[OMPT-svn-commit] SF.net SVN: modplug:[2182] trunk/OpenMPT/soundlib

[<man...@us...>]

Revision: 2182
          http://sourceforge.net/p/modplug/code/2182
Author:   manxorist
Date:     2013-05-24 20:01:34 +0000 (Fri, 24 May 2013)
Log Message:
-----------
[Mod] Remove rather questionable frequency rounding in TransposeToFrequency which was inherited from the modplug codebase.
[Mod] Remove other questionable rounding and frequency clamping in ReadNote(). Hope that nothing breaks.
[Ref] Remove inline asm in really not performance cirtical codepaths (TransposeToFrequency, FrequencyToTranspose, PatchFreqToNote) and replace it with a readable c++ implementation.

Modified Paths:
--------------
    trunk/OpenMPT/soundlib/ModSample.cpp
    trunk/OpenMPT/soundlib/SampleFormats.cpp
    trunk/OpenMPT/soundlib/Sndmix.cpp

Modified: trunk/OpenMPT/soundlib/ModSample.cpp
===================================================================
--- trunk/OpenMPT/soundlib/ModSample.cpp	2013-05-24 12:42:41 UTC (rev 2181)
+++ trunk/OpenMPT/soundlib/ModSample.cpp	2013-05-24 20:01:34 UTC (rev 2182)
@@ -185,45 +185,10 @@
 /////////////////////////////////////////////////////////////
 // Transpose <-> Frequency conversions
 
-// returns 8363*2^((transp*128+ftune)/(12*128))
 uint32 ModSample::TransposeToFrequency(int transpose, int finetune)
 //-----------------------------------------------------------------
 {
-	// return (unsigned int) (8363.0 * pow(2, (transp * 128.0 + ftune) / 1536.0));
-	const float _fbase = 8363;
-	const float _factor = 1.0f / (12.0f * 128.0f);
-	uint32 freq;
-
-#if defined(ENABLE_X86)
-	int result;
-	transpose = (transpose << 7) + finetune;
-	_asm
-	{
-		fild transpose
-		fld _factor
-		fmulp st(1), st(0)
-		fist result
-		fisub result
-		f2xm1
-		fild result
-		fld _fbase
-		fscale
-		fstp st(1)
-		fmul st(1), st(0)
-		faddp st(1), st(0)
-		fistp freq
-	}
-#else // !ENABLE_X86
-	freq = static_cast<uint32>(std::pow(2.0f, (transpose * 128 + finetune) * _factor) * _fbase);
-#endif // ENABLE_X86
-
-	uint32 derr = freq % 11025;
-	if(derr <= 8) freq -= derr;
-	if(derr >= 11015) freq += 11025 - derr;
-	derr = freq % 1000;
-	if(derr <= 5) freq -= derr;
-	if(derr >= 995) freq += 1000 - derr;
-	return freq;
+	return Util::Round<uint32>(std::pow(2.0f, (transpose * 128.0f + finetune) * (1.0f / (12.0f * 128.0f))) * 8363.0f);
 }
 
 
@@ -234,36 +199,11 @@
 }
 
 
-// returns 12*128*log2(freq/8363)
 int ModSample::FrequencyToTranspose(uint32 freq)
 //----------------------------------------------
 {
-	// return (int) (1536.0 * (log(freq / 8363.0) / log(2)));
-
-	const float _f1_8363 = 1.0f / 8363.0f;
-	const float _factor = 128 * 12;
-	int result;
-
-	if(!freq)
-	{
-		return 0;
-	}
-
-#if defined(ENABLE_X86)
-	_asm
-	{
-		fld _factor
-		fild freq
-		fld _f1_8363
-		fmulp st(1), st(0)
-		fyl2x
-		fistp result
-	}
-#else // !ENABLE_X86
 	const float inv_log_2 = 1.44269504089f; // 1.0f/std::log(2.0f)	
-	result = std::log(freq * _f1_8363) * (_factor * inv_log_2);
-#endif // ENABLE_X86
-	return result;
+	return Util::Round<int>(std::log(freq * (1.0f / 8363.0f)) * (12.0f * 128.0f * inv_log_2));
 }
 
 

Modified: trunk/OpenMPT/soundlib/SampleFormats.cpp
===================================================================
--- trunk/OpenMPT/soundlib/SampleFormats.cpp	2013-05-24 12:42:41 UTC (rev 2181)
+++ trunk/OpenMPT/soundlib/SampleFormats.cpp	2013-05-24 20:01:34 UTC (rev 2182)
@@ -677,28 +677,12 @@
 #pragma pack(pop)
 #endif
 
