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FFmpeg/libavformat/sol.c

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/*
* Sierra SOL decoder
* Copyright Konstantin Shishkov.
*
* This library 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 of the License, or (at your option) any later version.
*
* This library 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 this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/*
* Based on documents from Game Audio Player and own research
*/
#include "avformat.h"
#include "avi.h"
#include "bswap.h"
/* if we don't know the size in advance */
#define AU_UNKOWN_SIZE ((uint32_t)(~0))
static int sol_probe(AVProbeData *p)
{
/* check file header */
uint16_t magic;
if (p->buf_size <= 14)
return 0;
magic=le2me_16(*((uint16_t*)p->buf));
if ((magic == 0x0B8D || magic == 0x0C0D || magic == 0x0C8D) &&
p->buf[2] == 'S' && p->buf[3] == 'O' &&
p->buf[4] == 'L' && p->buf[5] == 0)
return AVPROBE_SCORE_MAX;
else
return 0;
}
#define SOL_DPCM 1
#define SOL_16BIT 4
#define SOL_STEREO 16
static int sol_codec_id(int magic, int type)
{
if (magic == 0x0B8D)
{
if (type & SOL_DPCM) return CODEC_ID_SOL_DPCM;
else return CODEC_ID_PCM_U8;
}
if (type & SOL_DPCM)
{
if (type & SOL_16BIT) return CODEC_ID_SOL_DPCM;
else if (magic == 0x0C8D) return CODEC_ID_SOL_DPCM;
else return CODEC_ID_SOL_DPCM;
}
if (type & SOL_16BIT) return CODEC_ID_PCM_S16LE;
return CODEC_ID_PCM_U8;
}
static int sol_codec_type(int magic, int type)
{
if (magic == 0x0B8D) return 1;//SOL_DPCM_OLD;
if (type & SOL_DPCM)
{
if (type & SOL_16BIT) return 3;//SOL_DPCM_NEW16;
else if (magic == 0x0C8D) return 1;//SOL_DPCM_OLD;
else return 2;//SOL_DPCM_NEW8;
}
return -1;
}
static int sol_channels(int magic, int type)
{
if (magic == 0x0B8D || !(type & SOL_STEREO)) return 1;
return 2;
}
static int sol_read_header(AVFormatContext *s,
AVFormatParameters *ap)
{
int size;
unsigned int magic,tag;
ByteIOContext *pb = &s->pb;
unsigned int id, codec, channels, rate, type;
AVStream *st;
/* check ".snd" header */
magic = get_le16(pb);
tag = get_le32(pb);
if (tag != MKTAG('S', 'O', 'L', 0))
return -1;
rate = get_le16(pb);
type = get_byte(pb);
size = get_le32(pb);
if (magic != 0x0B8D)
get_byte(pb); /* newer SOLs contain padding byte */
codec = sol_codec_id(magic, type);
channels = sol_channels(magic, type);
if (codec == CODEC_ID_SOL_DPCM)
id = sol_codec_type(magic, type);
else id = 0;
/* now we are ready: build format streams */
st = av_new_stream(s, 0);
if (!st)
return -1;
st->codec.codec_type = CODEC_TYPE_AUDIO;
st->codec.codec_tag = id;
st->codec.codec_id = codec;
st->codec.channels = channels;
st->codec.sample_rate = rate;
av_set_pts_info(st, 64, 1, rate);
return 0;
}
#define MAX_SIZE 4096
static int sol_read_packet(AVFormatContext *s,
AVPacket *pkt)
{
int ret;
if (url_feof(&s->pb))
return -EIO;
ret= av_get_packet(&s->pb, pkt, MAX_SIZE);
pkt->stream_index = 0;
/* note: we need to modify the packet size here to handle the last
packet */
pkt->size = ret;
return 0;
}
static int sol_read_close(AVFormatContext *s)
{
return 0;
}
static AVInputFormat sol_iformat = {
"sol",
"Sierra SOL Format",
0,
sol_probe,
sol_read_header,
sol_read_packet,
sol_read_close,
pcm_read_seek,
};
int sol_init(void)
{
av_register_input_format(&sol_iformat);
return 0;
}