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_ALAW, 27 },
  43     { 0, 0 },
  44 };
  45
  46 #ifdef CONFIG_MUXERS
  47 /* AUDIO_FILE header */
  48 static int put_au_header(ByteIOContext *pb, AVCodecContext *enc)
  49 {
  50     if(!enc->codec_tag)
  51         return -1;
  52     put_tag(pb, ".snd");       /* magic number */
  53     put_be32(pb, 24);           /* header size */
  54     put_be32(pb, AU_UNKNOWN_SIZE); /* data size */
  55     put_be32(pb, (uint32_t)enc->codec_tag);     /* codec ID */
  56     put_be32(pb, enc->sample_rate);
  57     put_be32(pb, (uint32_t)enc->channels);
  58     return 0;
  59 }
  60
  61 static int au_write_header(AVFormatContext *s)
  62 {
  63     ByteIOContext *pb = s->pb;
  64
  65     s->priv_data = NULL;
  66
  67     /* format header */
  68     if (put_au_header(pb, s->streams[0]->codec) < 0) {
  69         return -1;
  70     }
  71
  72     put_flush_packet(pb);
  73
  74     return 0;
  75 }
  76
  77 static int au_write_packet(AVFormatContext *s, AVPacket *pkt)
  78 {
  79     ByteIOContext *pb = s->pb;
  80     put_buffer(pb, pkt->data, pkt->size);
  81     return 0;
  82 }
  83
  84 static int au_write_trailer(AVFormatContext *s)
  85 {
  86     ByteIOContext *pb = s->pb;
  87     offset_t file_size;
  88
  89     if (!url_is_streamed(s->pb)) {
  90
  91         /* update file size */
  92         file_size = url_ftell(pb);
  93         url_fseek(pb, 8, SEEK_SET);
  94         put_be32(pb, (uint32_t)(file_size - 24));
  95         url_fseek(pb, file_size, SEEK_SET);
  96
  97         put_flush_packet(pb);
  98     }
  99
 100     return 0;
 101 }
 102 #endif //CONFIG_MUXERS
 103
 104 static int au_probe(AVProbeData *p)
 105 {
 106     /* check file header */
 107     if (p->buf[0] == '.' && p->buf[1] == 's' &&
 108         p->buf[2] == 'n' && p->buf[3] == 'd')
 109         return AVPROBE_SCORE_MAX;
 110     else
 111         return 0;
 112 }
 113
 114 /* au input */
 115 static int au_read_header(AVFormatContext *s,
 116                           AVFormatParameters *ap)
 117 {
 118     int size;
 119     unsigned int tag;
 120     ByteIOContext *pb = s->pb;
 121     unsigned int id, codec, channels, rate;
 122     AVStream *st;
 123
 124     /* check ".snd" header */
 125     tag = get_le32(pb);
 126     if (tag != MKTAG('.', 's', 'n', 'd'))
 127         return -1;
 128     size = get_be32(pb); /* header size */
 129     get_be32(pb); /* data size */
 130
 131     id = get_be32(pb);
 132     rate = get_be32(pb);
 133     channels = get_be32(pb);
 134
 135     codec = codec_get_id(codec_au_tags, id);
 136
 137     if (size >= 24) {
 138         /* skip unused data */
 139         url_fseek(pb, size - 24, SEEK_CUR);
 140     }
 141
 142     /* now we are ready: build format streams */
 143     st = av_new_stream(s, 0);
 144     if (!st)
 145         return -1;
 146     st->codec->codec_type = CODEC_TYPE_AUDIO;
 147     st->codec->codec_tag = id;
 148     st->codec->codec_id = codec;
 149     st->codec->channels = channels;
 150     st->codec->sample_rate = rate;
 151     av_set_pts_info(st, 64, 1, rate);
 152     return 0;
 153 }
 154
 155 #define MAX_SIZE 4096
 156
 157 static int au_read_packet(AVFormatContext *s,
 158                           AVPacket *pkt)
 159 {
 160     int ret;
 161
 162     if (url_feof(s->pb))
 163         return AVERROR(EIO);
 164     ret= av_get_packet(s->pb, pkt, MAX_SIZE);
 165     if (ret < 0)
 166         return AVERROR(EIO);
 167     pkt->stream_index = 0;
 168
 169     /* note: we need to modify the packet size here to handle the last
 170        packet */
 171     pkt->size = ret;
 172     return 0;
 173 }
 174
 175 static int au_read_close(AVFormatContext *s)
 176 {
 177     return 0;
 178 }
 179
 180 #ifdef CONFIG_AU_DEMUXER
 181 AVInputFormat au_demuxer = {
 182     "au",
 183     "SUN AU Format",
 184     0,
 185     au_probe,
 186     au_read_header,
 187     au_read_packet,
 188     au_read_close,
 189     pcm_read_seek,
 190     .codec_tag= (const AVCodecTag*[]){codec_au_tags, 0},
 191 };
 192 #endif
 193
 194 #ifdef CONFIG_AU_MUXER
 195 AVOutputFormat au_muxer = {
 196     "au",
 197     "SUN AU Format",
 198     "audio/basic",
 199     "au",
 200     0,
 201     CODEC_ID_PCM_S16BE,
 202     CODEC_ID_NONE,
 203     au_write_header,
 204     au_write_packet,
 205     au_write_trailer,
 206     .codec_tag= (const AVCodecTag*[]){codec_au_tags, 0},
 207 };
 208 #endif //CONFIG_AU_MUXER