libavformat/act.c

   1 /*
   2  * ACT file format demuxer
   3  * Copyright (c) 2007-2008 Vladimir Voroshilov
   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 "libavutil/intreadwrite.h"
  23 #include "avformat.h"
  24 #include "avio_internal.h"
  25 #include "demux.h"
  26 #include "riff.h"
  27 #include "internal.h"
  28
  29 #define CHUNK_SIZE 512
  30 #define RIFF_TAG MKTAG('R','I','F','F')
  31 #define WAVE_TAG MKTAG('W','A','V','E')
  32
  33 typedef struct{
  34     int bytes_left_in_chunk;
  35     uint8_t audio_buffer[22];///< temporary buffer for ACT frame
  36     char second_packet;      ///< 1 - if temporary buffer contains valid (second) G.729 packet
  37 } ACTContext;
  38
  39 static int probe(const AVProbeData *p)
  40 {
  41     int i;
  42
  43     if ((AV_RL32(&p->buf[0]) != RIFF_TAG) ||
  44         (AV_RL32(&p->buf[8]) != WAVE_TAG) ||
  45         (AV_RL32(&p->buf[16]) != 16))
  46     return 0;
  47
  48     //We can't be sure that this is ACT and not regular WAV
  49     if (p->buf_size<512)
  50         return 0;
  51
  52     for(i=44; i<256; i++)
  53         if(p->buf[i])
  54             return 0;
  55
  56     if(p->buf[256]!=0x84)
  57         return 0;
  58
  59     for(i=264; i<512; i++)
  60         if(p->buf[i])
  61             return 0;
  62
  63     return AVPROBE_SCORE_MAX;
  64 }
  65
  66 static int read_header(AVFormatContext *s)
  67 {
  68     ACTContext* ctx = s->priv_data;
  69     AVIOContext *pb = s->pb;
  70     int size;
  71     AVStream* st;
  72     int ret;
  73
  74     int min,sec,msec;
  75
  76     st = avformat_new_stream(s, NULL);
  77     if (!st)
  78         return AVERROR(ENOMEM);
  79
  80     avio_skip(pb, 16);
  81     size=avio_rl32(pb);
  82     ret = ff_get_wav_header(s, pb, st->codecpar, size, 0);
  83     if (ret < 0)
  84         return ret;
  85
  86     /*
  87       8000Hz (Fine-rec) file format has 10 bytes long
  88       packets with 10ms of sound data in them
  89     */
  90     if (st->codecpar->sample_rate != 8000) {
  91         av_log(s, AV_LOG_ERROR, "Sample rate %d is not supported.\n", st->codecpar->sample_rate);
  92         return AVERROR_INVALIDDATA;
  93     }
  94
  95     st->codecpar->frame_size=80;
  96     st->codecpar->ch_layout.nb_channels = 1;
  97     avpriv_set_pts_info(st, 64, 1, 100);
  98
  99     st->codecpar->codec_id=AV_CODEC_ID_G729;
 100
 101     avio_seek(pb, 257, SEEK_SET);
 102     msec=avio_rl16(pb);
 103     sec=avio_r8(pb);
 104     min=avio_rl32(pb);
 105
 106     st->duration = av_rescale(1000*(min*60+sec)+msec, st->codecpar->sample_rate, 1000 * st->codecpar->frame_size);
 107
 108     ctx->bytes_left_in_chunk=CHUNK_SIZE;
 109
 110     avio_seek(pb, 512, SEEK_SET);
 111
 112     return 0;
 113 }
 114
 115
 116 static int read_packet(AVFormatContext *s,
 117                           AVPacket *pkt)
 118 {
 119     ACTContext *ctx = s->priv_data;
 120     AVIOContext *pb = s->pb;
 121     int ret;
 122     int frame_size=s->streams[0]->codecpar->sample_rate==8000?10:22;
 123
 124
 125     if(s->streams[0]->codecpar->sample_rate==8000)
 126         ret=av_new_packet(pkt, 10);
 127     else
 128         ret=av_new_packet(pkt, 11);
 129
 130     if(ret)
 131         return ret;
 132
 133     if(s->streams[0]->codecpar->sample_rate==4400 && !ctx->second_packet)
 134     {
 135         ret = ffio_read_size(pb, ctx->audio_buffer, frame_size);
 136
 137         if(ret<0)
 138             return ret;
 139
 140         pkt->data[0]=ctx->audio_buffer[11];
 141         pkt->data[1]=ctx->audio_buffer[0];
 142         pkt->data[2]=ctx->audio_buffer[12];
 143         pkt->data[3]=ctx->audio_buffer[1];
 144         pkt->data[4]=ctx->audio_buffer[13];
 145         pkt->data[5]=ctx->audio_buffer[2];
 146         pkt->data[6]=ctx->audio_buffer[14];
 147         pkt->data[7]=ctx->audio_buffer[3];
 148         pkt->data[8]=ctx->audio_buffer[15];
 149         pkt->data[9]=ctx->audio_buffer[4];
 150         pkt->data[10]=ctx->audio_buffer[16];
 151
 152         ctx->second_packet=1;
 153     }
 154     else if(s->streams[0]->codecpar->sample_rate==4400 && ctx->second_packet)
 155     {
 156         pkt->data[0]=ctx->audio_buffer[5];
 157         pkt->data[1]=ctx->audio_buffer[17];
 158         pkt->data[2]=ctx->audio_buffer[6];
 159         pkt->data[3]=ctx->audio_buffer[18];
 160         pkt->data[4]=ctx->audio_buffer[7];
 161         pkt->data[5]=ctx->audio_buffer[19];
 162         pkt->data[6]=ctx->audio_buffer[8];
 163         pkt->data[7]=ctx->audio_buffer[20];
 164         pkt->data[8]=ctx->audio_buffer[9];
 165         pkt->data[9]=ctx->audio_buffer[21];
 166         pkt->data[10]=ctx->audio_buffer[10];
 167
 168         ctx->second_packet=0;
 169     }
 170     else // 8000 Hz
 171     {
 172         ret = ffio_read_size(pb, ctx->audio_buffer, frame_size);
 173
 174         if(ret<0)
 175             return ret;
 176
 177         pkt->data[0]=ctx->audio_buffer[5];
 178         pkt->data[1]=ctx->audio_buffer[0];
 179         pkt->data[2]=ctx->audio_buffer[6];
 180         pkt->data[3]=ctx->audio_buffer[1];
 181         pkt->data[4]=ctx->audio_buffer[7];
 182         pkt->data[5]=ctx->audio_buffer[2];
 183         pkt->data[6]=ctx->audio_buffer[8];
 184         pkt->data[7]=ctx->audio_buffer[3];
 185         pkt->data[8]=ctx->audio_buffer[9];
 186         pkt->data[9]=ctx->audio_buffer[4];
 187     }
 188
 189     ctx->bytes_left_in_chunk -= frame_size;
 190
 191     if(ctx->bytes_left_in_chunk < frame_size)
 192     {
 193         avio_skip(pb, ctx->bytes_left_in_chunk);
 194         ctx->bytes_left_in_chunk=CHUNK_SIZE;
 195     }
 196
 197     pkt->duration=1;
 198
 199     return ret;
 200 }
 201
 202 const FFInputFormat ff_act_demuxer = {
 203     .p.name         = "act",
 204     .p.long_name    = "ACT Voice file format",
 205     .priv_data_size = sizeof(ACTContext),
 206     .read_probe     = probe,
 207     .read_header    = read_header,
 208     .read_packet    = read_packet,
 209 };