Merge branch 'release/1.0.3'

Author: adamstark

AudioFile.cpp

@@ -337,9 +337,7 @@ bool AudioFile<T>::decodeWaveFile (std::vector<uint8_t>& fileData)
 
             if (bitDepth == 8)
             {
-                int32_t sampleAsInt = (int32_t) fileData[sampleIndex];
-                T sample = (T)(sampleAsInt - 128) / (T)128.;
-                
+                T sample = singleByteToSample (fileData[sampleIndex]);
                 samples[channel].push_back (sample);
             }
             else if (bitDepth == 16)
@@ -584,13 +582,12 @@ bool AudioFile<T>::saveToWaveFile (std::string filePath)
         {
             if (bitDepth == 8)
             {
-                int32_t sampleAsInt = ((samples[channel][i] * (T)128.) + 128.);
-                uint8_t byte = (uint8_t)sampleAsInt;
+                uint8_t byte = sampleToSingleByte (samples[channel][i]);
                 fileData.push_back (byte);
             }
             else if (bitDepth == 16)
             {
-                int16_t sampleAsInt = (int16_t) (samples[channel][i] * (T)32768.);
+                int16_t sampleAsInt = sampleToSixteenBitInt (samples[channel][i]);
                 addInt16ToFileData (fileData, sampleAsInt);
             }
             else if (bitDepth == 24)
@@ -669,13 +666,12 @@ bool AudioFile<T>::saveToAiffFile (std::string filePath)
         {
             if (bitDepth == 8)
             {
-                int32_t sampleAsInt = (int32_t)(samples[channel][i] * (T)128.);
-                uint8_t byte = (uint8_t)sampleAsInt;
+                uint8_t byte = sampleToSingleByte (samples[channel][i]);
                 fileData.push_back (byte);
             }
             else if (bitDepth == 16)
             {
-                int16_t sampleAsInt = (int16_t) (samples[channel][i] * (T)32768.);
+                int16_t sampleAsInt = sampleToSixteenBitInt (samples[channel][i]);
                 addInt16ToFileData (fileData, sampleAsInt, Endianness::BigEndian);
             }
             else if (bitDepth == 24)
@@ -865,7 +861,40 @@ int AudioFile<T>::getIndexOfString (std::vector<uint8_t>& source, std::string st
 template <class T>
 T AudioFile<T>::sixteenBitIntToSample (int16_t sample)
 {
-    return (T)sample / (T)32768.;
+    return static_cast<T> (sample) / static_cast<T> (32768.);
+}
+
+//=============================================================
+template <class T>
+int16_t AudioFile<T>::sampleToSixteenBitInt (T sample)
+{
+    sample = clamp (sample, -1., 1.);
+    return static_cast<int16_t> (sample * 32767.);
+}
+
+//=============================================================
+template <class T>
+uint8_t AudioFile<T>::sampleToSingleByte (T sample)
+{
+    sample = clamp (sample, -1., 1.);
+    sample = (sample + 1.) / 2.;
+    return static_cast<uint8_t> (sample * 255.);
+}
+
+//=============================================================
+template <class T>
+T AudioFile<T>::singleByteToSample (uint8_t sample)
+{
+    return static_cast<T> (sample - 128) / static_cast<T> (128.);
+}
+
+//=============================================================
+template <class T>
+T AudioFile<T>::clamp (T value, T minValue, T maxValue)
+{
+    value = std::min (value, maxValue);
+    value = std::max (value, minValue);
+    return value;
 }
 
 //===========================================================

AudioFile.h

@@ -150,10 +150,19 @@ class AudioFile
     int32_t fourBytesToInt (std::vector<uint8_t>& source, int startIndex, Endianness endianness = Endianness::LittleEndian);
     int16_t twoBytesToInt (std::vector<uint8_t>& source, int startIndex, Endianness endianness = Endianness::LittleEndian);
     int getIndexOfString (std::vector<uint8_t>& source, std::string s);
+    
+    //=============================================================
     T sixteenBitIntToSample (int16_t sample);
+    int16_t sampleToSixteenBitInt (T sample);
+    
+    //=============================================================
+    uint8_t sampleToSingleByte (T sample);
+    T singleByteToSample (uint8_t sample);
+    
     uint32_t getAiffSampleRate (std::vector<uint8_t>& fileData, int sampleRateStartIndex);
     bool tenByteMatch (std::vector<uint8_t>& v1, int startIndex1, std::vector<uint8_t>& v2, int startIndex2);
     void addSampleRateToAiffData (std::vector<uint8_t>& fileData, uint32_t sampleRate);
+    T clamp (T v1, T minValue, T maxValue);
 
     //=============================================================
     void addStringToFileData (std::vector<uint8_t>& fileData, std::string s);

README.md

@@ -1,7 +1,7 @@
 # AudioFile
 
 <!-- Version and License Badges -->
-![Version](https://img.shields.io/badge/version-1.0.2-green.svg?style=flat-square) 
+![Version](https://img.shields.io/badge/version-1.0.3-green.svg?style=flat-square) 
 ![License](https://img.shields.io/badge/license-GPL-blue.svg?style=flat-square) 
 ![Language](https://img.shields.io/badge/language-C++-yellow.svg?style=flat-square) 
 
@@ -71,7 +71,24 @@ Usage
 	buffer[0].resize (100000);
 	buffer[1].resize (100000);
 
-	// 4. do something here to fill the buffer with samples
+	// 4. do something here to fill the buffer with samples, e.g.
+	
+	#include <math.h> // somewhere earler (for M_PI and sinf())
+	
+	// then...
+	
+	int numChannels = 2;
+	int numSamplesPerChannel = 100000;
+	float sampleRate = 44100.f;
+	float frequency = 440.f;
+
+	for (int i = 0; i < numSamplesPerChannel; i++)
+	{
+        float sample = sinf (2. * M_PI * ((float) i / sampleRate) * frequency) ;
+        
+        for (int channel = 0; channel < numChannels; channel++)
+             buffer[channel][i] = sample * 0.5;
+	}
 
 	// 5. Put into the AudioFile object
 	bool ok = audioFile.setAudioBuffer (buffer);
@@ -121,6 +138,11 @@ This simply reflects the data type you would like to use to store the underlying
 Versions
 -------
 
+##### 1.0.3 - 28th October 2018
+
+- Bug fixes
+- Documentation updates
+
 ##### 1.0.2 - 6th June 2017
 
 - Bug fixes

tests/AudioFileTests.xcodeproj/project.xcworkspace/xcshareddata/IDEWorkspaceChecks.plist

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>IDEDidComputeMac32BitWarning</key>
+	<true/>
+</dict>
+</plist>