/*
  * iLBC storage file format
  * Copyright (c) 2012 Martin Storsjo
  *

  * 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 "internal.h"
 
 static const char mode20_header[] = "#!iLBC20\n";
 static const char mode30_header[] = "#!iLBC30\n";
 
 static int ilbc_write_header(AVFormatContext *s)
 {
     AVIOContext *pb = s->pb;
     AVCodecContext *enc;
 
     if (s->nb_streams != 1) {
         av_log(s, AV_LOG_ERROR, "Unsupported number of streams\n");
         return AVERROR(EINVAL);
     }
     enc = s->streams[0]->codec;
 

     if (enc->codec_id != AV_CODEC_ID_ILBC) {

         av_log(s, AV_LOG_ERROR, "Unsupported codec\n");
         return AVERROR(EINVAL);
     }
 
     if (enc->block_align == 50) {
         avio_write(pb, mode30_header, sizeof(mode30_header) - 1);
     } else if (enc->block_align == 38) {
         avio_write(pb, mode20_header, sizeof(mode20_header) - 1);
     } else {
         av_log(s, AV_LOG_ERROR, "Unsupported mode\n");
         return AVERROR(EINVAL);
     }
     avio_flush(pb);
     return 0;
 }
 
 static int ilbc_write_packet(AVFormatContext *s, AVPacket *pkt)
 {
     avio_write(s->pb, pkt->data, pkt->size);
     return 0;
 }
 
 static int ilbc_probe(AVProbeData *p)
 {
     // Only check for "#!iLBC" which matches both formats
     if (!memcmp(p->buf, mode20_header, 6))
         return AVPROBE_SCORE_MAX;
     else
         return 0;
 }
 
 static int ilbc_read_header(AVFormatContext *s)
 {
     AVIOContext *pb = s->pb;
     AVStream *st;
     uint8_t header[9];
 
     avio_read(pb, header, 9);
 
     st = avformat_new_stream(s, NULL);
     if (!st)
         return AVERROR(ENOMEM);

     st->codec->codec_id = AV_CODEC_ID_ILBC;

     st->codec->sample_rate = 8000;
     st->codec->channels = 1;
     st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
     st->start_time = 0;
     avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
     if (!memcmp(header, mode20_header, sizeof(mode20_header) - 1)) {
         st->codec->block_align = 38;
         st->codec->bit_rate = 15200;
     } else if (!memcmp(header, mode30_header, sizeof(mode30_header) - 1)) {
         st->codec->block_align = 50;
         st->codec->bit_rate = 13333;
     } else {
         av_log(s, AV_LOG_ERROR, "Unrecognized iLBC file header\n");
         return AVERROR_INVALIDDATA;
     }
 
     return 0;
 }
 
 static int ilbc_read_packet(AVFormatContext *s,
                           AVPacket *pkt)
 {
     AVCodecContext *enc = s->streams[0]->codec;
     int ret;
 
     if ((ret = av_new_packet(pkt, enc->block_align)) < 0)
         return ret;
 
     pkt->stream_index = 0;
     pkt->pos = avio_tell(s->pb);
     pkt->duration = enc->block_align == 38 ? 160 : 240;
     if ((ret = avio_read(s->pb, pkt->data, enc->block_align)) != enc->block_align) {
         av_free_packet(pkt);
         return ret < 0 ? ret : AVERROR(EIO);
     }
 
     return 0;
 }
 
 AVInputFormat ff_ilbc_demuxer = {
     .name         = "ilbc",

     .long_name    = NULL_IF_CONFIG_SMALL("iLBC storage"),

     .read_probe   = ilbc_probe,
     .read_header  = ilbc_read_header,
     .read_packet  = ilbc_read_packet,
     .flags        = AVFMT_GENERIC_INDEX,
 };
 
 AVOutputFormat ff_ilbc_muxer = {
     .name         = "ilbc",

     .long_name    = NULL_IF_CONFIG_SMALL("iLBC storage"),

     .mime_type    = "audio/iLBC",
     .extensions   = "lbc",

     .audio_codec  = AV_CODEC_ID_ILBC,

     .write_header = ilbc_write_header,
     .write_packet = ilbc_write_packet,
     .flags        = AVFMT_NOTIMESTAMPS,
 };