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
  24
  25 typedef struct voc_enc_context {
  26     int param_written;
  27 } voc_enc_context_t;
  28
  29 static int voc_write_header(AVFormatContext *s)
  30 {
  31     ByteIOContext *pb = s->pb;
  32     const int header_size = 26;
  33     const int version = 0x0114;
  34
  35     if (s->nb_streams != 1
  36         || s->streams[0]->codec->codec_type != CODEC_TYPE_AUDIO)
  37         return AVERROR_PATCHWELCOME;
  38
  39     put_buffer(pb, voc_magic, sizeof(voc_magic) - 1);
  40     put_le16(pb, header_size);
  41     put_le16(pb, version);
  42     put_le16(pb, ~version + 0x1234);
  43
  44     return 0;
  45 }
  46
  47 static int voc_write_packet(AVFormatContext *s, AVPacket *pkt)
  48 {
  49     voc_enc_context_t *voc = s->priv_data;
  50     AVCodecContext *enc = s->streams[0]->codec;
  51     ByteIOContext *pb = s->pb;
  52
  53     if (!voc->param_written) {
  54         if (enc->codec_tag > 0xFF) {
  55             put_byte(pb, VOC_TYPE_NEW_VOICE_DATA);
  56             put_le24(pb, pkt->size + 12);
  57             put_le32(pb, enc->sample_rate);
  58             put_byte(pb, enc->bits_per_sample);
  59             put_byte(pb, enc->channels);
  60             put_le16(pb, enc->codec_tag);
  61             put_le32(pb, 0);
  62         } else {
  63             if (s->streams[0]->codec->channels > 1) {
  64                 put_byte(pb, VOC_TYPE_EXTENDED);
  65                 put_le24(pb, 4);
  66                 put_le16(pb, 65536-256000000/(enc->sample_rate*enc->channels));
  67                 put_byte(pb, enc->codec_tag);
  68                 put_byte(pb, enc->channels - 1);
  69             }
  70             put_byte(pb, VOC_TYPE_VOICE_DATA);
  71             put_le24(pb, pkt->size + 2);
  72             put_byte(pb, 256 - 1000000 / enc->sample_rate);
  73             put_byte(pb, enc->codec_tag);
  74         }
  75         voc->param_written = 1;
  76     } else {
  77         put_byte(pb, VOC_TYPE_VOICE_DATA_CONT);
  78         put_le24(pb, pkt->size);
  79     }
  80
  81     put_buffer(pb, pkt->data, pkt->size);
  82     return 0;
  83 }
  84
  85 static int voc_write_trailer(AVFormatContext *s)
  86 {
  87     put_byte(s->pb, 0);
  88     return 0;
  89 }
  90
  91 AVOutputFormat voc_muxer = {
  92     "voc",
  93     "Creative Voice File format",
  94     "audio/x-voc",
  95     "voc",
  96     sizeof(voc_enc_context_t),
  97     CODEC_ID_PCM_U8,
  98     CODEC_ID_NONE,
  99     voc_write_header,
 100     voc_write_packet,
 101     voc_write_trailer,
 102     .codec_tag=(const AVCodecTag*[]){voc_codec_tags, 0},
 103 };