Skip to content

Increase MIDI speed by 20% by saturating at end #792

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
earlephilhower merged 1 commit into from
Oct 23, 2025
Merged

Increase MIDI speed by 20% by saturating at end #792

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
2 changes: 1 addition & 1 deletion lib/TinySoundFont
Open in desktop
Submodule TinySoundFont updated 3 files
+3 −1 examples/example2.c
+3 −2 examples/example3.c
+23 −10 tsf.h
6 changes: 3 additions & 3 deletions src/AudioGeneratorMIDI.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -559,11 +559,11 @@ bool AudioGeneratorMIDI::loop() {
break;
}
} else if (samplesToPlay) {
numSamplesRendered = (sizeof(samplesRendered) / sizeof(samplesRendered[0])) / 2;
if ((int)samplesToPlay < (int)(sizeof(samplesRendered) / sizeof(samplesRendered[0])) / 2) {
numSamplesRendered = (sizeof(samplesRendered) / sizeof(samplesRendered[0])) / 4;
if ((int)samplesToPlay < (int)(sizeof(samplesRendered) / sizeof(samplesRendered[0])) / 4) {
numSamplesRendered = samplesToPlay;
}
tsf_render_short(g_tsf, samplesRendered, numSamplesRendered, 0);
tsf_render_short_2x(g_tsf, samplesRendered, numSamplesRendered, 0);
samplesToPlay -= numSamplesRendered;
sentSamplesRendered = 0;
} else {
Expand Down
2 changes: 1 addition & 1 deletion src/AudioGeneratorMIDI.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -186,7 +186,7 @@ class AudioGeneratorMIDI : public AudioGenerator {
bool sawEOF;
int numSamplesRendered;
int sentSamplesRendered ;
short samplesRendered[256 * 2];
short samplesRendered[256 * 2 * 2];

tsf *_tsf = nullptr;
};
Expand Down
33 changes: 23 additions & 10 deletions src/libtinysoundfont/tsf.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -210,7 +210,12 @@ TSFDEF int tsf_active_voice_count(tsf* f);
// buffer: target buffer of size samples * output_channels * sizeof(type)
// samples: number of samples to render
// flag_mixing: if 0 clear the buffer first, otherwise mix into existing data
#ifndef TSF_SAMPLES_SHORT
TSFDEF void tsf_render_short(tsf* f, short* buffer, int samples, int flag_mixing CPP_DEFAULT0);
#else
// The short render needs space for a long (32b) for all samples, so pass in a buffer of 2x the expected size. Only the first `samples` samples will be valid on return
TSFDEF void tsf_render_short_2x_buffer(tsf* f, short* buffer_2x, int samples, int flag_mixing CPP_DEFAULT0);
#endif
TSFDEF void tsf_render_float(tsf* f, float* buffer, int samples, int flag_mixing CPP_DEFAULT0);

// Higher level channel based functions, set up channel parameters
Expand Down Expand Up @@ -1536,7 +1541,7 @@ static void tsf_voice_render(tsf* f, struct tsf_voice* v, float* outputBuffer, i
if (tmpLowpass.active || dynamicLowpass) v->lowpass = tmpLowpass;
}
#else
static void tsf_voice_render_short(tsf* f, struct tsf_voice* v, short* outputBuffer, int numSamples)
static void tsf_voice_render_short(tsf* f, struct tsf_voice* v, int32_t* outputBuffer, int numSamples)
{
#ifdef ESP8266
static unsigned int smps = 0;
Expand All @@ -1547,7 +1552,7 @@ static void tsf_voice_render_short(tsf* f, struct tsf_voice* v, short* outputBuf
#endif
TSF_CONST struct tsf_region* region = v->region;
TSF_CONST short* input = f->shortSamples;
short* outL = outputBuffer;
int32_t* outL = outputBuffer;
//short* outR = (f->outputmode == TSF_STEREO_UNWEAVED ? outL + numSamples : TSF_NULL);

// Cache some values, to give them at least some chance of ending up in registers.
Expand Down Expand Up @@ -1643,19 +1648,20 @@ static void tsf_voice_render_short(tsf* f, struct tsf_voice* v, short* outputBuf
// Do saturating adds for each channel
fixed16p16 smp;

// No clipping because it eats 20% of the performance on the M0+ Pico!

smp = *outL;
smp += (val * gainLeftF16P16) >> 16;
if (smp > 32767) smp = 32767;
else if (smp < -32768) smp = -32768;
// if (smp > 32767) smp = 32767;
// else if (smp < -32768) smp = -32768;
*outL++ = smp;

smp = *outL;
smp += (val * gainRightF16P16) >> 16;
if (smp > 32767) smp = 32767;
else if (smp < -32768) smp = -32768;
// if (smp > 32767) smp = 32767;
// else if (smp < -32768) smp = -32768;
*outL++ = smp;


// *outL++ += val * gainLeft;
// *outL++ += val * gainRight;

Expand Down Expand Up @@ -2161,13 +2167,20 @@ TSFDEF void tsf_render_float(tsf* f, float* buffer, int samples, int flag_mixing
tsf_voice_render(f, v, buffer, samples);
}
#else
TSFDEF void tsf_render_short(tsf* f, short* buffer, int samples, int flag_mixing)
TSFDEF void tsf_render_short_2x(tsf* f, short* buffer, int samples, int flag_mixing)
{
struct tsf_voice *v = f->voices, *vEnd = v + f->voiceNum;
if (!flag_mixing) TSF_MEMSET(buffer, 0, (f->outputmode == TSF_MONO ? 1 : 2) * sizeof(short) * samples);
int32_t *buffer32 = (int32_t *)buffer;
if (!flag_mixing) TSF_MEMSET(buffer, 0, (f->outputmode == TSF_MONO ? 1 : 2) * sizeof(short) * samples * 2 /* We sum in 32bs then downsample here to 16b to minimized saturation calcs */);
for (; v != vEnd; v++)
if (v->playingPreset != -1)
tsf_voice_render_short(f, v, buffer, samples);
tsf_voice_render_short(f, v, buffer32, samples);
for (int i = 0; i < samples * 2; i++) {
int32_t t = buffer32[i];
if (t > 32767) buffer[i] = 32767;
else if (t < -32768) buffer[i] = -32768;
else buffer[i] = t;
}
}
#endif

Expand Down