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Diffstat (limited to 'audio/softsynth/mt32/BReverbModel.cpp')
-rw-r--r--audio/softsynth/mt32/BReverbModel.cpp129
1 files changed, 79 insertions, 50 deletions
diff --git a/audio/softsynth/mt32/BReverbModel.cpp b/audio/softsynth/mt32/BReverbModel.cpp
index cc0219b741..c16f7f17da 100644
--- a/audio/softsynth/mt32/BReverbModel.cpp
+++ b/audio/softsynth/mt32/BReverbModel.cpp
@@ -15,10 +15,8 @@
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
+//#include <memory.h>
#include "mt32emu.h"
-
-#if MT32EMU_USE_REVERBMODEL == 2
-
#include "BReverbModel.h"
// Analysing of state of reverb RAM address lines gives exact sizes of the buffers of filters used. This also indicates that
@@ -62,9 +60,9 @@ static const Bit32u MODE_1_OUTL[] = {2618, 1760, 4518};
static const Bit32u MODE_1_OUTR[] = {1300, 3532, 2274};
static const Bit32u MODE_1_COMB_FACTOR[] = {0x80, 0x60, 0x60, 0x60};
static const Bit32u MODE_1_COMB_FEEDBACK[] = {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
- 0x28, 0x48, 0x60, 0x70, 0x78, 0x80, 0x90, 0x98,
- 0x28, 0x48, 0x60, 0x78, 0x80, 0x88, 0x90, 0x98,
- 0x28, 0x48, 0x60, 0x78, 0x80, 0x88, 0x90, 0x98};
+ 0x28, 0x48, 0x60, 0x70, 0x78, 0x80, 0x90, 0x98,
+ 0x28, 0x48, 0x60, 0x78, 0x80, 0x88, 0x90, 0x98,
+ 0x28, 0x48, 0x60, 0x78, 0x80, 0x88, 0x90, 0x98};
static const Bit32u MODE_1_DRY_AMP[] = {0xA0, 0xA0, 0xB0, 0xB0, 0xB0, 0xB0, 0xB0, 0xE0};
static const Bit32u MODE_1_WET_AMP[] = {0x10, 0x30, 0x50, 0x70, 0x90, 0xC0, 0xF0, 0xF0};
static const Bit32u MODE_1_LPF_AMP = 0x60;
@@ -103,7 +101,11 @@ static const BReverbSettings * const REVERB_SETTINGS[] = {&REVERB_MODE_0_SETTING
// This algorithm tries to emulate exactly Boss multiplication operation (at least this is what we see on reverb RAM data lines).
// Also LA32 is suspected to use the similar one to perform PCM interpolation and ring modulation.
-static Bit32s weirdMul(Bit32s a, Bit8u addMask, Bit8u carryMask) {
+static Sample weirdMul(Sample a, Bit8u addMask, Bit8u carryMask) {
+ (void)carryMask;
+#if MT32EMU_USE_FLOAT_SAMPLES
+ return a * addMask / 256.0f;
+#elif MT32EMU_BOSS_REVERB_PRECISE_MODE
Bit8u mask = 0x80;
Bit32s res = 0;
for (int i = 0; i < 8; i++) {
@@ -113,10 +115,13 @@ static Bit32s weirdMul(Bit32s a, Bit8u addMask, Bit8u carryMask) {
mask >>= 1;
}
return res;
+#else
+ return Sample(((Bit32s)a * addMask) >> 8);
+#endif
}
RingBuffer::RingBuffer(Bit32u newsize) : size(newsize), index(0) {
- buffer = new Bit16s[size];
+ buffer = new Sample[size];
}
RingBuffer::~RingBuffer() {
@@ -124,7 +129,7 @@ RingBuffer::~RingBuffer() {
buffer = NULL;
}
-Bit32s RingBuffer::next() {
+Sample RingBuffer::next() {
if (++index >= size) {
index = 0;
}
@@ -134,52 +139,69 @@ Bit32s RingBuffer::next() {
bool RingBuffer::isEmpty() const {
if (buffer == NULL) return true;
- Bit16s *buf = buffer;
+#if MT32EMU_USE_FLOAT_SAMPLES
+ Sample max = 0.001f;
+#else
+ Sample max = 8;
+#endif
+ Sample *buf = buffer;
for (Bit32u i = 0; i < size; i++) {
- if (*buf < -8 || *buf > 8) return false;
+ if (*buf < -max || *buf > max) return false;
buf++;
}
return true;
}
void RingBuffer::mute() {
- Bit16s *buf = buffer;
+#if MT32EMU_USE_FLOAT_SAMPLES
+ Sample *buf = buffer;
for (Bit32u i = 0; i < size; i++) {
*buf++ = 0;
}
+#else
+ memset(buffer, 0, size * sizeof(Sample));
+#endif
}
AllpassFilter::AllpassFilter(const Bit32u useSize) : RingBuffer(useSize) {}
-Bit32s AllpassFilter::process(const Bit32s in) {
+Sample AllpassFilter::process(const Sample in) {
// This model corresponds to the allpass filter implementation of the real CM-32L device
