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FFmpeg/libavformat/g729dec.c

104 lines
3.0 KiB
C

/*
* G.729 raw format demuxer
* Copyright (c) 2011 Vladimir Voroshilov
*
* 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
*/
#include "avformat.h"
#include "internal.h"
#include "libavutil/log.h"
#include "libavutil/opt.h"
typedef struct G729DemuxerContext {
AVClass *class;
int bit_rate;
} G729DemuxerContext;
static int g729_read_header(AVFormatContext *s, AVFormatParameters *ap)
{
AVStream* st;
G729DemuxerContext *s1 = s->priv_data;
st = avformat_new_stream(s, NULL);
if (!st)
return AVERROR(ENOMEM);
st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
st->codec->codec_id = CODEC_ID_G729;
st->codec->sample_rate = 8000;
st->codec->channels = 1;
if (s1 && s1->bit_rate) {
s->bit_rate = s1->bit_rate;
}
if (s->bit_rate == 0) {
av_log(s, AV_LOG_DEBUG, "No bitrate specified. Assuming 8000 b/s\n");
s->bit_rate = 8000;
}
if (s->bit_rate == 6400) {
st->codec->block_align = 8;
} else if (s->bit_rate == 8000) {
st->codec->block_align = 10;
} else {
av_log(s, AV_LOG_ERROR, "Only 8000 b/s and 6400 b/s bitrates are supported. Provided: %d b/s\n", s->bit_rate);
return AVERROR_INVALIDDATA;
}
avpriv_set_pts_info(st, st->codec->block_align << 3, 1, st->codec->sample_rate);
return 0;
}
static int g729_read_packet(AVFormatContext *s, AVPacket *pkt)
{
int ret;
ret = av_get_packet(s->pb, pkt, s->streams[0]->codec->block_align);
pkt->stream_index = 0;
if (ret < 0)
return ret;
pkt->dts = pkt->pts = pkt->pos / s->streams[0]->codec->block_align;
return ret;
}
static const AVOption g729_options[] = {
{ "bit_rate", "", offsetof(G729DemuxerContext, bit_rate), AV_OPT_TYPE_INT, {.dbl = 0}, 0, INT_MAX, AV_OPT_FLAG_DECODING_PARAM },
{ NULL },
};
static const AVClass g729_demuxer_class = {
.class_name = "g729 demuxer",
.item_name = av_default_item_name,
.option = g729_options,
.version = LIBAVUTIL_VERSION_INT,
};
AVInputFormat ff_g729_demuxer = {
.name = "g729",
.long_name = NULL_IF_CONFIG_SMALL("G.729 raw format demuxer"),
.priv_data_size = sizeof(G729DemuxerContext),
.read_header = g729_read_header,
.read_packet = g729_read_packet,
.flags = AVFMT_GENERIC_INDEX,
.extensions = "g729",
.priv_class = &g729_demuxer_class,
};