ffmpeg/libavformat/eacdata.c

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/*
* Electronic Arts .cdata file Demuxer
* Copyright (c) 2007 Peter Ross
*
* 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
* Electronic Arts cdata Format Demuxer
* by Peter Ross (pross@xvid.org)
*
* Technical details here:
* http://wiki.multimedia.cx/index.php?title=EA_Command_And_Conquer_3_Audio_Codec
*/
#include "avformat.h"
typedef struct {
unsigned int channels;
unsigned int audio_pts;
} CdataDemuxContext;
static int cdata_probe(AVProbeData *p)
{
const uint8_t *b = p->buf;
if (b[0] == 0x04 && (b[1] == 0x00 || b[1] == 0x04 || b[1] == 0x0C))
return AVPROBE_SCORE_MAX/8;
return 0;
}
static int cdata_read_header(AVFormatContext *s, AVFormatParameters *ap)
{
CdataDemuxContext *cdata = s->priv_data;
AVIOContext *pb = s->pb;
unsigned int sample_rate, header;
AVStream *st;
header = avio_rb16(pb);
switch (header) {
case 0x0400: cdata->channels = 1; break;
case 0x0404: cdata->channels = 2; break;
case 0x040C: cdata->channels = 4; break;
default:
av_log(s, AV_LOG_INFO, "unknown header 0x%04x\n", header);
return -1;
};
sample_rate = avio_rb16(pb);
url_fskip(pb, 12);
st = av_new_stream(s, 0);
if (!st)
return AVERROR(ENOMEM);
st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
st->codec->codec_tag = 0; /* no fourcc */
st->codec->codec_id = CODEC_ID_ADPCM_EA_XAS;
st->codec->channels = cdata->channels;
st->codec->sample_rate = sample_rate;
av_set_pts_info(st, 64, 1, sample_rate);
cdata->audio_pts = 0;
return 0;
}
static int cdata_read_packet(AVFormatContext *s, AVPacket *pkt)
{
CdataDemuxContext *cdata = s->priv_data;
int packet_size = 76*cdata->channels;
int ret = av_get_packet(s->pb, pkt, packet_size);
if (ret < 0)
return ret;
pkt->pts = cdata->audio_pts++;
return 0;
}
AVInputFormat ff_ea_cdata_demuxer = {
"ea_cdata",
NULL_IF_CONFIG_SMALL("Electronic Arts cdata"),
sizeof(CdataDemuxContext),
cdata_probe,
cdata_read_header,
cdata_read_packet,
.extensions = "cdata",
};