vgmstream/src/meta/dc_str.c
2009-01-12 21:38:23 +00:00

96 lines
2.8 KiB
C

#include "meta.h"
#include "../coding/coding.h"
#include "../util.h"
VGMSTREAM * init_vgmstream_dc_str(STREAMFILE *streamFile) {
VGMSTREAM * vgmstream = NULL;
char filename[260];
off_t start_offset;
int loop_flag = 0;
int interleave;
int channel_count;
int samples;
int i;
/* check extension, case insensitive */
streamFile->get_name(streamFile,filename,sizeof(filename));
if (strcasecmp("str",filename_extension(filename))) goto fail;
/* check header */
if (read_32bitBE(0xD5,streamFile) != 0x53656761) /* "Sega" */
goto fail;
interleave = read_32bitLE(0xC,streamFile);
if ((get_streamfile_size(streamFile)-0x800) != (read_32bitLE(0x10,streamFile) *
((read_32bitLE(0x0,streamFile)*(read_32bitLE(0x18,streamFile))))*interleave))
goto fail;
loop_flag = 0; /* (read_32bitLE(0x00,streamFile)!=0x00000000); */
samples = read_32bitLE(0x08,streamFile);
channel_count = (read_32bitLE(0x0,streamFile))*(read_32bitLE(0x18,streamFile));
vgmstream = allocate_vgmstream(channel_count,loop_flag);
if (!vgmstream) goto fail;
/* fill in the vital statistics */
switch (samples) {
case 4:
vgmstream->coding_type = coding_AICA;
vgmstream->num_samples = read_32bitLE(0x14,streamFile);
if (loop_flag) {
vgmstream->loop_start_sample = 0;
vgmstream->loop_end_sample = read_32bitLE(0x14,streamFile);
}
break;
case 16:
vgmstream->coding_type = coding_PCM16LE;
vgmstream->num_samples = read_32bitLE(0x14,streamFile)/2/channel_count;
if (loop_flag) {
vgmstream->loop_start_sample = 0;
vgmstream->loop_end_sample = read_32bitLE(0x14,streamFile)/2/channel_count;
}
break;
default:
goto fail;
}
start_offset = 0x800;
vgmstream->channels = channel_count;
vgmstream->sample_rate = read_32bitLE(0x04,streamFile);
if (vgmstream->channels == 1) {
vgmstream->layout_type = layout_none;
} else if (vgmstream->channels > 1) {
vgmstream->interleave_block_size = interleave;
vgmstream->layout_type = layout_interleave;
}
vgmstream->meta_type = meta_DC_STR;
/* open the file for reading */
{
int i;
STREAMFILE * file;
file = streamFile->open(streamFile,filename,STREAMFILE_DEFAULT_BUFFER_SIZE);
if (!file) goto fail;
for (i=0;i<channel_count;i++) {
vgmstream->ch[i].streamfile = file;
vgmstream->ch[i].channel_start_offset=
vgmstream->ch[i].offset=start_offset+
vgmstream->interleave_block_size*i;
}
}
return vgmstream;
/* clean up anything we may have opened */
fail:
if (vgmstream) close_vgmstream(vgmstream);
return NULL;
}