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libavformat/soxdec.c

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00001 /*
00002  * SoX native format demuxer
00003  * Copyright (c) 2009 Daniel Verkamp <daniel@drv.nu>
00004  *
00005  * Based on libSoX sox-fmt.c
00006  * Copyright (c) 2008 robs@users.sourceforge.net
00007  *
00008  * This file is part of FFmpeg.
00009  *
00010  * FFmpeg is free software; you can redistribute it and/or
00011  * modify it under the terms of the GNU Lesser General Public
00012  * License as published by the Free Software Foundation; either
00013  * version 2.1 of the License, or (at your option) any later version.
00014  *
00015  * FFmpeg is distributed in the hope that it will be useful,
00016  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00017  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00018  * Lesser General Public License for more details.
00019  *
00020  * You should have received a copy of the GNU Lesser General Public
00021  * License along with FFmpeg; if not, write to the Free Software
00022  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00023  */
00024 
00032 #include "libavutil/intreadwrite.h"
00033 #include "avformat.h"
00034 #include "raw.h"
00035 #include "sox.h"
00036 
00037 static int sox_probe(AVProbeData *p)
00038 {
00039     if (AV_RL32(p->buf) == SOX_TAG || AV_RB32(p->buf) == SOX_TAG)
00040         return AVPROBE_SCORE_MAX;
00041     return 0;
00042 }
00043 
00044 static int sox_read_header(AVFormatContext *s,
00045                            AVFormatParameters *ap)
00046 {
00047     ByteIOContext *pb = s->pb;
00048     unsigned header_size, comment_size;
00049     double sample_rate, sample_rate_frac;
00050     AVStream *st;
00051 
00052     st = av_new_stream(s, 0);
00053     if (!st)
00054         return AVERROR(ENOMEM);
00055 
00056     st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
00057 
00058     if (get_le32(pb) == SOX_TAG) {
00059         st->codec->codec_id = CODEC_ID_PCM_S32LE;
00060         header_size         = get_le32(pb);
00061         url_fskip(pb, 8); /* sample count */
00062         sample_rate         = av_int2dbl(get_le64(pb));
00063         st->codec->channels = get_le32(pb);
00064         comment_size        = get_le32(pb);
00065     } else {
00066         st->codec->codec_id = CODEC_ID_PCM_S32BE;
00067         header_size         = get_be32(pb);
00068         url_fskip(pb, 8); /* sample count */
00069         sample_rate         = av_int2dbl(get_be64(pb));
00070         st->codec->channels = get_be32(pb);
00071         comment_size        = get_be32(pb);
00072     }
00073 
00074     if (comment_size > 0xFFFFFFFFU - SOX_FIXED_HDR - 4U) {
00075         av_log(s, AV_LOG_ERROR, "invalid comment size (%u)\n", comment_size);
00076         return -1;
00077     }
00078 
00079     if (sample_rate <= 0 || sample_rate > INT_MAX) {
00080         av_log(s, AV_LOG_ERROR, "invalid sample rate (%f)\n", sample_rate);
00081         return -1;
00082     }
00083 
00084     sample_rate_frac = sample_rate - floor(sample_rate);
00085     if (sample_rate_frac)
00086         av_log(s, AV_LOG_WARNING,
00087                "truncating fractional part of sample rate (%f)\n",
00088                sample_rate_frac);
00089 
00090     if ((header_size + 4) & 7 || header_size < SOX_FIXED_HDR + comment_size
00091         || st->codec->channels > 65535) /* Reserve top 16 bits */ {
00092         av_log(s, AV_LOG_ERROR, "invalid header\n");
00093         return -1;
00094     }
00095 
00096     if (comment_size && comment_size < UINT_MAX) {
00097         char *comment = av_malloc(comment_size+1);
00098         if (get_buffer(pb, comment, comment_size) != comment_size) {
00099             av_freep(&comment);
00100             return AVERROR(EIO);
00101         }
00102         comment[comment_size] = 0;
00103 
00104         av_metadata_set2(&s->metadata, "comment", comment,
00105                                AV_METADATA_DONT_STRDUP_VAL);
00106     }
00107 
00108     url_fskip(pb, header_size - SOX_FIXED_HDR - comment_size);
00109 
00110     st->codec->sample_rate           = sample_rate;
00111     st->codec->bits_per_coded_sample = 32;
00112     st->codec->bit_rate              = st->codec->sample_rate *
00113                                        st->codec->bits_per_coded_sample *
00114                                        st->codec->channels;
00115     st->codec->block_align           = st->codec->bits_per_coded_sample *
00116                                        st->codec->channels / 8;
00117 
00118     av_set_pts_info(st, 64, 1, st->codec->sample_rate);
00119 
00120     return 0;
00121 }
00122 
00123 #define SOX_SAMPLES 1024
00124 
00125 static int sox_read_packet(AVFormatContext *s,
00126                            AVPacket *pkt)
00127 {
00128     int ret, size;
00129 
00130     if (url_feof(s->pb))
00131         return AVERROR_EOF;
00132 
00133     size = SOX_SAMPLES*s->streams[0]->codec->block_align;
00134     ret = av_get_packet(s->pb, pkt, size);
00135     if (ret < 0)
00136         return AVERROR(EIO);
00137     pkt->stream_index = 0;
00138     pkt->size = ret;
00139 
00140     return 0;
00141 }
00142 
00143 AVInputFormat sox_demuxer = {
00144     "sox",
00145     NULL_IF_CONFIG_SMALL("SoX native format"),
00146     0,
00147     sox_probe,
00148     sox_read_header,
00149     sox_read_packet,
00150     NULL,
00151     pcm_read_seek,
00152 };

Generated on Fri Sep 16 2011 17:17:51 for FFmpeg by  doxygen 1.7.1