mirror of https://github.com/FFmpeg/FFmpeg.git
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
99 lines
2.8 KiB
99 lines
2.8 KiB
/* |
|
* 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 |
|
*/ |
|
|
|
#include "libavutil/mathematics.h" |
|
#include "libavutil/opt.h" |
|
#include "avformat.h" |
|
#include "internal.h" |
|
|
|
#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; |
|
|
|
size = GSM_BLOCK_SIZE; |
|
|
|
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); |
|
} |
|
pkt->size = ret; |
|
pkt->duration = 1; |
|
pkt->pts = pkt->pos / GSM_BLOCK_SIZE; |
|
|
|
return 0; |
|
} |
|
|
|
static int gsm_read_header(AVFormatContext *s, AVFormatParameters *ap) |
|
{ |
|
GSMDemuxerContext *c = s->priv_data; |
|
AVStream *st = avformat_new_stream(s, NULL); |
|
if (!st) |
|
return AVERROR(ENOMEM); |
|
|
|
st->codec->codec_type = AVMEDIA_TYPE_AUDIO; |
|
st->codec->codec_id = s->iformat->value; |
|
st->codec->channels = 1; |
|
st->codec->sample_rate = c->sample_rate; |
|
st->codec->bit_rate = GSM_BLOCK_SIZE * 8 * c->sample_rate / GSM_BLOCK_SAMPLES; |
|
|
|
avpriv_set_pts_info(st, 64, GSM_BLOCK_SAMPLES, GSM_SAMPLE_RATE); |
|
|
|
return 0; |
|
} |
|
|
|
static const AVOption options[] = { |
|
{ "sample_rate", "", offsetof(GSMDemuxerContext, sample_rate), |
|
AV_OPT_TYPE_INT, {.dbl = GSM_SAMPLE_RATE}, 1, INT_MAX / GSM_BLOCK_SIZE, |
|
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, |
|
.flags = AVFMT_GENERIC_INDEX, |
|
.extensions = "gsm", |
|
.value = CODEC_ID_GSM, |
|
.priv_class = &class, |
|
};
|
|
|