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irmc/src/beep.c

171 lines
4.3 KiB

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <unistd.h> // for usleep()
#include <portaudio.h>
#include "beep.h"
#ifdef RASPI
#define RASPI_AUDIO_LATENCY_FIX (30./5.) // https://app.assembla.com/spaces/portaudio/tickets/246-paex_sine-choppy-on-raspberry-pi---defaultlowoutputlatency-too-low/details
#else
#define RASPI_AUDIO_LATENCY_FIX (1.)
#endif
// http://stackoverflow.com/questions/7678470/generating-sound-of-a-particular-frequency-using-gcc-in-ubuntu
static PaStream *stream;
static paTestData data;
/* This routine will be called by the PortAudio engine when audio is needed.
** It may called at interrupt level on some machines so don't do anything
** that could mess up the system like calling malloc() or free().
*/
static int patestCallback( const void *inputBuffer, void *outputBuffer,
unsigned long framesPerBuffer,
const PaStreamCallbackTimeInfo* timeInfo,
PaStreamCallbackFlags statusFlags,
void *userData )
{
paTestData *data = (paTestData*)userData;
uint8_t *out = (uint8_t*)outputBuffer;
unsigned long i;
uint32_t freq = data->freq;
(void) timeInfo; /* Prevent unused variable warnings. */
(void) statusFlags;
(void) inputBuffer;
for( i=0; i<framesPerBuffer; i++ )
{
if(data->up_count > 0 && data->total_count == data->up_count) {
*out++ = 0x00;
continue;
}
data->total_count++;
if(freq != data->prev_freq) {
data->counter = 0;
}
if(freq) {
int overflow_max = SAMPLE_RATE / freq;
uint32_t data_cnt = data->counter % overflow_max;
if(data_cnt > overflow_max/2)
*out++ = 0xff;
else {
*out++ = 0x00;
}
data->counter++;
}
else {
data->counter = 0;
*out++ = 0;
}
data->prev_freq = freq;
}
return paContinue;
}
void buzzer_set_freq(int frequency)
{
data.up_count = 0; // do not stop!
data.freq = frequency;
}
void buzzer_beep(int frequency, int msecs)
{
data.total_count = 0;
data.up_count = SAMPLE_RATE * msecs / 1000;
data.freq = frequency;
}
int buzzer_start(void)
{
PaStreamParameters outputParameters;
PaError err;
err = Pa_Initialize();
if( err != paNoError ) goto error;
outputParameters.device = Pa_GetDefaultOutputDevice(); /* default output device */
outputParameters.channelCount = 1; /* stereo output */
outputParameters.sampleFormat = paUInt8; /* 32 bit floating point output */
outputParameters.suggestedLatency = Pa_GetDeviceInfo( outputParameters.device )->defaultLowOutputLatency * RASPI_AUDIO_LATENCY_FIX;
outputParameters.hostApiSpecificStreamInfo = NULL;
err = Pa_OpenStream(
&stream,
NULL, /* no input */
&outputParameters,
SAMPLE_RATE,
FRAMES_PER_BUFFER,
paClipOff, /* we won't output out of range samples so don't bother clipping them */
patestCallback,
&data );
if( err != paNoError ) goto error;
err = Pa_StartStream( stream );
if( err != paNoError ) goto error;
return err;
error:
Pa_Terminate();
fprintf( stderr, "An error occured while using the portaudio stream\n" );
fprintf( stderr, "Error number: %d\n", err );
fprintf( stderr, "Error message: %s\n", Pa_GetErrorText( err ) );
return err;
}
int buzzer_stop()
{
PaError err = 0;
err = Pa_StopStream( stream );
if( err != paNoError ) goto error;
err = Pa_CloseStream( stream );
if( err != paNoError ) goto error;
Pa_Terminate();
return err;
error:
Pa_Terminate();
fprintf( stderr, "An error occured while using the portaudio stream\n" );
fprintf( stderr, "Error number: %d\n", err );
fprintf( stderr, "Error message: %s\n", Pa_GetErrorText( err ) );
return err;
}
void msleep(int d){
usleep(d*1000);
}
int beep(double freq_hz, double duration_sec)
{
buzzer_set_freq(freq_hz);
msleep(duration_sec*1000.);
buzzer_set_freq(0.);
return 0;
}
int beep_init()
{
buzzer_start();
return 0;
}
int beep_test(void)
{
buzzer_start();
buzzer_set_freq(261);
msleep(250);
buzzer_set_freq(0);
buzzer_stop();
return 0;
}