view src/portaudio_20161030_catalina_patch/bindings/cpp/example/sine.cxx @ 83:ae30d91d2ffe

Replace these with versions built using an older toolset (so as to avoid ABI compatibilities when linking on Ubuntu 14.04 for packaging purposes)
author Chris Cannam
date Fri, 07 Feb 2020 11:51:13 +0000
parents 4edcd14160a5
children
line wrap: on
line source
// ---------------------------------------------------------------------------------------

#include <iostream>
#include <cmath>
#include <cassert>
#include <cstddef>
#include "portaudiocpp/PortAudioCpp.hxx"

// ---------------------------------------------------------------------------------------

// Some constants:
const int NUM_SECONDS = 5;
const double SAMPLE_RATE = 44100.0;
const int FRAMES_PER_BUFFER = 64;
const int TABLE_SIZE = 200;

// ---------------------------------------------------------------------------------------

// SineGenerator class:
class SineGenerator
{
public:
	SineGenerator(int tableSize) : tableSize_(tableSize), leftPhase_(0), rightPhase_(0)
	{
		const double PI = 3.14159265;
		table_ = new float[tableSize];
		for (int i = 0; i < tableSize; ++i)
		{
			table_[i] = 0.125f * (float)sin(((double)i/(double)tableSize)*PI*2.);
		}
	}

	~SineGenerator()
	{
		delete[] table_;
	}

	int generate(const void *inputBuffer, void *outputBuffer, unsigned long framesPerBuffer, 
		const PaStreamCallbackTimeInfo *timeInfo, PaStreamCallbackFlags statusFlags)
	{
		assert(outputBuffer != NULL);

		float **out = static_cast<float **>(outputBuffer);

		for (unsigned int i = 0; i < framesPerBuffer; ++i)
		{
			out[0][i] = table_[leftPhase_];
			out[1][i] = table_[rightPhase_];

			leftPhase_ += 1;
			if (leftPhase_ >= tableSize_)
				leftPhase_ -= tableSize_;

			rightPhase_ += 3;
			if (rightPhase_ >= tableSize_)
				rightPhase_ -= tableSize_;
		}

		return paContinue;
	}

private:
	float *table_;
	int tableSize_;
	int leftPhase_;
	int rightPhase_;
};

// ---------------------------------------------------------------------------------------

// main:
int main(int, char *[]);
int main(int, char *[])
{
	try
	{
		// Create a SineGenerator object:
		SineGenerator sineGenerator(TABLE_SIZE);

		std::cout << "Setting up PortAudio..." << std::endl;

		// Set up the System:
		portaudio::AutoSystem autoSys;
		portaudio::System &sys = portaudio::System::instance();

		// Set up the parameters required to open a (Callback)Stream:
		portaudio::DirectionSpecificStreamParameters outParams(sys.defaultOutputDevice(), 2, portaudio::FLOAT32, false, sys.defaultOutputDevice().defaultLowOutputLatency(), NULL);
		portaudio::StreamParameters params(portaudio::DirectionSpecificStreamParameters::null(), outParams, SAMPLE_RATE, FRAMES_PER_BUFFER, paClipOff);

		std::cout << "Opening stereo output stream..." << std::endl;

		// Create (and open) a new Stream, using the SineGenerator::generate function as a callback:
		portaudio::MemFunCallbackStream<SineGenerator> stream(params, sineGenerator, &SineGenerator::generate);

		std::cout << "Starting playback for " << NUM_SECONDS << " seconds." << std::endl;

		// Start the Stream (audio playback starts):
		stream.start();

		// Wait for 5 seconds:
		sys.sleep(NUM_SECONDS * 1000);

		std::cout << "Closing stream..." <<std::endl;

		// Stop the Stream (not strictly needed as termintating the System will also stop all open Streams):
		stream.stop();

		// Close the Stream (not strictly needed as terminating the System will also close all open Streams):
		stream.close();

		// Terminate the System (not strictly needed as the AutoSystem will also take care of this when it 
		// goes out of scope):
		sys.terminate();

		std::cout << "Test finished." << std::endl;
	}
	catch (const portaudio::PaException &e)
	{
		std::cout << "A PortAudio error occured: " << e.paErrorText() << std::endl;
	}
	catch (const portaudio::PaCppException &e)
	{
		std::cout << "A PortAudioCpp error occured: " << e.what() << std::endl;
	}
	catch (const std::exception &e)
	{
		std::cout << "A generic exception occured: " << e.what() << std::endl;
	}
	catch (...)
	{
		std::cout << "An unknown exception occured." << std::endl;
	}

	return 0;
}