andrewm@89: /*
andrewm@89:  * render.cpp
andrewm@89:  *
andrewm@89:  *  Created on: Oct 24, 2014
andrewm@89:  *      Author: parallels
andrewm@89:  */
andrewm@89: 
andrewm@89: 
andrewm@89: #include <BeagleRT.h>
andrewm@89: #include <Utilities.h>
andrewm@89: #include <cmath>
andrewm@89: 
andrewm@89: int gBufferSize = 8192;
andrewm@89: 
andrewm@89: // Buffers to hold samples for noise analysis
andrewm@89: float* gBuffers[10];
andrewm@89: int gBufferPointers[10];
andrewm@89: 
andrewm@89: // Outputs to display
andrewm@89: float gDCLevels[10];
andrewm@89: float gNoiseLevels[10];
andrewm@89: float gNumSamplesAnalysed[10];
andrewm@89: 
andrewm@89: // Task to print results which would otherwise be too slow for render()
andrewm@89: AuxiliaryTask gPrintTask;
andrewm@89: 
andrewm@89: void printResults();
andrewm@89: 
andrewm@89: // setup() is called once before the audio rendering starts.
andrewm@89: // Use it to perform any initialisation and allocation which is dependent
andrewm@89: // on the period size or sample rate.
andrewm@89: //
andrewm@89: // userData holds an opaque pointer to a data structure that was passed
andrewm@89: // in from the call to initAudio().
andrewm@89: //
andrewm@89: // Return true on success; returning false halts the program.
andrewm@89: 
andrewm@89: bool setup(BeagleRTContext *context, void *userData)
andrewm@89: {	
andrewm@89: 	// Clear the filter data structures
andrewm@89: 	for(int i = 0; i < 10; i++) {
andrewm@89: 		gBufferPointers[i] = 0;
andrewm@89: 		gBuffers[i] = new float[gBufferSize];
andrewm@89: 		if(gBuffers[i] == 0) {
andrewm@89: 			rt_printf("Error allocating buffer %d\n", i);
andrewm@89: 			return false;
andrewm@89: 		}
andrewm@89: 	}
andrewm@89: 	
andrewm@89: 	gPrintTask = BeagleRT_createAuxiliaryTask(printResults, 50, "beaglert-print-results");
andrewm@89: 
andrewm@89: 	return true;
andrewm@89: }
andrewm@89: 
andrewm@89: // render() is called regularly at the highest priority by the audio engine.
andrewm@89: // Input and output are given from the audio hardware and the other
andrewm@89: // ADCs and DACs (if available). If only audio is available, numMatrixFrames
andrewm@89: // will be 0.
andrewm@89: 
andrewm@89: void render(BeagleRTContext *context, void *userData)
andrewm@89: {
andrewm@89: 	bool bufferIsFull = false;	// Whether at least one buffer has filled
andrewm@89: 	
andrewm@89: 	for(unsigned int n = 0; n < context->audioFrames; n++) {
andrewm@89: 		// Store audio inputs in buffer
andrewm@89: 		for(unsigned int ch = 0; ch < context->audioChannels; ch++) {
andrewm@89: 			if(gBufferPointers[ch] < gBufferSize) {
andrewm@89: 				gBuffers[ch][gBufferPointers[ch]] = 
andrewm@89: 					context->audioIn[n * context->audioChannels + ch];
andrewm@89: 				gBufferPointers[ch]++;
andrewm@89: 				if(gBufferPointers[ch] >= gBufferSize)
andrewm@89: 					bufferIsFull = true;
andrewm@89: 			}
andrewm@89: 		}
andrewm@89: 	}
andrewm@89: 	
andrewm@89: 	if(context->analogChannels != 0) {
andrewm@89: 		for(unsigned int n = 0; n < context->analogFrames; n++) {
