dsptool: refactor

2025-02-21 04:09:25 +11:00 · 2023-03-19 09:58:26 +11:00
parent ac89564669
commit 99bf061438
9 changed files with 848 additions and 804 deletions
--- a/dsptools/CMakeLists.txt
+++ b/dsptools/CMakeLists.txt
@@ -1,9 +1,18 @@
-cmake_minimum_required(VERSION 3.1 FATAL_ERROR)
+cmake_minimum_required(VERSION 3.15 FATAL_ERROR)
 project(DspTool LANGUAGES C)

-set(CMAKE_C_STANDARD 99)
+option(BUILD_SHARED_LIBS "Build as a Shared Object or DLL" ON)

-set(HEADERS dsptool.h)
+set(HEADERS common.h dsptool.h)
 set(SOURCES math.c decode.c encode.c)

 add_library(DspTool ${HEADERS} ${SOURCES})
+set_property(TARGET DspTool PROPERTY C_STANDARD 99)
+if (BUILD_SHARED_LIBS)
+	target_compile_definitions(DspTool PRIVATE BUILD_SHARED)
+else()
+	target_compile_definitions(DspTool PRIVATE BUILD_STATIC)
+endif()
+target_compile_options(DspTool PRIVATE
+	$<$<C_COMPILER_ID:AppleClang,Clang,GNU>:-Wall -Wextra -pedantic -Wno-unused-parameter>
+	$<$<C_COMPILER_ID:MSVC>:/Wall /wd4100>)
--- a/dsptools/decode.c
+++ b/dsptools/decode.c
@@ -1,101 +0,0 @@
-#include <stdint.h>
-#include "dsptool.h"
-#include <limits.h>
-
-#define MIN(a,b) (((a)<(b))?(a):(b))
-#define MAX(a,b) (((a)>(b))?(a):(b))
-
-inline int DivideByRoundUp(int dividend, int divisor)
-{
-	return (dividend + divisor - 1) / divisor;
-}
-
-inline char GetHighNibble(char value)
-{
-	return value >> 4 & 0xF;
-}
-
-inline char GetLowNibble(char value)
-{
-	return value & 0xF;
-}
-
-inline short Clamp16(int value)
-{
-	if (value > SHRT_MAX)
-		return SHRT_MAX;
-	if (value < SHRT_MIN)
-		return SHRT_MIN;
-	return value;
-}
-
-void decode(uint8_t* src, int16_t* dst, ADPCMINFO* cxt, uint32_t samples)
-{
-	short hist1 = cxt->yn1;
-	short hist2 = cxt->yn2;
-	short* coefs = cxt->coef;
-	int frameCount = DivideByRoundUp(samples, SAMPLES_PER_FRAME);
-	int samplesRemaining = samples;
-
-	for (int i = 0; i < frameCount; i++)
-	{
-		int predictor = GetHighNibble(*src);
-		int scale = 1 << GetLowNibble(*src++);
-		short coef1 = coefs[predictor * 2];
-		short coef2 = coefs[predictor * 2 + 1];
-
-		int samplesToRead = MIN(SAMPLES_PER_FRAME, samplesRemaining);
-
-		for (int s = 0; s < samplesToRead; s++)
-		{
-			int sample = s % 2 == 0 ? GetHighNibble(*src) : GetLowNibble(*src++);
-			sample = sample >= 8 ? sample - 16 : sample;
-			sample = (((scale * sample) << 11) + 1024 + (coef1 * hist1 + coef2 * hist2)) >> 11;
-			short finalSample = Clamp16(sample);
-
-			hist2 = hist1;
-			hist1 = finalSample;
-
-			*dst++ = finalSample;
-		}
-
-		samplesRemaining -= samplesToRead;
-	}
-}
-
-void getLoopContext(uint8_t* src, ADPCMINFO* cxt, uint32_t samples)
-{
-	short hist1 = cxt->yn1;
-	short hist2 = cxt->yn2;
-	short* coefs = cxt->coef;
-	char ps = 0;
-	int frameCount = DivideByRoundUp(samples, SAMPLES_PER_FRAME);
-	int samplesRemaining = samples;
-
-	for (int i = 0; i < frameCount; i++)
-	{
-		ps = *src;
-		int predictor = GetHighNibble(*src);
-		int scale = 1 << GetLowNibble(*src++);
-		short coef1 = coefs[predictor * 2];
-		short coef2 = coefs[predictor * 2 + 1];
-
-		int samplesToRead = MIN(SAMPLES_PER_FRAME, samplesRemaining);
-
-		for (int s = 0; s < samplesToRead; s++)
-		{
-			int sample = s % 2 == 0 ? GetHighNibble(*src) : GetLowNibble(*src++);
-			sample = sample >= 8 ? sample - 16 : sample;
-			sample = (((scale * sample) << 11) + 1024 + (coef1 * hist1 + coef2 * hist2)) >> 11;
-			short finalSample = Clamp16(sample);
-
-			hist2 = hist1;
-			hist1 = finalSample;
-		}
-		samplesRemaining -= samplesToRead;
-	}
-
-	cxt->loop_pred_scale = ps;
-	cxt->loop_yn1 = hist1;
-	cxt->loop_yn2 = hist2;
-}
--- a/dsptools/libdsptool/CMakeLists.txt
+++ b/dsptools/libdsptool/CMakeLists.txt
@@ -0,0 +1,19 @@
+cmake_minimum_required(VERSION 3.15 FATAL_ERROR)
+project(DspTool LANGUAGES C)
+
+option(BUILD_SHARED_LIBS "Build as a Shared Object or DLL" OFF)
