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cog/Frameworks/vgmstream/vgmstream/src/meta/adx.c

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#ifdef _MSC_VER
#define _USE_MATH_DEFINES
#endif
#include <math.h>
#include <limits.h>
#include "meta.h"
#include "adx_keys.h"
#include "../coding/coding.h"
#ifdef VGM_DEBUG_OUTPUT
//#define ADX_BRUTEFORCE
#endif
#define ADX_KEY_MAX_TEST_FRAMES 32768
#define ADX_KEY_TEST_BUFFER_SIZE 0x8000
static int find_adx_key(STREAMFILE* sf, uint8_t type, uint16_t* xor_start, uint16_t* xor_mult, uint16_t* xor_add, uint16_t subkey);
VGMSTREAM* init_vgmstream_adx(STREAMFILE* sf) {
return init_vgmstream_adx_subkey(sf, 0);
}
/* ADX - CRI Middleware format */
VGMSTREAM* init_vgmstream_adx_subkey(STREAMFILE* sf, uint16_t subkey) {
VGMSTREAM* vgmstream = NULL;
off_t start_offset, hist_offset = 0;
int loop_flag = 0, channels, sample_rate;
int32_t num_samples, loop_start_sample = 0, loop_end_sample = 0;
uint16_t cutoff;
uint16_t version;
uint8_t encoding_type, frame_size;
int16_t coef1, coef2;
uint16_t xor_start = 0, xor_mult = 0, xor_add = 0;
meta_t header_type;
coding_t coding_type;
/* checks*/
if (read_u16be(0x00,sf) != 0x8000)
goto fail;
/* .adx: standard
* .adp: Headhunter (DC) */
if (!check_extensions(sf,"adx,adp"))
goto fail;
/* CRI checks both 0x8000 and memcmps this */
start_offset = read_u16be(0x02,sf) + 0x04;
if (read_u16be(start_offset - 0x06,sf) != 0x2863 || /* "(c" */
read_u32be(start_offset - 0x04,sf) != 0x29435249) /* ")CRI" */
goto fail;
encoding_type = read_u8(0x04, sf);
switch (encoding_type) {
case 0x02:
coding_type = coding_CRI_ADX_fixed;
break;
case 0x03:
coding_type = coding_CRI_ADX;
break;
case 0x04:
coding_type = coding_CRI_ADX_exp;
break;
default: /* 0x10 is AHX for DC, 0x11 is AHX */
goto fail;
}
/* ADX encoders can't set this value, but is honored by ADXPlay if changed and multiple of 0x12,
* though output is unusual and may not be fully supported (works in mono so not an interleave)
* Later versions of the decode just use constant 0x12 ignoring it, though. */
frame_size = read_u8(0x05, sf);
if (read_u8(0x06,sf) != 4) /* bits per sample */
goto fail;
/* older ADX (adxencd) up to 2ch, newer ADX (criatomencd) up to 8 */
channels = read_u8(0x07,sf);
sample_rate = read_s32be(0x08,sf);
num_samples = read_s32be(0x0c,sf);
cutoff = read_u16be(0x10,sf); /* high-pass cutoff frequency, always 500 */
version = read_u16be(0x12,sf); /* version + revision, originally read as separate */
/* encryption */
if (version == 0x0408) {
if (!find_adx_key(sf, 8, &xor_start, &xor_mult, &xor_add, 0)) {
vgm_logi("ADX: decryption keystring not found\n");
}
coding_type = coding_CRI_ADX_enc_8;
version = 0x0400;
}
else if (version == 0x0409) {
if (!find_adx_key(sf, 9, &xor_start, &xor_mult, &xor_add, subkey)) {
vgm_logi("ADX: decryption keycode not found\n");
}
coding_type = coding_CRI_ADX_enc_9;
version = 0x0400;
}
/* version + extra data */
if (version == 0x0300) { /* early ADX (~1998) [Grandia (SAT), Baroque (SAT)] */
size_t base_size = 0x14, loops_size = 0x18;
header_type = meta_ADX_03;
/* no sample history */
