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/*
* ISS (.iss) 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 libavformat/iss.c
* Funcom ISS file demuxer
* @author Jaikrishnan Menon
* for more information on the .iss file format, visit:
* http://wiki.multimedia.cx/index.php?title=FunCom_ISS
*/
#include "avformat.h"
#include "libavutil/avstring.h"
#define ISS_SIG "IMA_ADPCM_Sound"
#define ISS_SIG_LEN 15
#define MAX_TOKEN_SIZE 20
typedef struct {
int packet_size;
int sample_start_pos;
} IssDemuxContext;
static void get_token(ByteIOContext *s, char *buf, int maxlen)
{
int i = 0;
char c;
while ((c = get_byte(s))) {
if(c == ' ')
break;
if (i < maxlen-1)
buf[i++] = c;
}
if(!c)
get_byte(s);
buf[i] = 0; /* Ensure null terminated, but may be truncated */
}
static int iss_probe(AVProbeData *p)
{
if (strncmp(p->buf, ISS_SIG, ISS_SIG_LEN))
return 0;
return AVPROBE_SCORE_MAX;
}
static av_cold int iss_read_header(AVFormatContext *s, AVFormatParameters *ap)
{
IssDemuxContext *iss = s->priv_data;
ByteIOContext *pb = s->pb;
AVStream *st;
char token[MAX_TOKEN_SIZE];
int stereo, rate_divisor;
get_token(pb, token, sizeof(token)); //"IMA_ADPCM_Sound"
get_token(pb, token, sizeof(token)); //packet size
sscanf(token, "%d", &iss->packet_size);
get_token(pb, token, sizeof(token)); //File ID
get_token(pb, token, sizeof(token)); //out size
get_token(pb, token, sizeof(token)); //stereo
sscanf(token, "%d", &stereo);
get_token(pb, token, sizeof(token)); //Unknown1
get_token(pb, token, sizeof(token)); //RateDivisor
sscanf(token, "%d", &rate_divisor);
get_token(pb, token, sizeof(token)); //Unknown2
get_token(pb, token, sizeof(token)); //Version ID
get_token(pb, token, sizeof(token)); //Size
iss->sample_start_pos = url_ftell(pb);
st = av_new_stream(s, 0);
if (!st)
return AVERROR(ENOMEM);
st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
st->codec->codec_id = CODEC_ID_ADPCM_IMA_ISS;
st->codec->channels = stereo ? 2 : 1;
st->codec->sample_rate = 44100;
if(rate_divisor > 0)
st->codec->sample_rate /= rate_divisor;
st->codec->bits_per_coded_sample = 4;
st->codec->bit_rate = st->codec->channels * st->codec->sample_rate
* st->codec->bits_per_coded_sample;
st->codec->block_align = iss->packet_size;
av_set_pts_info(st, 32, 1, st->codec->sample_rate);
return 0;
}
static int iss_read_packet(AVFormatContext *s, AVPacket *pkt)
{
IssDemuxContext *iss = s->priv_data;
int ret = av_get_packet(s->pb, pkt, iss->packet_size);
if(ret != iss->packet_size)
return AVERROR(EIO);
pkt->stream_index = 0;
pkt->pts = url_ftell(s->pb) - iss->sample_start_pos;
if(s->streams[0]->codec->channels > 0)
pkt->pts /= s->streams[0]->codec->channels*2;
return 0;
}
AVInputFormat iss_demuxer = {
"ISS",
NULL_IF_CONFIG_SMALL("Funcom ISS format"),
sizeof(IssDemuxContext),
iss_probe,
iss_read_header,
iss_read_packet,
};
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