// found from sample analysis
- Bit16s bufferOut = next();
+ const Sample bufferOut = next();
+#if MT32EMU_USE_FLOAT_SAMPLES
+ // store input - feedback / 2
+ buffer[index] = in - 0.5f * bufferOut;
+
+ // return buffer output + feedforward / 2
+ return bufferOut + 0.5f * buffer[index];
+#else
// store input - feedback / 2
buffer[index] = in - (bufferOut >> 1);
// return buffer output + feedforward / 2
return bufferOut + (buffer[index] >> 1);
+#endif
}
CombFilter::CombFilter(const Bit32u useSize, const Bit32u useFilterFactor) : RingBuffer(useSize), filterFactor(useFilterFactor) {}
-void CombFilter::process(const Bit32s in) {
+void CombFilter::process(const Sample in) {
// This model corresponds to the comb filter implementation of the real CM-32L device
// the previously stored value
- Bit32s last = buffer[index];
+ const Sample last = buffer[index];
// prepare input + feedback
- Bit32s filterIn = in + weirdMul(next(), feedbackFactor, 0xF0 /* Maybe 0x80 ? */);
+ const Sample filterIn = in + weirdMul(next(), feedbackFactor, 0xF0 /* Maybe 0x80 ? */);
// store input + feedback processed by a low-pass filter
buffer[index] = weirdMul(last, filterFactor, 0x40) - filterIn;
}
-Bit32s CombFilter::getOutputAt(const Bit32u outIndex) const {
+Sample CombFilter::getOutputAt(const Bit32u outIndex) const {
return buffer[(size + index - outIndex) % size];
}
@@ -190,15 +212,15 @@ void CombFilter::setFeedbackFactor(const Bit32u useFeedbackFactor) {
DelayWithLowPassFilter::DelayWithLowPassFilter(const Bit32u useSize, const Bit32u useFilterFactor, const Bit32u useAmp)
: CombFilter(useSize, useFilterFactor), amp(useAmp) {}
-void DelayWithLowPassFilter::process(const Bit32s in) {
+void DelayWithLowPassFilter::process(const Sample in) {
// the previously stored value
- Bit32s last = buffer[index];
+ const Sample last = buffer[index];
// move to the next index
next();
// low-pass filter process
- Bit32s lpfOut = weirdMul(last, filterFactor, 0xFF) + in;
+ Sample lpfOut = weirdMul(last, filterFactor, 0xFF) + in;
// store lpfOut multiplied by LPF amp factor
buffer[index] = weirdMul(lpfOut, amp, 0xFF);
@@ -206,26 +228,26 @@ void DelayWithLowPassFilter::process(const Bit32s in) {
TapDelayCombFilter::TapDelayCombFilter(const Bit32u useSize, const Bit32u useFilterFactor) : CombFilter(useSize, useFilterFactor) {}
-void TapDelayCombFilter::process(const Bit32s in) {
+void TapDelayCombFilter::process(const Sample in) {
// the previously stored value
- Bit32s last = buffer[index];
+ const Sample last = buffer[index];
// move to the next index
next();
// prepare input + feedback
// Actually, the size of the filter varies with the TIME parameter, the feedback sample is taken from the position just below the right output
- Bit32s filterIn = in + weirdMul(getOutputAt(outR + MODE_3_FEEDBACK_DELAY), feedbackFactor, 0xF0);
+ const Sample filterIn = in + weirdMul(getOutputAt(outR + MODE_3_FEEDBACK_DELAY), feedbackFactor, 0xF0);
// store input + feedback processed by a low-pass filter
buffer[index] = weirdMul(last, filterFactor, 0xF0) - filterIn;
}
-Bit32s TapDelayCombFilter::getLeftOutput() const {
+Sample TapDelayCombFilter::getLeftOutput() const {
return getOutputAt(outL + PROCESS_DELAY + MODE_3_ADDITIONAL_DELAY);
}
-Bit32s TapDelayCombFilter::getRightOutput() const {
+Sample TapDelayCombFilter::getRightOutput() const {
return getOutputAt(outR + PROCESS_DELAY + MODE_3_ADDITIONAL_DELAY);
}
@@ -327,14 +349,14 @@ bool BReverbModel::isActive() const {
return false;
}
-void BReverbModel::process(const float *inLeft, const float *inRight, float *outLeft, float *outRight, unsigned long numSamples) {
