libavformat/amr.c

   1 /*
   2  * amr file format
   3  * Copyright (c) 2001 ffmpeg project
   4  *
   5  * This file is part of FFmpeg.
   6  *
   7  * FFmpeg is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * FFmpeg is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with FFmpeg; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 /*
  23 Write and read amr data according to RFC3267, http://www.ietf.org/rfc/rfc3267.txt?number=3267
  24
  25 Only mono files are supported.
  26
  27 */
  28 #include "avformat.h"
  29
  30 static const char AMR_header [] = "#!AMR\n";
  31 static const char AMRWB_header [] = "#!AMR-WB\n";
  32
  33 #if CONFIG_AMR_MUXER
  34 static int amr_write_header(AVFormatContext *s)
  35 {
  36     ByteIOContext *pb = s->pb;
  37     AVCodecContext *enc = s->streams[0]->codec;
  38
  39     s->priv_data = NULL;
  40
  41     if (enc->codec_id == CODEC_ID_AMR_NB)
  42     {
  43         put_tag(pb, AMR_header);       /* magic number */
  44     }
  45     else if(enc->codec_id == CODEC_ID_AMR_WB)
  46     {
  47         put_tag(pb, AMRWB_header);       /* magic number */
  48     }
  49     else
  50     {
  51         return -1;
  52     }
  53     put_flush_packet(pb);
  54     return 0;
  55 }
  56
  57 static int amr_write_packet(AVFormatContext *s, AVPacket *pkt)
  58 {
  59     put_buffer(s->pb, pkt->data, pkt->size);
  60     put_flush_packet(s->pb);
  61     return 0;
  62 }
  63 #endif /* CONFIG_AMR_MUXER */
  64
  65 static int amr_probe(AVProbeData *p)
  66 {
  67     //Only check for "#!AMR" which could be amr-wb, amr-nb.
  68     //This will also trigger multichannel files: "#!AMR_MC1.0\n" and
  69     //"#!AMR-WB_MC1.0\n" (not supported)
  70
  71     if(memcmp(p->buf,AMR_header,5)==0)
  72         return AVPROBE_SCORE_MAX;
  73     else
  74         return 0;
  75 }
  76
  77 /* amr input */
  78 static int amr_read_header(AVFormatContext *s,
  79                            AVFormatParameters *ap)
  80 {
  81     ByteIOContext *pb = s->pb;
  82     AVStream *st;
  83     uint8_t header[9];
  84
  85     get_buffer(pb, header, 6);
  86
  87     st = av_new_stream(s, 0);
  88     if (!st)
  89     {
  90         return AVERROR(ENOMEM);
  91     }
  92     if(memcmp(header,AMR_header,6)!=0)
  93     {
  94         get_buffer(pb, header+6, 3);
  95         if(memcmp(header,AMRWB_header,9)!=0)
  96         {
  97             return -1;
  98         }
  99
 100         st->codec->codec_tag = MKTAG('s', 'a', 'w', 'b');
 101         st->codec->codec_id = CODEC_ID_AMR_WB;
 102         st->codec->sample_rate = 16000;
 103     }
 104     else
 105     {
 106         st->codec->codec_tag = MKTAG('s', 'a', 'm', 'r');
 107         st->codec->codec_id = CODEC_ID_AMR_NB;
 108         st->codec->sample_rate = 8000;
 109     }
 110     st->codec->channels = 1;
 111     st->codec->codec_type = CODEC_TYPE_AUDIO;
 112     av_set_pts_info(st, 64, 1, st->codec->sample_rate);
 113
 114     return 0;
 115 }
 116
 117 static int amr_read_packet(AVFormatContext *s,
 118                           AVPacket *pkt)
 119 {
 120     AVCodecContext *enc = s->streams[0]->codec;
 121     int read, size = 0, toc, mode;
 122
 123     if (url_feof(s->pb))
 124     {
 125         return AVERROR(EIO);
 126     }
 127
 128 //FIXME this is wrong, this should rather be in a AVParset
 129     toc=get_byte(s->pb);
 130     mode = (toc >> 3) & 0x0F;
 131
 132     if (enc->codec_id == CODEC_ID_AMR_NB)
 133     {
 134         static const uint8_t packed_size[16] = {12, 13, 15, 17, 19, 20, 26, 31, 5, 0, 0, 0, 0, 0, 0, 0};
 135
 136         size=packed_size[mode]+1;
 137     }
 138     else if(enc->codec_id == CODEC_ID_AMR_WB)
 139     {
 140         static uint8_t packed_size[16] = {18, 24, 33, 37, 41, 47, 51, 59, 61, 6, 6, 0, 0, 0, 1, 1};
 141
 142         size=packed_size[mode];
 143     }
 144     else
 145     {
 146         assert(0);
 147     }
 148
 149     if ( (size==0) || av_new_packet(pkt, size))
 150     {
 151         return AVERROR(EIO);
 152     }
 153
 154     pkt->stream_index = 0;
 155     pkt->pos= url_ftell(s->pb);
 156     pkt->data[0]=toc;
 157     pkt->duration= enc->codec_id == CODEC_ID_AMR_NB ? 160 : 320;
 158     read = get_buffer(s->pb, pkt->data+1, size-1);
 159
 160     if (read != size-1)
 161     {
 162         av_free_packet(pkt);
 163         return AVERROR(EIO);
 164     }
 165
 166     return 0;
 167 }
 168
 169 #if CONFIG_AMR_DEMUXER
 170 AVInputFormat amr_demuxer = {
 171     "amr",
 172     NULL_IF_CONFIG_SMALL("3GPP AMR file format"),
 173     0, /*priv_data_size*/
 174     amr_probe,
 175     amr_read_header,
 176     amr_read_packet,
 177     NULL,
 178 };
 179 #endif
 180
 181 #if CONFIG_AMR_MUXER
 182 AVOutputFormat amr_muxer = {
 183     "amr",
 184     NULL_IF_CONFIG_SMALL("3GPP AMR file format"),
 185     "audio/amr",
 186     "amr",
 187     0,
 188     CODEC_ID_AMR_NB,
 189     CODEC_ID_NONE,
 190     amr_write_header,
 191     amr_write_packet,
 192 };
 193 #endif