87c57d80 |
/*
* RAW GSM demuxer
* Copyright (c) 2011 Justin Ruggles
*
* 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
*/
|
d4a105ae |
#include "libavutil/channel_layout.h" |
87c57d80 |
#include "libavutil/mathematics.h"
#include "libavutil/opt.h"
#include "avformat.h" |
c3f9ebf7 |
#include "internal.h" |
87c57d80 |
#define GSM_BLOCK_SIZE 33
#define GSM_BLOCK_SAMPLES 160
#define GSM_SAMPLE_RATE 8000
typedef struct {
AVClass *class;
int sample_rate;
} GSMDemuxerContext;
static int gsm_read_packet(AVFormatContext *s, AVPacket *pkt)
{
int ret, size;
|
467879eb |
size = GSM_BLOCK_SIZE; |
87c57d80 |
pkt->pos = avio_tell(s->pb);
pkt->stream_index = 0;
ret = av_get_packet(s->pb, pkt, size);
if (ret < GSM_BLOCK_SIZE) {
av_free_packet(pkt);
return ret < 0 ? ret : AVERROR(EIO);
} |
467879eb |
pkt->duration = 1; |
87c57d80 |
pkt->pts = pkt->pos / GSM_BLOCK_SIZE;
return 0;
}
|
6e9651d1 |
static int gsm_read_header(AVFormatContext *s) |
87c57d80 |
{
GSMDemuxerContext *c = s->priv_data;
AVStream *st = avformat_new_stream(s, NULL);
if (!st)
return AVERROR(ENOMEM);
st->codec->codec_type = AVMEDIA_TYPE_AUDIO; |
f7fe41a0 |
st->codec->codec_id = s->iformat->raw_codec_id; |
87c57d80 |
st->codec->channels = 1; |
d4a105ae |
st->codec->channel_layout = AV_CH_LAYOUT_MONO; |
87c57d80 |
st->codec->sample_rate = c->sample_rate;
st->codec->bit_rate = GSM_BLOCK_SIZE * 8 * c->sample_rate / GSM_BLOCK_SAMPLES;
|
c3f9ebf7 |
avpriv_set_pts_info(st, 64, GSM_BLOCK_SAMPLES, GSM_SAMPLE_RATE); |
87c57d80 |
return 0;
}
static const AVOption options[] = {
{ "sample_rate", "", offsetof(GSMDemuxerContext, sample_rate), |
e6153f17 |
AV_OPT_TYPE_INT, {.i64 = GSM_SAMPLE_RATE}, 1, INT_MAX / GSM_BLOCK_SIZE, |
87c57d80 |
AV_OPT_FLAG_DECODING_PARAM },
{ NULL },
};
static const AVClass class = {
.class_name = "gsm demuxer",
.item_name = av_default_item_name,
.option = options,
.version = LIBAVUTIL_VERSION_INT,
};
AVInputFormat ff_gsm_demuxer = {
.name = "gsm",
.long_name = NULL_IF_CONFIG_SMALL("raw GSM"),
.priv_data_size = sizeof(GSMDemuxerContext),
.read_header = gsm_read_header,
.read_packet = gsm_read_packet, |
f01f6a84 |
.flags = AVFMT_GENERIC_INDEX, |
87c57d80 |
.extensions = "gsm", |
36ef5369 |
.raw_codec_id = AV_CODEC_ID_GSM, |
87c57d80 |
.priv_class = &class,
}; |