1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
|
/* $Id: patest_ringmix.c,v 1.1.1.1 2003-05-09 16:03:56 ggeiger Exp $ */
#include "stdio.h"
#include "portaudio.h"
/* This will be called asynchronously by the PortAudio engine. */
static int myCallback( void *inputBuffer, void *outputBuffer,
unsigned long framesPerBuffer, PaTimestamp outTime, void *userData )
{
float *out = (float *) outputBuffer;
float *in = (float *) inputBuffer;
float leftInput, rightInput;
unsigned int i;
if( inputBuffer == NULL ) return 0;
/* Read input buffer, process data, and fill output buffer. */
for( i=0; i<framesPerBuffer; i++ )
{
leftInput = *in++; /* Get interleaved samples from input buffer. */
rightInput = *in++;
*out++ = leftInput * rightInput; /* ring modulation */
*out++ = 0.5f * (leftInput + rightInput); /* mix */
}
return 0;
}
/* Open a PortAudioStream to input and output audio data. */
int main(void)
{
PortAudioStream *stream;
Pa_Initialize();
Pa_OpenDefaultStream(
&stream,
2, 2, /* stereo input and output */
paFloat32, 44100.0,
64, 0, /* 64 frames per buffer, let PA determine numBuffers */
myCallback, NULL );
Pa_StartStream( stream );
Pa_Sleep( 10000 ); /* Sleep for 10 seconds while processing. */
Pa_StopStream( stream );
Pa_CloseStream( stream );
Pa_Terminate();
return 0;
}
|
