vgmstream/src/meta/rsf.c

72 lines
1.9 KiB
C

#include "meta.h"
#include "../util.h"
#include "../coding/coding.h"
/* .rsf - from Metroid Prime */
VGMSTREAM* init_vgmstream_rsf(STREAMFILE* sf) {
VGMSTREAM* vgmstream = NULL;
int channels, loop_flag;
uint32_t interleave, file_size;
/* checks */
if (!check_extensions(sf,"rsf"))
goto fail;
/* this is all we have to go on, rsf is completely headerless */
file_size = get_streamfile_size(sf);
interleave = (file_size + 1) / 2;
/* G.721 has no zero nibbles, so we look at the first few bytes
* (known files start with 0xFFFFFFFF, but probably an oddity of the codec) */
{
uint8_t test_byte;
off_t i;
/* 0x20 is arbitrary, all files are much larger */
for (i = 0; i < 0x20; i++) {
test_byte = read_u8(i,sf);
if (!(test_byte&0xf) || !(test_byte&0xf0)) goto fail;
}
/* and also check start of second channel */
for (i = interleave; i < interleave + 0x20; i++) {
test_byte = read_u8(i,sf);
if (!(test_byte&0xf) || !(test_byte&0xf0)) goto fail;
}
}
channels = 2;
loop_flag = 0;
/* build the VGMSTREAM */
vgmstream = allocate_vgmstream(channels, loop_flag);
if (!vgmstream) goto fail;
vgmstream->num_samples = file_size;
vgmstream->sample_rate = 32000;
vgmstream->coding_type = coding_G721;
vgmstream->layout_type = layout_none;
vgmstream->meta_type = meta_RSF;
if (!vgmstream_open_stream(vgmstream, sf, 0))
goto fail;
/* open the file for reading by each channel */
{
int i;
for (i = 0; i < channels; i++) {
vgmstream->ch[i].channel_start_offset= vgmstream->ch[i].offset = interleave * i;
g72x_init_state(&(vgmstream->ch[i].g72x_state));
}
}
return vgmstream;
fail:
close_vgmstream(vgmstream);
return NULL;
}