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 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 "avformat.h"
  31
  32 #define ID_8SVX       MKTAG('8','S','V','X')
  33 #define ID_VHDR       MKTAG('V','H','D','R')
  34 #define ID_ATAK       MKTAG('A','T','A','K')
  35 #define ID_RLSE       MKTAG('R','L','S','E')
  36 #define ID_CHAN       MKTAG('C','H','A','N')
  37
  38 #define ID_FORM       MKTAG('F','O','R','M')
  39 #define ID_ANNO       MKTAG('A','N','N','O')
  40 #define ID_AUTH       MKTAG('A','U','T','H')
  41 #define ID_CHRS       MKTAG('C','H','R','S')
  42 #define ID_COPYRIGHT  MKTAG('(','c',')',' ')
  43 #define ID_CSET       MKTAG('C','S','E','T')
  44 #define ID_FVER       MKTAG('F','V','E','R')
  45 #define ID_NAME       MKTAG('N','A','M','E')
  46 #define ID_TEXT       MKTAG('T','E','X','T')
  47 #define ID_BODY       MKTAG('B','O','D','Y')
  48
  49 #define LEFT    2
  50 #define RIGHT   4
  51 #define STEREO  6
  52
  53 #define PACKET_SIZE 1024
  54
  55 typedef enum {COMP_NONE, COMP_FIB, COMP_EXP} svx8_compression_t;
  56
  57 typedef struct {
  58     uint32_t  body_size;
  59     uint32_t  sent_bytes;
  60     uint32_t  audio_frame_count;
  61 } IffDemuxContext;
  62
  63
  64 static void interleave_stereo(const uint8_t *src, uint8_t *dest, int size)
  65 {
  66     uint8_t *end = dest + size;
  67     size = size>>1;
  68
  69     while(dest < end) {
  70         *dest++ = *src;
  71         *dest++ = *(src+size);
  72         src++;
  73     }
  74 }
  75
  76 static int iff_probe(AVProbeData *p)
  77 {
  78     const uint8_t *d = p->buf;
  79
  80     if ( AV_RL32(d)   == ID_FORM &&
  81          AV_RL32(d+8) == ID_8SVX)
  82         return AVPROBE_SCORE_MAX;
  83     return 0;
  84 }
  85
  86 static int iff_read_header(AVFormatContext *s,
  87                            AVFormatParameters *ap)
  88 {
  89     IffDemuxContext *iff = s->priv_data;
  90     ByteIOContext *pb = s->pb;
  91     AVStream *st;
  92     uint32_t chunk_id, data_size;
  93     int padding, done = 0;
  94
  95     st = av_new_stream(s, 0);
  96     if (!st)
  97       return AVERROR(ENOMEM);
  98
  99     st->codec->channels = 1;
 100     url_fskip(pb, 12);
 101
 102     while(!done && !url_feof(pb)) {
 103         chunk_id = get_le32(pb);
 104         data_size = get_be32(pb);
 105         padding = data_size & 1;
 106
 107         switch(chunk_id) {
 108         case ID_VHDR:
 109             url_fskip(pb, 12);
 110             st->codec->sample_rate = get_be16(pb);
 111             url_fskip(pb, 1);
 112             st->codec->codec_tag = get_byte(pb);
 113             url_fskip(pb, 4);
 114             break;
 115
 116         case ID_BODY:
 117             iff->body_size = data_size;
 118             done = 1;
 119             break;
 120
 121         case ID_CHAN:
 122             st->codec->channels = (get_be32(pb) < 6) ? 1 : 2;
 123             break;
 124
 125         default:
 126             url_fseek(pb, data_size + padding, SEEK_CUR);
 127             break;
 128         }
 129     }
 130
 131     if(!st->codec->sample_rate)
 132         return AVERROR_INVALIDDATA;
 133
 134     av_set_pts_info(st, 32, 1, st->codec->sample_rate);
 135     st->codec->codec_type = CODEC_TYPE_AUDIO;
 136
 137     switch(st->codec->codec_tag) {
 138     case COMP_NONE:
 139         st->codec->codec_id = CODEC_ID_PCM_S8;
 140         break;
 141     case COMP_FIB:
 142         st->codec->codec_id = CODEC_ID_8SVX_FIB;
 143         break;
 144     case COMP_EXP:
 145         st->codec->codec_id = CODEC_ID_8SVX_EXP;
 146         break;
 147     default:
 148         av_log(s, AV_LOG_ERROR, "iff: unknown compression method\n");
 149         return -1;
 150     }
 151
 152     st->codec->bits_per_sample = 8;
 153     st->codec->bit_rate = st->codec->channels * st->codec->sample_rate * st->codec->bits_per_sample;
 154     st->codec->block_align = st->codec->channels * st->codec->bits_per_sample;
 155
 156     return 0;
 157 }
 158
 159 static int iff_read_packet(AVFormatContext *s,
 160                            AVPacket *pkt)
 161 {
 162     IffDemuxContext *iff = s->priv_data;
 163     ByteIOContext *pb = s->pb;
 164     int ret;
 165
 166     if(iff->sent_bytes > iff->body_size)
 167         return AVERROR(EIO);
 168
 169     if(s->streams[0]->codec->channels == 2) {
 170         uint8_t sample_buffer[PACKET_SIZE];
 171
 172         ret = get_buffer(pb, sample_buffer, PACKET_SIZE);
 173         if(av_new_packet(pkt, PACKET_SIZE) < 0) {
 174             av_log(s, AV_LOG_ERROR, "iff: cannot allocate packet \n");
 175             return AVERROR(ENOMEM);
 176         }
 177         interleave_stereo(sample_buffer, pkt->data, PACKET_SIZE);
 178     }
 179     else {
 180         ret = av_get_packet(pb, pkt, PACKET_SIZE);
 181     }
 182
 183     if(iff->sent_bytes == 0)
 184         pkt->flags |= PKT_FLAG_KEY;
 185
 186     iff->sent_bytes += PACKET_SIZE;
 187     pkt->stream_index = 0;
 188     pkt->pts = iff->audio_frame_count;
 189     iff->audio_frame_count += ret / s->streams[0]->codec->channels;
 190     return ret;
 191 }
 192
 193 AVInputFormat iff_demuxer = {
 194     "IFF",
 195     "IFF format",
 196     sizeof(IffDemuxContext),
 197     iff_probe,
 198     iff_read_header,
 199     iff_read_packet,
 200 };