+
+set(HEADERS common.h dsptool.h)
+set(SOURCES math.c decode.c encode.c)
+
+add_library(DspTool ${HEADERS} ${SOURCES})
+add_library(DspTool::DspTool ALIAS DspTool)
+
+target_include_directories(DspTool PUBLIC ${CMAKE_CURRENT_SOURCE_DIR})
+set_property(TARGET DspTool PROPERTY C_STANDARD 99)
+if (BUILD_SHARED_LIBS)
+	target_compile_definitions(DspTool PRIVATE BUILD_SHARED)
+endif()
+target_compile_options(DspTool PRIVATE
+	$<$<C_COMPILER_ID:AppleClang,Clang,GNU>:-Wall -Wextra -pedantic -Wno-unused-parameter>
+	$<$<C_COMPILER_ID:MSVC>:/Wall /wd4100>)
--- a/dsptools/libdsptool/LICENSE
+++ b/dsptools/libdsptool/LICENSE
--- a/dsptools/libdsptool/common.h
+++ b/dsptools/libdsptool/common.h
@@ -0,0 +1,7 @@
+#ifndef COMMON_H
+#define COMMON_H
+
+#define MIN(a,b) (((a)<(b))?(a):(b))
+#define MAX(a,b) (((a)>(b))?(a):(b))
+
+#endif//COMMON_H
--- a/dsptools/libdsptool/decode.c
+++ b/dsptools/libdsptool/decode.c
@@ -0,0 +1,101 @@
+/* (c) 2017 Alex Barney (MIT) */
+
+#include <stdint.h>
+#include "common.h"
+#include "dsptool.h"
+
+static inline uint8_t GetHighNibble(uint8_t value)
+{
+	return value >> 4 & 0xF;
+}
+
+static inline uint8_t GetLowNibble(uint8_t value)
+{
+	return value & 0xF;
+}
+
+static inline int16_t Clamp16(int value)
+{
+	if (value > INT16_MAX)
+		return INT16_MAX;
+	if (value < INT16_MIN)
+		return INT16_MIN;
+	return (int16_t)value;
+}
+
+void decode(uint8_t* src, int16_t* dst, ADPCMINFO* cxt, uint32_t samples)
+{
+	short hist1 = cxt->yn1;
+	short hist2 = cxt->yn2;
+	short* coefs = cxt->coef;
+	uint32_t frameCount = (samples + SAMPLES_PER_FRAME - 1) / SAMPLES_PER_FRAME;
+	uint32_t samplesRemaining = samples;
+
+	for (uint32_t i = 0; i < frameCount; i++)
+	{
+		int predictor = GetHighNibble(*src);
+		int scale = 1 << GetLowNibble(*src++);
+		short coef1 = coefs[predictor * 2];
+		short coef2 = coefs[predictor * 2 + 1];
+
+		uint32_t samplesToRead = MIN(SAMPLES_PER_FRAME, samplesRemaining);
+
+		for (uint32_t s = 0; s < samplesToRead; s++)
+		{
+			int sample = (s & 0x1)
+				? GetLowNibble(*src++)
+				: GetHighNibble(*src);
+			sample = sample >= 8 ? sample - 16 : sample;
+			sample = (scale * sample) << 11;
+			sample = (sample + 1024 + (coef1 * hist1 + coef2 * hist2)) >> 11;
+			short finalSample = Clamp16(sample);
+
+			hist2 = hist1;
+			hist1 = finalSample;
+
+			*dst++ = finalSample;
+		}
+
+		samplesRemaining -= samplesToRead;
+	}
+}
+
+void getLoopContext(uint8_t* src, ADPCMINFO* cxt, uint32_t samples)
+{
+	short hist1 = cxt->yn1;
+	short hist2 = cxt->yn2;
+	short* coefs = cxt->coef;
+	uint8_t ps = 0;
+	int frameCount = (int)((samples + SAMPLES_PER_FRAME - 1) / SAMPLES_PER_FRAME);
+	uint32_t samplesRemaining = samples;
+
+	for (int i = 0; i < frameCount; i++)
+	{
+		ps = *src;
+		int predictor = GetHighNibble(*src);
+		int scale = 1 << GetLowNibble(*src++);
+		short coef1 = coefs[predictor * 2];
+		short coef2 = coefs[predictor * 2 + 1];
+
+		uint32_t samplesToRead = MIN(SAMPLES_PER_FRAME, samplesRemaining);
+
+		for (uint32_t s = 0; s < samplesToRead; s++)
+		{
+			int sample = (s & 0x1)
+				? GetLowNibble(*src++)
+				: GetHighNibble(*src);
+			sample = sample >= 8 ? sample - 16 : sample;
+			sample = (scale * sample) << 11;
+			sample = (sample + 1024 + (coef1 * hist1 + coef2 * hist2)) >> 11;
+			short finalSample = Clamp16(sample);
+
+			hist2 = hist1;
+			hist1 = finalSample;
+		}
+		samplesRemaining -= samplesToRead;
+	}
+
+	cxt->loop_pred_scale = ps;
+	cxt->loop_yn1 = hist1;
+	cxt->loop_yn2 = hist2;
+}
--- a/dsptools/libdsptool/dsptool.h
+++ b/dsptools/libdsptool/dsptool.h
@@ -1,4 +1,6 @@
-#pragma once
+#ifndef DSPTOOL_H
+#define DSPTOOL_H
+
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -9,10 +11,18 @@ extern "C" {
 #define SAMPLES_PER_FRAME 14
 #define NIBBLES_PER_FRAME 16

