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vgmstream/src/coding/ima_decoder.c
NicknineTheEagle d4754b00b0 Split Ubi IMA and Ubi SCE IMA into different codecs
2020-12-06 21:05:13 +03:00

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#include "../util.h"
#include "coding.h"
/**
* IMA ADPCM algorithms (expand one nibble to one sample, based on prev sample/history and step table).
* Nibbles are usually grouped in blocks/chunks, with a header, containing 1 or N channels
*
* All IMAs are mostly the same with these variations:
* - interleave: blocks and channels are handled externally (layouts) or internally (mixed channels)
* - block header: none (external), normal (4 bytes of history 16b + step 8b + reserved 8b) or others; per channel/global
* - expand type: IMA style or variations; low or high nibble first
*/
static const int ADPCMTable[90] = {
7, 8, 9, 10, 11, 12, 13, 14,
16, 17, 19, 21, 23, 25, 28, 31,
34, 37, 41, 45, 50, 55, 60, 66,
73, 80, 88, 97, 107, 118, 130, 143,
157, 173, 190, 209, 230, 253, 279, 307,
337, 371, 408, 449, 494, 544, 598, 658,
724, 796, 876, 963, 1060, 1166, 1282, 1411,
1552, 1707, 1878, 2066, 2272, 2499, 2749, 3024,
3327, 3660, 4026, 4428, 4871, 5358, 5894, 6484,
7132, 7845, 8630, 9493, 10442, 11487, 12635, 13899,
15289, 16818, 18500, 20350, 22385, 24623, 27086, 29794,
32767,
0 /* garbage value for Ubisoft IMA (see blocked_ubi_sce.c) */
};
static const int IMA_IndexTable[16] = {
-1, -1, -1, -1, 2, 4, 6, 8,
-1, -1, -1, -1, 2, 4, 6, 8
};
/* Original IMA expansion, using shift+ADDs to avoid MULs (slow back then) */
static void std_ima_expand_nibble(VGMSTREAMCHANNEL * stream, off_t byte_offset, int nibble_shift, int32_t * hist1, int32_t * step_index) {
int sample_nibble, sample_decoded, step, delta;
/* simplified through math from:
* - diff = (code + 1/2) * (step / 4)
* > diff = ((step * nibble) + (step / 2)) / 4
* > diff = (step * nibble / 4) + (step / 8)
* final diff = [signed] (step / 8) + (step / 4) + (step / 2) + (step) [when code = 4+2+1] */
sample_nibble = (read_8bit(byte_offset,stream->streamfile) >> nibble_shift)&0xf; /* ADPCM code */
sample_decoded = *hist1; /* predictor value */
step = ADPCMTable[*step_index]; /* current step */
delta = step >> 3;
if (sample_nibble & 1) delta += step >> 2;
if (sample_nibble & 2) delta += step >> 1;
if (sample_nibble & 4) delta += step;
if (sample_nibble & 8) delta = -delta;
sample_decoded += delta;
*hist1 = clamp16(sample_decoded);
*step_index += IMA_IndexTable[sample_nibble];
if (*step_index < 0) *step_index=0;
if (*step_index > 88) *step_index=88;
}
/* Apple's IMA variation. Exactly the same except it uses 16b history (probably more sensitive to overflow/sign extend?) */
static void std_ima_expand_nibble_16(VGMSTREAMCHANNEL * stream, off_t byte_offset, int nibble_shift, int16_t * hist1, int32_t * step_index) {
int sample_nibble, sample_decoded, step, delta;
sample_nibble = (read_8bit(byte_offset,stream->streamfile) >> nibble_shift)&0xf;
sample_decoded = *hist1;
step = ADPCMTable[*step_index];
delta = step >> 3;
if (sample_nibble & 1) delta += step >> 2;
if (sample_nibble & 2) delta += step >> 1;
if (sample_nibble & 4) delta += step;
if (sample_nibble & 8) delta = -delta;
sample_decoded += delta;
*hist1 = clamp16(sample_decoded); /* no need for this, actually */
*step_index += IMA_IndexTable[sample_nibble];
if (*step_index < 0) *step_index=0;
if (*step_index > 88) *step_index=88;
}
/* Original IMA expansion, but using MULs rather than shift+ADDs (faster for newer processors).
* There is minor rounding difference between ADD and MUL expansions, noticeable/propagated in non-headered IMAs. */
static void std_ima_expand_nibble_mul(VGMSTREAMCHANNEL * stream, off_t byte_offset, int nibble_shift, int32_t * hist1, int32_t * step_index) {
int sample_nibble, sample_decoded, step, delta;
/* simplified through math from:
* - diff = (code + 1/2) * (step / 4)
* > diff = (code + 1/2) * step) / 4) * (2 / 2)
* > diff = (code + 1/2) * 2 * step / 8
* final diff = [signed] ((code * 2 + 1) * step) / 8 */
sample_nibble = (read_8bit(byte_offset,stream->streamfile) >> nibble_shift)&0xf;
sample_decoded = *hist1;
step = ADPCMTable[*step_index];
delta = (sample_nibble & 0x7);
delta = ((delta * 2 + 1) * step) >> 3;
if (sample_nibble & 8) delta = -delta;
sample_decoded += delta;
*hist1 = clamp16(sample_decoded);
*step_index += IMA_IndexTable[sample_nibble];
if (*step_index < 0) *step_index=0;
if (*step_index > 88) *step_index=88;
}
/* 3DS IMA (Mario Golf, Mario Tennis; maybe other Camelot games) */
static void n3ds_ima_expand_nibble(VGMSTREAMCHANNEL * stream, off_t byte_offset, int nibble_shift, int32_t * hist1, int32_t * step_index) {
int sample_nibble, sample_decoded, step, delta;
sample_nibble = (read_8bit(byte_offset,stream->streamfile) >> nibble_shift)&0xf;
sample_decoded = *hist1;
step = ADPCMTable[*step_index];
sample_decoded = sample_decoded << 3;
delta = (sample_nibble & 0x07);
delta = step * delta * 2 + step; /* custom */
if (sample_nibble & 8) delta = -delta;
sample_decoded += delta;
sample_decoded = sample_decoded >> 3;
*hist1 = clamp16(sample_decoded);
*step_index += IMA_IndexTable[sample_nibble];
if (*step_index < 0) *step_index=0;
if (*step_index > 88) *step_index=88;
}
/* The Incredibles PC, updates step_index before doing current sample */
static void snds_ima_expand_nibble(VGMSTREAMCHANNEL * stream, off_t byte_offset, int nibble_shift, int32_t * hist1, int32_t * step_index) {
int sample_nibble, sample_decoded, step, delta;
sample_nibble = (read_8bit(byte_offset,stream->streamfile) >> nibble_shift)&0xf;
sample_decoded = *hist1;
*step_index += IMA_IndexTable[sample_nibble];
if (*step_index < 0) *step_index=0;
if (*step_index > 88) *step_index=88;
step = ADPCMTable[*step_index];
delta = (sample_nibble & 7) * step / 4 + step / 8; /* standard IMA */
if (sample_nibble & 8) delta = -delta;
sample_decoded += delta;
*hist1 = clamp16(sample_decoded);
}
/* Omikron: The Nomad Soul, algorithm from the .exe */
static void otns_ima_expand_nibble(VGMSTREAMCHANNEL * stream, off_t byte_offset, int nibble_shift, int32_t * hist1, int32_t * step_index) {
int sample_nibble, sample_decoded, step, delta;
sample_nibble = (read_8bit(byte_offset,stream->streamfile) >> nibble_shift)&0xf;
sample_decoded = *hist1;
step = ADPCMTable[*step_index];
delta = 0;
if(sample_nibble & 4) delta = step * 4;
if(sample_nibble & 2) delta += step * 2;
