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cleanup

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This commit is contained in:
bnnm 2021-10-10 13:31:04 +02:00
parent 92800e6544
commit f052c97cfb
2 changed files with 33 additions and 13 deletions
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42
src/coding/xa_decoder.c
View File

@ -6,13 +6,20 @@
// May be implemented like the SNES/SPC700 BRR.
/* XA ADPCM gain values */
#if 0
//#define XA_FLOAT 1
//#define XA_INTB 1
#if XA_FLOAT
static const float K0[4] = { 0.0, 0.9375, 1.796875, 1.53125 };
static const float K1[4] = { 0.0, 0.0, -0.8125, -0.859375 };
#endif
#elif XA_INTB
/* K0/1 floats to int, -K*2^10 = -K*(1<<10) = -K*1024 */
static const int IK0[4] = { 0, -960, -1840, -1568 };
static const int IK1[4] = { 0, 0, 832, 880 };
static const int K0[4] = { 0, 60, 115, 98 };
static const int K1[4] = { 0, 0, -52, -55 };
#else
/* K0/1 floats to int, -K*2^10 = -K*(1<<10) = -K*1024 */
static const int K0[4] = { 0, -960, -1840, -1568 };
static const int K1[4] = { 0, 0, 832, 880 };
#endif
/* Sony XA ADPCM, defined for CD-DA/CD-i in the "Red Book" (private) or "Green Book" (public) specs.
* The algorithm basically is BRR (Bit Rate Reduction) from the SNES SPC700, while the data layout is new.
@ -74,6 +81,9 @@ static const int IK1[4] = { 0, 0, 832, 880 };
* subframe 1: header @ 0x01 or 0x05/09/0d, 28 bytes @ 0x11,16,19,1d,21 ... 7d
* ...
* subframe 3: header @ 0x03 or 0x07/0b/0f, 28 bytes @ 0x13,17,1b,1f,23 ... 7f
*
* Raw XA found in EA SAT games set subframes header like: 0..3 null + 0..3 ok + 4..7 ok + 4..7 null
* (maybe first/last are CD-error correction only?) so decoder only reads those.
*/
void decode_xa(VGMSTREAMCHANNEL* stream, sample_t* outbuf, int channelspacing, int32_t first_sample, int32_t samples_to_do, int channel, int is_xa8) {
@ -96,30 +106,34 @@ void decode_xa(VGMSTREAMCHANNEL* stream, sample_t* outbuf, int channelspacing, i
frame_offset = stream->offset + bytes_per_frame * frames_in;
read_streamfile(frame, frame_offset, bytes_per_frame, stream->streamfile); /* ignore EOF errors */
VGM_ASSERT(get_u32be(frame+0x0) != get_u32be(frame+0x4) || get_u32be(frame+0x8) != get_u32be(frame+0xC),
VGM_ASSERT_ONCE(get_u32be(frame+0x0) != get_u32be(frame+0x4) || get_u32be(frame+0x8) != get_u32be(frame+0xC),
"bad frames at %x\n", (uint32_t)frame_offset);
/* decode subframes */
for (i = 0; i < subframes / channelspacing; i++) {
#if XA_FLOAT
float coef1, coef2;
#else
int32_t coef1, coef2;
#endif
uint8_t coef_index, shift_factor;
/* parse current subframe (sound unit)'s header (sound parameters) */
sp_pos = is_xa8 ?
i*channelspacing + channel:
i*channelspacing + channel :
0x04 + i*channelspacing + channel;
coef_index = (frame[sp_pos] >> 4) & 0xf;
shift_factor = (frame[sp_pos] >> 0) & 0xf;
/* mastered values like 0xFF exist [Micro Machines (CDi), demo and release] */
VGM_ASSERT(coef_index > 4 || shift_factor > (is_xa8 ? 8 : 12), "XA: incorrect coefs/shift at %x\n", (uint32_t)frame_offset + sp_pos);
VGM_ASSERT_ONCE(coef_index > 4 || shift_factor > (is_xa8 ? 8 : 12), "XA: incorrect coefs/shift at %x\n", (uint32_t)frame_offset + sp_pos);
if (coef_index > 4)
coef_index = 0; /* only 4 filters are used, rest is apparently 0 */
if (shift_factor > (is_xa8 ? 8 : 12))
shift_factor = (is_xa8 ? 8 : 9); /* supposedly, from Nocash PSX docs (in 8-bit mode max range should be 8 though) */
coef1 = IK0[coef_index];
coef2 = IK1[coef_index];
coef1 = K0[coef_index];
coef2 = K1[coef_index];
/* decode subframe nibbles */
@ -156,8 +170,14 @@ void decode_xa(VGMSTREAMCHANNEL* stream, sample_t* outbuf, int channelspacing, i
sample = (int16_t)((sample << 12) & 0xf000) >> shift_factor; /* 16b sign extend + scale */
}
sample = sample << 4; /* scale for current IK */
sample = sample - ((coef1*hist1 + coef2*hist2) >> 10);
sample = sample << 4; /* scale for K */
#if XA_FLOAT
sample = sample + (coef1 * hist1 + coef2 * hist2);
#elif XA_INTB
sample = sample + ((coef1 * hist1 + coef2 * hist2) >> 6);
#else
sample = sample - ((coef1 * hist1 + coef2 * hist2) >> 10);
#endif
hist2 = hist1;
hist1 = sample; /* must go before clamp, somehow */

4
src/meta/adx.c
View File

@ -80,14 +80,14 @@ VGMSTREAM* init_vgmstream_adx_subkey(STREAMFILE* sf, uint16_t subkey) {
/* encryption */
if (version == 0x0408) {
if (find_adx_key(sf, 8, &xor_start, &xor_mult, &xor_add, 0)) {
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)) {
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;