comparison examples/02-Digital/level-meter/render.cpp @ 543:8f8809c77dda prerelease

updated basics, digital, instruments, extras examples

 	// sample rates are the same. But check it to be sure!
 	if(context->audioFrames != context->digitalFrames) {
 		rt_printf("Error: this project needs the audio and digital sample rates to be the same.\n");
 		return false;
 	}
+
+	// For this example we need the same amount of audio input and output channels
+	if(context->audioInChannels != context->audioOutChannels){
+		printf("Error: for this project, you need the same number of audio input and output channels.\n");
+		return false;
+	}
 	
 	// Initialise threshold levels in -3dB steps. One extra for efficiency in render()
 	// Level = 10^(dB/20)
 	for(int i = 0; i < NUMBER_OF_SEGMENTS + 1; i++) {
 		gThresholds[i] = powf(10.0f, (-1.0 * (NUMBER_OF_SEGMENTS - i)) * .05);

 void render(BelaContext *context, void *userData)
 {
 	for(unsigned int n = 0; n < context->audioFrames; n++) {
 		// Get average of audio input channels
 		float sample = 0;
-		for(unsigned int ch = 0; ch < context->audioChannels; ch++) {
-			context->audioOut[n * context->audioChannels + ch] = 
-				context->audioIn[n * context->audioChannels + ch];
-			sample += context->audioIn[n * context->audioChannels + ch];
+		for(unsigned int ch = 0; ch < context->audioInChannels; ch++) {
+			context->audioOut[n * context->audioOutChannels + ch] = 
+				context->audioIn[n * context->audioInChannels + ch];
+			sample += context->audioIn[n * context->audioInChannels + ch];
 		}
 		
 		// Do DC-blocking on the sum
 		float out = gB0 * sample + gB1 * gLastX[0] + gB2 * gLastX[1]
 						- gA1 * gLastY[0] - gA2 * gLastY[1];

 		gLastX[1] = gLastX[0];
 		gLastX[0] = sample;
 		gLastY[1] = gLastY[0];
 		gLastY[0] = out;
 		
-		out = fabsf(out / (float)context->audioChannels);
+		out = fabsf(out / (float)context->audioOutChannels);
 		
 		// Do peak detection: fast-responding local level
 		if(out > gAudioLocalLevel)
 			gAudioLocalLevel = out;
 		else