-#ifdef COMPILING_DLL 
-#define DLLEXPORT __declspec(dllexport)
+#if defined( _WIN32 ) || defined( __CYGWIN__ )
+# ifdef BUILD_SHARED
+#  define DLLEXPORT __declspec(dllexport)
+# elif defined( WHY_ARE_YOU_USING_THIS_AS_A_DLL )
+#  define DLLEXPORT __declspec(dllimport)
+# else
+#  define DLLEXPORT
+# endif
+#elif __GNUC__ >= 4
+# define DLLEXPORT __attribute__((visibility("default")))
 #else
-#define DLLEXPORT __declspec(dllimport)  
+# define DLLEXPORT
 #endif

 typedef struct
@@ -47,3 +57,5 @@ DLLEXPORT uint32_t getBytesForAdpcmInfo(void);
 #ifdef __cplusplus
 }
 #endif
+
+#endif
--- a/dsptools/libdsptool/encode.c
+++ b/dsptools/libdsptool/encode.c
@@ -1,41 +1,40 @@
+/* (c) 2017 Alex Barney (MIT) */
+
 #include <stdint.h>
 #include <stdlib.h>
 #include <stdbool.h>
 #include <math.h>
 #include <float.h>
 #include <string.h>
+#include "common.h"
 #include "dsptool.h"