if(sample_nibble & 1) delta += step;
delta >>= 2;
if (sample_nibble & 8) delta = -delta;
sample_decoded += delta;
*hist1 = clamp16(sample_decoded);
*step_index += IMA_IndexTable[sample_nibble];
if (*step_index < 0) *step_index=0;
if (*step_index > 88) *step_index=88;
}
/* Fairly OddParents (PC) .WV6: minor variation, reverse engineered from the .exe */
static void wv6_ima_expand_nibble(VGMSTREAMCHANNEL * stream, off_t byte_offset, int nibble_shift, int32_t * hist1, int32_t * step_index) {
int sample_nibble, sample_decoded, step, delta;
sample_nibble = (read_8bit(byte_offset,stream->streamfile) >> nibble_shift)&0xf;
sample_decoded = *hist1;
step = ADPCMTable[*step_index];
delta = (sample_nibble & 0x7);
delta = ((delta * step) >> 3) + ((delta * step) >> 2);
if (sample_nibble & 8) delta = -delta;
sample_decoded += delta;
*hist1 = clamp16(sample_decoded);
*step_index += IMA_IndexTable[sample_nibble];
if (*step_index < 0) *step_index=0;
if (*step_index > 88) *step_index=88;
}
/* Lego Racers (PC) .TUN variation, reverse engineered from the .exe */
static void alp_ima_expand_nibble(VGMSTREAMCHANNEL * stream, off_t byte_offset, int nibble_shift, int32_t * hist1, int32_t * step_index) {
int sample_nibble, sample_decoded, step, delta;
sample_nibble = (read_8bit(byte_offset,stream->streamfile) >> nibble_shift)&0xf;
sample_decoded = *hist1;
step = ADPCMTable[*step_index];
delta = (sample_nibble & 0x7);
delta = (delta * step) >> 2;
if (sample_nibble & 8) delta = -delta;
sample_decoded += delta;
*hist1 = clamp16(sample_decoded);
*step_index += IMA_IndexTable[sample_nibble];
if (*step_index < 0) *step_index=0;
if (*step_index > 88) *step_index=88;
}
/* FFTA2 IMA, different hist and sample rounding, reverse engineered from the ROM */
static void ffta2_ima_expand_nibble(VGMSTREAMCHANNEL * stream, off_t byte_offset, int nibble_shift, int32_t * hist1, int32_t * step_index, int16_t *out_sample) {
int sample_nibble, sample_decoded, step, delta;
sample_nibble = (read_8bit(byte_offset,stream->streamfile) >> nibble_shift)&0xf; /* ADPCM code */
sample_decoded = *hist1; /* predictor value */
step = ADPCMTable[*step_index] * 0x100; /* current step (table in ROM is pre-multiplied though) */
delta = step >> 3;
if (sample_nibble & 1) delta += step >> 2;
if (sample_nibble & 2) delta += step >> 1;
if (sample_nibble & 4) delta += step;
if (sample_nibble & 8) delta = -delta;
sample_decoded += delta;
/* custom clamp16 */
if (sample_decoded > 0x7FFF00)
sample_decoded = 0x7FFF00;
else if (sample_decoded < -0x800000)
sample_decoded = -0x800000;
*hist1 = sample_decoded;
*out_sample = (short)((sample_decoded + 128) / 256); /* int16 sample rounding, hist is kept as int32 */
*step_index += IMA_IndexTable[sample_nibble];
if (*step_index < 0) *step_index=0;
if (*step_index > 88) *step_index=88;
}
/* Yet another IMA expansion, from the exe */
static void blitz_ima_expand_nibble(VGMSTREAMCHANNEL * stream, off_t byte_offset, int nibble_shift, int32_t * hist1, int32_t * step_index) {
int sample_nibble, sample_decoded, step, delta;
sample_nibble = (read_8bit(byte_offset,stream->streamfile) >> nibble_shift)&0xf; /* ADPCM code */
sample_decoded = *hist1; /* predictor value */
step = ADPCMTable[*step_index]; /* current step */
/* table has 2 different values, not enough to bother adding the full table */
if (step == 22385)
step = 22358;
else if (step == 24623)
step = 24633;
delta = (sample_nibble & 0x07);
if (sample_nibble & 8) delta = -delta;
delta = (step >> 1) + delta * step; /* custom */
sample_decoded += delta;
/* in Zapper somehow the exe tries to clamp hist but actually doesn't (bug? not in Lilo & Stitch),
* seems the pcm buffer must be clamped outside though to fix some scratchiness */
*hist1 = sample_decoded;//clamp16(sample_decoded);
*step_index += IMA_IndexTable[sample_nibble];
if (*step_index < 0) *step_index=0;
if (*step_index > 88) *step_index=88;
}
static const int CIMAADPCM_INDEX_TABLE[16] = {8, 6, 4, 2, -1, -1, -1, -1,
-1, -1, -1, -1, 2, 4, 6, 8};
/* Capcom's MT Framework modified IMA, reverse engineered from the exe */
static void mtf_ima_expand_nibble(VGMSTREAMCHANNEL * stream, off_t byte_offset, int nibble_shift, int32_t * hist1, int32_t * step_index) {
int sample_nibble, sample_decoded, step, delta;
sample_nibble = (read_8bit(byte_offset,stream->streamfile) >> nibble_shift) & 0xf;
sample_decoded = *hist1;
step = ADPCMTable[*step_index];
delta = step * (2 * sample_nibble - 15);
sample_decoded += delta;
*hist1 = sample_decoded;
*step_index += CIMAADPCM_INDEX_TABLE[sample_nibble];
if (*step_index < 0) *step_index=0;
if (*step_index > 88) *step_index=88;
}
/* IMA table pre-modified like this:
for i=0..89
adpcm = clamp(adpcm[i], 0x1fff) * 4;
*/
static const int16_t mul_adpcm_table[89] = {
28, 32, 36, 40, 44, 48, 52, 56,
64, 68, 76, 84, 92, 100, 112, 124,
136, 148, 164, 180, 200, 220, 240, 264,
292, 320, 352, 388, 428, 472, 520, 572,
628, 692, 760, 836, 920, 1012, 1116, 1228,
1348, 1484, 1632, 1796, 1976, 2176, 2392, 2632,
2896, 3184, 3504, 3852, 4240, 4664, 5128, 5644,
6208, 6828, 7512, 8264, 9088, 9996, 10996, 12096,
13308, 14640, 16104, 17712, 19484, 21432, 23576, 25936,
28528, 31380, 32764, 32764, 32764, 32764, 32764, 32764,
32764, 32764, 32764, 32764, 32764, 32764, 32764, 32764,
32764
};
/* step table is the same */
/* ops per code, generated like this:
for i=0..15
v = 0x800
if (i & 1) v = 0x1800
if (i & 2) v += 0x2000
if (i & 4) v += 0x4000
if (i & 8) v = -v;
mul_op_table[i] = v;
*/
static const int16_t mul_delta_table[16] = {
0x0800, 0x1800, 0x2800, 0x3800, 0x4800, 0x5800, 0x6800, 0x7800,
-0x0800,-0x1800,-0x2800,-0x3800,-0x4800,-0x5800,-0x6800,-0x7800
};
/* Crystal Dynamics IMA, reverse engineered from the exe, also info: https://github.com/sephiroth99/MulDeMu */
static void cd_ima_expand_nibble(uint8_t byte, int shift, int32_t* hist1, int32_t* index) {
int code, sample, step, delta;
/* could do the above table calcs during decode too */
code = (byte >> shift) & 0xf;
sample = *hist1;
step = mul_adpcm_table[*index];
delta = (int16_t)((step * mul_delta_table[code]) >> 16);
sample += delta;
*hist1 = clamp16(sample);
*index += IMA_IndexTable[code];
if (*index < 0) *index=0;
if (*index > 88) *index=88;
}
/* ************************************ */
/* DVI/IMA */
/* ************************************ */
/* Standard DVI/IMA ADPCM (as in, ADPCM recommended by the IMA using Intel/DVI's implementation).
