X-Git-Url: http://git.linex4red.de/pub/USBasp.git/blobdiff_plain/db435c4995ef71f08b2867716453c96886b26105..046fff2aff485c550e55125bb059e001e39a6730:/Demos/Device/ClassDriver/AudioOutput/AudioOutput.c

diff --git a/Demos/Device/ClassDriver/AudioOutput/AudioOutput.c b/Demos/Device/ClassDriver/AudioOutput/AudioOutput.c
index a73f1c96e..a95e43fd5 100644
--- a/Demos/Device/ClassDriver/AudioOutput/AudioOutput.c
+++ b/Demos/Device/ClassDriver/AudioOutput/AudioOutput.c
@@ -95,27 +95,20 @@ void ProcessNextSample(void)
 		/* Clear the sample reload timer */
 		TIFR0 |= (1 << OCF0A);
 
-		/* Retrieve the signed 16-bit left and right audio samples */
-		int16_t LeftSample_16Bit  = Audio_Device_ReadSample16(&Speaker_Audio_Interface);
-		int16_t RightSample_16Bit = Audio_Device_ReadSample16(&Speaker_Audio_Interface);
-
-		/* Massage signed 16-bit left and right audio samples into signed 8-bit */
-		int8_t  LeftSample_8Bit   = (LeftSample_16Bit  >> 8);
-		int8_t  RightSample_8Bit  = (RightSample_16Bit >> 8);
+		/* Retrieve the signed 16-bit left and right audio samples, convert to 8-bit */
+		int8_t  LeftSample_8Bit   = (Audio_Device_ReadSample16(&Speaker_Audio_Interface) >> 8);
+		int8_t  RightSample_8Bit  = (Audio_Device_ReadSample16(&Speaker_Audio_Interface) >> 8);
 
 		/* Mix the two channels together to produce a mono, 8-bit sample */
 		int8_t  MixedSample_8Bit  = (((int16_t)LeftSample_8Bit + (int16_t)RightSample_8Bit) >> 1);
 
-		/* Get absolute value of mixed sample value */
-		uint8_t MixedSample_8Bit_Abs = abs(MixedSample_8Bit);
-
 #if defined(AUDIO_OUT_MONO)
 		/* Load the sample into the PWM timer channel */
-		OCR3A = ((uint8_t)MixedSample_8Bit ^ (1 << 7));
+		OCR3A = (MixedSample_8Bit ^ (1 << 7));
 #elif defined(AUDIO_OUT_STEREO)
 		/* Load the dual 8-bit samples into the PWM timer channels */
-		OCR3A = ((uint8_t)LeftSample_8Bit  ^ (1 << 7));
-		OCR3B = ((uint8_t)RightSample_8Bit ^ (1 << 7));
+		OCR3A = (LeftSample_8Bit  ^ (1 << 7));
+		OCR3B = (RightSample_8Bit ^ (1 << 7));
 #elif defined(AUDIO_OUT_PORTC)
 		/* Load the 8-bit mixed sample into PORTC */
 		PORTC = MixedSample_8Bit;
@@ -124,13 +117,13 @@ void ProcessNextSample(void)
 		uint8_t LEDMask = LEDS_NO_LEDS;
 
 		/* Turn on LEDs as the sample amplitude increases */
-		if (MixedSample_8Bit_Abs > 16)
+		if (MixedSample_8Bit > 16)
 		  LEDMask = (LEDS_LED1 | LEDS_LED2 | LEDS_LED3 | LEDS_LED4);
-		else if (MixedSample_8Bit_Abs > 8)
+		else if (MixedSample_8Bit > 8)
 		  LEDMask = (LEDS_LED1 | LEDS_LED2 | LEDS_LED3);
-		else if (MixedSample_8Bit_Abs > 4)
+		else if (MixedSample_8Bit > 4)
 		  LEDMask = (LEDS_LED1 | LEDS_LED2);
-		else if (MixedSample_8Bit_Abs > 2)
+		else if (MixedSample_8Bit > 2)
 		  LEDMask = (LEDS_LED1);
 
 		LEDs_SetAllLEDs(LEDMask);