-// returns 12*Log2(nFreq/2044)
-LONG PatchFreqToNote(ULONG nFreq)
-//-------------------------------
+static int32 PatchFreqToNote(uint32 nFreq)
+//----------------------------------------
 {
-	const float k_base = 1.0f / 2044.0f;
-	const float k_12 = 12;
-	LONG result;
-	if (nFreq < 1) return 0;
-#if defined(ENABLE_X86)
-	_asm {
-	fld k_12
-	fild nFreq
-	fld k_base
-	fmulp ST(1), ST(0)
-	fyl2x
-	fistp result
-	}
-#else // !ENABLE_X86
 	const float inv_log_2 = 1.44269504089f; // 1.0f/std::log(2.0f)
-	result = std::log(nFreq * k_base) * (k_12 * inv_log_2);
-#endif // ENABLE_X86
-	return result;
+	const float base = 1.0f / 2044.0f;
+	return Util::Round<int32>(std::log(nFreq * base) * (12.0f * inv_log_2));
 }
 
 

Modified: trunk/OpenMPT/soundlib/Sndmix.cpp
===================================================================
--- trunk/OpenMPT/soundlib/Sndmix.cpp	2013-05-24 12:42:41 UTC (rev 2181)
+++ trunk/OpenMPT/soundlib/Sndmix.cpp	2013-05-24 20:01:34 UTC (rev 2182)
@@ -1906,13 +1906,15 @@
 				pChn->nCalcVolume = 0;
 			}
 
-			int32 ninc = Util::muldiv(freq, 0x10000, m_MixerSettings.gdwMixingFreq << FREQ_FRACBITS);
-			if ((ninc >= 0xFFB0) && (ninc <= 0x10090)) ninc = 0x10000;
+			uint32 ninc = Util::muldivr(freq, 0x10000, m_MixerSettings.gdwMixingFreq << FREQ_FRACBITS);
 #ifndef MODPLUG_TRACKER
 			ninc = Util::muldivr(ninc, m_nFreqFactor, 128);
 #endif // !MODPLUG_TRACKER
-			Limit(ninc, 3, 0xFF0000);
-			pChn->nInc = (ninc + 1) & ~3;
+			if(ninc == 0)
+			{
+				ninc = 1;
+			}
+			pChn->nInc = ninc;
 		} else
 		{
 			// Avoid nasty noises...
@@ -2008,27 +2010,19 @@
 			//if (pChn->nNewRightVol > 0xFFFF) pChn->nNewRightVol = 0xFFFF;
 			//if (pChn->nNewLeftVol > 0xFFFF) pChn->nNewLeftVol = 0xFFFF;
 
-			ResamplingMode resamplingMode = m_Resampler.m_Settings.SrcMode; // default to global mixer settings
-			if(pChn->pModInstrument && IsKnownResamplingMode(pChn->pModInstrument->nResampling))
-			{
-				// for defined resampling modes, use per-instrument resampling modes if set
-				resamplingMode = (ResamplingMode)pChn->pModInstrument->nResampling;
-			}
-			// disable interpolation in certain cases
 			if(pChn->nInc == 0x10000)
 			{
 				// exact samplerate match, do not resample at all, regardless of selected resampler
-				resamplingMode = SRCMODE_NEAREST;
-			} else if(resamplingMode == SRCMODE_LINEAR)
+				pChn->resamplingMode = SRCMODE_NEAREST;
+			} else if(pChn->pModInstrument && IsKnownResamplingMode(pChn->pModInstrument->nResampling))
 			{
-				if(((pChn->nInc >= 0xFF00) && (pChn->nInc < 0x10100)))
-				{
-					// disable interpolation if rates are too close
-					resamplingMode = SRCMODE_NEAREST;
-				}
+				// for defined resampling modes, use per-instrument resampling mode if set
+				pChn->resamplingMode = (ResamplingMode)pChn->pModInstrument->nResampling;
+			} else
+			{
+				// default to global mixer settings
+				pChn->resamplingMode = m_Resampler.m_Settings.SrcMode;
 			}
-			// store for the mixer
-			pChn->resamplingMode = (uint8)resamplingMode;
 
 			/*if (m_pConfig->getUseGlobalPreAmp())
 			{

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