* Configurable: stereo or mono/interleave nibbles, and high or low nibble first.
* For vgmstream, low nibble is called "IMA ADPCM" and high nibble is "DVI IMA ADPCM" (same thing though). */
void decode_standard_ima(VGMSTREAMCHANNEL * stream, sample_t * outbuf, int channelspacing, int32_t first_sample, int32_t samples_to_do, int channel, int is_stereo, int is_high_first) {
int i, sample_count = 0;
int32_t hist1 = stream->adpcm_history1_32;
int step_index = stream->adpcm_step_index;
/* external interleave */
/* no header (external setup), pre-clamp for wrong values */
if (step_index < 0) step_index=0;
if (step_index > 88) step_index=88;
/* decode nibbles (layout: varies) */
for (i = first_sample; i < first_sample + samples_to_do; i++, sample_count += channelspacing) {
off_t byte_offset = is_stereo ?
stream->offset + i : /* stereo: one nibble per channel */
stream->offset + i/2; /* mono: consecutive nibbles */
int nibble_shift = is_high_first ?
is_stereo ? (!(channel&1) ? 4:0) : (!(i&1) ? 4:0) : /* even = high, odd = low */
is_stereo ? (!(channel&1) ? 0:4) : (!(i&1) ? 0:4); /* even = low, odd = high */
std_ima_expand_nibble(stream, byte_offset,nibble_shift, &hist1, &step_index);
outbuf[sample_count] = (short)(hist1);
}
stream->adpcm_history1_32 = hist1;
stream->adpcm_step_index = step_index;
}
void decode_mtf_ima(VGMSTREAMCHANNEL * stream, sample_t * outbuf, int channelspacing, int32_t first_sample, int32_t samples_to_do, int channel, int is_stereo) {
int i, sample_count = 0;
int32_t hist1 = stream->adpcm_history1_32;
int step_index = stream->adpcm_step_index;
/* external interleave */
/* no header (external setup), pre-clamp for wrong values */
if (step_index < 0) step_index=0;
if (step_index > 88) step_index=88;
/* decode nibbles (layout: varies) */
for (i = first_sample; i < first_sample + samples_to_do; i++, sample_count += channelspacing) {
off_t byte_offset = is_stereo ?
stream->offset + i : /* stereo: one nibble per channel */
stream->offset + i/2; /* mono: consecutive nibbles */
int nibble_shift = is_stereo ?
((channel&1) ? 0:4) :
((i&1) ? 0:4);
mtf_ima_expand_nibble(stream, byte_offset,nibble_shift, &hist1, &step_index);
outbuf[sample_count] = clamp16(hist1 >> 4);
}
stream->adpcm_history1_32 = hist1;
stream->adpcm_step_index = step_index;
}
void decode_3ds_ima(VGMSTREAMCHANNEL * stream, sample_t * outbuf, int channelspacing, int32_t first_sample, int32_t samples_to_do) {
int i, sample_count;
int32_t hist1 = stream->adpcm_history1_32;
int step_index = stream->adpcm_step_index;
//external interleave
//no header
for (i=first_sample,sample_count=0; i<first_sample+samples_to_do; i++,sample_count+=channelspacing) {
off_t byte_offset = stream->offset + i/2;
int nibble_shift = (i&1?4:0); //low nibble order
n3ds_ima_expand_nibble(stream, byte_offset,nibble_shift, &hist1, &step_index);
outbuf[sample_count] = (short)(hist1);
}
stream->adpcm_history1_32 = hist1;
stream->adpcm_step_index = step_index;
}
void decode_snds_ima(VGMSTREAMCHANNEL * stream, sample_t * outbuf, int channelspacing, int32_t first_sample, int32_t samples_to_do, int channel) {
int i, sample_count;
int32_t hist1 = stream->adpcm_history1_32;
int step_index = stream->adpcm_step_index;
//external interleave
//no header
for (i=first_sample,sample_count=0; i<first_sample+samples_to_do; i++,sample_count+=channelspacing) {
off_t byte_offset = stream->offset + i;//one nibble per channel
int nibble_shift = (channel==0?0:4); //high nibble first, based on channel
snds_ima_expand_nibble(stream, byte_offset,nibble_shift, &hist1, &step_index);
outbuf[sample_count] = (short)(hist1);
}
stream->adpcm_history1_32 = hist1;
stream->adpcm_step_index = step_index;
}
void decode_otns_ima(VGMSTREAM * vgmstream, VGMSTREAMCHANNEL * stream, sample_t * outbuf, int channelspacing, int32_t first_sample, int32_t samples_to_do, int channel) {
int i, sample_count;
int32_t hist1 = stream->adpcm_history1_32;
int step_index = stream->adpcm_step_index;
//internal/byte interleave
//no header
for (i=first_sample,sample_count=0; i<first_sample+samples_to_do; i++,sample_count+=channelspacing) {
off_t byte_offset = stream->offset + (vgmstream->channels==1 ? i/2 : i); //one nibble per channel if stereo
int nibble_shift = (vgmstream->channels==1) ? //todo simplify
(i&1?0:4) : //high nibble first(?)
