libavformat/soxenc.c

   1 /*
   2  * SoX native format muxer
   3  * Copyright (c) 2009 Daniel Verkamp <daniel@drv.nu>
   4  *
   5  * Based on libSoX sox-fmt.c
   6  * Copyright (c) 2008 robs@users.sourceforge.net
   7  *
   8  * This file is part of Libav.
   9  *
  10  * Libav is free software; you can redistribute it and/or
  11  * modify it under the terms of the GNU Lesser General Public
  12  * License as published by the Free Software Foundation; either
  13  * version 2.1 of the License, or (at your option) any later version.
  14  *
  15  * Libav is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  18  * Lesser General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU Lesser General Public
  21  * License along with Libav; if not, write to the Free Software
  22  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  23  */
  24
  25 /**
  26  * @file
  27  * SoX native format muxer
  28  * @author Daniel Verkamp
  29  * @see http://wiki.multimedia.cx/index.php?title=SoX_native_intermediate_format
  30  */
  31
  32 #include "libavutil/intreadwrite.h"
  33 #include "libavutil/intfloat.h"
  34 #include "libavutil/dict.h"
  35 #include "avformat.h"
  36 #include "avio_internal.h"
  37 #include "sox.h"
  38
  39 typedef struct {
  40     int64_t header_size;
  41 } SoXContext;
  42
  43 static int sox_write_header(AVFormatContext *s)
  44 {
  45     SoXContext *sox = s->priv_data;
  46     AVIOContext *pb = s->pb;
  47     AVCodecContext *enc = s->streams[0]->codec;
  48     AVDictionaryEntry *comment;
  49     size_t comment_len = 0, comment_size;
  50
  51     comment = av_dict_get(s->metadata, "comment", NULL, 0);
  52     if (comment)
  53         comment_len = strlen(comment->value);
  54     comment_size = (comment_len + 7) & ~7;
  55
  56     sox->header_size = SOX_FIXED_HDR + comment_size;
  57
  58     if (enc->codec_id == AV_CODEC_ID_PCM_S32LE) {
  59         ffio_wfourcc(pb, ".SoX");
  60         avio_wl32(pb, sox->header_size);
  61         avio_wl64(pb, 0); /* number of samples */
  62         avio_wl64(pb, av_double2int(enc->sample_rate));
  63         avio_wl32(pb, enc->channels);
  64         avio_wl32(pb, comment_size);
  65     } else if (enc->codec_id == AV_CODEC_ID_PCM_S32BE) {
  66         ffio_wfourcc(pb, "XoS.");
  67         avio_wb32(pb, sox->header_size);
  68         avio_wb64(pb, 0); /* number of samples */
  69         avio_wb64(pb, av_double2int(enc->sample_rate));
  70         avio_wb32(pb, enc->channels);
  71         avio_wb32(pb, comment_size);
  72     } else {
  73         av_log(s, AV_LOG_ERROR, "invalid codec; use pcm_s32le or pcm_s32be\n");
  74         return -1;
  75     }
  76
  77     if (comment_len)
  78         avio_write(pb, comment->value, comment_len);
  79
  80     for ( ; comment_size > comment_len; comment_len++)
  81         avio_w8(pb, 0);
  82
  83     avio_flush(pb);
  84
  85     return 0;
  86 }
  87
  88 static int sox_write_packet(AVFormatContext *s, AVPacket *pkt)
  89 {
  90     AVIOContext *pb = s->pb;
  91     avio_write(pb, pkt->data, pkt->size);
  92     return 0;
  93 }
  94
  95 static int sox_write_trailer(AVFormatContext *s)
  96 {
  97     SoXContext *sox = s->priv_data;
  98     AVIOContext *pb = s->pb;
  99     AVCodecContext *enc = s->streams[0]->codec;
 100
 101     if (s->pb->seekable) {
 102         /* update number of samples */
 103         int64_t file_size = avio_tell(pb);
 104         int64_t num_samples = (file_size - sox->header_size - 4LL) >> 2LL;
 105         avio_seek(pb, 8, SEEK_SET);
 106         if (enc->codec_id == AV_CODEC_ID_PCM_S32LE) {
 107             avio_wl64(pb, num_samples);
 108         } else
 109             avio_wb64(pb, num_samples);
 110         avio_seek(pb, file_size, SEEK_SET);
 111
 112         avio_flush(pb);
 113     }
 114
 115     return 0;
 116 }
 117
 118 AVOutputFormat ff_sox_muxer = {
 119     .name              = "sox",
 120     .long_name         = NULL_IF_CONFIG_SMALL("SoX native"),
 121     .extensions        = "sox",
 122     .priv_data_size    = sizeof(SoXContext),
 123     .audio_codec       = AV_CODEC_ID_PCM_S32LE,
 124     .video_codec       = AV_CODEC_ID_NONE,
 125     .write_header      = sox_write_header,
 126     .write_packet      = sox_write_packet,
 127     .write_trailer     = sox_write_trailer,
 128 };