Class ExampleRunner

main.cpp:10–112

#include <array>

class ExampleRunner {
	Wav inputWav;
	std::string outputPrefix;

	template<class Processor>
	void monoProcessor(std::string name, Processor &&processor) {
		Wav outputWav;
		outputWav.sampleRate = inputWav.sampleRate;
		outputWav.channels = 1;
		
		srand(1);
		processor.configure(outputWav.sampleRate);
		
		int durationSamples = inputWav.samples.size()/inputWav.channels;
		outputWav.samples.resize(durationSamples);
		for (int i = 0; i < durationSamples; ++i) {
			outputWav.samples[i] = processor.process(inputWav.samples[i*inputWav.channels]);
		}
		outputWav.write(outputPrefix + name + ".wav");
		if (!outputWav.result) {
			std::cerr << outputWav.result.reason << "\n";
			std::exit(1);
		}
	}

	template<int channels, bool averageOutputs=true, class Processor>
	void multiProcessor(std::string name, Processor &&processor) {
		static_assert(channels%2 == 0, "there must be an even number of channels");

		Wav outputWav;
		outputWav.sampleRate = inputWav.sampleRate;
		outputWav.channels = 2;
		
		srand(1);
		processor.configure(outputWav.sampleRate);
		
		int durationSamples = inputWav.samples.size()/inputWav.channels;
		outputWav.samples.resize(durationSamples*2);
		for (int i = 0; i < durationSamples; ++i) {

			// Duplicate input channels as many times as needed
			std::array<double, channels> array;
			for (int c = 0; c < channels; ++c) {
				int inputChannel = c%inputWav.channels;
				array[c] = inputWav.samples[i*inputWav.channels + inputChannel];
			}
			
			array = processor.process(array);
			
			if (averageOutputs) {
				// Mix down into stereo for example output
				double left = 0, right = 0;
				for (int c = 0; c < channels; c += 2) {
					left += array[c];
					right += array[c + 1];
				}
				
				constexpr double scaling = 2.0/channels;