-#define MIN(a,b) (((a)<(b))?(a):(b))
-#define MAX(a,b) (((a)>(b))?(a):(b))
-
 /* Temporal Vector
 * A contiguous history of 3 samples starting with
 * 'current' and going 2 backwards
 */
 typedef double tvec[3];
-void correlateCoefs(int16_t* source, uint32_t samples, int16_t* coefsOut);
-void DSPEncodeFrame(short pcmInOut[16], int sampleCount, unsigned char adpcmOut[8], const short coefsIn[8][2]);
+static void DSPEncodeFrame(short pcmInOut[16], int sampleCount, unsigned char adpcmOut[8], const short coefsIn[8][2]);

 void encode(int16_t* src, uint8_t* dst, ADPCMINFO* cxt, uint32_t samples)
 {
 	int16_t* coefs = cxt->coef;
 	correlateCoefs(src, samples, coefs);

-	int32_t frameCount = samples / SAMPLES_PER_FRAME + (samples % SAMPLES_PER_FRAME != 0);
+	uint32_t frameCount = samples / SAMPLES_PER_FRAME + (samples % SAMPLES_PER_FRAME != 0);

 	int16_t* pcm = src;
 	uint8_t* adpcm = dst;
 	int16_t pcmFrame[SAMPLES_PER_FRAME + 2] = { 0 };
 	uint8_t adpcmFrame[BYTES_PER_FRAME] = { 0 };

-	for (int i = 0; i < frameCount; ++i, pcm += SAMPLES_PER_FRAME, adpcm += BYTES_PER_FRAME)
+	for (uint32_t i = 0; i < frameCount; ++i, pcm += SAMPLES_PER_FRAME, adpcm += BYTES_PER_FRAME)
 	{
-		int32_t sampleCount = MIN(samples - i * SAMPLES_PER_FRAME, SAMPLES_PER_FRAME);
+		uint32_t sampleCount = MIN(samples - i * SAMPLES_PER_FRAME, SAMPLES_PER_FRAME);
 		memset(pcmFrame + 2, 0, SAMPLES_PER_FRAME * sizeof(int16_t));
 		memcpy(pcmFrame + 2, pcm, sampleCount * sizeof(int16_t));

-		DSPEncodeFrame(pcmFrame, SAMPLES_PER_FRAME, adpcmFrame, (short(*)[2])&coefs[0]);
+		DSPEncodeFrame(pcmFrame, SAMPLES_PER_FRAME, adpcmFrame, (const short(*)[2])&coefs[0]);

 		pcmFrame[0] = pcmFrame[14];
 		pcmFrame[1] = pcmFrame[15];
@@ -49,7 +48,7 @@ void encode(int16_t* src, uint8_t* dst, ADPCMINFO* cxt, uint32_t samples)
 	cxt->yn2 = 0;
 }

-void InnerProductMerge(tvec vecOut, short pcmBuf[14])
+static void InnerProductMerge(tvec vecOut, const short pcmBuf[14])
 {
 	for (int i = 0; i <= 2; i++)
 	{
@@ -59,7 +58,7 @@ void InnerProductMerge(tvec vecOut, short pcmBuf[14])
 	}
 }

-void OuterProductMerge(tvec mtxOut[3], short pcmBuf[14])
+static void OuterProductMerge(tvec mtxOut[3], const short pcmBuf[14])
 {
 	for (int x = 1; x <= 2; x++)
 		for (int y = 1; y <= 2; y++)
@@ -70,12 +69,12 @@ void OuterProductMerge(tvec mtxOut[3], short pcmBuf[14])
 		}
 }

-bool AnalyzeRanges(tvec mtx[3], int* vecIdxsOut)
+static bool AnalyzeRanges(tvec mtx[3], int* vecIdxsOut)
 {
 	double recips[3];
 	double val, tmp, min, max;

-	/* Get greatest distance from zero */
+	// Get greatest distance from zero
 	for (int x = 1; x <= 2; x++)
 	{
 		val = MAX(fabs(mtx[x][1]), fabs(mtx[x][2]));
@@ -136,7 +135,7 @@ bool AnalyzeRanges(tvec mtx[3], int* vecIdxsOut)
 		}
 	}

-	/* Get range */
+	// Get range
 	min = 1.0e10;
 	max = 0.0;
 	for (int i = 1; i <= 2; i++)
@@ -154,7 +153,7 @@ bool AnalyzeRanges(tvec mtx[3], int* vecIdxsOut)
 	return false;
 }

-void BidirectionalFilter(tvec mtx[3], int* vecIdxs, tvec vecOut)
+static void BidirectionalFilter(tvec mtx[3], const int* vecIdxs, tvec vecOut)
 {
 	double tmp;