(channel==0?4:0); //low=ch0, high=ch1 (this is correct compared to vids)
otns_ima_expand_nibble(stream, byte_offset,nibble_shift, &hist1, &step_index);
outbuf[sample_count] = (short)(hist1);
}
stream->adpcm_history1_32 = hist1;
stream->adpcm_step_index = step_index;
}
/* WV6 IMA, DVI IMA with custom nibble expand */
void decode_wv6_ima(VGMSTREAMCHANNEL * stream, sample_t * outbuf, int channelspacing, int32_t first_sample, int32_t samples_to_do) {
int i, sample_count;
int32_t hist1 = stream->adpcm_history1_32;
int step_index = stream->adpcm_step_index;
//external interleave
//no header
for (i=first_sample,sample_count=0; i<first_sample+samples_to_do; i++,sample_count+=channelspacing) {
off_t byte_offset = stream->offset + i/2;
int nibble_shift = (i&1?0:4); //high nibble first
wv6_ima_expand_nibble(stream, byte_offset,nibble_shift, &hist1, &step_index);
outbuf[sample_count] = (short)(hist1);
}
stream->adpcm_history1_32 = hist1;
stream->adpcm_step_index = step_index;
}
/* ALT IMA, DVI IMA with custom nibble expand */
void decode_alp_ima(VGMSTREAMCHANNEL * stream, sample_t * outbuf, int channelspacing, int32_t first_sample, int32_t samples_to_do) {
int i, sample_count;
int32_t hist1 = stream->adpcm_history1_32;
int step_index = stream->adpcm_step_index;
//external interleave
//no header
for (i=first_sample,sample_count=0; i<first_sample+samples_to_do; i++,sample_count+=channelspacing) {
off_t byte_offset = stream->offset + i/2;
int nibble_shift = (i&1?0:4); //high nibble first
alp_ima_expand_nibble(stream, byte_offset,nibble_shift, &hist1, &step_index);
outbuf[sample_count] = (short)(hist1);
}
stream->adpcm_history1_32 = hist1;
stream->adpcm_step_index = step_index;
}
/* FFTA2 IMA, DVI IMA with custom nibble expand/rounding */
void decode_ffta2_ima(VGMSTREAMCHANNEL * stream, sample_t * outbuf, int channelspacing, int32_t first_sample, int32_t samples_to_do) {
int i, sample_count;
int32_t hist1 = stream->adpcm_history1_32;
int step_index = stream->adpcm_step_index;
int16_t out_sample;
//external interleave
//no header
for (i=first_sample,sample_count=0; i<first_sample+samples_to_do; i++,sample_count+=channelspacing) {
off_t byte_offset = stream->offset + i/2;
int nibble_shift = (i&1?0:4); //high nibble first
ffta2_ima_expand_nibble(stream, byte_offset,nibble_shift, &hist1, &step_index, &out_sample);
outbuf[sample_count] = out_sample;
}
stream->adpcm_history1_32 = hist1;
stream->adpcm_step_index = step_index;
}
/* Blitz IMA, IMA with custom nibble expand */
void decode_blitz_ima(VGMSTREAMCHANNEL * stream, sample_t * outbuf, int channelspacing, int32_t first_sample, int32_t samples_to_do) {
int i, sample_count;
int32_t hist1 = stream->adpcm_history1_32;
int step_index = stream->adpcm_step_index;
//external interleave
//no header
for (i=first_sample,sample_count=0; i<first_sample+samples_to_do; i++,sample_count+=channelspacing) {
off_t byte_offset = stream->offset + i/2;
int nibble_shift = (i&1?4:0); //low nibble first
blitz_ima_expand_nibble(stream, byte_offset,nibble_shift, &hist1, &step_index);
outbuf[sample_count] = (short)clamp16(hist1);
}
stream->adpcm_history1_32 = hist1;
stream->adpcm_step_index = step_index;
}
/* ************************************ */
/* MS-IMA */
/* ************************************ */
/* IMA with custom frame sizes, header and nibble layout. Outputs an odd number of samples per frame,
* so to simplify calcs this decodes full frames, thus hist doesn't need to be mantained.
* Officially defined in "Microsoft Multimedia Standards Update" doc (RIFFNEW.pdf). */
void decode_ms_ima(VGMSTREAM * vgmstream, VGMSTREAMCHANNEL * stream, sample_t * outbuf, int channelspacing, int32_t first_sample, int32_t samples_to_do, int channel) {
int i, samples_read = 0, samples_done = 0, max_samples;
int32_t hist1;// = stream->adpcm_history1_32;
int step_index;// = stream->adpcm_step_index;
/* internal interleave (configurable size), mixed channels */
int block_samples = ((vgmstream->interleave_block_size - 0x04*vgmstream->channels) * 2 / vgmstream->channels) + 1;
first_sample = first_sample % block_samples;
/* normal header (hist+step+reserved), per channel */
{ //if (first_sample == 0) {
off_t header_offset = stream->offset + 0x04*channel;
hist1 = read_16bitLE(header_offset+0x00,stream->streamfile);
step_index = read_8bit(header_offset+0x02,stream->streamfile); /* 0x03: reserved */
if (step_index < 0) step_index = 0;
if (step_index > 88) step_index = 88;
/* write header sample (odd samples per block) */
if (samples_read >= first_sample && samples_done < samples_to_do) {
outbuf[samples_done * channelspacing] = (short)hist1;
samples_done++;
}
samples_read++;
}
max_samples = (block_samples - samples_read);
if (max_samples > samples_to_do + first_sample - samples_done)
max_samples = samples_to_do + first_sample - samples_done; /* for smaller last block */
/* decode nibbles (layout: alternates 4 bytes/4*2 nibbles per channel) */
for (i = 0; i < max_samples; i++) {
off_t byte_offset = stream->offset + 0x04*vgmstream->channels + 0x04*channel + 0x04*vgmstream->channels*(i/8) + (i%8)/2;
int nibble_shift = (i&1?4:0); /* low nibble first */
std_ima_expand_nibble(stream, byte_offset,nibble_shift, &hist1, &step_index); /* original expand */
if (samples_read >= first_sample && samples_done < samples_to_do) {
outbuf[samples_done * channelspacing] = (short)(hist1);
samples_done++;
}
samples_read++;
}
/* internal interleave: increment offset on complete frame */
if (first_sample + samples_done == block_samples) {
stream->offset += vgmstream->interleave_block_size;
}
//stream->adpcm_history1_32 = hist1;
//stream->adpcm_step_index = step_index;
}
/* Reflection's MS-IMA with custom nibble layout (some info from XA2WAV by Deniz Oezmen) */
void decode_ref_ima(VGMSTREAM * vgmstream, VGMSTREAMCHANNEL * stream, sample_t * outbuf, int channelspacing, int32_t first_sample, int32_t samples_to_do, int channel) {
int i, samples_read = 0, samples_done = 0, max_samples;
int32_t hist1;// = stream->adpcm_history1_32;
int step_index;// = stream->adpcm_step_index;
/* internal interleave (configurable size), mixed channels */
int block_channel_size = (vgmstream->interleave_block_size - 0x04*vgmstream->channels) / vgmstream->channels;
int block_samples = ((vgmstream->interleave_block_size - 0x04*vgmstream->channels) * 2 / vgmstream->channels) + 1;
first_sample = first_sample % block_samples;
/* normal header (hist+step+reserved), per channel */
{ //if (first_sample == 0) {
off_t header_offset = stream->offset + 0x04*channel;
hist1 = read_16bitLE(header_offset+0x00,stream->streamfile);
step_index = read_8bit(header_offset+0x02,stream->streamfile);
if (step_index < 0) step_index = 0;
if (step_index > 88) step_index = 88;
/* write header sample */
if (samples_read >= first_sample && samples_done < samples_to_do) {
outbuf[samples_done * channelspacing] = (short)hist1;
samples_done++;
}
samples_read++;
}
max_samples = (block_samples - samples_read);
if (max_samples > samples_to_do + first_sample - samples_done)
max_samples = samples_to_do + first_sample - samples_done; /* for smaller last block */
/* decode nibbles (layout: all nibbles from one channel, then other channels) */
for (i = 0; i < max_samples; i++) {
off_t byte_offset = stream->offset + 0x04*vgmstream->channels + block_channel_size*channel + i/2;
int nibble_shift = (i&1?4:0); /* low nibble first */
std_ima_expand_nibble(stream, byte_offset,nibble_shift, &hist1, &step_index);
if (samples_read >= first_sample && samples_done < samples_to_do) {
outbuf[samples_done * channelspacing] = (short)(hist1);
samples_done++;
}
samples_read++;
}
/* internal interleave: increment offset on complete frame */
if (first_sample + samples_done == block_samples) {
stream->offset += vgmstream->interleave_block_size;
}
//stream->adpcm_history1_32 = hist1;
//stream->adpcm_step_index = step_index;
}
/* ************************************ */
/* XBOX-IMA */
/* ************************************ */
/* MS-IMA with fixed frame size, and outputs an even number of samples per frame (skips last nibble).