if (start_offset - 0x06 >= base_size + loops_size) { /* enough space for loop info? */
off_t loops_offset = base_size;
/* 0x00 (2): initial loop padding (the encoder adds a few blank samples so loop start is block-aligned; max 31)
* ex. loop_start=12: enc_start=32, padding=20 (32-20=12); loop_start=35: enc_start=64, padding=29 (64-29=35)
* 0x02 (2): loop flag? (always 1) */
loop_flag = read_s32be(loops_offset+0x04,sf) != 0; /* loop count + loop type? (always 1) */
loop_start_sample = read_s32be(loops_offset+0x08,sf);
//loop_start_offset = read_u32be(loops_offset+0x0c,sf);
loop_end_sample = read_s32be(loops_offset+0x10,sf);
//loop_end_offset = read_u32be(loops_offset+0x14,sf);
}
}
else if (version == 0x0400) { /* common */
size_t base_size = 0x18, hist_size, ainf_size = 0, loops_size = 0x18;
off_t ainf_offset;
header_type = meta_ADX_04;
hist_offset = base_size; /* always present but often blank */
hist_size = (channels > 1 ? 0x04 * channels : 0x04 + 0x04); /* min is 0x8, even in 1ch files */
ainf_offset = base_size + hist_size + 0x04; /* not seen with >2ch though */
if (is_id32be(ainf_offset+0x00,sf, "AINF"))
ainf_size = read_u32be(ainf_offset+0x04,sf);
if (start_offset - ainf_size - 0x06 >= hist_offset + hist_size + loops_size) { /* enough space for loop info? */
off_t loops_offset = base_size + hist_size;
/* 0x00 (2): initial loop padding (the encoder adds a few blank samples so loop start is block-aligned; max 31)
* ex. loop_start=12: enc_start=32, padding=20 (32-20=12); loop_start=35: enc_start=64, padding=29 (64-29=35)
* 0x02 (2): loop flag? (always 1) */
loop_flag = read_s32be(loops_offset+0x04,sf) != 0; /* loop count + loop type? (always 1) */
loop_start_sample = read_s32be(loops_offset+0x08,sf);
//loop_start_offset = read_u32be(loops_offset+0x0c,sf);
loop_end_sample = read_s32be(loops_offset+0x10,sf);
//loop_end_offset = read_u32be(loops_offset+0x14,sf);
}
/* AINF header info (may be inserted by CRI's tools but is rarely used)
* Can also start right after the loop points (base_size + hist_size + loops_size)
* 0x00 (4): "AINF"
* 0x04 (4): size
* 0x08 (10): str_id
* 0x18 (2): volume (0=base/max?, negative=reduce)
* 0x1c (2): pan l
* 0x1e (2): pan r (0=base, max +-128) */
/* CINF header info (very rare, found after loops) [Sakura Taisen 3 (PS2)]
* 0x00 (4): "CINF"
* 0x04 (4): size
* 0x08 (4): "ASO ", unknown
* 0x28 (4): "SND ", unknown
* 0x48 (-): file name, null terminated
*/
}
else if (version == 0x0500) { /* found in some SFD: Buggy Heat, appears to have no loop */
header_type = meta_ADX_05;
}
else { /* not a known/supported version signature */
goto fail;
}
/* build the VGMSTREAM */
vgmstream = allocate_vgmstream(channels, loop_flag);
if (!vgmstream) goto fail;
vgmstream->sample_rate = sample_rate;
vgmstream->num_samples = num_samples;
vgmstream->loop_start_sample = loop_start_sample;
vgmstream->loop_end_sample = loop_end_sample;
vgmstream->coding_type = coding_type;
vgmstream->layout_type = layout_interleave;
vgmstream->interleave_block_size = frame_size;
vgmstream->meta_type = header_type;
/* calculate filter coefficients */
