robert@464: /*
robert@464:  ____  _____ _        _    
robert@464: | __ )| ____| |      / \   
robert@464: |  _ \|  _| | |     / _ \  
robert@464: | |_) | |___| |___ / ___ \ 
robert@464: |____/|_____|_____/_/   \_\
robert@464: 
robert@464: The platform for ultra-low latency audio and sensor processing
robert@464: 
robert@464: http://bela.io
robert@464: 
robert@464: A project of the Augmented Instruments Laboratory within the
robert@464: Centre for Digital Music at Queen Mary University of London.
robert@464: http://www.eecs.qmul.ac.uk/~andrewm
robert@464: 
robert@464: (c) 2016 Augmented Instruments Laboratory: Andrew McPherson,
robert@464:   Astrid Bin, Liam Donovan, Christian Heinrichs, Robert Jack,
robert@464:   Giulio Moro, Laurel Pardue, Victor Zappi. All rights reserved.
robert@464: 
robert@464: The Bela software is distributed under the GNU Lesser General Public License
robert@464: (LGPL 3.0), available here: https://www.gnu.org/licenses/lgpl-3.0.txt
robert@464: */
robert@464: 
robert@464: 
robert@464: #include <Bela.h>
robert@464: #include <cmath>
robert@464: 
robert@464: int gBufferSize = 8192;
robert@464: 
robert@464: // Double buffers to hold samples for noise analysis
robert@464: float *gReadBuffers[10], *gWriteBuffers[10];
robert@464: float *gBuffers0[10], *gBuffers1[10];
robert@464: 
robert@464: int gWriteBufferPointers[10], gReadBufferPointers[10];
robert@464: 
robert@464: // Task to analyse and print results which would otherwise be too slow for render()
robert@464: AuxiliaryTask gAnalysisTask;
robert@464: 
robert@464: void analyseResults();
robert@464: 
robert@464: // setup() is called once before the audio rendering starts.
robert@464: // Use it to perform any initialisation and allocation which is dependent
robert@464: // on the period size or sample rate.
robert@464: //
robert@464: // userData holds an opaque pointer to a data structure that was passed
robert@464: // in from the call to initAudio().
robert@464: //
robert@464: // Return true on success; returning false halts the program.
robert@464: 
robert@464: bool setup(BelaContext *context, void *userData)
robert@464: {	
robert@544: 
robert@544: 	// Check that we have the same number of inputs and outputs.
robert@544: 	if(context->audioInChannels != context->audioOutChannels ||
robert@544: 			context->analogInChannels != context-> analogOutChannels){
robert@544: 		printf("Error: for this project, you need the same number of input and output channels.\n");
robert@544: 		return false;
robert@544: 	}
robert@544: 
robert@464: 	// Clear the filter data structures
robert@464: 	for(int i = 0; i < 10; i++) {
robert@464: 		gReadBufferPointers[i] = gWriteBufferPointers[i] = 0;
robert@464: 		gBuffers0[i] = new float[gBufferSize];
robert@464: 		gBuffers1[i] = new float[gBufferSize];		
robert@464: 		gWriteBuffers[i] = gBuffers0[i];
robert@464: 		gReadBuffers[i] = gBuffers1[i];
robert@464: 		if(gBuffers0[i] == 0 || gBuffers1[i] == 0) {
robert@464: 			rt_printf("Error allocating buffer %d\n", i);
robert@464: 			return false;
robert@464: 		}
robert@464: 	}
robert@464: 	
robert@464: 	gAnalysisTask = Bela_createAuxiliaryTask(analyseResults, 50, "bela-analyse-results");
robert@464: 
robert@464: 	return true;
robert@464: }
robert@464: 
robert@464: // render() is called regularly at the highest priority by the audio engine.
robert@464: // Input and output are given from the audio hardware and the other
robert@464: // ADCs and DACs (if available). If only audio is available, numMatrixFrames
robert@464: // will be 0.
