libavformat/au.c

   1 /*
   2  * AU muxer and demuxer
   3  * Copyright (c) 2001 Fabrice Bellard
   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  * First version by Francois Revol revol@free.fr
  24  *
  25  * Reference documents:
  26  * http://www.opengroup.org/public/pubs/external/auformat.html
  27  * http://www.goice.co.jp/member/mo/formats/au.html
  28  */
  29
  30 #include "avformat.h"
  31 #include "raw.h"
  32 #include "riff.h"
  33
  34 /* if we don't know the size in advance */
  35 #define AU_UNKNOWN_SIZE ((uint32_t)(~0))
  36
  37 /* The ffmpeg codecs we support, and the IDs they have in the file */
  38 static const AVCodecTag codec_au_tags[] = {
  39     { CODEC_ID_PCM_MULAW, 1 },
  40     { CODEC_ID_PCM_S8, 2 },
  41     { CODEC_ID_PCM_S16BE, 3 },
  42     { CODEC_ID_PCM_S24BE, 4 },
  43     { CODEC_ID_PCM_S32BE, 5 },
  44     { CODEC_ID_PCM_F32BE, 6 },
  45     { CODEC_ID_PCM_F64BE, 7 },
  46     { CODEC_ID_PCM_ALAW, 27 },
  47     { 0, 0 },
  48 };
  49
  50 #if CONFIG_AU_MUXER
  51 /* AUDIO_FILE header */
  52 static int put_au_header(ByteIOContext *pb, AVCodecContext *enc)
  53 {
  54     if(!enc->codec_tag)
  55         return -1;
  56     put_tag(pb, ".snd");       /* magic number */
  57     put_be32(pb, 24);           /* header size */
  58     put_be32(pb, AU_UNKNOWN_SIZE); /* data size */
  59     put_be32(pb, (uint32_t)enc->codec_tag);     /* codec ID */
  60     put_be32(pb, enc->sample_rate);
  61     put_be32(pb, (uint32_t)enc->channels);
  62     return 0;
  63 }
  64
  65 static int au_write_header(AVFormatContext *s)
  66 {
  67     ByteIOContext *pb = s->pb;
  68
  69     s->priv_data = NULL;
  70
  71     /* format header */
  72     if (put_au_header(pb, s->streams[0]->codec) < 0) {
  73         return -1;
  74     }
  75
  76     put_flush_packet(pb);
  77
  78     return 0;
  79 }
  80
  81 static int au_write_packet(AVFormatContext *s, AVPacket *pkt)
  82 {
  83     ByteIOContext *pb = s->pb;
  84     put_buffer(pb, pkt->data, pkt->size);
  85     return 0;
  86 }
  87
  88 static int au_write_trailer(AVFormatContext *s)
  89 {
  90     ByteIOContext *pb = s->pb;
  91     int64_t file_size;
  92
  93     if (!url_is_streamed(s->pb)) {
  94
  95         /* update file size */
  96         file_size = url_ftell(pb);
  97         url_fseek(pb, 8, SEEK_SET);
  98         put_be32(pb, (uint32_t)(file_size - 24));
  99         url_fseek(pb, file_size, SEEK_SET);
 100
 101         put_flush_packet(pb);
 102     }
 103
 104     return 0;
 105 }
 106 #endif /* CONFIG_AU_MUXER */
 107
 108 static int au_probe(AVProbeData *p)
 109 {
 110     /* check file header */
 111     if (p->buf[0] == '.' && p->buf[1] == 's' &&
 112         p->buf[2] == 'n' && p->buf[3] == 'd')
 113         return AVPROBE_SCORE_MAX;
 114     else
 115         return 0;
 116 }
 117
 118 /* au input */
 119 static int au_read_header(AVFormatContext *s,
 120                           AVFormatParameters *ap)
 121 {
 122     int size;
 123     unsigned int tag;
 124     ByteIOContext *pb = s->pb;
 125     unsigned int id, channels, rate;
 126     enum CodecID codec;
 127     AVStream *st;
 128
 129     /* check ".snd" header */
 130     tag = get_le32(pb);
 131     if (tag != MKTAG('.', 's', 'n', 'd'))
 132         return -1;
 133     size = get_be32(pb); /* header size */
 134     get_be32(pb); /* data size */
 135
 136     id = get_be32(pb);
 137     rate = get_be32(pb);
 138     channels = get_be32(pb);
 139
 140     codec = ff_codec_get_id(codec_au_tags, id);
 141
 142     if (size >= 24) {
 143         /* skip unused data */
 144         url_fseek(pb, size - 24, SEEK_CUR);
 145     }
 146
 147     /* now we are ready: build format streams */
 148     st = av_new_stream(s, 0);
 149     if (!st)
 150         return -1;
 151     st->codec->codec_type = CODEC_TYPE_AUDIO;
 152     st->codec->codec_tag = id;
 153     st->codec->codec_id = codec;
 154     st->codec->channels = channels;
 155     st->codec->sample_rate = rate;
 156     av_set_pts_info(st, 64, 1, rate);
 157     return 0;
 158 }
 159
 160 #define MAX_SIZE 4096
 161
 162 static int au_read_packet(AVFormatContext *s,
 163                           AVPacket *pkt)
 164 {
 165     int ret;
 166
 167     ret= av_get_packet(s->pb, pkt, MAX_SIZE);
 168     if (ret < 0)
 169         return ret;
 170     pkt->stream_index = 0;
 171
 172     /* note: we need to modify the packet size here to handle the last
 173        packet */
 174     pkt->size = ret;
 175     return 0;
 176 }
 177
 178 #if CONFIG_AU_DEMUXER
 179 AVInputFormat au_demuxer = {
 180     "au",
 181     NULL_IF_CONFIG_SMALL("SUN AU format"),
 182     0,
 183     au_probe,
 184     au_read_header,
 185     au_read_packet,
 186     NULL,
 187     pcm_read_seek,
 188     .codec_tag= (const AVCodecTag* const []){codec_au_tags, 0},
 189 };
 190 #endif
 191
 192 #if CONFIG_AU_MUXER
 193 AVOutputFormat au_muxer = {
 194     "au",
 195     NULL_IF_CONFIG_SMALL("SUN AU format"),
 196     "audio/basic",
 197     "au",
 198     0,
 199     CODEC_ID_PCM_S16BE,
 200     CODEC_ID_NONE,
 201     au_write_header,
 202     au_write_packet,
 203     au_write_trailer,
 204     .codec_tag= (const AVCodecTag* const []){codec_au_tags, 0},
 205 };
 206 #endif //CONFIG_AU_MUXER