mirror of
https://github.com/FFmpeg/FFmpeg.git
synced 2024-12-28 20:53:54 +02:00
129 lines
3.7 KiB
C
129 lines
3.7 KiB
C
/*
|
|
* Maxis XA (.xa) File Demuxer
|
|
* Copyright (c) 2008 Robert Marston
|
|
*
|
|
* 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
|
|
* Maxis XA File Demuxer
|
|
* by Robert Marston (rmarston@gmail.com)
|
|
* for more information on the XA audio format see
|
|
* http://wiki.multimedia.cx/index.php?title=Maxis_XA
|
|
*/
|
|
|
|
#include "libavutil/intreadwrite.h"
|
|
#include "avformat.h"
|
|
|
|
#define XA00_TAG MKTAG('X', 'A', 0, 0)
|
|
#define XAI0_TAG MKTAG('X', 'A', 'I', 0)
|
|
#define XAJ0_TAG MKTAG('X', 'A', 'J', 0)
|
|
|
|
typedef struct MaxisXADemuxContext {
|
|
uint32_t out_size;
|
|
uint32_t sent_bytes;
|
|
uint32_t audio_frame_counter;
|
|
} MaxisXADemuxContext;
|
|
|
|
static int xa_probe(AVProbeData *p)
|
|
{
|
|
int channels, srate, bits_per_sample;
|
|
if (p->buf_size < 24)
|
|
return 0;
|
|
switch(AV_RL32(p->buf)) {
|
|
case XA00_TAG:
|
|
case XAI0_TAG:
|
|
case XAJ0_TAG:
|
|
break;
|
|
default:
|
|
return 0;
|
|
}
|
|
channels = AV_RL16(p->buf + 10);
|
|
srate = AV_RL32(p->buf + 12);
|
|
bits_per_sample = AV_RL16(p->buf + 22);
|
|
if (!channels || channels > 8 || !srate || srate > 192000 ||
|
|
bits_per_sample < 4 || bits_per_sample > 32)
|
|
return 0;
|
|
return AVPROBE_SCORE_MAX/2;
|
|
}
|
|
|
|
static int xa_read_header(AVFormatContext *s,
|
|
AVFormatParameters *ap)
|
|
{
|
|
MaxisXADemuxContext *xa = s->priv_data;
|
|
AVIOContext *pb = s->pb;
|
|
AVStream *st;
|
|
|
|
/*Set up the XA Audio Decoder*/
|
|
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_EA_MAXIS_XA;
|
|
avio_skip(pb, 4); /* Skip the XA ID */
|
|
xa->out_size = avio_rl32(pb);
|
|
avio_skip(pb, 2); /* Skip the tag */
|
|
st->codec->channels = avio_rl16(pb);
|
|
st->codec->sample_rate = avio_rl32(pb);
|
|
/* Value in file is average byte rate*/
|
|
st->codec->bit_rate = avio_rl32(pb) * 8;
|
|
st->codec->block_align = avio_rl16(pb);
|
|
st->codec->bits_per_coded_sample = avio_rl16(pb);
|
|
|
|
av_set_pts_info(st, 64, 1, st->codec->sample_rate);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int xa_read_packet(AVFormatContext *s,
|
|
AVPacket *pkt)
|
|
{
|
|
MaxisXADemuxContext *xa = s->priv_data;
|
|
AVStream *st = s->streams[0];
|
|
AVIOContext *pb = s->pb;
|
|
unsigned int packet_size;
|
|
int ret;
|
|
|
|
if(xa->sent_bytes > xa->out_size)
|
|
return AVERROR(EIO);
|
|
/* 1 byte header and 14 bytes worth of samples * number channels per block */
|
|
packet_size = 15*st->codec->channels;
|
|
|
|
ret = av_get_packet(pb, pkt, packet_size);
|
|
if(ret < 0)
|
|
return ret;
|
|
|
|
pkt->stream_index = st->index;
|
|
xa->sent_bytes += packet_size;
|
|
pkt->pts = xa->audio_frame_counter;
|
|
/* 14 bytes Samples per channel with 2 samples per byte */
|
|
xa->audio_frame_counter += 28 * st->codec->channels;
|
|
|
|
return ret;
|
|
}
|
|
|
|
AVInputFormat ff_xa_demuxer = {
|
|
"xa",
|
|
NULL_IF_CONFIG_SMALL("Maxis XA File Format"),
|
|
sizeof(MaxisXADemuxContext),
|
|
xa_probe,
|
|
xa_read_header,
|
|
xa_read_packet,
|
|
};
|