/*

  * amr file format
  * Copyright (c) 2001 ffmpeg project
  *

  * 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

  */
 
 /*
 Write and read amr data according to RFC3267, http://www.ietf.org/rfc/rfc3267.txt?number=3267
 

 Only mono files are supported.

 
 */
 #include "avformat.h"

 #include "internal.h"

 static const char AMR_header [] = "#!AMR\n";
 static const char AMRWB_header [] = "#!AMR-WB\n";

 #if CONFIG_AMR_MUXER

 static int amr_write_header(AVFormatContext *s)
 {

     AVIOContext *pb = s->pb;

     AVCodecContext *enc = s->streams[0]->codec;

 
     s->priv_data = NULL;
 

     if (enc->codec_id == CODEC_ID_AMR_NB)
     {

         avio_write(pb, AMR_header,   sizeof(AMR_header)   - 1); /* magic number */

     }
     else if(enc->codec_id == CODEC_ID_AMR_WB)
     {

         avio_write(pb, AMRWB_header, sizeof(AMRWB_header) - 1); /* magic number */

     }
     else
     {

         return -1;

     }

     avio_flush(pb);

     return 0;
 }
 

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

 {

     avio_write(s->pb, pkt->data, pkt->size);

     avio_flush(s->pb);

     return 0;
 }

 #endif /* CONFIG_AMR_MUXER */

 
 static int amr_probe(AVProbeData *p)
 {

     //Only check for "#!AMR" which could be amr-wb, amr-nb.
     //This will also trigger multichannel files: "#!AMR_MC1.0\n" and

     //"#!AMR-WB_MC1.0\n" (not supported)
 
     if(memcmp(p->buf,AMR_header,5)==0)

         return AVPROBE_SCORE_MAX;
     else
         return 0;
 }
 
 /* amr input */
 static int amr_read_header(AVFormatContext *s,
                            AVFormatParameters *ap)
 {

     AVIOContext *pb = s->pb;

     AVStream *st;

     uint8_t header[9];

     avio_read(pb, header, 6);

     st = avformat_new_stream(s, NULL);

     if (!st)
     {

         return AVERROR(ENOMEM);

     }

     if(memcmp(header,AMR_header,6)!=0)
     {

         avio_read(pb, header+6, 3);

         if(memcmp(header,AMRWB_header,9)!=0)
         {
             return -1;
         }

         st->codec->codec_tag = MKTAG('s', 'a', 'w', 'b');
         st->codec->codec_id = CODEC_ID_AMR_WB;
         st->codec->sample_rate = 16000;

         st->codec->frame_size = 320;

     }
     else
     {

         st->codec->codec_tag = MKTAG('s', 'a', 'm', 'r');
         st->codec->codec_id = CODEC_ID_AMR_NB;
         st->codec->sample_rate = 8000;

         st->codec->frame_size = 160;

     }

     st->codec->channels = 1;

     st->codec->codec_type = AVMEDIA_TYPE_AUDIO;

     avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);

 
     return 0;
 }
 
 static int amr_read_packet(AVFormatContext *s,
                           AVPacket *pkt)
 {

     AVCodecContext *enc = s->streams[0]->codec;

     int read, size = 0, toc, mode;

     int64_t pos = avio_tell(s->pb);

     if (url_feof(s->pb))

     {

         return AVERROR(EIO);

     }

 //FIXME this is wrong, this should rather be in a AVParset

     toc=avio_r8(s->pb);

     mode = (toc >> 3) & 0x0F;

     if (enc->codec_id == CODEC_ID_AMR_NB)
     {
         static const uint8_t packed_size[16] = {12, 13, 15, 17, 19, 20, 26, 31, 5, 0, 0, 0, 0, 0, 0, 0};

         size=packed_size[mode]+1;

     }
     else if(enc->codec_id == CODEC_ID_AMR_WB)
     {
         static uint8_t packed_size[16] = {18, 24, 33, 37, 41, 47, 51, 59, 61, 6, 6, 0, 0, 0, 1, 1};

         size=packed_size[mode];

     }
     else

     {

         assert(0);

     }

 
     if ( (size==0) || av_new_packet(pkt, size))
     {

         return AVERROR(EIO);

     }
 

     /* Both AMR formats have 50 frames per second */
     s->streams[0]->codec->bit_rate = size*8*50;
 

     pkt->stream_index = 0;

     pkt->pos = pos;

     pkt->data[0]=toc;

     pkt->duration= enc->codec_id == CODEC_ID_AMR_NB ? 160 : 320;

     read = avio_read(s->pb, pkt->data+1, size-1);

 
     if (read != size-1)
     {
         av_free_packet(pkt);

         return AVERROR(EIO);

     }
 

     return 0;

 }
 

 #if CONFIG_AMR_DEMUXER

 AVInputFormat ff_amr_demuxer = {

     .name           = "amr",
     .long_name      = NULL_IF_CONFIG_SMALL("3GPP AMR file format"),
     .read_probe     = amr_probe,
     .read_header    = amr_read_header,
     .read_packet    = amr_read_packet,

     .flags = AVFMT_GENERIC_INDEX,

 };

 #endif

 #if CONFIG_AMR_MUXER

 AVOutputFormat ff_amr_muxer = {

     .name              = "amr",
     .long_name         = NULL_IF_CONFIG_SMALL("3GPP AMR file format"),
     .mime_type         = "audio/amr",
     .extensions        = "amr",
     .audio_codec       = CODEC_ID_AMR_NB,
     .video_codec       = CODEC_ID_NONE,
     .write_header      = amr_write_header,
     .write_packet      = amr_write_packet,

 };

 #endif