ffmpeg/libavformat/iff.c

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/*
* IFF (.iff) file demuxer
* Copyright (c) 2008 Jaikrishnan Menon <realityman@gmx.net>
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file iff.c
* IFF file demuxer
* by Jaikrishnan Menon
* for more information on the .iff file format, visit:
* http://wiki.multimedia.cx/index.php?title=IFF
*/
#include "avformat.h"
#define ID_8SVX MKTAG('8','S','V','X')
#define ID_VHDR MKTAG('V','H','D','R')
#define ID_ATAK MKTAG('A','T','A','K')
#define ID_RLSE MKTAG('R','L','S','E')
#define ID_CHAN MKTAG('C','H','A','N')
#define ID_FORM MKTAG('F','O','R','M')
#define ID_ANNO MKTAG('A','N','N','O')
#define ID_AUTH MKTAG('A','U','T','H')
#define ID_CHRS MKTAG('C','H','R','S')
#define ID_COPYRIGHT MKTAG('(','c',')',' ')
#define ID_CSET MKTAG('C','S','E','T')
#define ID_FVER MKTAG('F','V','E','R')
#define ID_NAME MKTAG('N','A','M','E')
#define ID_TEXT MKTAG('T','E','X','T')
#define ID_BODY MKTAG('B','O','D','Y')
#define LEFT 2
#define RIGHT 4
#define STEREO 6
#define PACKET_SIZE 1024
typedef enum {COMP_NONE, COMP_FIB, COMP_EXP} svx8_compression_t;
typedef struct {
uint32_t body_size;
uint32_t sent_bytes;
uint32_t audio_frame_count;
} IffDemuxContext;
static void interleave_stereo(const uint8_t *src, uint8_t *dest, int size)
{
uint8_t *end = dest + size;
size = size>>1;
while(dest < end) {
*dest++ = *src;
*dest++ = *(src+size);
src++;
}
}
static int iff_probe(AVProbeData *p)
{
const uint8_t *d = p->buf;
if ( AV_RL32(d) == ID_FORM &&
AV_RL32(d+8) == ID_8SVX)
return AVPROBE_SCORE_MAX;
return 0;
}
static int iff_read_header(AVFormatContext *s,
AVFormatParameters *ap)
{
IffDemuxContext *iff = s->priv_data;
ByteIOContext *pb = s->pb;
AVStream *st;
uint32_t chunk_id, data_size;
int padding, done = 0;
st = av_new_stream(s, 0);
if (!st)
return AVERROR(ENOMEM);
st->codec->channels = 1;
url_fskip(pb, 12);
while(!done && !url_feof(pb)) {
chunk_id = get_le32(pb);
data_size = get_be32(pb);
padding = data_size & 1;
switch(chunk_id) {
case ID_VHDR:
url_fskip(pb, 12);
st->codec->sample_rate = get_be16(pb);
url_fskip(pb, 1);
st->codec->codec_tag = get_byte(pb);
url_fskip(pb, 4);
break;
case ID_BODY:
iff->body_size = data_size;
done = 1;
break;
case ID_CHAN:
st->codec->channels = (get_be32(pb) < 6) ? 1 : 2;
break;
default:
url_fseek(pb, data_size + padding, SEEK_CUR);
break;
}
}
if(!st->codec->sample_rate)
return AVERROR_INVALIDDATA;
av_set_pts_info(st, 32, 1, st->codec->sample_rate);
st->codec->codec_type = CODEC_TYPE_AUDIO;
switch(st->codec->codec_tag) {
case COMP_NONE:
st->codec->codec_id = CODEC_ID_PCM_S8;
break;
case COMP_FIB:
st->codec->codec_id = CODEC_ID_8SVX_FIB;
break;
case COMP_EXP:
st->codec->codec_id = CODEC_ID_8SVX_EXP;
break;
default:
av_log(s, AV_LOG_ERROR, "iff: unknown compression method\n");
return -1;
}
st->codec->bits_per_sample = 8;
st->codec->bit_rate = st->codec->channels * st->codec->sample_rate * st->codec->bits_per_sample;
st->codec->block_align = st->codec->channels * st->codec->bits_per_sample;
return 0;
}
static int iff_read_packet(AVFormatContext *s,
AVPacket *pkt)
{
IffDemuxContext *iff = s->priv_data;
ByteIOContext *pb = s->pb;
int ret;
if(iff->sent_bytes > iff->body_size)
return AVERROR(EIO);
if(s->streams[0]->codec->channels == 2) {
uint8_t sample_buffer[PACKET_SIZE];
ret = get_buffer(pb, sample_buffer, PACKET_SIZE);
if(av_new_packet(pkt, PACKET_SIZE) < 0) {
av_log(s, AV_LOG_ERROR, "iff: cannot allocate packet \n");
return AVERROR(ENOMEM);
}
interleave_stereo(sample_buffer, pkt->data, PACKET_SIZE);
}
else {
ret = av_get_packet(pb, pkt, PACKET_SIZE);
}
if(iff->sent_bytes == 0)
pkt->flags |= PKT_FLAG_KEY;
iff->sent_bytes += PACKET_SIZE;
pkt->stream_index = 0;
pkt->pts = iff->audio_frame_count;
iff->audio_frame_count += ret / s->streams[0]->codec->channels;
return ret;
}
AVInputFormat iff_demuxer = {
"IFF",
"IFF format",
sizeof(IffDemuxContext),
iff_probe,
iff_read_header,
iff_read_packet,
};