Floating Point Dither For All

1 files changed, 8 insertions, 18 deletions

diff --git a/plugins/MacAU/DubCenter/DubCenter.cpp b/plugins/MacAU/DubCenter/DubCenter.cpp
index e0bfcae..397d118 100755
--- a/plugins/MacAU/DubCenter/DubCenter.cpp
+++ b/plugins/MacAU/DubCenter/DubCenter.cpp
@@ -608,18 +608,14 @@ OSStatus		DubCenter::ProcessBufferLists(AudioUnitRenderActionFlags & ioActionFla
 		bflip++;
 		if (bflip < 1 || bflip > 3) bflip = 1;
 		
-		//noise shaping to 32-bit floating point
-		Float32 fpTemp = inputSampleL;
-		fpNShapeL += (inputSampleL-fpTemp);
-		inputSampleL += fpNShapeL;
-		//if this confuses you look at the wordlength for fpTemp :)
-		fpTemp = inputSampleR;
-		fpNShapeR += (inputSampleR-fpTemp);
-		inputSampleR += fpNShapeR;
-		//for deeper space and warmth, we try a non-oscillating noise shaping
-		//that is kind of ruthless: it will forever retain the rounding errors
-		//except we'll dial it back a hair at the end of every buffer processed
-		//end noise shaping on 32 bit output
+		//stereo 32 bit dither, made small and tidy.
+		int expon; frexpf((Float32)inputSampleL, &expon);
+		long double dither = (rand()/(RAND_MAX*7.737125245533627e+25))*pow(2,expon+62);
+		inputSampleL += (dither-fpNShapeL); fpNShapeL = dither;
+		frexpf((Float32)inputSampleR, &expon);
+		dither = (rand()/(RAND_MAX*7.737125245533627e+25))*pow(2,expon+62);
+		inputSampleR += (dither-fpNShapeR); fpNShapeR = dither;
+		//end 32 bit dither
 		
 		*outputL = inputSampleL;
 		*outputR = inputSampleR;
@@ -630,12 +626,6 @@ OSStatus		DubCenter::ProcessBufferLists(AudioUnitRenderActionFlags & ioActionFla
 		outputL += 1;
 		outputR += 1;
 	}
-	fpNShapeL *= 0.999999;
-	fpNShapeR *= 0.999999;
-	//we will just delicately dial back the FP noise shaping, not even every sample
-	//this is a good place to put subtle 'no runaway' calculations, though bear in mind
-	//that it will be called more often when you use shorter sample buffers in the DAW.
-	//So, very low latency operation will call these calculations more often.	
 	return noErr;
 }