vgmstream/src/meta/ps2_bmdx.c

117 lines
3.8 KiB
C

#include "meta.h"
#include "../coding/coding.h"
static STREAMFILE* setup_bmdx_streamfile(STREAMFILE *streamFile, off_t start_offset, size_t data_size);
/* .bmdx - from Beatmania IIDX (PS2) games */
VGMSTREAM * init_vgmstream_ps2_bmdx(STREAMFILE *streamFile) {
VGMSTREAM * vgmstream = NULL;
STREAMFILE *temp_streamFile = NULL;
off_t start_offset;
size_t data_size;
int loop_flag, channel_count, encryption;
/* checks */
if (!check_extensions(streamFile, "bmdx"))
goto fail;
if (read_32bitBE(0x00,streamFile) != 0x01006408 ||
read_32bitBE(0x04,streamFile) != 0x00)
goto fail;
start_offset = read_32bitLE(0x08,streamFile);
data_size = read_32bitLE(0x0c,streamFile);
loop_flag = (read_32bitLE(0x10,streamFile) != 0x00);
channel_count = read_32bitLE(0x1C,streamFile);
encryption = (read_32bitLE(0x20,streamFile) == 1);
/* build the VGMSTREAM */
vgmstream = allocate_vgmstream(channel_count,loop_flag);
if (!vgmstream) goto fail;
vgmstream->sample_rate = read_32bitLE(0x18,streamFile);
vgmstream->num_samples = ps_bytes_to_samples(data_size, channel_count);
vgmstream->loop_start_sample = ps_bytes_to_samples(read_32bitLE(0x10,streamFile), channel_count);
vgmstream->loop_end_sample = vgmstream->num_samples;
vgmstream->meta_type = meta_PS2_BMDX;
vgmstream->coding_type = coding_PSX;
vgmstream->layout_type = (channel_count == 1) ? layout_none : layout_interleave;
vgmstream->interleave_block_size = read_32bitLE(0x24,streamFile);
/* later games are encrypted [beatmaniaIIDX 14 GOLD (PS2)] */
if (encryption) {
temp_streamFile = setup_bmdx_streamfile(streamFile, start_offset, data_size);
if (!temp_streamFile) goto fail;
}
if (!vgmstream_open_stream(vgmstream,encryption ? temp_streamFile : streamFile,start_offset))
goto fail;
close_streamfile(temp_streamFile);
return vgmstream;
fail:
close_streamfile(temp_streamFile);
close_vgmstream(vgmstream);
return NULL;
}
typedef struct {
uint8_t xor;
uint8_t add;
off_t start_offset;
size_t data_size;
} bmdx_decryption_data;
static size_t bmdx_decryption_read(STREAMFILE *streamfile, uint8_t *dest, off_t offset, size_t length, bmdx_decryption_data* data) {
size_t bytes_read;
int i;
bytes_read = streamfile->read(streamfile, dest, offset, length);
/* decrypt data (xor) */
for (i = 0; i < bytes_read; i++) {
if (offset+i >= data->start_offset && offset+i < data->start_offset + data->data_size) {
if (((offset+i) % 0x10) == 0) /* XOR header byte per frame */
dest[i] = dest[i] ^ data->xor;
else if (((offset+i) % 0x10) == 2) /* ADD first data byte per frame */
dest[i] = (uint8_t)(dest[i] + data->add);
}
}
return bytes_read;
}
static STREAMFILE* setup_bmdx_streamfile(STREAMFILE *streamFile, off_t start_offset, size_t data_size) {
STREAMFILE *temp_streamFile = NULL, *new_streamFile = NULL;
bmdx_decryption_data io_data = {0};
size_t io_data_size = sizeof(bmdx_decryption_data);
/* setup decryption (usually xor=0xFF and add=0x02) */
io_data.xor = read_8bit(start_offset,streamFile);
io_data.add = (~(uint8_t)read_8bit(start_offset+2,streamFile)) + 0x01;
io_data.start_offset = start_offset;
io_data.data_size = data_size;
/* setup custom streamfile */
new_streamFile = open_wrap_streamfile(streamFile);
if (!new_streamFile) goto fail;
temp_streamFile = new_streamFile;
new_streamFile = open_io_streamfile(temp_streamFile, &io_data,io_data_size, bmdx_decryption_read,NULL);
if (!new_streamFile) goto fail;
temp_streamFile = new_streamFile;
return temp_streamFile;
fail:
close_streamfile(temp_streamFile);
return NULL;
}