@@ -182,7 +181,7 @@ void BidirectionalFilter(tvec mtx[3], int* vecIdxs, tvec vecOut)
 	vecOut[0] = 1.0;
 }

-bool QuadraticMerge(tvec inOutVec)
+static bool QuadraticMerge(tvec inOutVec)
 {
 	double v0, v1, v2 = inOutVec[2];
 	double tmp = 1.0 - (v2 * v2);
@@ -199,7 +198,7 @@ bool QuadraticMerge(tvec inOutVec)
 	return fabs(v1) > 1.0;
 }

-void FinishRecord(tvec in, tvec out)
+static void FinishRecord(tvec in, tvec out)
 {
 	for (int z = 1; z <= 2; z++)
 	{
@@ -213,7 +212,7 @@ void FinishRecord(tvec in, tvec out)
 	out[2] = in[2];
 }

-void MatrixFilter(tvec src, tvec dst)
+static void MatrixFilter(const tvec src, tvec dst)
 {
 	tvec mtx[3];

@@ -237,7 +236,7 @@ void MatrixFilter(tvec src, tvec dst)
 	}
 }

-void MergeFinishRecord(tvec src, tvec dst)
+static void MergeFinishRecord(const tvec src, tvec dst)
 {
 	tvec tmp;
 	double val = src[0];
@@ -265,7 +264,7 @@ void MergeFinishRecord(tvec src, tvec dst)
 	FinishRecord(tmp, dst);
 }

-double ContrastVectors(tvec source1, tvec source2)
+static double ContrastVectors(const tvec source1, const tvec source2)
 {
 	double val = (source2[2] * source2[1] + -source2[1]) / (1.0 - source2[2] * source2[2]);
 	double val1 = (source1[0] * source1[0]) + (source1[1] * source1[1]) + (source1[2] * source1[2]);
@@ -274,7 +273,7 @@ double ContrastVectors(tvec source1, tvec source2)
 	return val1 + (2.0 * val * val2) + (2.0 * (-source2[1] * val + -source2[2]) * val3);
 }

-void FilterRecords(tvec vecBest[8], int exp, tvec records[], int recordCount)
+static void FilterRecords(tvec vecBest[8], int exp, tvec records[], int recordCount)
 {
 	tvec bufferList[8];

@@ -323,8 +322,8 @@ void FilterRecords(tvec vecBest[8], int exp, tvec records[], int recordCount)

 void correlateCoefs(int16_t* source, uint32_t samples, int16_t* coefsOut)
 {
-	int numFrames = (samples + 13) / 14;
-	int frameSamples;
+	uint32_t numFrames = (samples + 13) / 14;
+	uint32_t frameSamples;

 	short* blockBuffer = (short*)calloc(sizeof(short), 0x3800);
 	short pcmHistBuffer[2][14] = { 0 };
@@ -340,29 +339,29 @@ void correlateCoefs(int16_t* source, uint32_t samples, int16_t* coefsOut)

 	tvec vecBest[8];

-	/* Iterate though 1024-block frames */
-	for (int x = samples; x > 0;)
+	// Iterate though 1024-block frames
+	for (uint32_t x = samples; x > 0;)
 	{
-		if (x > 0x3800) /* Full 1024-block frame */
+		if (x > 0x3800) // Full 1024-block frame
 		{
 			frameSamples = 0x3800;
 			x -= 0x3800;
 		}
-		else /* Partial frame */
+		else // Partial frame
 		{
-			/* Zero lingering block samples */
+			// Zero lingering block samples
 			frameSamples = x;
 			for (int z = 0; z < 14 && z + frameSamples < 0x3800; z++)
 				blockBuffer[frameSamples + z] = 0;
 			x = 0;
 		}

-		/* Copy (potentially non-frame-aligned PCM samples into aligned buffer) */
+		// Copy (potentially non-frame-aligned PCM samples into aligned buffer)
 		memcpy(blockBuffer, source, frameSamples * sizeof(short));
 		source += frameSamples;


-		for (int i = 0; i < frameSamples;)
+		for (uint32_t i = 0; i < frameSamples;)
 		{
 			for (int z = 0; z < 14; z++)
 				pcmHistBuffer[0][z] = pcmHistBuffer[1][z];
@@ -416,7 +415,7 @@ void correlateCoefs(int16_t* source, uint32_t samples, int16_t* coefsOut)
 		FilterRecords(vecBest, exp, records, recordCount);
 	}

