Fix sign compare issues

src/util/audio/AudioQueue.h

@@ -62,7 +62,7 @@ public:
 	{
 		XOJ_CHECK_TYPE(AudioQueue);
 
-		for (long i = 0; i < nSamples; i++)
+		for (unsigned long i = 0; i < nSamples; i++)
 		{
 			this->push_front(samples[i]);
 		}

src/util/audio/PortAudioConsumer.cpp

@@ -78,7 +78,7 @@ void PortAudioConsumer::startPlaying(double sampleRate, unsigned int channels)
 		return;
 	}
 
-	if (device->maxOutputChannels() < channels)
+	if ((unsigned int) device->maxOutputChannels() < channels)
 	{
 		this->audioQueue->signalEndOfStream();
 		g_warning("Output device has not enough channels to play audio file. (Requires at least 2 channels)");
@@ -129,7 +129,7 @@ int PortAudioConsumer::playCallback(const void* inputBuffer, void* outputBuffer,
 
 		// Fill buffer to requested length if necessary
 
-		if (outputBufferLength < framesPerBuffer * this->outputChannels)
+		if ((unsigned int) outputBufferLength < framesPerBuffer * this->outputChannels)
 		{
 			g_warning("PortAudioConsumer: Frame underflow");
 

src/util/audio/VorbisConsumer.cpp

@@ -51,7 +51,7 @@ bool VorbisConsumer::start(string filename, unsigned int inputChannels)
 						// apply gain
 						if (audioGain != 1.0)
 						{
-							for (int i = 0; i < 64 * inputChannels; ++i)
+							for (unsigned int i = 0; i < 64 * inputChannels; ++i)
 							{
 								// check for overflow
 								if (std::abs(buffer[i]) < std::floor(INT_MAX / audioGain))