* Defined in Xbox's SDK. Usable in mono or stereo modes (both suitable for interleaved multichannel). */
void decode_xbox_ima(VGMSTREAMCHANNEL * stream, sample_t * outbuf, int channelspacing, int32_t first_sample, int32_t samples_to_do, int channel, int is_stereo) {
int i, frames_in, sample_pos = 0, block_samples, frame_size;
int32_t hist1 = stream->adpcm_history1_32;
int step_index = stream->adpcm_step_index;
off_t frame_offset;
/* external interleave (fixed size), stereo/mono */
block_samples = (0x24 - 0x4) * 2;
frames_in = first_sample / block_samples;
first_sample = first_sample % block_samples;
frame_size = is_stereo ? 0x24*2 : 0x24;
frame_offset = stream->offset + frame_size*frames_in;
/* normal header (hist+step+reserved), stereo/mono */
if (first_sample == 0) {
off_t header_offset = is_stereo ?
frame_offset + 0x04*(channel % 2) :
frame_offset + 0x00;
hist1 = read_16bitLE(header_offset+0x00,stream->streamfile);
step_index = read_8bit(header_offset+0x02,stream->streamfile);
if (step_index < 0) step_index=0;
if (step_index > 88) step_index=88;
/* write header sample (even samples per block, skips last nibble) */
outbuf[sample_pos] = (short)(hist1);
sample_pos += channelspacing;
first_sample += 1;
samples_to_do -= 1;
}
/* decode nibbles (layout: straight in mono or 4 bytes per channel in stereo) */
for (i = first_sample; i < first_sample + samples_to_do; i++) {
off_t byte_offset = is_stereo ?
frame_offset + 0x04*2 + 0x04*(channel % 2) + 0x04*2*((i-1)/8) + ((i-1)%8)/2 :
frame_offset + 0x04 + (i-1)/2;
int nibble_shift = (!((i-1)&1) ? 0:4); /* low first */
/* must skip last nibble per spec, rarely needed though (ex. Gauntlet Dark Legacy) */
if (i < block_samples) {
std_ima_expand_nibble(stream, byte_offset,nibble_shift, &hist1, &step_index);
outbuf[sample_pos] = (short)(hist1);
sample_pos += channelspacing;
}
}
stream->adpcm_history1_32 = hist1;
stream->adpcm_step_index = step_index;
}
/* Multichannel XBOX-IMA ADPCM, with all channels mixed in the same block (equivalent to multichannel MS-IMA; seen in .rsd XADP). */
void decode_xbox_ima_mch(VGMSTREAMCHANNEL * stream, sample_t * outbuf, int channelspacing, int32_t first_sample, int32_t samples_to_do, int channel) {
int i, sample_count = 0, num_frame;
int32_t hist1 = stream->adpcm_history1_32;
int step_index = stream->adpcm_step_index;
/* external interleave (fixed size), multichannel */
int block_samples = (0x24 - 0x4) * 2;
num_frame = first_sample / block_samples;
first_sample = first_sample % block_samples;
/* normal header (hist+step+reserved), multichannel */
if (first_sample == 0) {
off_t header_offset = stream->offset + 0x24*channelspacing*num_frame + 0x04*channel;
hist1 = read_16bitLE(header_offset+0x00,stream->streamfile);
step_index = read_8bit(header_offset+0x02,stream->streamfile);
if (step_index < 0) step_index=0;
if (step_index > 88) step_index=88;
/* write header sample (even samples per block, skips last nibble) */
outbuf[sample_count] = (short)(hist1);
sample_count += channelspacing;
first_sample += 1;
samples_to_do -= 1;
}
/* decode nibbles (layout: alternates 4 bytes/4*2 nibbles per channel) */
for (i = first_sample; i < first_sample + samples_to_do; i++) {
off_t byte_offset = (stream->offset + 0x24*channelspacing*num_frame + 0x04*channelspacing) + 0x04*channel + 0x04*channelspacing*((i-1)/8) + ((i-1)%8)/2;
int nibble_shift = ((i-1)&1?4:0); /* low nibble first */
/* must skip last nibble per spec, rarely needed though */
if (i < block_samples) {
std_ima_expand_nibble(stream, byte_offset,nibble_shift, &hist1, &step_index);
outbuf[sample_count] = (short)(hist1);
sample_count += channelspacing;
}
}
stream->adpcm_history1_32 = hist1;
stream->adpcm_step_index = step_index;
}
/* Similar to MS-IMA with even number of samples, header sample is not written (setup only).
* Apparently clamps to -32767 unlike standard's -32768 (probably not noticeable).
* Info here: http://problemkaputt.de/gbatek.htm#dssoundnotes */
void decode_nds_ima(VGMSTREAMCHANNEL * stream, sample_t * outbuf, int channelspacing, int32_t first_sample, int32_t samples_to_do) {
int i, sample_count;
int32_t hist1 = stream->adpcm_history1_32;
int step_index = stream->adpcm_step_index;
/* external interleave (configurable size), mono */
/* normal header (hist+step+reserved), single channel */
if (first_sample == 0) {
off_t header_offset = stream->offset;
hist1 = read_16bitLE(header_offset,stream->streamfile);
step_index = read_16bitLE(header_offset+2,stream->streamfile);
if (step_index < 0) step_index=0; /* probably pre-adjusted */
if (step_index > 88) step_index=88;
}
/* decode nibbles (layout: all nibbles from the channel) */
for (i=first_sample,sample_count=0; i<first_sample+samples_to_do; i++,sample_count+=channelspacing) {
off_t byte_offset = stream->offset + 0x04 + i/2;
int nibble_shift = (i&1?4:0); /* low nibble first */
//todo waveform has minor deviations using known expands
std_ima_expand_nibble(stream, byte_offset,nibble_shift, &hist1, &step_index);
outbuf[sample_count] = (short)(hist1);
}
stream->adpcm_history1_32 = hist1;
stream->adpcm_step_index = step_index;
}
void decode_dat4_ima(VGMSTREAMCHANNEL * stream, sample_t * outbuf, int channelspacing, int32_t first_sample, int32_t samples_to_do) {
int i, sample_count;
int32_t hist1 = stream->adpcm_history1_16;//todo unneeded 16?
int step_index = stream->adpcm_step_index;
//external interleave
//normal header
if (first_sample == 0) {
off_t header_offset = stream->offset;
hist1 = read_16bitLE(header_offset,stream->streamfile);
step_index = read_8bit(header_offset+2,stream->streamfile);
//todo clip step_index?