if (coding_type == coding_CRI_ADX_fixed) {
int i;
/* standard XA coefs * (2<<11) */
for (i = 0; i < channels; i++) {
vgmstream->ch[i].adpcm_coef[0] = 0x0000;
vgmstream->ch[i].adpcm_coef[1] = 0x0000;
vgmstream->ch[i].adpcm_coef[2] = 0x0F00;
vgmstream->ch[i].adpcm_coef[3] = 0x0000;
vgmstream->ch[i].adpcm_coef[4] = 0x1CC0;
vgmstream->ch[i].adpcm_coef[5] = 0xF300;
vgmstream->ch[i].adpcm_coef[6] = 0x1880;
vgmstream->ch[i].adpcm_coef[7] = 0xF240;
}
}
else {
/* coefs from cutoff frequency (some info from decomps, uses floats but no diffs if using doubles due to rounding) */
int i;
float x, y, z, a, b, c;
x = cutoff;
y = sample_rate;
z = cosf(2.0 * M_PI * x / y); /* 2.0 * M_PI: 6.28318548202515f (decomp) */
a = M_SQRT2 - z; /* M_SQRT2: 1.41421353816986f (decomp) */
b = M_SQRT2 - 1.0; /* M_SQRT2 - 1: 0.414213538169861f (decomp) */
c = (a - sqrtf((a + b) * (a - b))) / b; /* this seems calculated with a custom algorithm */
coef1 = (short)(c * 8192);
coef2 = (short)(c * c * -4096);
for (i = 0; i < channels; i++) {
vgmstream->ch[i].adpcm_coef[0] = coef1;
vgmstream->ch[i].adpcm_coef[1] = coef2;
}
}
/* init decoder */
{
int i;
for (i = 0; i < channels; i++) {
/* 2 hist shorts per ch, corresponding to the very first original sample repeated (verified with CRI's encoders).
* Not vital as their effect is small, after a few samples they don't matter, and most songs start in silence. */
if (hist_offset) {
vgmstream->ch[i].adpcm_history1_32 = read_s16be(hist_offset + i*4 + 0x00,sf);
vgmstream->ch[i].adpcm_history2_32 = read_s16be(hist_offset + i*4 + 0x02,sf);
}
if (coding_type == coding_CRI_ADX_enc_8 || coding_type == coding_CRI_ADX_enc_9) {
int j;
vgmstream->ch[i].adx_channels = channels;
vgmstream->ch[i].adx_xor = xor_start;
vgmstream->ch[i].adx_mult = xor_mult;
vgmstream->ch[i].adx_add = xor_add;
for (j = 0; j < i; j++)
adx_next_key(&vgmstream->ch[i]);
}
}
}
if (!vgmstream_open_stream(vgmstream, sf, start_offset))
goto fail;
return vgmstream;
fail:
close_vgmstream(vgmstream);
return NULL;
}
/* ADX key detection works by reading XORed ADPCM scales in frames, and un-XORing with keys in
* a list. If resulting values are within the expected range for N scales we accept that key. */
static int find_adx_key(STREAMFILE* sf, uint8_t type, uint16_t *xor_start, uint16_t *xor_mult, uint16_t *xor_add, uint16_t subkey) {
const int frame_size = 0x12;
uint16_t *scales = NULL;
uint16_t *prescales = NULL;
int bruteframe_start = 0, bruteframe_count = -1;
off_t start_offset;
int i, rc = 0;
/* try to find key in external file first */
{
uint8_t keybuf[0x40+1] = {0}; /* known max ~0x30, +1 extra null for keystrings */
size_t key_size;
/* handle type8 keystrings, key9 keycodes and derived keys too */
key_size = read_key_file(keybuf, sizeof(keybuf), sf);
if (key_size > 0) {
int is_ascii = 0;
/* keystrings should be ASCII, also needed to tell apart 0x06 strings from derived keys */
if (type == 8) {
is_ascii = 1;
for (i = 0; i < key_size; i++) {
if (keybuf[i] < 0x20 || keybuf[i] > 0x7f) {
is_ascii = 0;
break;
}
}
}
if (key_size == 0x06 && !is_ascii) {
*xor_start = get_u16be(keybuf + 0x00);
