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/*
* Creative Voice File demuxer.
* Copyright (c) 2006 Aurelien Jacobs <aurel@gnuage.org>
*
* 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 St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "voc.h"
static const int voc_max_pkt_size = 2048;
static int voc_probe(AVProbeData *p)
{
int version, check;
if (p->buf_size < 26)
return 0;
if (memcmp(p->buf, voc_magic, sizeof(voc_magic) - 1))
return 0;
version = p->buf[22] | (p->buf[23] << 8);
check = p->buf[24] | (p->buf[25] << 8);
if (~version + 0x1234 != check)
return 10;
return AVPROBE_SCORE_MAX;
}
static int voc_read_header(AVFormatContext *s, AVFormatParameters *ap)
{
voc_dec_context_t *voc = s->priv_data;
ByteIOContext *pb = &s->pb;
int header_size;
AVStream *st;
url_fskip(pb, 20);
header_size = get_le16(pb) - 22;
if (header_size != 4) {
av_log(s, AV_LOG_ERROR, "unkown header size: %d\n", header_size);
return AVERROR_NOTSUPP;
}
url_fskip(pb, header_size);
st = av_new_stream(s, 0);
if (!st)
return AVERROR_NOMEM;
st->codec->codec_type = CODEC_TYPE_AUDIO;
voc->remaining_size = 0;
return 0;
}
int
voc_get_packet(AVFormatContext *s, AVPacket *pkt, AVStream *st, int max_size)
{
voc_dec_context_t *voc = s->priv_data;
AVCodecContext *dec = st->codec;
ByteIOContext *pb = &s->pb;
voc_type_t type;
int size;
int sample_rate = 0;
int channels = 1;
while (!voc->remaining_size) {
type = get_byte(pb);
if (type == VOC_TYPE_EOF)
return AVERROR_IO;
voc->remaining_size = get_le24(pb);
max_size -= 4;
switch (type) {
case VOC_TYPE_VOICE_DATA:
dec->sample_rate = 1000000 / (256 - get_byte(pb));
if (sample_rate)
dec->sample_rate = sample_rate;
dec->channels = channels;
dec->codec_id = codec_get_id(voc_codec_tags, get_byte(pb));
dec->bits_per_sample = av_get_bits_per_sample(dec->codec_id);
voc->remaining_size -= 2;
max_size -= 2;
channels = 1;
break;
case VOC_TYPE_VOICE_DATA_CONT:
break;
case VOC_TYPE_EXTENDED:
sample_rate = get_le16(pb);
get_byte(pb);
channels = get_byte(pb) + 1;
sample_rate = 256000000 / (channels * (65536 - sample_rate));
voc->remaining_size = 0;
max_size -= 4;
break;
case VOC_TYPE_NEW_VOICE_DATA:
dec->sample_rate = get_le32(pb);
dec->bits_per_sample = get_byte(pb);
dec->channels = get_byte(pb);
dec->codec_id = codec_get_id(voc_codec_tags, get_le16(pb));
url_fskip(pb, 4);
voc->remaining_size -= 12;
max_size -= 12;
break;
default:
url_fskip(pb, voc->remaining_size);
max_size -= voc->remaining_size;
voc->remaining_size = 0;
break;
}
}
dec->bit_rate = dec->sample_rate * dec->bits_per_sample;
if (max_size <= 0)
max_size = voc_max_pkt_size;
size = FFMIN(voc->remaining_size, max_size);
voc->remaining_size -= size;
return av_get_packet(pb, pkt, size);
}
static int voc_read_packet(AVFormatContext *s, AVPacket *pkt)
{
return voc_get_packet(s, pkt, s->streams[0], 0);
}
static int voc_read_close(AVFormatContext *s)
{
return 0;
}
AVInputFormat voc_demuxer = {
"voc",
"Creative Voice File format",
sizeof(voc_dec_context_t),
voc_probe,
voc_read_header,
voc_read_packet,
voc_read_close,
};
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