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ADPCM mode doesn't entirely die with larger accesses, gain is PCM only

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xperia64 2022-06-19 15:23:05 -04:00 • committed by Tillmann Karras
parent ff8c800689
commit 0bb3de4d7b
1 changed files with 22 additions and 27 deletions
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49
Source/Core/Core/DSP/DSPAccelerator.cpp
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@ -143,41 +143,18 @@ u16 Accelerator::ReadSample(const s16* coefs)
s32 coef1 = coefs[coef_idx * 2 + 0];
s32 coef2 = coefs[coef_idx * 2 + 1];
u8 gain_shift = 0;
switch (m_sample_format.gain_cfg)
{
case FormatGainCfg::GainShift11:
gain_shift = 11;
break;
case FormatGainCfg::GainShift0:
gain_shift = 0;
break;
case FormatGainCfg::GainShift16:
gain_shift = 16;
break;
default:
ERROR_LOG_FMT(DSPLLE, "dsp_read_accelerator_sample() invalid gain mode in format {:#x}",
m_sample_format.hex);
break;
}
switch (m_sample_format.decode)
{
case FormatDecode::ADPCM: // ADPCM audio
{
if (m_sample_format.size != FormatSize::Size4Bit)
{
ERROR_LOG_FMT(
DSPLLE, "dsp_read_accelerator_sample() tried to read ADPCM with bad size in format {:#x}",
m_sample_format.hex);
break;
}
// ADPCM really only supports 4-bit decoding, but for larger values on hardware, it just ignores
// the upper 12 bits
raw_sample &= 0xF;
int scale = 1 << (m_pred_scale & 0xF);
if (raw_sample >= 8)
raw_sample -= 16;
// Not sure if GAIN is applied for ADPCM or not
s32 val32 = (scale * raw_sample) + ((0x400 + coef1 * m_yn1 + coef2 * m_yn2) >> 11);
val = static_cast<s16>(std::clamp<s32>(val32, -0x7FFF, 0x7FFF));
step_size = 2;
@ -189,7 +166,7 @@ u16 Accelerator::ReadSample(const s16* coefs)
// These two cases are handled in a special way, separate from normal overflow handling:
// the ACCOV exception does not fire at all, the predscale register is not updated,
// and if the end address is 16-byte aligned, the DSP loops to start_address + 1
// instead of start_address.
// instead of start_address. This probably needs to be adjusted when using 8 or 16-bit accesses.
if ((m_end_address & 0xf) == 0x0 && m_current_address == m_end_address)
{
m_current_address = m_start_address + 1;
@ -209,6 +186,24 @@ u16 Accelerator::ReadSample(const s16* coefs)
}
case FormatDecode::PCM: // 16-bit PCM audio
{
// Gain seems to only apply for PCM decoding
u8 gain_shift = 0;
switch (m_sample_format.gain_cfg)
{
case FormatGainCfg::GainShift11:
gain_shift = 11;
break;
case FormatGainCfg::GainShift0:
gain_shift = 0;
break;
case FormatGainCfg::GainShift16:
gain_shift = 16;
break;
default:
ERROR_LOG_FMT(DSPLLE, "dsp_read_accelerator_sample() invalid gain mode in format {:#x}",
m_sample_format.hex);
break;
}
s32 val32 = ((static_cast<s32>(m_gain) * raw_sample) >> gain_shift) +
(((coef1 * m_yn1) >> gain_shift) + ((coef2 * m_yn2) >> gain_shift));
val = static_cast<s16>(val32);