libavformat/vocenc.c

   1 /*
   2  * Creative Voice File muxer.
   3  * Copyright (c) 2006  Aurelien Jacobs <aurel@gnuage.org>
   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 #include "voc.h"
  23 #include "internal.h"
  24 #include "mux.h"
  25
  26
  27 typedef struct voc_enc_context {
  28     int param_written;
  29 } VocEncContext;
  30
  31 static int voc_write_header(AVFormatContext *s)
  32 {
  33     AVIOContext *pb = s->pb;
  34     AVCodecParameters *par = s->streams[0]->codecpar;
  35     const int header_size = 26;
  36     const int version = 0x0114;
  37
  38     if (s->nb_streams != 1
  39         || s->streams[0]->codecpar->codec_type != AVMEDIA_TYPE_AUDIO)
  40         return AVERROR_PATCHWELCOME;
  41
  42     if (!par->codec_tag && par->codec_id != AV_CODEC_ID_PCM_U8) {
  43         av_log(s, AV_LOG_ERROR, "unsupported codec\n");
  44         return AVERROR(EINVAL);
  45     }
  46
  47     avio_write(pb, ff_voc_magic, sizeof(ff_voc_magic) - 1);
  48     avio_wl16(pb, header_size);
  49     avio_wl16(pb, version);
  50     avio_wl16(pb, ~version + 0x1234);
  51
  52     return 0;
  53 }
  54
  55 static int voc_write_packet(AVFormatContext *s, AVPacket *pkt)
  56 {
  57     VocEncContext *voc = s->priv_data;
  58     AVCodecParameters *par = s->streams[0]->codecpar;
  59     AVIOContext *pb = s->pb;
  60
  61     if (!voc->param_written) {
  62         if (par->codec_tag > 3) {
  63             avio_w8(pb, VOC_TYPE_NEW_VOICE_DATA);
  64             avio_wl24(pb, pkt->size + 12);
  65             avio_wl32(pb, par->sample_rate);
  66             avio_w8(pb, par->bits_per_coded_sample);
  67             avio_w8(pb, par->ch_layout.nb_channels);
  68             avio_wl16(pb, par->codec_tag);
  69             avio_wl32(pb, 0);
  70         } else {
  71             if (s->streams[0]->codecpar->ch_layout.nb_channels > 1) {
  72                 avio_w8(pb, VOC_TYPE_EXTENDED);
  73                 avio_wl24(pb, 4);
  74                 avio_wl16(pb, 65536 - (256000000 + par->sample_rate * par->ch_layout.nb_channels / 2) /
  75                                       (par->sample_rate * par->ch_layout.nb_channels));
  76                 avio_w8(pb, par->codec_tag);
  77                 avio_w8(pb, par->ch_layout.nb_channels - 1);
  78             }
  79             avio_w8(pb, VOC_TYPE_VOICE_DATA);
  80             avio_wl24(pb, pkt->size + 2);
  81             avio_w8(pb, 256 - (1000000 + par->sample_rate/2) / par->sample_rate);
  82             avio_w8(pb, par->codec_tag);
  83         }
  84         voc->param_written = 1;
  85     } else {
  86         avio_w8(pb, VOC_TYPE_VOICE_DATA_CONT);
  87         avio_wl24(pb, pkt->size);
  88     }
  89
  90     avio_write(pb, pkt->data, pkt->size);
  91     return 0;
  92 }
  93
  94 static int voc_write_trailer(AVFormatContext *s)
  95 {
  96     avio_w8(s->pb, 0);
  97     return 0;
  98 }
  99
 100 const FFOutputFormat ff_voc_muxer = {
 101     .p.name            = "voc",
 102     .p.long_name       = NULL_IF_CONFIG_SMALL("Creative Voice"),
 103     .p.mime_type       = "audio/x-voc",
 104     .p.extensions      = "voc",
 105     .priv_data_size    = sizeof(VocEncContext),
 106     .p.audio_codec     = AV_CODEC_ID_PCM_S16LE,
 107     .p.video_codec     = AV_CODEC_ID_NONE,
 108     .write_header      = voc_write_header,
 109     .write_packet      = voc_write_packet,
 110     .write_trailer     = voc_write_trailer,
 111     .p.codec_tag       = ff_voc_codec_tags_list,
 112     .p.flags           = AVFMT_NOTIMESTAMPS,
 113 };