www.pudn.com > lib.zip > myaudio.C

#include  
#include  
#include  
 
#include "private.h" 
#include "myaudio.h" 
 
static audio *Audio; 
static coroutine *pco; 
 
static audio_pval pvals[] = 
  { { AU_INPUT_RATE, AU_RATE_9600    }, 
    { AU_OUTPUT_RATE, AU_RATE_9600   }, 
    { AU_INPUT_SOURCE, AU_INPUT_LINE }, 
    { AU_LEFT_INPUT_ATTEN, 0	     }, 
    { AU_RIGHT_INPUT_ATTEN, 0	     }, 
    { AU_SPEAKER_MUTE_CTL, 1	     }, 
    { AU_MONITOR_CTL, 0		     }, 
    { -1, -1			     }, 
  }; 
 
global int samplecount; 
 
global void openaudio() 
  { Audio = new audio(AU_IN | AU_OUT | AU_LOCK | AU_SAVE, pvals); 
    pco = NULL; samplecount = 0; 
  } 
 
global void closeaudio() 
  { delete Audio; 
  } 
 
global void setduplex(int n) 
  { Audio -> setduplex(n); 
  } 
 
global void discardinput() 
  { Audio -> idiscard(); 
  } 
 
global void discardoutput() 
  { Audio -> odiscard(); 
  } 
 
global void flushoutput() 
  { Audio -> oflush(); 
  } 
 
global void inparallel(coroutine *co1, coroutine *co2) 
  { coroutine *spco = pco; 
    pco = co1; 
    callco(co2); 
    pco = spco; 
  } 
 
inline void swapit() 
  { coroutine *p = pco; 
    if (p != NULL) 
      { pco = currentco; 
	callco(p); 
      } 
  } 
 
global float insample() 
  { swapit(); 
    samplecount++; 
    return (float) (Audio -> read() * 2e-6f); 
  } 
 
global void outsample(float x) 
  { swapit(); 
    if (x > 2.0f || x < -2.0f) 
      { fprintf(stderr, "outsample value out of range: %f\r\n", x); 
	abort(); 
      } 
    Audio -> write((int) (x * 2e6f));	/* hardware accepts signed 24-bit but reduce to limit power to line */ 
  }