-	/* Write output */
+	// Write output
 	for (int z = 0; z < 8; z++)
 	{
 		double d;
@@ -433,12 +432,12 @@ void correlateCoefs(int16_t* source, uint32_t samples, int16_t* coefsOut)
 			coefsOut[z * 2 + 1] = (d < -32768.0) ? (short)-32768 : (short)lround(d);
 	}

-	/* Free memory */
+	// Free memory
 	free(records);
 	free(blockBuffer);
 }

-/* Make sure source includes the yn values (16 samples total) */
+// Make sure source includes the yn values (16 samples total)
 void DSPEncodeFrame(short pcmInOut[16], int sampleCount, unsigned char adpcmOut[8], const short coefsIn[8][2])
 {
 	int inSamples[8][16];
@@ -449,32 +448,32 @@ void DSPEncodeFrame(short pcmInOut[16], int sampleCount, unsigned char adpcmOut[
 	int scale[8];
 	double distAccum[8];

-	/* Iterate through each coef set, finding the set with the smallest error */
+	// Iterate through each coef set, finding the set with the smallest error
 	for (int i = 0; i < 8; i++)
 	{
 		int v1, v2, v3;
 		int distance, index;

-		/* Set yn values */
+		// Set yn values
 		inSamples[i][0] = pcmInOut[0];
 		inSamples[i][1] = pcmInOut[1];

-		/* Round and clamp samples for this coef set */
+		// Round and clamp samples for this coef set
 		distance = 0;
 		for (int s = 0; s < sampleCount; s++)
 		{
-			/* Multiply previous samples by coefs */
+			// Multiply previous samples by coefs
 			inSamples[i][s + 2] = v1 = ((pcmInOut[s] * coefsIn[i][1]) + (pcmInOut[s + 1] * coefsIn[i][0])) / 2048;
-			/* Subtract from current sample */
+			// Subtract from current sample
 			v2 = pcmInOut[s + 2] - v1;
-			/* Clamp */
+			// Clamp
 			v3 = (v2 >= 32767) ? 32767 : (v2 <= -32768) ? -32768 : v2;
-			/* Compare distance */
+			// Compare distance
 			if (abs(v3) > abs(distance))
 				distance = v3;
 		}

-		/* Set initial scale */
+		// Set initial scale
 		for (scale[i] = 0; (scale[i] <= 12) && ((distance > 7) || (distance < -8)); scale[i]++, distance /= 2)
 		{
 		}
@@ -488,14 +487,14 @@ void DSPEncodeFrame(short pcmInOut[16], int sampleCount, unsigned char adpcmOut[

 			for (int s = 0; s < sampleCount; s++)
 			{
-				/* Multiply previous */
+				// Multiply previous
 				v1 = ((inSamples[i][s] * coefsIn[i][1]) + (inSamples[i][s + 1] * coefsIn[i][0]));
-				/* Evaluate from real sample */
+				// Evaluate from real sample
 				v2 = (pcmInOut[s + 2] << 11) - v1;
-				/* Round to nearest sample */
+				// Round to nearest sample
 				v3 = (v2 > 0) ? (int)((double)v2 / (1 << scale[i]) / 2048 + 0.4999999f) : (int)((double)v2 / (1 << scale[i]) / 2048 - 0.4999999f);

-				/* Clamp sample and set index */
+				// Clamp sample and set index
 				if (v3 < -8)
 				{
 					if (index < (v3 = -8 - v3))
@@ -509,14 +508,14 @@ void DSPEncodeFrame(short pcmInOut[16], int sampleCount, unsigned char adpcmOut[
 					v3 = 7;
 				}

-				/* Store result */
+				// Store result
 				outSamples[i][s] = v3;

-				/* Round and expand */
+				// Round and expand
 				v1 = (v1 + ((v3 * (1 << scale[i])) << 11) + 1024) >> 11;
-				/* Clamp and store */
+				// Clamp and store
 				inSamples[i][s + 2] = v2 = (v1 >= 32767) ? 32767 : (v1 <= -32768) ? -32768 : v1;
-				/* Accumulate distance */
+				// Accumulate distance
 				v3 = pcmInOut[s + 2] - v2;
 				distAccum[i] += v3 * (double)v3;
 			}
@@ -537,25 +536,23 @@ void DSPEncodeFrame(short pcmInOut[16], int sampleCount, unsigned char adpcmOut[
 		}
 	}

