libavformat/iff.c

   1 /*
   2  * IFF (.iff) file demuxer
   3  * Copyright (c) 2008 Jaikrishnan Menon <realityman@gmx.net>
   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 /**
  23  * @file libavformat/iff.c
  24  * IFF file demuxer
  25  * by Jaikrishnan Menon
  26  * for more information on the .iff file format, visit:
  27  * http://wiki.multimedia.cx/index.php?title=IFF
  28  */
  29
  30 #include "libavutil/intreadwrite.h"
  31 #include "avformat.h"
  32
  33 #define ID_8SVX       MKTAG('8','S','V','X')
  34 #define ID_VHDR       MKTAG('V','H','D','R')
  35 #define ID_ATAK       MKTAG('A','T','A','K')
  36 #define ID_RLSE       MKTAG('R','L','S','E')
  37 #define ID_CHAN       MKTAG('C','H','A','N')
  38
  39 #define ID_FORM       MKTAG('F','O','R','M')
  40 #define ID_ANNO       MKTAG('A','N','N','O')
  41 #define ID_AUTH       MKTAG('A','U','T','H')
  42 #define ID_CHRS       MKTAG('C','H','R','S')
  43 #define ID_COPYRIGHT  MKTAG('(','c',')',' ')
  44 #define ID_CSET       MKTAG('C','S','E','T')
  45 #define ID_FVER       MKTAG('F','V','E','R')
  46 #define ID_NAME       MKTAG('N','A','M','E')
  47 #define ID_TEXT       MKTAG('T','E','X','T')
  48 #define ID_BODY       MKTAG('B','O','D','Y')
  49
  50 #define LEFT    2
  51 #define RIGHT   4
  52 #define STEREO  6
  53
  54 #define PACKET_SIZE 1024
  55
  56 typedef enum {COMP_NONE, COMP_FIB, COMP_EXP} svx8_compression_type;
  57
  58 typedef struct {
  59     uint32_t  body_size;
  60     uint32_t  sent_bytes;
  61     uint32_t  audio_frame_count;
  62 } IffDemuxContext;
  63
  64
  65 static void interleave_stereo(const uint8_t *src, uint8_t *dest, int size)
  66 {
  67     uint8_t *end = dest + size;
  68     size = size>>1;
  69
  70     while(dest < end) {
  71         *dest++ = *src;
  72         *dest++ = *(src+size);
  73         src++;
  74     }
  75 }
  76
  77 static int iff_probe(AVProbeData *p)
  78 {
  79     const uint8_t *d = p->buf;
  80
  81     if ( AV_RL32(d)   == ID_FORM &&
  82          AV_RL32(d+8) == ID_8SVX)
  83         return AVPROBE_SCORE_MAX;
  84     return 0;
  85 }
  86
  87 static int iff_read_header(AVFormatContext *s,
  88                            AVFormatParameters *ap)
  89 {
  90     IffDemuxContext *iff = s->priv_data;
  91     ByteIOContext *pb = s->pb;
  92     AVStream *st;
  93     uint32_t chunk_id, data_size;
  94     int padding, done = 0;
  95
  96     st = av_new_stream(s, 0);
  97     if (!st)
  98       return AVERROR(ENOMEM);
  99
 100     st->codec->channels = 1;
 101     url_fskip(pb, 12);
 102
 103     while(!done && !url_feof(pb)) {
 104         chunk_id = get_le32(pb);
 105         data_size = get_be32(pb);
 106         padding = data_size & 1;
 107
 108         switch(chunk_id) {
 109         case ID_VHDR:
 110             url_fskip(pb, 12);
 111             st->codec->sample_rate = get_be16(pb);
 112             url_fskip(pb, 1);
 113             st->codec->codec_tag = get_byte(pb);
 114             url_fskip(pb, 4);
 115             break;
 116
 117         case ID_BODY:
 118             iff->body_size = data_size;
 119             done = 1;
 120             break;
 121
 122         case ID_CHAN:
 123             st->codec->channels = (get_be32(pb) < 6) ? 1 : 2;
 124             break;
 125
 126         default:
 127             url_fseek(pb, data_size + padding, SEEK_CUR);
 128             break;
 129         }
 130     }
 131
 132     if(!st->codec->sample_rate)
 133         return AVERROR_INVALIDDATA;
 134
 135     av_set_pts_info(st, 32, 1, st->codec->sample_rate);
 136     st->codec->codec_type = CODEC_TYPE_AUDIO;
 137
 138     switch(st->codec->codec_tag) {
 139     case COMP_NONE:
 140         st->codec->codec_id = CODEC_ID_PCM_S8;
 141         break;
 142     case COMP_FIB:
 143         st->codec->codec_id = CODEC_ID_8SVX_FIB;
 144         break;
 145     case COMP_EXP:
 146         st->codec->codec_id = CODEC_ID_8SVX_EXP;
 147         break;
 148     default:
 149         av_log(s, AV_LOG_ERROR, "iff: unknown compression method\n");
 150         return -1;
 151     }
 152
 153     st->codec->bits_per_coded_sample = 8;
 154     st->codec->bit_rate = st->codec->channels * st->codec->sample_rate * st->codec->bits_per_coded_sample;
 155     st->codec->block_align = st->codec->channels * st->codec->bits_per_coded_sample;
 156
 157     return 0;
 158 }
 159
 160 static int iff_read_packet(AVFormatContext *s,
 161                            AVPacket *pkt)
 162 {
 163     IffDemuxContext *iff = s->priv_data;
 164     ByteIOContext *pb = s->pb;
 165     int ret;
 166
 167     if(iff->sent_bytes > iff->body_size)
 168         return AVERROR(EIO);
 169
 170     if(s->streams[0]->codec->channels == 2) {
 171         uint8_t sample_buffer[PACKET_SIZE];
 172
 173         ret = get_buffer(pb, sample_buffer, PACKET_SIZE);
 174         if(av_new_packet(pkt, PACKET_SIZE) < 0) {
 175             av_log(s, AV_LOG_ERROR, "iff: cannot allocate packet \n");
 176             return AVERROR(ENOMEM);
 177         }
 178         interleave_stereo(sample_buffer, pkt->data, PACKET_SIZE);
 179     }
 180     else {
 181         ret = av_get_packet(pb, pkt, PACKET_SIZE);
 182     }
 183
 184     if(iff->sent_bytes == 0)
 185         pkt->flags |= PKT_FLAG_KEY;
 186
 187     iff->sent_bytes += PACKET_SIZE;
 188     pkt->stream_index = 0;
 189     pkt->pts = iff->audio_frame_count;
 190     iff->audio_frame_count += ret / s->streams[0]->codec->channels;
 191     return ret;
 192 }
 193
 194 AVInputFormat iff_demuxer = {
 195     "IFF",
 196     NULL_IF_CONFIG_SMALL("IFF format"),
 197     sizeof(IffDemuxContext),
 198     iff_probe,
 199     iff_read_header,
 200     iff_read_packet,
 201 };