}
for (i=first_sample,sample_count=0; i<first_sample+samples_to_do; i++,sample_count+=channelspacing) {
off_t byte_offset = stream->offset + 4 + i/2;
int nibble_shift = (i&1?0:4); //high nibble first
std_ima_expand_nibble(stream, byte_offset,nibble_shift, &hist1, &step_index);
outbuf[sample_count] = (short)(hist1);
}
stream->adpcm_history1_16 = hist1;
stream->adpcm_step_index = step_index;
}
void decode_rad_ima(VGMSTREAM * vgmstream,VGMSTREAMCHANNEL * stream, sample_t * outbuf, int channelspacing, int32_t first_sample, int32_t samples_to_do,int channel) {
int i, sample_count;
int32_t hist1 = stream->adpcm_history1_32;
int step_index = stream->adpcm_step_index;
//internal interleave (configurable size), mixed channels (4 byte per ch)
int block_samples = (vgmstream->interleave_block_size - 4*vgmstream->channels) * 2 / vgmstream->channels;
first_sample = first_sample % block_samples;
//inverted header (per channel)
if (first_sample == 0) {
off_t header_offset = stream->offset + 4*channel;
step_index = read_16bitLE(header_offset,stream->streamfile);
hist1 = read_16bitLE(header_offset+2,stream->streamfile);
if (step_index < 0) step_index=0;
if (step_index > 88) step_index=88;
}
for (i=first_sample,sample_count=0; i<first_sample+samples_to_do; i++,sample_count+=channelspacing) {
off_t byte_offset = stream->offset + 4*vgmstream->channels + channel + i/2*vgmstream->channels;
int nibble_shift = (i&1?4:0); //low nibble first
std_ima_expand_nibble(stream, byte_offset,nibble_shift, &hist1, &step_index);
outbuf[sample_count] = (short)(hist1);
}
//internal interleave: increment offset on complete frame
if (i == block_samples) stream->offset += vgmstream->interleave_block_size;
stream->adpcm_history1_32 = hist1;
stream->adpcm_step_index = step_index;
}
void decode_rad_ima_mono(VGMSTREAMCHANNEL * stream, sample_t * outbuf, int channelspacing, int32_t first_sample, int32_t samples_to_do) {
int i, sample_count;
int32_t hist1 = stream->adpcm_history1_32;
int step_index = stream->adpcm_step_index;
//semi-external interleave?
int block_samples = 0x14 * 2;
first_sample = first_sample % block_samples;
//inverted header
if (first_sample == 0) {
off_t header_offset = stream->offset;
step_index = read_16bitLE(header_offset,stream->streamfile);
hist1 = read_16bitLE(header_offset+2,stream->streamfile);
if (step_index < 0) step_index=0;
if (step_index > 88) step_index=88;
}
for (i=first_sample,sample_count=0; i<first_sample+samples_to_do; i++,sample_count+=channelspacing) {
off_t byte_offset = stream->offset + 4 + i/2;
int nibble_shift = (i&1?4:0); //low nibble first
std_ima_expand_nibble(stream, byte_offset,nibble_shift, &hist1, &step_index);
outbuf[sample_count] = (short)(hist1);
}
stream->adpcm_history1_32 = hist1;
stream->adpcm_step_index = step_index;
}
/* Apple's IMA4, a.k.a QuickTime IMA. 2 byte header and header sample is not written (setup only). */
void decode_apple_ima4(VGMSTREAMCHANNEL * stream, sample_t * outbuf, int channelspacing, int32_t first_sample, int32_t samples_to_do) {
int i, sample_count, num_frame;
int16_t hist1 = stream->adpcm_history1_16;//todo unneeded 16?
int step_index = stream->adpcm_step_index;
//external interleave
int block_samples = (0x22 - 0x2) * 2;
num_frame = first_sample / block_samples;
first_sample = first_sample % block_samples;
//2-byte header
if (first_sample == 0) {
off_t header_offset = stream->offset + 0x22*num_frame;
hist1 = (int16_t)((uint16_t)read_16bitBE(header_offset,stream->streamfile) & 0xff80);
step_index = read_8bit(header_offset+1,stream->streamfile) & 0x7f;
if (step_index < 0) step_index=0;
if (step_index > 88) step_index=88;
}
for (i=first_sample,sample_count=0; i<first_sample+samples_to_do; i++,sample_count+=channelspacing) {
off_t byte_offset = (stream->offset + 0x22*num_frame + 0x2) + i/2;
int nibble_shift = (i&1?4:0); //low nibble first
std_ima_expand_nibble_16(stream, byte_offset,nibble_shift, &hist1, &step_index);
outbuf[sample_count] = (short)(hist1);
}
stream->adpcm_history1_16 = hist1;
stream->adpcm_step_index = step_index;
}
/* XBOX-IMA with modified data layout */
void decode_fsb_ima(VGMSTREAM * vgmstream, VGMSTREAMCHANNEL * stream, sample_t * outbuf, int channelspacing, int32_t first_sample, int32_t samples_to_do,int channel) {
int i, sample_count = 0;
int32_t hist1 = stream->adpcm_history1_32;
int step_index = stream->adpcm_step_index;
/* internal interleave (configurable size), mixed channels */
int block_samples = (0x24 - 0x4) * 2;
first_sample = first_sample % block_samples;
/* interleaved header (all hist per channel + all step_index+reserved per channel) */
if (first_sample == 0) {
off_t hist_offset = stream->offset + 0x02*channel + 0x00;
off_t step_offset = stream->offset + 0x02*channel + 0x02*vgmstream->channels;
hist1 = read_16bitLE(hist_offset,stream->streamfile);
step_index = read_8bit(step_offset,stream->streamfile);
if (step_index < 0) step_index=0;
if (step_index > 88) step_index=88;
/* write header sample (even samples per block, skips last nibble) */
outbuf[sample_count] = (short)(hist1);
sample_count += channelspacing;
first_sample += 1;
samples_to_do -= 1;
}
/* decode nibbles (layout: 2 bytes/2*2 nibbles per channel) */
for (i = first_sample; i < first_sample + samples_to_do; i++) {
off_t byte_offset = stream->offset + 0x04*vgmstream->channels + 0x02*channel + (i-1)/4*2*vgmstream->channels + ((i-1)%4)/2;
int nibble_shift = ((i-1)&1?4:0); /* low nibble first */
/* must skip last nibble per official decoder, probably not needed though */
if (i < block_samples) {
std_ima_expand_nibble(stream, byte_offset,nibble_shift, &hist1, &step_index);
outbuf[sample_count] = (short)(hist1);
sample_count += channelspacing;
}
}
/* internal interleave: increment offset on complete frame */
if (i == block_samples) {
stream->offset += 0x24*vgmstream->channels;
}
stream->adpcm_history1_32 = hist1;
stream->adpcm_step_index = step_index;
}
/* mono XBOX-IMA with header endianness and alt nibble expand (verified vs AK test demos) */
