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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 "libavutil/dict.h"
00034 #include "avformat.h"
00035 #include "pcm.h"
00036 #include "sox.h"
00037 
00038 static int sox_probe(AVProbeData *p)
00039 {
00040     if (AV_RL32(p->buf) == SOX_TAG || AV_RB32(p->buf) == SOX_TAG)
00041         return AVPROBE_SCORE_MAX;
00042     return 0;
00043 }
00044 
00045 static int sox_read_header(AVFormatContext *s,
00046                            AVFormatParameters *ap)
00047 {
00048     AVIOContext *pb = s->pb;
00049     unsigned header_size, comment_size;
00050     double sample_rate, sample_rate_frac;
00051     AVStream *st;
00052 
00053     st = av_new_stream(s, 0);
00054     if (!st)
00055         return AVERROR(ENOMEM);
00056 
00057     st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
00058 
00059     if (avio_rl32(pb) == SOX_TAG) {
00060         st->codec->codec_id = CODEC_ID_PCM_S32LE;
00061         header_size         = avio_rl32(pb);
00062         avio_skip(pb, 8); /* sample count */
00063         sample_rate         = av_int2dbl(avio_rl64(pb));
00064         st->codec->channels = avio_rl32(pb);
00065         comment_size        = avio_rl32(pb);
00066     } else {
00067         st->codec->codec_id = CODEC_ID_PCM_S32BE;
00068         header_size         = avio_rb32(pb);
00069         avio_skip(pb, 8); /* sample count */
00070         sample_rate         = av_int2dbl(avio_rb64(pb));
00071         st->codec->channels = avio_rb32(pb);
00072         comment_size        = avio_rb32(pb);
00073     }
00074 
00075     if (comment_size > 0xFFFFFFFFU - SOX_FIXED_HDR - 4U) {
00076         av_log(s, AV_LOG_ERROR, "invalid comment size (%u)\n", comment_size);
00077         return -1;
00078     }
00079 
00080     if (sample_rate <= 0 || sample_rate > INT_MAX) {
00081         av_log(s, AV_LOG_ERROR, "invalid sample rate (%f)\n", sample_rate);
00082         return -1;
00083     }
00084 
00085     sample_rate_frac = sample_rate - floor(sample_rate);
00086     if (sample_rate_frac)
00087         av_log(s, AV_LOG_WARNING,
00088                "truncating fractional part of sample rate (%f)\n",
00089                sample_rate_frac);
00090 
00091     if ((header_size + 4) & 7 || header_size < SOX_FIXED_HDR + comment_size
00092         || st->codec->channels > 65535) /* Reserve top 16 bits */ {
00093         av_log(s, AV_LOG_ERROR, "invalid header\n");
00094         return -1;
00095     }
00096 
00097     if (comment_size && comment_size < UINT_MAX) {
00098         char *comment = av_malloc(comment_size+1);
00099         if (avio_read(pb, comment, comment_size) != comment_size) {
00100             av_freep(&comment);
00101             return AVERROR(EIO);
00102         }
00103         comment[comment_size] = 0;
00104 
00105         av_dict_set(&s->metadata, "comment", comment,
00106                                AV_DICT_DONT_STRDUP_VAL);
00107     }
00108 
00109     avio_skip(pb, header_size - SOX_FIXED_HDR - comment_size);
00110 
00111     st->codec->sample_rate           = sample_rate;
00112     st->codec->bits_per_coded_sample = 32;
00113     st->codec->bit_rate              = st->codec->sample_rate *
00114                                        st->codec->bits_per_coded_sample *
00115                                        st->codec->channels;
00116     st->codec->block_align           = st->codec->bits_per_coded_sample *
00117                                        st->codec->channels / 8;
00118 
00119     av_set_pts_info(st, 64, 1, st->codec->sample_rate);
00120 
00121     return 0;
00122 }
00123 
00124 #define SOX_SAMPLES 1024
00125 
00126 static int sox_read_packet(AVFormatContext *s,
00127                            AVPacket *pkt)
00128 {
00129     int ret, size;
00130 
00131     if (url_feof(s->pb))
00132         return AVERROR_EOF;
00133 
00134     size = SOX_SAMPLES*s->streams[0]->codec->block_align;
00135     ret = av_get_packet(s->pb, pkt, size);
00136     if (ret < 0)
00137         return AVERROR(EIO);
00138     pkt->stream_index = 0;
00139     pkt->size = ret;
00140 
00141     return 0;
00142 }
00143 
00144 AVInputFormat ff_sox_demuxer = {
00145     "sox",
00146     NULL_IF_CONFIG_SMALL("SoX native format"),
00147     0,
00148     sox_probe,
00149     sox_read_header,
00150     sox_read_packet,
00151     NULL,
00152     pcm_read_seek,
00153 };

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