yading@11: /*
yading@11:  * G.729 raw format demuxer
yading@11:  * Copyright (c) 2011 Vladimir Voroshilov
yading@11:  *
yading@11:  * This file is part of FFmpeg.
yading@11:  *
yading@11:  * FFmpeg is free software; you can redistribute it and/or
yading@11:  * modify it under the terms of the GNU Lesser General Public
yading@11:  * License as published by the Free Software Foundation; either
yading@11:  * version 2.1 of the License, or (at your option) any later version.
yading@11:  *
yading@11:  * FFmpeg is distributed in the hope that it will be useful,
yading@11:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@11:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@11:  * Lesser General Public License for more details.
yading@11:  *
yading@11:  * You should have received a copy of the GNU Lesser General Public
yading@11:  * License along with FFmpeg; if not, write to the Free Software
yading@11:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@11:  */
yading@11: 
yading@11: #include "avformat.h"
yading@11: #include "internal.h"
yading@11: #include "libavutil/log.h"
yading@11: #include "libavutil/opt.h"
yading@11: 
yading@11: typedef struct G729DemuxerContext {
yading@11:     AVClass *class;
yading@11:     int bit_rate;
yading@11: } G729DemuxerContext;
yading@11: 
yading@11: static int g729_read_header(AVFormatContext *s)
yading@11: {
yading@11:     AVStream* st;
yading@11:     G729DemuxerContext *s1 = s->priv_data;
yading@11: 
yading@11:     st = avformat_new_stream(s, NULL);
yading@11:     if (!st)
yading@11:         return AVERROR(ENOMEM);
yading@11: 
yading@11:     st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
yading@11:     st->codec->codec_id = AV_CODEC_ID_G729;
yading@11:     st->codec->sample_rate = 8000;
yading@11:     st->codec->channels = 1;
yading@11: 
yading@11:     if (s1 && s1->bit_rate) {
yading@11:         s->bit_rate = s1->bit_rate;
yading@11:     }
yading@11: 
yading@11:     if (s->bit_rate == 0) {
yading@11:         av_log(s, AV_LOG_DEBUG, "No bitrate specified. Assuming 8000 b/s\n");
yading@11:         s->bit_rate = 8000;
yading@11:     }
yading@11: 
yading@11:     if (s->bit_rate == 6400) {
yading@11:         st->codec->block_align = 8;
yading@11:     } else if (s->bit_rate == 8000) {
yading@11:         st->codec->block_align = 10;
yading@11:     } else {
yading@11:         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);
yading@11:         return AVERROR_INVALIDDATA;
yading@11:     }
yading@11: 
yading@11:     avpriv_set_pts_info(st, st->codec->block_align << 3, 1, st->codec->sample_rate);
yading@11:     return 0;
yading@11: }
yading@11: static int g729_read_packet(AVFormatContext *s, AVPacket *pkt)
yading@11: {
yading@11:     int ret;
yading@11: 
yading@11:     ret = av_get_packet(s->pb, pkt, s->streams[0]->codec->block_align);
yading@11: 
yading@11:     pkt->stream_index = 0;
yading@11:     if (ret < 0)
yading@11:         return ret;
yading@11: 
yading@11:     pkt->dts = pkt->pts = pkt->pos / s->streams[0]->codec->block_align;
yading@11: 
yading@11:     return ret;
yading@11: }
yading@11: 
yading@11: static const AVOption g729_options[] = {
yading@11:     { "bit_rate", "", offsetof(G729DemuxerContext, bit_rate), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, AV_OPT_FLAG_DECODING_PARAM },
yading@11:     { NULL },
yading@11: };
yading@11: 
yading@11: static const AVClass g729_demuxer_class = {
yading@11:     .class_name = "g729 demuxer",
yading@11:     .item_name  = av_default_item_name,
yading@11:     .option     = g729_options,
yading@11:     .version    = LIBAVUTIL_VERSION_INT,
yading@11: };
yading@11: 
yading@11: AVInputFormat ff_g729_demuxer = {
yading@11:     .name           = "g729",
yading@11:     .long_name      = NULL_IF_CONFIG_SMALL("G.729 raw format demuxer"),
yading@11:     .priv_data_size = sizeof(G729DemuxerContext),
yading@11:     .read_header    = g729_read_header,
yading@11:     .read_packet    = g729_read_packet,
yading@11:     .flags          = AVFMT_GENERIC_INDEX,
yading@11:     .extensions     = "g729",
yading@11:     .priv_class     = &g729_demuxer_class,
yading@11: };