-	/* Write converted samples */
+	// Write converted samples
 	for (int s = 0; s < sampleCount; s++)
-		pcmInOut[s + 2] = inSamples[bestIndex][s + 2];
+		pcmInOut[s + 2] = (short)inSamples[bestIndex][s + 2];

-	/* Write ps */
+	// Write ps
 	adpcmOut[0] = (char)((bestIndex << 4) | (scale[bestIndex] & 0xF));

-	/* Zero remaining samples */
+	// Zero remaining samples
 	for (int s = sampleCount; s < 14; s++)
 		outSamples[bestIndex][s] = 0;

-	/* Write output samples */
+	// Write output samples
 	for (int y = 0; y < 7; y++)
-	{
 		adpcmOut[y + 1] = (char)((outSamples[bestIndex][y * 2] << 4) | (outSamples[bestIndex][y * 2 + 1] & 0xF));
-	}
 }

 void encodeFrame(int16_t* src, uint8_t* dst, int16_t* coefs, uint8_t one)
 {
-	DSPEncodeFrame(src, 14, dst, (short(*)[2])&coefs[0]);
+	DSPEncodeFrame(src, 14, dst, (const short(*)[2])&coefs[0]);
 }
--- a/dsptools/libdsptool/math.c
+++ b/dsptools/libdsptool/math.c
@@ -1,3 +1,5 @@
+/* (c) 2017 Alex Barney (MIT) */
+
 #include "dsptool.h"

 uint32_t getBytesForAdpcmBuffer(uint32_t samples)
@@ -9,7 +11,7 @@ uint32_t getBytesForAdpcmBuffer(uint32_t samples)
 	return frames * BYTES_PER_FRAME;
 }

-uint32_t getBytesForAdpcmInfo()
+uint32_t getBytesForAdpcmInfo(void)
 {
 	return sizeof(ADPCMINFO);
 }
@@ -21,9 +23,7 @@ uint32_t getBytesForAdpcmSamples(uint32_t samples)
 	uint32_t extraSamples = samples % SAMPLES_PER_FRAME;

 	if (extraSamples)
-	{
 		extraBytes = (extraSamples / 2) + (extraSamples % 2) + 1;
-	}

 	return BYTES_PER_FRAME * frames + extraBytes;
 }
@@ -44,8 +44,8 @@ uint32_t getBytesForPcmSamples(uint32_t samples)

 uint32_t getNibbleAddress(uint32_t samples)
 {
-	int frames = samples / SAMPLES_PER_FRAME;
-	int extraSamples = samples % SAMPLES_PER_FRAME;
+	uint32_t frames = samples / SAMPLES_PER_FRAME;
+	uint32_t extraSamples = samples - (frames * SAMPLES_PER_FRAME);

 	return NIBBLES_PER_FRAME * frames + extraSamples + 2;
 }
@@ -53,7 +53,7 @@ uint32_t getNibbleAddress(uint32_t samples)
 uint32_t getNibblesForNSamples(uint32_t samples)
 {
 	uint32_t frames = samples / SAMPLES_PER_FRAME;
-	uint32_t extraSamples = samples % SAMPLES_PER_FRAME;
+	uint32_t extraSamples = samples - (frames * SAMPLES_PER_FRAME);
 	uint32_t extraNibbles = extraSamples == 0 ? 0 : extraSamples + 2;

 	return NIBBLES_PER_FRAME * frames + extraNibbles;
@@ -62,7 +62,7 @@ uint32_t getNibblesForNSamples(uint32_t samples)
 uint32_t getSampleForAdpcmNibble(uint32_t nibble)
 {
 	uint32_t frames = nibble / NIBBLES_PER_FRAME;
-	uint32_t extraNibbles = nibble % NIBBLES_PER_FRAME;
+	uint32_t extraNibbles = nibble - (frames * NIBBLES_PER_FRAME);
 	uint32_t samples = SAMPLES_PER_FRAME * frames;

 	return samples + extraNibbles - 2;