- Bit32s dry, link, outL1, outR1;
+void BReverbModel::process(const Sample *inLeft, const Sample *inRight, Sample *outLeft, Sample *outRight, unsigned long numSamples) {
+ Sample dry;
- for (unsigned long i = 0; i < numSamples; i++) {
+ while (numSamples > 0) {
if (tapDelayMode) {
- dry = Bit32s(*inLeft * 8192.0f) + Bit32s(*inRight * 8192.0f);
+ dry = *inLeft + *inRight;
} else {
- dry = Bit32s(*inLeft * 8192.0f) / 2 + Bit32s(*inRight * 8192.0f) / 2;
+ dry = *inLeft / 2 + *inRight / 2;
}
// Looks like dryAmp doesn't change in MT-32 but it does in CM-32L / LAPC-I
@@ -343,44 +365,53 @@ void BReverbModel::process(const float *inLeft, const float *inRight, float *out
if (tapDelayMode) {
TapDelayCombFilter *comb = static_cast<TapDelayCombFilter *> (*combs);
comb->process(dry);
- *outLeft = weirdMul(comb->getLeftOutput(), wetLevel, 0xFF) / 8192.0f;
- *outRight = weirdMul(comb->getRightOutput(), wetLevel, 0xFF) / 8192.0f;
+ *outLeft = weirdMul(comb->getLeftOutput(), wetLevel, 0xFF);
+ *outRight = weirdMul(comb->getRightOutput(), wetLevel, 0xFF);
} else {
- // Get the last stored sample before processing in order not to loose it
- link = combs[0]->getOutputAt(currentSettings.combSizes[0] - 1);
+ // If the output position is equal to the comb size, get it now in order not to loose it
+ Sample link = combs[0]->getOutputAt(currentSettings.combSizes[0] - 1);
// Entrance LPF. Note, comb.process() differs a bit here.
combs[0]->process(dry);
+#if !MT32EMU_USE_FLOAT_SAMPLES
// This introduces reverb noise which actually makes output from the real Boss chip nondeterministic
link = link - 1;
+#endif
link = allpasses[0]->process(link);
link = allpasses[1]->process(link);
link = allpasses[2]->process(link);
// If the output position is equal to the comb size, get it now in order not to loose it
- outL1 = combs[1]->getOutputAt(currentSettings.outLPositions[0] - 1);
- outL1 += outL1 >> 1;
+ Sample outL1 = combs[1]->getOutputAt(currentSettings.outLPositions[0] - 1);
combs[1]->process(link);
combs[2]->process(link);
combs[3]->process(link);
- link = combs[2]->getOutputAt(currentSettings.outLPositions[1]);
- link += link >> 1;
- link += outL1;
- link += combs[3]->getOutputAt(currentSettings.outLPositions[2]);
- *outLeft = weirdMul(link, wetLevel, 0xFF) / 8192.0f;
+ Sample outL2 = combs[2]->getOutputAt(currentSettings.outLPositions[1]);
+ Sample outL3 = combs[3]->getOutputAt(currentSettings.outLPositions[2]);
+ Sample outR1 = combs[1]->getOutputAt(currentSettings.outRPositions[0]);
+ Sample outR2 = combs[2]->getOutputAt(currentSettings.outRPositions[1]);
+ Sample outR3 = combs[3]->getOutputAt(currentSettings.outRPositions[2]);
+
+#if MT32EMU_USE_FLOAT_SAMPLES
+ *outLeft = 1.5f * (outL1 + outL2) + outL3;
+ *outRight = 1.5f * (outR1 + outR2) + outR3;
+#else
+ outL1 += outL1 >> 1;
+ outL2 += outL2 >> 1;
+ *outLeft = outL1 + outL2 + outL3;
- outR1 = combs[1]->getOutputAt(currentSettings.outRPositions[0]);
outR1 += outR1 >> 1;
- link = combs[2]->getOutputAt(currentSettings.outRPositions[1]);
- link += link >> 1;
- link += outR1;
- link += combs[3]->getOutputAt(currentSettings.outRPositions[2]);
- *outRight = weirdMul(link, wetLevel, 0xFF) / 8192.0f;
+ outR2 += outR2 >> 1;
+ *outRight = outR1 + outR2 + outR3;
+#endif
+ *outLeft = weirdMul(*outLeft, wetLevel, 0xFF);
+ *outRight = weirdMul(*outRight, wetLevel, 0xFF);
}
+ numSamples--;
inLeft++;
inRight++;
outLeft++;
@@ -389,5 +420,3 @@ void BReverbModel::process(const float *inLeft, const float *inRight, float *out
}
}
-
-#endif
generated by cgit v1.2.3 (git 2.25.1) at 2024-07-02 00:10:42 +0000