EIO;
packet_read = 1;
break;
default:
printf (" unknown RoQ chunk (%04X)\n", chunk_type);
return AVERROR_INVALIDDATA;
break;
}
}
return ret;
}
static int roq_read_close(AVFormatContext *s)
{
// RoqDemuxContext *roq = (RoqDemuxContext *)s->priv_data;
return 0;
}
static AVInputFormat roq_iformat = {
"RoQ",
"Id RoQ format",
sizeof(RoqDemuxContext),
roq_probe,
roq_read_header,
roq_read_packet,
roq_read_close,
};
int roq_init(void)
{
av_register_input_format(&roq_iformat);
return 0;
}