/*

  * 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(s, pb, st->codecpar, size, 0);

 
     /*
       8000Hz (Fine-rec) file format has 10 bytes long
       packets with 10ms of sound data in them
     */

     if (st->codecpar->sample_rate != 8000) {
         av_log(s, AV_LOG_ERROR, "Sample rate %d is not supported.\n", st->codecpar->sample_rate);

         return AVERROR_INVALIDDATA;

     }
 

     st->codecpar->frame_size=80;
     st->codecpar->channels=1;

     avpriv_set_pts_info(st, 64, 1, 100);

     st->codecpar->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->codecpar->sample_rate, 1000 * st->codecpar->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]->codecpar->sample_rate==8000?10:22;

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

         ret=av_new_packet(pkt, 10);
     else
         ret=av_new_packet(pkt, 11);
 
     if(ret)
         return ret;
 

     if(s->streams[0]->codecpar->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]->codecpar->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,

 };