void decode_wwise_ima(VGMSTREAM * vgmstream, VGMSTREAMCHANNEL * stream, sample_t * outbuf, int channelspacing, int32_t first_sample, int32_t samples_to_do, int channel) {
int i, sample_count = 0, num_frame;
int32_t hist1 = stream->adpcm_history1_32;
int step_index = stream->adpcm_step_index;
/* external interleave (fixed size), mono */
int block_samples = (0x24 - 0x4) * 2;
num_frame = first_sample / block_samples;
first_sample = first_sample % block_samples;
/* normal header (hist+step+reserved), single channel */
if (first_sample == 0) {
int16_t (*read_16bit)(off_t,STREAMFILE*) = vgmstream->codec_endian ? read_16bitBE : read_16bitLE;
off_t header_offset = stream->offset + 0x24*num_frame;
hist1 = read_16bit(header_offset,stream->streamfile);
step_index = read_8bit(header_offset+2,stream->streamfile);
if (step_index < 0) step_index=0;
if (step_index > 88) step_index=88;
/* write header sample (even samples per block, skips last nibble) */
outbuf[sample_count] = (short)(hist1);
sample_count += channelspacing;
first_sample += 1;
samples_to_do -= 1;
}
/* decode nibbles (layout: all nibbles from one channel) */
for (i = first_sample; i < first_sample + samples_to_do; i++) {
off_t byte_offset = (stream->offset + 0x24*num_frame + 0x4) + (i-1)/2;
int nibble_shift = ((i-1)&1?4:0); /* low nibble first */
/* must skip last nibble like other XBOX-IMAs, often needed (ex. Bayonetta 2 sfx) */
if (i < block_samples) {
std_ima_expand_nibble_mul(stream, byte_offset,nibble_shift, &hist1, &step_index);
outbuf[sample_count] = (short)(hist1);
sample_count += channelspacing;
}
}
stream->adpcm_history1_32 = hist1;
stream->adpcm_step_index = step_index;
}
/* MS-IMA with possibly the XBOX-IMA model of even number of samples per block (more tests are needed) */
void decode_awc_ima(VGMSTREAMCHANNEL * stream, sample_t * outbuf, int channelspacing, int32_t first_sample, int32_t samples_to_do) {
int i, sample_count;
int32_t hist1 = stream->adpcm_history1_32;
int step_index = stream->adpcm_step_index;
//internal interleave, mono
int block_samples = (0x800 - 4) * 2;
first_sample = first_sample % block_samples;
//inverted header
if (first_sample == 0) {
off_t header_offset = stream->offset;
step_index = read_16bitLE(header_offset,stream->streamfile);
hist1 = read_16bitLE(header_offset+2,stream->streamfile);
if (step_index < 0) step_index=0;
if (step_index > 88) step_index=88;
}
for (i=first_sample,sample_count=0; i<first_sample+samples_to_do; i++,sample_count+=channelspacing) {
off_t byte_offset = stream->offset + 4 + i/2;
int nibble_shift = (i&1?4:0); //low nibble first
std_ima_expand_nibble(stream, byte_offset,nibble_shift, &hist1, &step_index);
outbuf[sample_count] = (short)(hist1);
}
//internal interleave: increment offset on complete frame
if (i == block_samples) stream->offset += 0x800;
stream->adpcm_history1_32 = hist1;
stream->adpcm_step_index = step_index;
}
/* DVI stereo/mono with some mini header and sample output */
void decode_ubi_ima(VGMSTREAMCHANNEL * stream, sample_t * outbuf, int channelspacing, int32_t first_sample, int32_t samples_to_do, int channel) {
int i, sample_count = 0;
int32_t hist1 = stream->adpcm_history1_32;
int step_index = stream->adpcm_step_index;
//internal interleave
//header in the beginning of the stream
if (stream->channel_start_offset == stream->offset) {
int version, big_endian, header_samples, max_samples_to_do;
int16_t (*read_16bit)(off_t,STREAMFILE*) = NULL;
off_t offset = stream->offset;
/* header fields mostly unknown (vary a lot or look like flags, tool version?, 0x08: stereo flag?) */
version = read_8bit(offset + 0x00, stream->streamfile);
big_endian = version < 5;
read_16bit = big_endian ? read_16bitBE : read_16bitLE;
header_samples = read_16bit(offset + 0x0E, stream->streamfile); /* always 10 (per channel) */
hist1 = read_16bit(offset + 0x10 + channel*0x04,stream->streamfile);
step_index = read_8bit(offset + 0x12 + channel*0x04,stream->streamfile);
offset += 0x10 + 0x08;
if (version >= 3)
offset += 0x04;
if (version >= 6) /* later BAOs */
offset += 0x08;
/* write PCM samples, must be written to match header's num_samples (hist mustn't) */
max_samples_to_do = ((samples_to_do > header_samples) ? header_samples : samples_to_do);
for (i = first_sample; i < max_samples_to_do; i++, sample_count += channelspacing) {
outbuf[sample_count] = read_16bit(offset + channel*sizeof(sample) + i*channelspacing*sizeof(sample),stream->streamfile);
first_sample++;
samples_to_do--;
}
/* header done */
if (i == header_samples) {
stream->offset = offset + header_samples*channelspacing*sizeof(sample);
}
}
first_sample -= 10; //todo fix hack (needed to adjust nibble offset below)
if (step_index < 0) step_index = 0;
if (step_index > 88) step_index = 88;
for (i = first_sample; i < first_sample + samples_to_do; i++, sample_count += channelspacing) {
off_t byte_offset = channelspacing == 1 ?
stream->offset + i/2 : /* mono mode */
stream->offset + i; /* stereo mode */
int nibble_shift = channelspacing == 1 ?
(!(i%2) ? 4:0) : /* mono mode (high first) */
(channel==0 ? 4:0); /* stereo mode (high=L,low=R) */
std_ima_expand_nibble_mul(stream, byte_offset,nibble_shift, &hist1, &step_index);
outbuf[sample_count] = (short)(hist1); /* all samples are written */
}
stream->adpcm_history1_32 = hist1;
stream->adpcm_step_index = step_index;
}
/* standard IMA but with a tweak for Ubi's encoder bug with step index (see blocked_ubi_sce.c) */
void decode_ubi_sce_ima(VGMSTREAMCHANNEL * stream, sample_t * outbuf, int channelspacing, int32_t first_sample, int32_t samples_to_do, int channel) {
int i, sample_count = 0;
int32_t hist1 = stream->adpcm_history1_32;
int step_index = stream->adpcm_step_index;
//internal interleave
if (step_index < 0) step_index = 0;
if (step_index > 89) step_index = 89;
for (i = first_sample; i < first_sample + samples_to_do; i++, sample_count += channelspacing) {
off_t byte_offset = channelspacing == 1 ?
stream->offset + i/2 : /* mono mode */
stream->offset + i; /* stereo mode */
int nibble_shift = channelspacing == 1 ?
