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 "allformats.h"
  32 #include "riff.h"
  33
  34 /* if we don't know the size in advance */
  35 #define AU_UNKOWN_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_S16BE, 3 },
  41     { CODEC_ID_PCM_ALAW, 27 },
  42     { 0, 0 },
  43 };
  44
  45 #ifdef CONFIG_MUXERS
  46 /* AUDIO_FILE header */
  47 static int put_au_header(ByteIOContext *pb, AVCodecContext *enc)
  48 {
  49     if(!enc->codec_tag)
  50         return -1;
  51     put_tag(pb, ".snd");       /* magic number */
  52     put_be32(pb, 24);           /* header size */
  53     put_be32(pb, AU_UNKOWN_SIZE); /* data size */
  54     put_be32(pb, (uint32_t)enc->codec_tag);     /* codec ID */
  55     put_be32(pb, enc->sample_rate);
  56     put_be32(pb, (uint32_t)enc->channels);
  57     return 0;
  58 }
  59
  60 static int au_write_header(AVFormatContext *s)
  61 {
  62     ByteIOContext *pb = &s->pb;
  63
  64     s->priv_data = NULL;
  65
  66     /* format header */
  67     if (put_au_header(pb, s->streams[0]->codec) < 0) {
  68         return -1;
  69     }
  70
  71     put_flush_packet(pb);
  72
  73     return 0;
  74 }
  75
  76 static int au_write_packet(AVFormatContext *s, AVPacket *pkt)
  77 {
  78     ByteIOContext *pb = &s->pb;
  79     put_buffer(pb, pkt->data, pkt->size);
  80     return 0;
  81 }
  82
  83 static int au_write_trailer(AVFormatContext *s)
  84 {
  85     ByteIOContext *pb = &s->pb;
  86     offset_t file_size;
  87
  88     if (!url_is_streamed(&s->pb)) {
  89
  90         /* update file size */
  91         file_size = url_ftell(pb);
  92         url_fseek(pb, 8, SEEK_SET);
  93         put_be32(pb, (uint32_t)(file_size - 24));
  94         url_fseek(pb, file_size, SEEK_SET);
  95
  96         put_flush_packet(pb);
  97     }
  98
  99     return 0;
 100 }
 101 #endif //CONFIG_MUXERS
 102
 103 static int au_probe(AVProbeData *p)
 104 {
 105     /* check file header */
 106     if (p->buf_size <= 24)
 107         return 0;
 108     if (p->buf[0] == '.' && p->buf[1] == 's' &&
 109         p->buf[2] == 'n' && p->buf[3] == 'd')
 110         return AVPROBE_SCORE_MAX;
 111     else
 112         return 0;
 113 }
 114
 115 /* au input */
 116 static int au_read_header(AVFormatContext *s,
 117                           AVFormatParameters *ap)
 118 {
 119     int size;
 120     unsigned int tag;
 121     ByteIOContext *pb = &s->pb;
 122     unsigned int id, codec, channels, rate;
 123     AVStream *st;
 124
 125     /* check ".snd" header */
 126     tag = get_le32(pb);
 127     if (tag != MKTAG('.', 's', 'n', 'd'))
 128         return -1;
 129     size = get_be32(pb); /* header size */
 130     get_be32(pb); /* data size */
 131
 132     id = get_be32(pb);
 133     rate = get_be32(pb);
 134     channels = get_be32(pb);
 135
 136     codec = codec_get_id(codec_au_tags, id);
 137
 138     if (size >= 24) {
 139         /* skip unused data */
 140         url_fseek(pb, size - 24, SEEK_CUR);
 141     }
 142
 143     /* now we are ready: build format streams */
 144     st = av_new_stream(s, 0);
 145     if (!st)
 146         return -1;
 147     st->codec->codec_type = CODEC_TYPE_AUDIO;
 148     st->codec->codec_tag = id;
 149     st->codec->codec_id = codec;
 150     st->codec->channels = channels;
 151     st->codec->sample_rate = rate;
 152     av_set_pts_info(st, 64, 1, rate);
 153     return 0;
 154 }
 155
 156 #define MAX_SIZE 4096
 157
 158 static int au_read_packet(AVFormatContext *s,
 159                           AVPacket *pkt)
 160 {
 161     int ret;
 162
 163     if (url_feof(&s->pb))
 164         return AVERROR_IO;
 165     ret= av_get_packet(&s->pb, pkt, MAX_SIZE);
 166     if (ret < 0)
 167         return AVERROR_IO;
 168     pkt->stream_index = 0;
 169
 170     /* note: we need to modify the packet size here to handle the last
 171        packet */
 172     pkt->size = ret;
 173     return 0;
 174 }
 175
 176 static int au_read_close(AVFormatContext *s)
 177 {
 178     return 0;
 179 }
 180
 181 #ifdef CONFIG_AU_DEMUXER
 182 AVInputFormat au_demuxer = {
 183     "au",
 184     "SUN AU Format",
 185     0,
 186     au_probe,
 187     au_read_header,
 188     au_read_packet,
 189     au_read_close,
 190     pcm_read_seek,
 191     .codec_tag= (const AVCodecTag*[]){codec_au_tags, 0},
 192 };
 193 #endif
 194
 195 #ifdef CONFIG_AU_MUXER
 196 AVOutputFormat au_muxer = {
 197     "au",
 198     "SUN AU Format",
 199     "audio/basic",
 200     "au",
 201     0,
 202     CODEC_ID_PCM_S16BE,
 203     CODEC_ID_NONE,
 204     au_write_header,
 205     au_write_packet,
 206     au_write_trailer,
 207     .codec_tag= (const AVCodecTag*[]){codec_au_tags, 0},
 208 };
 209 #endif //CONFIG_AU_MUXER