libavformat/amr.c

   1 /*
   2  * amr file format
   3  * Copyright (c) 2001 ffmpeg project
   4  *
   5  * This library is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Lesser General Public
   7  * License as published by the Free Software Foundation; either
   8  * version 2 of the License, or (at your option) any later version.
   9  *
  10  * This library is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * Lesser General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU Lesser General Public
  16  * License along with this library; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  18  */
  19
  20 /*
  21 Write and read amr data according to RFC3267, http://www.ietf.org/rfc/rfc3267.txt?number=3267
  22
  23 Only mono files are supported.
  24
  25 */
  26 #include "avformat.h"
  27
  28 static const unsigned char AMR_header [] = "#!AMR\n";
  29 static const unsigned char AMRWB_header [] = "#!AMR-WB\n";
  30
  31 #ifdef CONFIG_MUXERS
  32 static int amr_write_header(AVFormatContext *s)
  33 {
  34     ByteIOContext *pb = &s->pb;
  35     AVCodecContext *enc = s->streams[0]->codec;
  36
  37     s->priv_data = NULL;
  38
  39     if (enc->codec_id == CODEC_ID_AMR_NB)
  40     {
  41         put_tag(pb, AMR_header);       /* magic number */
  42     }
  43     else if(enc->codec_id == CODEC_ID_AMR_WB)
  44     {
  45         put_tag(pb, AMRWB_header);       /* magic number */
  46     }
  47     else
  48     {
  49         //This is an error!
  50     }
  51     put_flush_packet(pb);
  52     return 0;
  53 }
  54
  55 static int amr_write_packet(AVFormatContext *s, AVPacket *pkt)
  56 {
  57     put_buffer(&s->pb, pkt->data, pkt->size);
  58     put_flush_packet(&s->pb);
  59     return 0;
  60 }
  61
  62 static int amr_write_trailer(AVFormatContext *s)
  63 {
  64     return 0;
  65 }
  66 #endif /* CONFIG_MUXERS */
  67
  68 static int amr_probe(AVProbeData *p)
  69 {
  70     //Only check for "#!AMR" which could be amr-wb, amr-nb.
  71     //This will also trigger multichannel files: "#!AMR_MC1.0\n" and
  72     //"#!AMR-WB_MC1.0\n" (not supported)
  73
  74     if (p->buf_size < 5)
  75         return 0;
  76     if(memcmp(p->buf,AMR_header,5)==0)
  77         return AVPROBE_SCORE_MAX;
  78     else
  79         return 0;
  80 }
  81
  82 /* amr input */
  83 static int amr_read_header(AVFormatContext *s,
  84                            AVFormatParameters *ap)
  85 {
  86     ByteIOContext *pb = &s->pb;
  87     AVStream *st;
  88     uint8_t header[9];
  89
  90     get_buffer(pb, header, 6);
  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         st = av_new_stream(s, 0);
 100         if (!st)
 101         {
 102             return AVERROR_NOMEM;
 103         }
 104
 105         st->codec->codec_type = CODEC_TYPE_AUDIO;
 106         st->codec->codec_tag = MKTAG('s', 'a', 'w', 'b');
 107         st->codec->codec_id = CODEC_ID_AMR_WB;
 108         st->codec->channels = 1;
 109         st->codec->sample_rate = 16000;
 110     }
 111     else
 112     {
 113         st = av_new_stream(s, 0);
 114         if (!st)
 115         {
 116             return AVERROR_NOMEM;
 117         }
 118
 119         st->codec->codec_type = CODEC_TYPE_AUDIO;
 120         st->codec->codec_tag = MKTAG('s', 'a', 'm', 'r');
 121         st->codec->codec_id = CODEC_ID_AMR_NB;
 122         st->codec->channels = 1;
 123         st->codec->sample_rate = 8000;
 124     }
 125
 126     return 0;
 127 }
 128
 129 #define MAX_SIZE 32
 130
 131 static int amr_read_packet(AVFormatContext *s,
 132                           AVPacket *pkt)
 133 {
 134     AVCodecContext *enc = s->streams[0]->codec;
 135
 136     if (enc->codec_id == CODEC_ID_AMR_NB)
 137     {
 138         static const uint8_t packed_size[16] = {12, 13, 15, 17, 19, 20, 26, 31, 5, 0, 0, 0, 0, 0, 0, 0};
 139         uint8_t toc, q, ft;
 140         int read;
 141         int size;
 142
 143         if (url_feof(&s->pb))
 144         {
 145             return AVERROR_IO;
 146         }
 147
 148         toc=get_byte(&s->pb);
 149         q  = (toc >> 2) & 0x01;
 150         ft = (toc >> 3) & 0x0F;
 151
 152         size=packed_size[ft];
 153
 154         if (av_new_packet(pkt, size+1))
 155         {
 156             return AVERROR_IO;
 157         }
 158         pkt->stream_index = 0;
 159         pkt->pos= url_ftell(&s->pb);
 160         pkt->data[0]=toc;
 161
 162         read = get_buffer(&s->pb, pkt->data+1, size);
 163
 164         if (read != size)
 165         {
 166             av_free_packet(pkt);
 167             return AVERROR_IO;
 168         }
 169
 170         return 0;
 171     }
 172     else if(enc->codec_id == CODEC_ID_AMR_WB)
 173     {
 174         static uint8_t packed_size[16] = {18, 24, 33, 37, 41, 47, 51, 59, 61, 6, 6, 0, 0, 0, 1, 1};
 175         uint8_t toc, mode;
 176         int read;
 177         int size;
 178
 179         if (url_feof(&s->pb))
 180         {
 181             return AVERROR_IO;
 182         }
 183
 184         toc=get_byte(&s->pb);
 185         mode = (uint8_t)((toc >> 3) & 0x0F);
 186         size = packed_size[mode];
 187
 188         if ( (size==0) || av_new_packet(pkt, size))
 189         {
 190             return AVERROR_IO;
 191         }
 192
 193         pkt->stream_index = 0;
 194         pkt->pos= url_ftell(&s->pb);
 195         pkt->data[0]=toc;
 196
 197         read = get_buffer(&s->pb, pkt->data+1, size-1);
 198
 199         if (read != (size-1))
 200         {
 201             av_free_packet(pkt);
 202             return AVERROR_IO;
 203         }
 204
 205         return 0;
 206     }
 207     else
 208     {
 209         return AVERROR_IO;
 210     }
 211 }
 212
 213 static int amr_read_close(AVFormatContext *s)
 214 {
 215     return 0;
 216 }
 217
 218 #ifdef CONFIG_AMR_DEMUXER
 219 AVInputFormat amr_demuxer = {
 220     "amr",
 221     "3gpp amr file format",
 222     0, /*priv_data_size*/
 223     amr_probe,
 224     amr_read_header,
 225     amr_read_packet,
 226     amr_read_close,
 227 };
 228 #endif
 229
 230 #ifdef CONFIG_AMR_MUXER
 231 AVOutputFormat amr_muxer = {
 232     "amr",
 233     "3gpp amr file format",
 234     "audio/amr",
 235     "amr",
 236     0,
 237     CODEC_ID_AMR_NB,
 238     CODEC_ID_NONE,
 239     amr_write_header,
 240     amr_write_packet,
 241     amr_write_trailer,
 242 };
 243 #endif