robert@464: 
robert@464: void render(BelaContext *context, void *userData)
robert@464: {
robert@464: 	bool bufferIsFull = false;	// Whether at least one buffer has filled
robert@464: 	
robert@464: 	for(unsigned int n = 0; n < context->audioFrames; n++) {
robert@464: 		// Store audio inputs in buffer
robert@544: 		for(unsigned int ch = 0; ch < context->audioOutChannels; ch++) {
robert@464: 			if(gWriteBufferPointers[ch] < gBufferSize) {
robert@464: 				gWriteBuffers[ch][gWriteBufferPointers[ch]] = 
robert@544: 					context->audioIn[n * context->audioOutChannels + ch];
robert@464: 				gWriteBufferPointers[ch]++;
robert@464: 				if(gWriteBufferPointers[ch] >= gBufferSize)
robert@464: 					bufferIsFull = true;
robert@464: 			}
robert@464: 		}
robert@464: 	}
robert@464: 	
robert@544: 	if(context->analogOutChannels != 0) {
robert@464: 		for(unsigned int n = 0; n < context->analogFrames; n++) {
robert@464: 			// Store analog inputs in buffer, starting at channel 2
robert@544: 			for(unsigned int ch = 0; ch < context->analogOutChannels; ch++) {
robert@464: 				if(gWriteBufferPointers[ch + 2] < gBufferSize) {
robert@464: 					gWriteBuffers[ch + 2][gWriteBufferPointers[ch + 2]] = 
robert@544: 						context->analogIn[n * context->analogOutChannels + ch];
robert@464: 					gWriteBufferPointers[ch + 2]++;
robert@464: 					if(gWriteBufferPointers[ch + 2] >= gBufferSize)
robert@464: 						bufferIsFull = true;
robert@464: 				}
robert@464: 				
robert@464: 				// Set all analog outputs to halfway point so they can be more
robert@464: 				// easily measured for noise
robert@544: 				context->analogOut[n * context->analogOutChannels + ch] = 0.5;
robert@464: 			}
robert@464: 		}	
robert@464: 	}
robert@464: 	
robert@464: 
robert@464: 	if(bufferIsFull) {
robert@464: 		// Swap buffers and reset write pointers
robert@464: 		for(int ch = 0; ch < 10; ch++) {
robert@464: 			gReadBufferPointers[ch] = gWriteBufferPointers[ch];
robert@464: 			gWriteBufferPointers[ch] = 0;
robert@464: 			
robert@464: 			if(gReadBuffers[ch] == gBuffers0[ch]) {
robert@464: 				gReadBuffers[ch] = gBuffers1[ch];
robert@464: 				gWriteBuffers[ch] = gBuffers0[ch];
robert@464: 			}
robert@464: 			else {
robert@464: 				gReadBuffers[ch] = gBuffers0[ch];
robert@464: 				gWriteBuffers[ch] = gBuffers1[ch];				
robert@464: 			}
robert@464: 		}
robert@464: 		
robert@464: 		Bela_scheduleAuxiliaryTask(gAnalysisTask);
robert@464: 	}
robert@464: }
robert@464: 
robert@464: void analyseResults()
robert@464: {
robert@464: 	rt_printf("\e[1;1H\e[2J");	// Command to clear the screen
robert@464: 
robert@464: 	// Print the analysis results. channels 0-1 are audio, channels 2-9 are analog
robert@464: 	for(int ch = 0; ch < 10; ch++) {
robert@464: 		// Skip unused channels
robert@464: 		if(gReadBufferPointers[ch] == 0)
robert@464: 			continue;
robert@464: 		
robert@464: 		float mean = 0;
robert@464: 		for(int n = 0; n < gReadBufferPointers[ch]; n++) {
robert@464: 			mean += gReadBuffers[ch][n];
robert@464: 		}
robert@464: 		mean /= (float)gReadBufferPointers[ch];
robert@464: 		
robert@464: 		float rms = 0;
robert@464: 		for(int n = 0; n < gReadBufferPointers[ch]; n++) {
robert@464: 			rms += (gReadBuffers[ch][n] - mean) * (gReadBuffers[ch][n] - mean);
robert@464: 		}				
robert@464: 		rms = sqrtf(rms / (float)gReadBufferPointers[ch]);
robert@464: 		
robert@464: 		if(ch == 0)
robert@464: 			rt_printf("Audio In L:  ");
robert@464: 		else if(ch == 1)
robert@464: 			rt_printf("Audio In R:  ");
robert@464: 		else
robert@464: 			rt_printf("Analog In %d: ", ch - 2);
robert@464: 		
robert@464: 		rt_printf("Noise %6.1fdB    DC offset %6.4f (%6.1fdB)    window size: %d\n", 
robert@464: 					20.0f * log10f(rms),
robert@464: 					mean, 
robert@464: 					20.0f * log10f(fabsf(mean)),
robert@464: 					gReadBufferPointers[ch]);
robert@464: 	}
robert@464: }
robert@464: 
robert@464: // cleanup() is called once at the end, after the audio has stopped.
robert@464: // Release any resources that were allocated in setup().
robert@464: 
robert@464: void cleanup(BelaContext *context, void *userData)
robert@464: {
robert@464: 	for(int i = 0; i < 10; i++) {
robert@464: 		delete gBuffers0[i];
robert@464: 		delete gBuffers1[i];
robert@464: 	}
robert@464: }