*xor_mult = get_u16be(keybuf + 0x02);
*xor_add = get_u16be(keybuf + 0x04);
return 1;
}
else if (type == 8 && is_ascii) {
const char* keystring = (const char*)keybuf;
derive_adx_key8(keystring, xor_start, xor_mult, xor_add);
return 1;
}
else if (type == 9 && key_size == 0x08) {
uint64_t keycode = get_u64be(keybuf);
derive_adx_key9(keycode, subkey, xor_start, xor_mult, xor_add);
return 1;
}
else if (type == 9 && key_size == 0x08+0x02) {
uint64_t file_keycode = get_u64be(keybuf+0x00);
uint16_t file_subkey = get_u16be(keybuf+0x08);
derive_adx_key9(file_keycode, file_subkey, xor_start, xor_mult, xor_add);
return 1;
}
}
/* no key set or unknown format, try list */
}
/* setup totals */
{
int frame_count;
int channels = read_u8(0x07, sf);
int num_samples = read_s32be(0x0c, sf);
off_t end_offset;
start_offset = read_u16be(0x02, sf) + 0x4;
end_offset = (num_samples + 31) / 32 * frame_size * channels + start_offset; /* samples-to-bytes */
frame_count = (end_offset - start_offset) / frame_size;
if (frame_count < bruteframe_count || bruteframe_count < 0)
bruteframe_count = frame_count;
}
/* find longest run of non-zero frames (zero frames aren't good for key testing) */
{
static const uint8_t zeroes[0x12] = {0};
uint8_t frame[0x12];
int longest_start = -1, longest_count = -1;
int count = 0;
for (i = 0; i < bruteframe_count; i++) {
read_streamfile(frame, start_offset + i*frame_size, frame_size, sf);
if (memcmp(zeroes, frame, frame_size) != 0)
count++;
else
count = 0;
/* update new record of non-zero frames */
if (count > longest_count) {
longest_count = count;
longest_start = i - count + 1;
if (longest_count >= ADX_KEY_MAX_TEST_FRAMES)
break;
}
}
/* no non-zero frames */
if (longest_start == -1) {
goto done;
}
bruteframe_start = longest_start;
bruteframe_count = longest_count;
if (bruteframe_count > ADX_KEY_MAX_TEST_FRAMES) //?
bruteframe_count = ADX_KEY_MAX_TEST_FRAMES;
}
/* pre-load scales in a table, to avoid re-reading them per key */
{
/* allocate storage for scales */
scales = malloc(bruteframe_count * sizeof(uint16_t));
if (!scales) goto done;
/* prescales are scales before the first test frame, with some blank frames no good
* for key testing, but we must read to compute XOR value at bruteframe_start */
if (bruteframe_start > 0) {
/* allocate storage for prescales */
prescales = malloc(bruteframe_start * sizeof(uint16_t));
if (!prescales) goto done;
/* read the prescales */
for (i = 0; i < bruteframe_start; i++) {
prescales[i] = read_16bitBE(start_offset + i*frame_size, sf);
}
}
/* read in the scales */
for (i = 0; i < bruteframe_count; i++) {
scales[i] = read_16bitBE(start_offset + (bruteframe_start + i)*frame_size, sf);
}
}
/* try to guess key */
{
const adxkey_info *keys = NULL;
int keycount = 0, keymask = 0;
int key_id;
/* setup test mask (used to check high bits that signal un-XORed scale would be too high to be valid) */
if (type == 8) {
keys = adxkey8_list;
keycount = adxkey8_list_count;
keymask = 0x6000;
}
else { //if (type == 9)
/* smarter XOR as seen in PSO2. The scale is technically 13 bits,
* but the maximum value assigned by the encoder is 0x1000.
