ffmpeg/libavformat/xa.c
Stefano Sabatini 72415b2adb Define AVMediaType enum, and use it instead of enum CodecType, which
is deprecated and will be dropped at the next major bump.

Originally committed as revision 22735 to svn://svn.ffmpeg.org/ffmpeg/trunk
2010-03-30 23:30:55 +00:00

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 libavformat/xa.c
* 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;
ByteIOContext *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;
url_fskip(pb, 4); /* Skip the XA ID */
xa->out_size = get_le32(pb);
url_fskip(pb, 2); /* Skip the tag */
st->codec->channels = get_le16(pb);
st->codec->sample_rate = get_le32(pb);
/* Value in file is average byte rate*/
st->codec->bit_rate = get_le32(pb) * 8;
st->codec->block_align = get_le16(pb);
st->codec->bits_per_coded_sample = get_le16(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];
ByteIOContext *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 xa_demuxer = {
"xa",
NULL_IF_CONFIG_SMALL("Maxis XA File Format"),
sizeof(MaxisXADemuxContext),
xa_probe,
xa_read_header,
xa_read_packet,
};