(!(i%2) ? 4:0) : /* mono mode (high first) */
(channel==0 ? 4:0); /* stereo mode (high=L,low=R) */
std_ima_expand_nibble(stream, byte_offset,nibble_shift, &hist1, &step_index);
outbuf[sample_count] = (short)(hist1); /* all samples are written */
}
stream->adpcm_history1_32 = hist1;
stream->adpcm_step_index = step_index;
}
/* IMA with variable frame formats controlled by the block layout. The original code uses
* tables mapping all standard IMA combinations (to optimize calculations), but decodes the same.
* Based on HCS's and Nisto's reverse engineering in h4m_audio_decode. */
void decode_h4m_ima(VGMSTREAMCHANNEL * stream, sample_t * outbuf, int channelspacing, int32_t first_sample, int32_t samples_to_do, int channel, uint16_t frame_format) {
int i, samples_done = 0;
int32_t hist1 = stream->adpcm_history1_32;
int step_index = stream->adpcm_step_index;
size_t header_size;
int is_stereo = (channelspacing > 1);
/* external interleave (blocked, should call 1 frame) */
/* custom header, per channel */
if (first_sample == 0) {
int channel_pos = is_stereo ? (1 - channel) : channel; /* R hist goes first */
switch(frame_format) {
case 1: /* combined hist+index */
hist1 = read_16bitBE(stream->offset + 0x02*channel_pos + 0x00,stream->streamfile) & 0xFFFFFF80;
step_index = (uint8_t)read_8bit(stream->offset + 0x02*channel_pos + 0x01,stream->streamfile) & 0x7f;
break;
case 3: /* separate hist+index */
hist1 = read_16bitBE(stream->offset + 0x03*channel_pos + 0x00,stream->streamfile);
step_index = (uint8_t)read_8bit(stream->offset + 0x03*channel_pos + 0x02,stream->streamfile);
break;
case 2: /* no hist/index (continues from previous frame) */
default:
break;
}
/* write header sample (last nibble is skipped) */
if (frame_format == 1 || frame_format == 3) {
outbuf[samples_done * channelspacing] = (short)hist1;
samples_done++;
samples_to_do--;
}
/* clamp corrupted data just in case */
if (step_index < 0) step_index = 0;
if (step_index > 88) step_index = 88;
}
else {
/* offset adjust for header sample */
if (frame_format == 1 || frame_format == 3) {
first_sample--;
}
}
/* offset adjust */
switch(frame_format) {
case 1: header_size = (channelspacing*0x02); break;
case 3: header_size = (channelspacing*0x03); break;
default: header_size = 0; break;
}
/* decode block nibbles */
for (i = first_sample; i < first_sample + samples_to_do; i++) {
off_t byte_offset = is_stereo ?
stream->offset + header_size + i : /* stereo: one nibble per channel */
stream->offset + header_size + i/2; /* mono: consecutive nibbles */
int nibble_shift = is_stereo ?
(!(channel&1) ? 0:4) : /* stereo: L=low, R=high */
(!(i&1) ? 0:4); /* mono: low first */
std_ima_expand_nibble(stream, byte_offset,nibble_shift, &hist1, &step_index);
outbuf[samples_done * channelspacing] = (short)(hist1);
samples_done++;
}
stream->adpcm_history1_32 = hist1;
stream->adpcm_step_index = step_index;
}
/* test... */
static inline int _clamp_s32(int value, int min, int max) {
if (value < min)
return min;
else if (value > max)
return max;
else
return value;
}
/* Crystal Dynamics IMA. Original code uses mind-bending intrinsics, so this may not be fully accurate.
* Has another table with delta_table MMX combos, and uses header sample (first nibble is always 0). */
void decode_cd_ima(VGMSTREAMCHANNEL* stream, sample_t* outbuf, int channelspacing, int32_t first_sample, int32_t samples_to_do, int channel) {
uint8_t frame[0x24] = {0};
int i, frames_in, sample_pos = 0, block_samples, frame_size;
int32_t hist1 = stream->adpcm_history1_32;
int step_index = stream->adpcm_step_index;
off_t frame_offset;
/* external interleave (fixed size), mono */
frame_size = 0x24;
block_samples = (frame_size - 0x4) * 2;
frames_in = first_sample / block_samples;
first_sample = first_sample % block_samples;
frame_offset = stream->offset + frame_size * frames_in;
read_streamfile(frame, frame_offset, frame_size, stream->streamfile); /* ignore EOF errors */
/* normal header (hist+step+reserved), mono */
if (first_sample == 0) {
hist1 = get_s16le(frame + 0x00);
step_index = get_u8(frame + 0x02);
step_index = _clamp_s32(step_index, 0, 88);
/* write header sample (even samples per block, skips first nibble) */
outbuf[sample_pos] = (short)(hist1);
sample_pos += channelspacing;
first_sample += 1;
samples_to_do -= 1;
}
/* decode nibbles (layout: straight in mono) */
for (i = first_sample; i < first_sample + samples_to_do; i++) {
int pos = 0x04 + (i/2);
int shift = (i&1 ? 4:0); /* low first, but first low nibble is skipped */
cd_ima_expand_nibble(frame[pos], shift, &hist1, &step_index);
outbuf[sample_pos] = (short)(hist1);
sample_pos += channelspacing;
}
stream->adpcm_history1_32 = hist1;
stream->adpcm_step_index = step_index;
}
/* ************************************************************* */
size_t ima_bytes_to_samples(size_t bytes, int channels) {
if (channels <= 0) return 0;
/* 2 samples per byte (2 nibbles) in stereo or mono config */
return bytes * 2 / channels;
}
size_t ms_ima_bytes_to_samples(size_t bytes, int block_align, int channels) {
if (block_align <= 0 || channels <= 0) return 0;
/* MS-IMA blocks have a 4 byte header per channel; 2 samples per byte (2 nibbles) */
return (bytes / block_align) * ((block_align - 0x04*channels) * 2 / channels + 1)
+ ((bytes % block_align) ? (((bytes % block_align) - 0x04*channels) * 2 / channels + 1) : 0);
}
size_t xbox_ima_bytes_to_samples(size_t bytes, int channels) {
int mod;
int block_align = 0x24 * channels;
if (channels <= 0) return 0;
mod = bytes % block_align;
/* XBOX IMA blocks have a 4 byte header per channel; 2 samples per byte (2 nibbles) */
return (bytes / block_align) * (block_align - 4 * channels) * 2 / channels
+ ((mod > 0 && mod > 0x04*channels) ? (mod - 0x04*channels) * 2 / channels : 0); /* unlikely (encoder aligns) */
}
size_t dat4_ima_bytes_to_samples(size_t bytes, int channels) {
int block_align = 0x20 * channels;
if (channels <= 0) return 0;
/* DAT4 IMA blocks have a 4 byte header per channel; 2 samples per byte (2 nibbles) */
return (bytes / block_align) * (block_align - 4 * channels) * 2 / channels
+ ((bytes % block_align) ? ((bytes % block_align) - 4 * channels) * 2 / channels : 0); /* unlikely (encoder aligns) */
}
size_t apple_ima4_bytes_to_samples(size_t bytes, int channels) {
int block_align = 0x22 * channels;
if (channels <= 0) return 0;
return (bytes / block_align) * (block_align - 0x02*channels) * 2 / channels
+ ((bytes % block_align) ? ((bytes % block_align) - 0x02*channels) * 2 / channels : 0);
}
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