Philips Philips / Mbed 2 deprecated Yodareverseeffectsguitar

Increased the buffer the force is strong in you young jedi(.)(.) Hello my name is guitar reverse me and it is karaoke time

main.cpp@0:27de5cbb4833, 2011-07-14 (annotated)

Committer:
mbed2f
Date:
Thu Jul 14 19:16:19 2011 +0000
Revision:
0:27de5cbb4833
Increased the buffer the force is strong in you young jedi(.)(.)



Hello my name is guitar reverse me and it is karaoke time

Who changed what in which revision?

UserRevisionLine numberNew contents of line
mbed2f 0:27de5cbb4833 1 #include <mbed.h>
mbed2f 0:27de5cbb4833 2
mbed2f 0:27de5cbb4833 3 // Boolean types
mbed2f 0:27de5cbb4833 4 #define TRUE 1
mbed2f 0:27de5cbb4833 5 #define FALSE 0
mbed2f 0:27de5cbb4833 6
mbed2f 0:27de5cbb4833 7 //#define NUM_SAMPLES 48000
mbed2f 0:27de5cbb4833 8 /* ADC for the microphone/input, DAC for the speaker/output */
mbed2f 0:27de5cbb4833 9 AnalogIn mic(p19);
mbed2f 0:27de5cbb4833 10 AnalogOut speaker(p18);
mbed2f 0:27de5cbb4833 11
mbed2f 0:27de5cbb4833 12 // Allocate a buffer to be used for the audio recording
mbed2f 0:27de5cbb4833 13 static const size_t BufferSize = 15 * 1066;
mbed2f 0:27de5cbb4833 14 static unsigned short Buffer[BufferSize];
mbed2f 0:27de5cbb4833 15 //int16_t Buffer[ 32768];
mbed2f 0:27de5cbb4833 16 //unsigned short Buffer[NUM_SAMPLES];
mbed2f 0:27de5cbb4833 17
mbed2f 0:27de5cbb4833 18
mbed2f 0:27de5cbb4833 19 int main(void)
mbed2f 0:27de5cbb4833 20 {
mbed2f 0:27de5cbb4833 21
mbed2f 0:27de5cbb4833 22 //int i;
mbed2f 0:27de5cbb4833 23 // for (i = 0; ; )
mbed2f 0:27de5cbb4833 24
mbed2f 0:27de5cbb4833 25 { unsigned short ReadSample = 0xFFFF;
mbed2f 0:27de5cbb4833 26 // Indices to track where the playback and recording should take place in the
mbed2f 0:27de5cbb4833 27 // audio buffer. The recording can occur one sample behind the current playback
mbed2f 0:27de5cbb4833 28 // index since it is no longer required.
mbed2f 0:27de5cbb4833 29 int Index = 0;
mbed2f 0:27de5cbb4833 30 // Reverse the direction the buffer is walked between each iteration to save memory
mbed2f 0:27de5cbb4833 31 int Direction = 1;
mbed2f 0:27de5cbb4833 32 // Have audio to playback
mbed2f 0:27de5cbb4833 33 int Playback = FALSE;
mbed2f 0:27de5cbb4833 34 // The amount of data to be recorded before starting reverse playback
mbed2f 0:27de5cbb4833 35 // NOTE: Probably want this to be configured at runtime via a knob, etc.
mbed2f 0:27de5cbb4833 36 //int ChunkSize = 9024;
mbed2f 0:27de5cbb4833 37 int ChunkSize = BufferSize;
mbed2f 0:27de5cbb4833 38 // Infinite loop of recording and reverse playback
mbed2f 0:27de5cbb4833 39 for (;;)
mbed2f 0:27de5cbb4833 40 {
mbed2f 0:27de5cbb4833 41 unsigned short PlaySample;
mbed2f 0:27de5cbb4833 42
mbed2f 0:27de5cbb4833 43 // Read out the sample from the buffer to be played back
mbed2f 0:27de5cbb4833 44 if (Playback)
mbed2f 0:27de5cbb4833 45 {
mbed2f 0:27de5cbb4833 46 PlaySample = Buffer[Index];
mbed2f 0:27de5cbb4833 47 speaker.write_u16(PlaySample);
mbed2f 0:27de5cbb4833 48 //i = (i+0) % NUM_SAMPLES;
mbed2f 0:27de5cbb4833 49
mbed2f 0:27de5cbb4833 50 //wait(0.2f);
mbed2f 0:27de5cbb4833 51 }
mbed2f 0:27de5cbb4833 52
mbed2f 0:27de5cbb4833 53 // Obtain current audio sample from the A/D converter.
mbed2f 0:27de5cbb4833 54 // NOTE: I am just faking these values in this sample with an incrementing value
mbed2f 0:27de5cbb4833 55 ReadSample = mic.read_u16();
mbed2f 0:27de5cbb4833 56
mbed2f 0:27de5cbb4833 57 // Record the sample into the buffer right where a space was freed up from the PlaySample read above
mbed2f 0:27de5cbb4833 58 Buffer[Index] = ReadSample += mic.read_u16();
mbed2f 0:27de5cbb4833 59
mbed2f 0:27de5cbb4833 60 // Increment the buffer pointer
mbed2f 0:27de5cbb4833 61 Index += Direction;
mbed2f 0:27de5cbb4833 62
mbed2f 0:27de5cbb4833 63 // Check to see if the chunk has been filled
mbed2f 0:27de5cbb4833 64 if (Index < 0)
mbed2f 0:27de5cbb4833 65 {
mbed2f 0:27de5cbb4833 66 // Now have a chunk to be played back
mbed2f 0:27de5cbb4833 67 Playback = TRUE;
mbed2f 0:27de5cbb4833 68 // Reverse the direction of playback and recording
mbed2f 0:27de5cbb4833 69 Direction *= -1;
mbed2f 0:27de5cbb4833 70 Index = 0;
mbed2f 0:27de5cbb4833 71 }
mbed2f 0:27de5cbb4833 72 else if (Index >= ChunkSize)
mbed2f 0:27de5cbb4833 73 {
mbed2f 0:27de5cbb4833 74 // Now have a chunk to be played back
mbed2f 0:27de5cbb4833 75 Playback = TRUE;
mbed2f 0:27de5cbb4833 76 // Reverse the direction of playback and recording
mbed2f 0:27de5cbb4833 77 Direction *= -1;
mbed2f 0:27de5cbb4833 78 Index = ChunkSize - 1;
mbed2f 0:27de5cbb4833 79 }
mbed2f 0:27de5cbb4833 80 }
mbed2f 0:27de5cbb4833 81 }
mbed2f 0:27de5cbb4833 82 }