/*
  * Creative Voice File demuxer.
  * Copyright (c) 2006  Aurelien Jacobs <aurel@gnuage.org>
  *
  * 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/intreadwrite.h"

 #include "voc.h"

 #include "internal.h"

 
 
 static int voc_probe(AVProbeData *p)
 {
     int version, check;
 

     if (memcmp(p->buf, ff_voc_magic, sizeof(ff_voc_magic) - 1))

         return 0;

     version = AV_RL16(p->buf + 22);
     check = AV_RL16(p->buf + 24);

     if (~version + 0x1234 != check)
         return 10;
 
     return AVPROBE_SCORE_MAX;
 }
 

 static int voc_read_header(AVFormatContext *s)

 {

     VocDecContext *voc = s->priv_data;

     AVIOContext *pb = s->pb;

     int header_size;
     AVStream *st;
 

     avio_skip(pb, 20);

     header_size = avio_rl16(pb) - 22;

     if (header_size != 4) {

         av_log(s, AV_LOG_ERROR, "unknown header size: %d\n", header_size);

         return AVERROR(ENOSYS);

     }

     avio_skip(pb, header_size);

     st = avformat_new_stream(s, NULL);

     if (!st)

         return AVERROR(ENOMEM);

     st->codec->codec_type = AVMEDIA_TYPE_AUDIO;

 
     voc->remaining_size = 0;
     return 0;
 }
 
 int

 ff_voc_get_packet(AVFormatContext *s, AVPacket *pkt, AVStream *st, int max_size)

 {

     VocDecContext *voc = s->priv_data;

     AVCodecContext *dec = st->codec;

     AVIOContext *pb = s->pb;

     VocType type;

     int size, tmp_codec=-1;

     int sample_rate = 0;
     int channels = 1;
 
     while (!voc->remaining_size) {

         type = avio_r8(pb);

         if (type == VOC_TYPE_EOF)

             return AVERROR_EOF;

         voc->remaining_size = avio_rl24(pb);

         if (!voc->remaining_size) {

             if (!s->pb->seekable)

                 return AVERROR(EIO);

             voc->remaining_size = avio_size(pb) - avio_tell(pb);

         }

         max_size -= 4;
 
         switch (type) {
         case VOC_TYPE_VOICE_DATA:

             if (!dec->sample_rate) {
                 dec->sample_rate = 1000000 / (256 - avio_r8(pb));
                 if (sample_rate)
                     dec->sample_rate = sample_rate;
                 avpriv_set_pts_info(st, 64, 1, dec->sample_rate);

                 dec->channels = channels;
                 dec->bits_per_coded_sample = av_get_bits_per_sample(dec->codec_id);

             } else
                 avio_skip(pb, 1);

             tmp_codec = avio_r8(pb);

             voc->remaining_size -= 2;
             max_size -= 2;
             channels = 1;
             break;
 
         case VOC_TYPE_VOICE_DATA_CONT:
             break;
 
         case VOC_TYPE_EXTENDED:

             sample_rate = avio_rl16(pb);
             avio_r8(pb);
             channels = avio_r8(pb) + 1;

             sample_rate = 256000000 / (channels * (65536 - sample_rate));
             voc->remaining_size = 0;
             max_size -= 4;
             break;
 
         case VOC_TYPE_NEW_VOICE_DATA:

             if (!dec->sample_rate) {
                 dec->sample_rate = avio_rl32(pb);
                 avpriv_set_pts_info(st, 64, 1, dec->sample_rate);

                 dec->bits_per_coded_sample = avio_r8(pb);
                 dec->channels = avio_r8(pb);

             } else

                 avio_skip(pb, 6);

             tmp_codec = avio_rl16(pb);

             avio_skip(pb, 4);

             voc->remaining_size -= 12;
             max_size -= 12;
             break;
 
         default:

             avio_skip(pb, voc->remaining_size);

             max_size -= voc->remaining_size;
             voc->remaining_size = 0;
             break;
         }

     }
 
     if (tmp_codec >= 0) {
         tmp_codec = ff_codec_get_id(ff_voc_codec_tags, tmp_codec);

         if (dec->codec_id == AV_CODEC_ID_NONE)

             dec->codec_id = tmp_codec;
         else if (dec->codec_id != tmp_codec)
             av_log(s, AV_LOG_WARNING, "Ignoring mid-stream change in audio codec\n");

         if (dec->codec_id == AV_CODEC_ID_NONE) {
             if (s->audio_codec_id == AV_CODEC_ID_NONE) {

                 av_log(s, AV_LOG_ERROR, "unknown codec tag\n");
                 return AVERROR(EINVAL);
             }
             av_log(s, AV_LOG_WARNING, "unknown codec tag\n");

         }

     }
 

     dec->bit_rate = dec->sample_rate * dec->channels * dec->bits_per_coded_sample;

 
     if (max_size <= 0)

         max_size = 2048;

     size = FFMIN(voc->remaining_size, max_size);
     voc->remaining_size -= size;
     return av_get_packet(pb, pkt, size);
 }
 
 static int voc_read_packet(AVFormatContext *s, AVPacket *pkt)
 {

     return ff_voc_get_packet(s, pkt, s->streams[0], 0);

 }
 

 AVInputFormat ff_voc_demuxer = {

     .name           = "voc",

     .long_name      = NULL_IF_CONFIG_SMALL("Creative Voice"),

     .priv_data_size = sizeof(VocDecContext),
     .read_probe     = voc_probe,
     .read_header    = voc_read_header,
     .read_packet    = voc_read_packet,

     .codec_tag      = (const AVCodecTag* const []){ ff_voc_codec_tags, 0 },

 };