andrewm@89: 			// Store analog inputs in buffer, starting at channel 2
andrewm@89: 			for(unsigned int ch = 0; ch < context->analogChannels; ch++) {
andrewm@89: 				if(gBufferPointers[ch + 2] < gBufferSize) {
andrewm@89: 					gBuffers[ch + 2][gBufferPointers[ch + 2]] = 
andrewm@89: 						context->analogIn[n * context->analogChannels + ch];
andrewm@89: 					gBufferPointers[ch + 2]++;
andrewm@89: 					if(gBufferPointers[ch + 2] >= gBufferSize)
andrewm@89: 						bufferIsFull = true;
andrewm@89: 				}
andrewm@89: 			}
andrewm@89: 		}	
andrewm@89: 	}
andrewm@89: 
andrewm@89: 	if(bufferIsFull) {
andrewm@89: 		// Analyse all active channels at once
andrewm@89: 		for(int ch = 0; ch < 10; ch++) {
andrewm@89: 			// gBufferPointers[ch] tells us how many samples were stored in the buffer
andrewm@89: 			gNumSamplesAnalysed[ch] = gBufferPointers[ch];
andrewm@89: 			
andrewm@89: 			if(gBufferPointers[ch] != 0) {
andrewm@89: 				float mean = 0;
andrewm@89: 				for(int n = 0; n < gBufferPointers[ch]; n++) {
andrewm@89: 					mean += gBuffers[ch][n];
andrewm@89: 				}
andrewm@89: 				mean /= (float)gBufferPointers[ch];
andrewm@89: 				
andrewm@89: 				float rms = 0;
andrewm@89: 				for(int n = 0; n < gBufferPointers[ch]; n++) {
andrewm@89: 					rms += (gBuffers[ch][n] - mean) * (gBuffers[ch][n] - mean);
andrewm@89: 				}				
andrewm@89: 				rms = sqrtf(rms / (float)gBufferPointers[ch]);
andrewm@89: 				
andrewm@89: 				gDCLevels[ch] = mean;
andrewm@89: 				gNoiseLevels[ch] = rms;
andrewm@89: 			}
andrewm@89: 			
andrewm@89: 			// Reset pointer to 0 for next time
andrewm@89: 			gBufferPointers[ch] = 0;
andrewm@89: 		}
andrewm@89: 		
andrewm@89: 		BeagleRT_scheduleAuxiliaryTask(gPrintTask);
andrewm@89: 	}
andrewm@89: }
andrewm@89: 
andrewm@89: void printResults()
andrewm@89: {
andrewm@89: 	rt_printf("\e[1;1H\e[2J");	// Command to clear the screen
andrewm@89: 	
andrewm@89: 	// Print the analysis results. channels 0-1 are audio, channels 2-9 are analog
andrewm@89: 	for(int ch = 0; ch < 10; ch++) {
andrewm@89: 		int samples = gNumSamplesAnalysed[ch];
andrewm@89: 		if(samples == 0)
andrewm@89: 			continue;
andrewm@89: 		
andrewm@89: 		if(ch == 0)
andrewm@89: 			rt_printf("Audio In L:  ");
andrewm@89: 		else if(ch == 1)
andrewm@89: 			rt_printf("Audio In R:  ");
andrewm@89: 		else
andrewm@89: 			rt_printf("Analog In %d: ", ch - 2);
andrewm@89: 		
andrewm@89: 		rt_printf("Noise %6.1fdB    DC offset %6.4f (%6.1fdB)    window size: %d\n", 
andrewm@89: 					20.0f * log10f(gNoiseLevels[ch]),
andrewm@89: 					gDCLevels[ch], 
andrewm@89: 					20.0f * log10f(fabsf(gDCLevels[ch])),
andrewm@89: 					samples);
andrewm@89: 	}
andrewm@89: }
andrewm@89: 
andrewm@89: // cleanup() is called once at the end, after the audio has stopped.
andrewm@89: // Release any resources that were allocated in setup().
andrewm@89: 
andrewm@89: void cleanup(BeagleRTContext *context, void *userData)
andrewm@89: {
andrewm@89: 	for(int i = 0; i < 10; i++)
andrewm@89: 		delete gBuffers[i];
andrewm@89: }