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/*

 * ACT file format demuxer

 * Copyright (c) 2007-2008 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 "riff.h"

#include "internal.h"

#include "libavcodec/get_bits.h"

#define CHUNK_SIZE 512

#define RIFF_TAG MKTAG('R','I','F','F')

#define WAVE_TAG MKTAG('W','A','V','E')

typedef struct{

    int bytes_left_in_chunk;

    uint8_t audio_buffer[22];///< temporary buffer for ACT frame

    char second_packet;      ///< 1 - if temporary buffer contains valid (second) G.729 packet

} ACTContext;

static int probe(AVProbeData *p)

{

    int i;

    if ((AV_RL32(&p->buf[0]) != RIFF_TAG) ||

        (AV_RL32(&p->buf[8]) != WAVE_TAG) ||

        (AV_RL32(&p->buf[16]) != 16))

    return 0;

    //We can't be sure that this is ACT and not regular WAV

    if (p->buf_size<512)

        return 0;

    for(i=44; i<256; i++)

        if(p->buf[i])

            return 0;

    if(p->buf[256]!=0x84)

        return 0;

    for(i=264; i<512; i++)

        if(p->buf[i])

            return 0;

    return AVPROBE_SCORE_MAX;

}

static int read_header(AVFormatContext *s)

{

    ACTContext* ctx = s->priv_data;

    AVIOContext *pb = s->pb;

    int size;

    AVStream* st;

    int min,sec,msec;

    st = avformat_new_stream(s, NULL);

    if (!st)

        return AVERROR(ENOMEM);

    avio_skip(pb, 16);

    size=avio_rl32(pb);

    ff_get_wav_header(pb, st->codec, size);

    /*

      8000Hz (Fine-rec) file format has 10 bytes long

      packets with 10ms of sound data in them

    */

    if (st->codec->sample_rate != 8000) {

        av_log(s, AV_LOG_ERROR, "Sample rate %d is not supported.\n", st->codec->sample_rate);

        return AVERROR_INVALIDDATA;

    }

    st->codec->frame_size=80;

    st->codec->channels=1;

    avpriv_set_pts_info(st, 64, 1, 100);

    st->codec->codec_id=AV_CODEC_ID_G729;

    avio_seek(pb, 257, SEEK_SET);

    msec=avio_rl16(pb);

    sec=avio_r8(pb);

    min=avio_rl32(pb);

    st->duration = av_rescale(1000*(min*60+sec)+msec, st->codec->sample_rate, 1000 * st->codec->frame_size);

    ctx->bytes_left_in_chunk=CHUNK_SIZE;

    avio_seek(pb, 512, SEEK_SET);

    return 0;

}

static int read_packet(AVFormatContext *s,

                          AVPacket *pkt)

{

    ACTContext *ctx = s->priv_data;

    AVIOContext *pb = s->pb;

    int ret;

    int frame_size=s->streams[0]->codec->sample_rate==8000?10:22;

    if(s->streams[0]->codec->sample_rate==8000)

        ret=av_new_packet(pkt, 10);

    else

        ret=av_new_packet(pkt, 11);

    if(ret)

        return ret;

    if(s->streams[0]->codec->sample_rate==4400 && !ctx->second_packet)

    {

        ret = avio_read(pb, ctx->audio_buffer, frame_size);

        if(ret<0)

            return ret;

        if(ret!=frame_size)

            return AVERROR(EIO);

        pkt->data[0]=ctx->audio_buffer[11];

        pkt->data[1]=ctx->audio_buffer[0];

        pkt->data[2]=ctx->audio_buffer[12];

        pkt->data[3]=ctx->audio_buffer[1];

        pkt->data[4]=ctx->audio_buffer[13];

        pkt->data[5]=ctx->audio_buffer[2];

        pkt->data[6]=ctx->audio_buffer[14];

        pkt->data[7]=ctx->audio_buffer[3];

        pkt->data[8]=ctx->audio_buffer[15];

        pkt->data[9]=ctx->audio_buffer[4];

        pkt->data[10]=ctx->audio_buffer[16];

        ctx->second_packet=1;

    }

    else if(s->streams[0]->codec->sample_rate==4400 && ctx->second_packet)

    {

        pkt->data[0]=ctx->audio_buffer[5];

        pkt->data[1]=ctx->audio_buffer[17];

        pkt->data[2]=ctx->audio_buffer[6];

        pkt->data[3]=ctx->audio_buffer[18];

        pkt->data[4]=ctx->audio_buffer[7];

        pkt->data[5]=ctx->audio_buffer[19];

        pkt->data[6]=ctx->audio_buffer[8];

        pkt->data[7]=ctx->audio_buffer[20];

        pkt->data[8]=ctx->audio_buffer[9];

        pkt->data[9]=ctx->audio_buffer[21];

        pkt->data[10]=ctx->audio_buffer[10];

        ctx->second_packet=0;

    }

    else // 8000 Hz

    {

        ret = avio_read(pb, ctx->audio_buffer, frame_size);

        if(ret<0)

            return ret;

        if(ret!=frame_size)

            return AVERROR(EIO);

        pkt->data[0]=ctx->audio_buffer[5];

        pkt->data[1]=ctx->audio_buffer[0];

        pkt->data[2]=ctx->audio_buffer[6];

        pkt->data[3]=ctx->audio_buffer[1];

        pkt->data[4]=ctx->audio_buffer[7];

        pkt->data[5]=ctx->audio_buffer[2];

        pkt->data[6]=ctx->audio_buffer[8];

        pkt->data[7]=ctx->audio_buffer[3];

        pkt->data[8]=ctx->audio_buffer[9];

        pkt->data[9]=ctx->audio_buffer[4];

    }

    ctx->bytes_left_in_chunk -= frame_size;

    if(ctx->bytes_left_in_chunk < frame_size)

    {

        avio_skip(pb, ctx->bytes_left_in_chunk);

        ctx->bytes_left_in_chunk=CHUNK_SIZE;

    }

    pkt->duration=1;

    return ret;

}

AVInputFormat ff_act_demuxer = {

    .name           = "act",

    .long_name      = "ACT Voice file format",

    .priv_data_size = sizeof(ACTContext),

    .read_probe     = probe,

    .read_header    = read_header,

    .read_packet    = read_packet,

};