/*

 * 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 "libavutil/log.h"

#include "libavutil/opt.h"

#include "avformat.h"

#include "demux.h"

#include "internal.h"

typedef struct G729DemuxerContext {

    AVClass *class;

    int bit_rate;

} G729DemuxerContext;

static int g729_read_header(AVFormatContext *s)

{

    AVStream* st;

    G729DemuxerContext *s1 = s->priv_data;

    st = avformat_new_stream(s, NULL);

    if (!st)

        return AVERROR(ENOMEM);

    st->codecpar->codec_type  = AVMEDIA_TYPE_AUDIO;

    st->codecpar->codec_id    = AV_CODEC_ID_G729;

    st->codecpar->sample_rate = 8000;

    st->codecpar->ch_layout   = (AVChannelLayout)AV_CHANNEL_LAYOUT_MONO;

    if (s1 && s1->bit_rate)

        s->bit_rate = s1->bit_rate;

    switch(s->bit_rate) {

    case 6400:

        st->codecpar->block_align = 8;

        break;

    case 8000:

        st->codecpar->block_align = 10;

        break;

    default:

        av_log(s, AV_LOG_ERROR, "Invalid bit_rate value %"PRId64". "

               "Only 6400 and 8000 b/s are supported.", s->bit_rate);

        return AVERROR(EINVAL);

    }

    avpriv_set_pts_info(st, 64, 80, st->codecpar->sample_rate);

    return 0;

}

static int g729_read_packet(AVFormatContext *s, AVPacket *pkt)

{

    AVStream *st = s->streams[0];

    int ret = av_get_packet(s->pb, pkt, st->codecpar->block_align);

    if (ret < 0)

        return ret;

    pkt->stream_index = 0;

    pkt->dts = pkt->pts = pkt->pos / st->codecpar->block_align;

    pkt->duration = 1;

    return 0;

}

#define OFFSET(x) offsetof(G729DemuxerContext, x)

static const AVOption g729_options[] = {

    { "bit_rate", "", OFFSET(bit_rate), AV_OPT_TYPE_INT, { .i64 = 8000 }, 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,

};

const FFInputFormat ff_g729_demuxer = {

    .p.name         = "g729",

    .p.long_name    = NULL_IF_CONFIG_SMALL("G.729 raw format demuxer"),

    .p.flags        = AVFMT_GENERIC_INDEX,

    .p.extensions   = "g729",

    .p.priv_class   = &g729_demuxer_class,

    .priv_data_size = sizeof(G729DemuxerContext),

    .read_header    = g729_read_header,

    .read_packet    = g729_read_packet,

};