* This is written to the ADX file as 0xFFF, leaving the high bit
* empty, which is used to validate a key */
keys = adxkey9_list;
keycount = adxkey9_list_count;
keymask = 0x1000;
}
#ifdef ADX_BRUTEFORCE
STREAMFILE* sf_keys = open_streamfile_by_filename(sf, "keys.bin");
uint8_t* buf = NULL;
uint64_t keycode = 0;
if (sf_keys) {
size_t keys_size = get_streamfile_size(sf_keys);
buf = malloc(keys_size);
read_streamfile(buf, 0, keys_size, sf_keys);
keycount = keys_size - 0x08;
VGM_LOG("ADX BF: test keys.bin (type %i)\n", 0);
}
#endif
/* try all keys until one decrypts correctly vs expected scales */
for (key_id = 0; key_id < keycount; key_id++) {
uint16_t key_xor, key_mul, key_add;
uint16_t xor, mul, add;
#ifdef ADX_BRUTEFORCE
if (buf) {
keycode = get_u64be(buf + key_id);
derive_adx_key9(keycode, subkey, &key_xor, &key_mul, &key_add);
}
else
#endif
/* get pre-derived XOR values or derive if needed */
if (keys[key_id].start || keys[key_id].mult || keys[key_id].add) {
key_xor = keys[key_id].start;
key_mul = keys[key_id].mult;
key_add = keys[key_id].add;
}
else if (type == 8 && keys[key_id].key8) {
derive_adx_key8(keys[key_id].key8, &key_xor, &key_mul, &key_add);
}
else if (type == 9 && keys[key_id].key9) {
uint64_t keycode = keys[key_id].key9;
derive_adx_key9(keycode, subkey, &key_xor, &key_mul, &key_add);
}
else {
VGM_LOG("ADX: incorrectly defined key id=%i\n", key_id);
continue;
}
/* temp test values */
xor = key_xor;
mul = key_mul;
add = key_add;
#if 0
/* derive and print all keys in the list, quick validity test */
{
uint16_t test_xor, test_mul, test_add;
xor = keys[key_id].start;
mul = keys[key_id].mult;
add = keys[key_id].add;
if (type == 8 && keys[key_id].key8) {
derive_adx_key8(keys[key_id].key8, &test_xor, &test_mul, &test_add);
VGM_LOG("key8: pre=%04x %04x %04x vs calc=%04x %04x %04x = %s (\"%s\")\n",
xor,mul,add, test_xor,test_mul,test_add,
xor==test_xor && mul==test_mul && add==test_add ? "ok" : "ko", keys[key_id].key8);
}
else if (type == 9 && keys[key_id].key9) {
derive_adx_key9(keys[key_id].key9, subkey, &test_xor, &test_mul, &test_add);
VGM_LOG("key9: pre=%04x %04x %04x vs calc=%04x %04x %04x = %s (%"PRIu64")\n",
xor,mul,add, test_xor,test_mul,test_add,
xor==test_xor && mul==test_mul && add==test_add ? "ok" : "ko", keys[key_id].key9);
}
continue;
}
#endif
/* test vs prescales while XOR looks valid */
for (i = 0; i < bruteframe_start; i++) {
if ((prescales[i] & keymask) != (xor & keymask) && prescales[i] != 0)
break;
xor = xor * mul + add;
}
if (i != bruteframe_start)
continue;
/* test vs scales while XOR looks valid */
for (i = 0; i < bruteframe_count; i++) {
if ((scales[i] & keymask) != (xor & keymask))
break;
xor = xor * mul + add;
}
if (i != bruteframe_count)
continue;
#ifdef ADX_BRUTEFORCE
VGM_LOG("ADX BF: good key at %x, %08x%08x\n", key_id, (uint32_t)(keycode>>32), (uint32_t)(keycode>>0));
#endif
/* all scales are valid, key is good */
*xor_start = key_xor;
*xor_mult = key_mul;
*xor_add = key_add;
rc = 1;
break;
}
#ifdef ADX_BRUTEFORCE
close_streamfile(sf_keys);
free(buf);
#endif
}
done:
free(scales);
free(prescales);
return rc;
}
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