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#include "config.h"
#include "sample_cvt.h"
#include "AL/al.h"
#include "alu.h"
#include "alBuffer.h"
namespace {
/* IMA ADPCM Stepsize table */
constexpr int IMAStep_size[89] = {
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,
11487,12635,13899,15289,16818,18500,20350,22358,24633,27086,29794,
32767
};
/* IMA4 ADPCM Codeword decode table */
constexpr int IMA4Codeword[16] = {
1, 3, 5, 7, 9, 11, 13, 15,
-1,-3,-5,-7,-9,-11,-13,-15,
};
/* IMA4 ADPCM Step index adjust decode table */
constexpr int IMA4Index_adjust[16] = {
-1,-1,-1,-1, 2, 4, 6, 8,
-1,-1,-1,-1, 2, 4, 6, 8
};
/* MSADPCM Adaption table */
constexpr int MSADPCMAdaption[16] = {
230, 230, 230, 230, 307, 409, 512, 614,
768, 614, 512, 409, 307, 230, 230, 230
};
/* MSADPCM Adaption Coefficient tables */
constexpr int MSADPCMAdaptionCoeff[7][2] = {
{ 256, 0 },
{ 512, -256 },
{ 0, 0 },
{ 192, 64 },
{ 240, 0 },
{ 460, -208 },
{ 392, -232 }
};
void DecodeIMA4Block(ALshort *dst, const al::byte *src, ALint numchans, ALsizei align)
{
ALint sample[MAX_INPUT_CHANNELS]{};
ALint index[MAX_INPUT_CHANNELS]{};
ALuint code[MAX_INPUT_CHANNELS]{};
for(int c{0};c < numchans;c++)
{
sample[c] = al::to_integer<int>(src[0]) | (al::to_integer<int>(src[1])<<8);
sample[c] = (sample[c]^0x8000) - 32768;
src += 2;
index[c] = al::to_integer<int>(src[0]) | (al::to_integer<int>(src[1])<<8);
index[c] = clampi((index[c]^0x8000) - 32768, 0, 88);
src += 2;
*(dst++) = sample[c];
}
for(int i{1};i < align;i++)
{
if((i&7) == 1)
{
for(int c{0};c < numchans;c++)
{
code[c] = al::to_integer<ALuint>(src[0]) | (al::to_integer<ALuint>(src[1])<< 8) |
(al::to_integer<ALuint>(src[2])<<16) | (al::to_integer<ALuint>(src[3])<<24);
src += 4;
}
}
for(int c{0};c < numchans;c++)
{
const ALuint nibble{code[c]&0xf};
code[c] >>= 4;
sample[c] += IMA4Codeword[nibble] * IMAStep_size[index[c]] / 8;
sample[c] = clampi(sample[c], -32768, 32767);
index[c] += IMA4Index_adjust[nibble];
index[c] = clampi(index[c], 0, 88);
*(dst++) = sample[c];
}
}
}
void DecodeMSADPCMBlock(ALshort *dst, const al::byte *src, ALint numchans, ALsizei align)
{
ALubyte blockpred[MAX_INPUT_CHANNELS]{};
ALint delta[MAX_INPUT_CHANNELS]{};
ALshort samples[MAX_INPUT_CHANNELS][2]{};
for(int c{0};c < numchans;c++)
{
blockpred[c] = minu(al::to_integer<ALubyte>(src[0]), 6);
++src;
}
for(int c{0};c < numchans;c++)
{
delta[c] = al::to_integer<int>(src[0]) | (al::to_integer<int>(src[1])<<8);
delta[c] = (delta[c]^0x8000) - 32768;
src += 2;
}
for(int c{0};c < numchans;c++)
{
samples[c][0] = al::to_integer<short>(src[0]) | (al::to_integer<short>(src[1])<<8);
samples[c][0] = (samples[c][0]^0x8000) - 32768;
src += 2;
}
for(int c{0};c < numchans;c++)
{
samples[c][1] = al::to_integer<short>(src[0]) | (al::to_integer<short>(src[1])<<8);
samples[c][1] = (samples[c][1]^0x8000) - 32768;
src += 2;
}
/* Second sample is written first. */
for(int c{0};c < numchans;c++)
*(dst++) = samples[c][1];
for(int c{0};c < numchans;c++)
*(dst++) = samples[c][0];
int num{0};
for(int i{2};i < align;i++)
{
for(int c{0};c < numchans;c++)
{
/* Read the nibble (first is in the upper bits). */
al::byte nibble;
if(!(num++ & 1))
nibble = *src >> 4;
else
nibble = *(src++) & 0x0f;
ALint pred{(samples[c][0]*MSADPCMAdaptionCoeff[blockpred[c]][0] +
samples[c][1]*MSADPCMAdaptionCoeff[blockpred[c]][1]) / 256};
pred += (al::to_integer<int>(nibble^0x08) - 0x08) * delta[c];
pred = clampi(pred, -32768, 32767);
samples[c][1] = samples[c][0];
samples[c][0] = pred;
delta[c] = (MSADPCMAdaption[al::to_integer<ALubyte>(nibble)] * delta[c]) / 256;
delta[c] = maxi(16, delta[c]);
*(dst++) = pred;
}
}
}
} // namespace
void Convert_ALshort_ALima4(ALshort *dst, const al::byte *src, ALsizei numchans, ALsizei len,
ALsizei align)
{
const ALsizei byte_align{((align-1)/2 + 4) * numchans};
len /= align;
while(len--)
{
DecodeIMA4Block(dst, src, numchans, align);
src += byte_align;
dst += align*numchans;
}
}
void Convert_ALshort_ALmsadpcm(ALshort *dst, const al::byte *src, ALsizei numchans, ALsizei len,
ALsizei align)
{
const ALsizei byte_align{((align-2)/2 + 7) * numchans};
len /= align;
while(len--)
{
DecodeMSADPCMBlock(dst, src, numchans, align);
src += byte_align;
dst += align*numchans;
}
}
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