vgmstream/src/meta/ps2_gcm.c
bnnm 887af76ef6 cleanup
- use LF instead of CRLF
- follow common name and code conventions used in other meta
- reduce comment verbosity (should mainly comment unusual points or )
- should declare variables at block level
- skip some checks that are unlikely to matter
- read stream name
2022-07-07 23:13:24 +02:00

79 lines
2.5 KiB
C

#include "meta.h"
#include "../util.h"
#include "../coding/coding.h"
/* .GCM - from PS2 Namco games [Gunvari Collection + Time Crisis (PS2), NamCollection (PS2)] */
VGMSTREAM* init_vgmstream_ps2_gcm(STREAMFILE* sf) {
VGMSTREAM* vgmstream = NULL;
uint32_t start_offset, name_offset;
uint32_t vagp_l_offset, vagp_r_offset, track_size, data_size, channel_size;
int channels, sample_rate, interleave;
/* checks */
if (!is_id32be(0x00,sf, "MCG\0"))
goto fail;
/* .gcm: actual extension */
if (!check_extensions(sf, "gcm"))
goto fail;
/* format is two v4 "VAGp" headers then interleaved data (even for 6ch files) */
vagp_l_offset = read_u32le(0x04, sf);
if (!is_id32be(vagp_l_offset,sf, "VAGp"))
goto fail;
vagp_r_offset = read_u32le(0x08, sf);
if (!is_id32be(vagp_r_offset,sf, "VAGp"))
goto fail;
start_offset = read_u32le(0x0c, sf);
track_size = read_u32le(0x10, sf); /* stereo size */
interleave = read_s32le(0x14, sf);
/* 0x18/1c: null */
/* nothing in the header indicates multi-channel files (*M.GCM), check expected sizes of stereo pairs */
data_size = get_streamfile_size(sf) - start_offset;
if (data_size == (track_size * 3)) {
channels = 6;
}
else if (data_size == track_size) {
channels = 2;
}
else {
goto fail; /* unknown setup (could also check start frames are null) */
}
/* get some values from the VAGp */
channel_size = read_u32be(vagp_l_offset + 0x0c, sf); /* without padding */
sample_rate = read_s32be(vagp_l_offset + 0x10, sf);
name_offset = vagp_l_offset + 0x20; /* both VAGp use the same name (sometimes with an L/R letter) */
if (channel_size != read_u32be(vagp_r_offset + 0x0c, sf)) /* unlikely... */
goto fail;
if (sample_rate != read_u32be(vagp_r_offset + 0x10, sf)) /* unlikely.. */
goto fail;
/* build the VGMSTREAM */
vgmstream = allocate_vgmstream(channels, 0);
if (!vgmstream) goto fail;
vgmstream->meta_type = meta_PS2_GCM;
vgmstream->sample_rate = sample_rate;
vgmstream->num_samples = ps_bytes_to_samples(channel_size, 1);
vgmstream->coding_type = coding_PSX;
vgmstream->layout_type = layout_interleave;
vgmstream->interleave_block_size = interleave;
read_string(vgmstream->stream_name,0x10+1, name_offset,sf);
if (!vgmstream_open_stream(vgmstream, sf, start_offset))
goto fail;
return vgmstream;
fail:
close_vgmstream(vgmstream);
return NULL;
}