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libavformat/au.c

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00001 /*
00002  * AU muxer and demuxer
00003  * Copyright (c) 2001 Fabrice Bellard
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * FFmpeg is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with FFmpeg; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00022 /*
00023  * First version by Francois Revol revol@free.fr
00024  *
00025  * Reference documents:
00026  * http://www.opengroup.org/public/pubs/external/auformat.html
00027  * http://www.goice.co.jp/member/mo/formats/au.html
00028  */
00029 
00030 #include "avformat.h"
00031 #include "raw.h"
00032 #include "riff.h"
00033 
00034 /* if we don't know the size in advance */
00035 #define AU_UNKNOWN_SIZE ((uint32_t)(~0))
00036 
00037 /* The ffmpeg codecs we support, and the IDs they have in the file */
00038 static const AVCodecTag codec_au_tags[] = {
00039     { CODEC_ID_PCM_MULAW, 1 },
00040     { CODEC_ID_PCM_S8, 2 },
00041     { CODEC_ID_PCM_S16BE, 3 },
00042     { CODEC_ID_PCM_S24BE, 4 },
00043     { CODEC_ID_PCM_S32BE, 5 },
00044     { CODEC_ID_PCM_F32BE, 6 },
00045     { CODEC_ID_PCM_F64BE, 7 },
00046     { CODEC_ID_PCM_ALAW, 27 },
00047     { CODEC_ID_NONE, 0 },
00048 };
00049 
00050 #if CONFIG_AU_MUXER
00051 /* AUDIO_FILE header */
00052 static int put_au_header(ByteIOContext *pb, AVCodecContext *enc)
00053 {
00054     if(!enc->codec_tag)
00055         return -1;
00056     put_tag(pb, ".snd");       /* magic number */
00057     put_be32(pb, 24);           /* header size */
00058     put_be32(pb, AU_UNKNOWN_SIZE); /* data size */
00059     put_be32(pb, (uint32_t)enc->codec_tag);     /* codec ID */
00060     put_be32(pb, enc->sample_rate);
00061     put_be32(pb, (uint32_t)enc->channels);
00062     return 0;
00063 }
00064 
00065 static int au_write_header(AVFormatContext *s)
00066 {
00067     ByteIOContext *pb = s->pb;
00068 
00069     s->priv_data = NULL;
00070 
00071     /* format header */
00072     if (put_au_header(pb, s->streams[0]->codec) < 0) {
00073         return -1;
00074     }
00075 
00076     put_flush_packet(pb);
00077 
00078     return 0;
00079 }
00080 
00081 static int au_write_packet(AVFormatContext *s, AVPacket *pkt)
00082 {
00083     ByteIOContext *pb = s->pb;
00084     put_buffer(pb, pkt->data, pkt->size);
00085     return 0;
00086 }
00087 
00088 static int au_write_trailer(AVFormatContext *s)
00089 {
00090     ByteIOContext *pb = s->pb;
00091     int64_t file_size;
00092 
00093     if (!url_is_streamed(s->pb)) {
00094 
00095         /* update file size */
00096         file_size = url_ftell(pb);
00097         url_fseek(pb, 8, SEEK_SET);
00098         put_be32(pb, (uint32_t)(file_size - 24));
00099         url_fseek(pb, file_size, SEEK_SET);
00100 
00101         put_flush_packet(pb);
00102     }
00103 
00104     return 0;
00105 }
00106 #endif /* CONFIG_AU_MUXER */
00107 
00108 static int au_probe(AVProbeData *p)
00109 {
00110     /* check file header */
00111     if (p->buf[0] == '.' && p->buf[1] == 's' &&
00112         p->buf[2] == 'n' && p->buf[3] == 'd')
00113         return AVPROBE_SCORE_MAX;
00114     else
00115         return 0;
00116 }
00117 
00118 /* au input */
00119 static int au_read_header(AVFormatContext *s,
00120                           AVFormatParameters *ap)
00121 {
00122     int size;
00123     unsigned int tag;
00124     ByteIOContext *pb = s->pb;
00125     unsigned int id, channels, rate;
00126     enum CodecID codec;
00127     AVStream *st;
00128 
00129     /* check ".snd" header */
00130     tag = get_le32(pb);
00131     if (tag != MKTAG('.', 's', 'n', 'd'))
00132         return -1;
00133     size = get_be32(pb); /* header size */
00134     get_be32(pb); /* data size */
00135 
00136     id = get_be32(pb);
00137     rate = get_be32(pb);
00138     channels = get_be32(pb);
00139 
00140     codec = ff_codec_get_id(codec_au_tags, id);
00141 
00142     if (size >= 24) {
00143         /* skip unused data */
00144         url_fseek(pb, size - 24, SEEK_CUR);
00145     }
00146 
00147     /* now we are ready: build format streams */
00148     st = av_new_stream(s, 0);
00149     if (!st)
00150         return -1;
00151     st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
00152     st->codec->codec_tag = id;
00153     st->codec->codec_id = codec;
00154     st->codec->channels = channels;
00155     st->codec->sample_rate = rate;
00156     av_set_pts_info(st, 64, 1, rate);
00157     return 0;
00158 }
00159 
00160 #define BLOCK_SIZE 1024
00161 
00162 static int au_read_packet(AVFormatContext *s,
00163                           AVPacket *pkt)
00164 {
00165     int ret;
00166 
00167     ret= av_get_packet(s->pb, pkt, BLOCK_SIZE *
00168                        s->streams[0]->codec->channels *
00169                        av_get_bits_per_sample(s->streams[0]->codec->codec_id) >> 3);
00170     if (ret < 0)
00171         return ret;
00172     pkt->stream_index = 0;
00173 
00174     /* note: we need to modify the packet size here to handle the last
00175        packet */
00176     pkt->size = ret;
00177     return 0;
00178 }
00179 
00180 #if CONFIG_AU_DEMUXER
00181 AVInputFormat au_demuxer = {
00182     "au",
00183     NULL_IF_CONFIG_SMALL("SUN AU format"),
00184     0,
00185     au_probe,
00186     au_read_header,
00187     au_read_packet,
00188     NULL,
00189     pcm_read_seek,
00190     .codec_tag= (const AVCodecTag* const []){codec_au_tags, 0},
00191 };
00192 #endif
00193 
00194 #if CONFIG_AU_MUXER
00195 AVOutputFormat au_muxer = {
00196     "au",
00197     NULL_IF_CONFIG_SMALL("SUN AU format"),
00198     "audio/basic",
00199     "au",
00200     0,
00201     CODEC_ID_PCM_S16BE,
00202     CODEC_ID_NONE,
00203     au_write_header,
00204     au_write_packet,
00205     au_write_trailer,
00206     .codec_tag= (const AVCodecTag* const []){codec_au_tags, 0},
00207 };
00208 #endif //CONFIG_AU_MUXER

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