///////////////////////////////////////////////////////////////////////////////////
//
//
///////////////////////////////////////////////////////////////////////////////////
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sched.h>
#include <errno.h>
#include <getopt.h>
#include <alsa/asoundlib.h>
#include <sys/time.h>
#include <math.h>
static char *device = "plughw:0,0"; /* playback device */
static snd_pcm_format_t format = SND_PCM_FORMAT_S16; /* sample format */
static unsigned int rate = 48000; /* stream rate */
static unsigned int buffer_time = 130000; /* ring buffer length in us */
static unsigned int period_time = 100000; /* period time in us */
static int verbose = 0; /* verbose flag */
static int resample = 1; /* enable alsa-lib resampling */
static int period_event = 0; /* produce poll event after each period */
static snd_pcm_sframes_t buffer_size; // size of buffer at sound card
static snd_pcm_sframes_t period_size; //samples per frame
static snd_output_t *output = NULL;
#define MAX_BINS 8
int sample_count;
double q0;
double q1[MAX_BINS];
double q2[MAX_BINS];
double r[MAX_BINS];
double coefs[MAX_BINS] ;
FILE *out;
double freqs[MAX_BINS] =
{
697,
770,
852,
941,
1209,
1336,
1477,
1633
};
/*----------------------------------------------------------------------------
* calc_coeffs
*----------------------------------------------------------------------------
* This is where we calculate the correct co-efficients.
*/
/*
* coef = 2.0 * cos( (2.0 * PI * k) / (float)GOERTZEL_N)) ;
* Where k = (int) (0.5 + ((float)GOERTZEL_N * target_freq) / SAMPLING_RATE));
*
* More simply: coef = 2.0 * cos( (2.0 * PI * target_freq) / SAMPLING_RATE );
*/
void calc_coeffs()
{
int n;
for(n = 0; n < MAX_BINS; n++)
{
coefs[n] = 2.0 * cos(2.0 * M_PI * freqs[n] / rate);
}
}
static int set_hwparams(snd_pcm_t *handle, snd_pcm_hw_params_t *params, unsigned int channels)
{
unsigned int rrate;
snd_pcm_uframes_t size;
int err, dir;
/* choose all parameters */
err = snd_pcm_hw_params_any(handle, params);
if (err < 0) {
printf("Broken configuration for playback: no configurations available: %s\n", snd_strerror(err));
return err;
}
/* set hardware resampling */
err = snd_pcm_hw_params_set_rate_resample(handle, params, resample);
if (err < 0) {
printf("Resampling setup failed for playback: %s\n", snd_strerror(err));
return err;
}
/* set the interleaved read/write format */
err = snd_pcm_hw_params_set_access(handle, params, SND_PCM_ACCESS_RW_INTERLEAVED);
if (err < 0) {
printf("Access type not available for playback: %s\n", snd_strerror(err));
return err;
}
/* set the sample format */
err = snd_pcm_hw_params_set_format(handle, params, format);
if (err < 0) {
printf("Sample format not available for playback: %s\n", snd_strerror(err));
return err;
}
/* set the count of channels */
err = snd_pcm_hw_params_set_channels(handle, params, channels);
if (err < 0) {
printf("Channels count (%i) not available for playbacks: %s\n", channels, snd_strerror(err));
return err;
}
/* set the stream rate */
rrate = rate;
err = snd_pcm_hw_params_set_rate_near(handle, params, &rrate, 0);
if (err < 0) {
printf("Rate %iHz not available for playback: %s\n", rate, snd_strerror(err));
return err;
}
if (rrate != rate) {
printf("Rate doesn't match (requested %iHz, get %iHz)\n", rate, err);
return -EINVAL;
}
else printf("Rate set to %i Hz\n", rate, err);
/* set the buffer time */
err = snd_pcm_hw_params_set_buffer_time_near(handle, params, &buffer_time, &dir);
if (err < 0) {
printf("Unable to set buffer time %i for playback: %s\n", buffer_time, snd_strerror(err));
return err;
}
err = snd_pcm_hw_params_get_buffer_size(params, &size);
if (err < 0) {
printf("Unable to get buffer size for playback: %s\n", snd_strerror(err));
return err;
}
buffer_size = size;
/* set the period time */
err = snd_pcm_hw_params_set_period_time_near(handle, params, &period_time, &dir);
if (err < 0) {
printf("Unable to set period time %i for playback: %s\n", period_time, snd_strerror(err));
return err;
}
err = snd_pcm_hw_params_get_period_size(params, &size, &dir);
if (err < 0) {
printf("Unable to get period size for playback: %s\n", snd_strerror(err));
return err;
}
period_size = size;
/* write the parameters to device */
err = snd_pcm_hw_params(handle, params);
if (err < 0) {
printf("Unable to set hw params for playback: %s\n", snd_strerror(err));
return err;
}
return 0;
}
static int set_swparams(snd_pcm_t *handle, snd_pcm_sw_params_t *swparams)
{
int err;
/* get the current swparams */
err = snd_pcm_sw_params_current(handle, swparams);
if (err < 0) {
printf("Unable to determine current swparams for playback: %s\n", snd_strerror(err));
return err;
}
/* start the transfer when the buffer is almost full: */
/* (buffer_size / avail_min) * avail_min */
err = snd_pcm_sw_params_set_start_threshold(handle, swparams, (buffer_size / period_size) * period_size);
if (err < 0) {
printf("Unable to set start threshold mode for playback: %s\n", snd_strerror(err));
return err;
}
/* allow the transfer when at least period_size samples can be processed */
/* or disable this mechanism when period event is enabled (aka interrupt like style processing) */
err = snd_pcm_sw_params_set_avail_min(handle, swparams, period_event ? buffer_size : period_size);
if (err < 0) {
printf("Unable to set avail min for playback: %s\n", snd_strerror(err));
return err;
}
/* enable period events when requested */
if (period_event) {
err = snd_pcm_sw_params_set_period_event(handle, swparams, 1);
if (err < 0) {
printf("Unable to set period event: %s\n", snd_strerror(err));
return err;
}
}
/* write the parameters to the playback device */
err = snd_pcm_sw_params(handle, swparams);
if (err < 0) {
printf("Unable to set sw params for playback: %s\n", snd_strerror(err));
return err;
}
return 0;
}
struct async_private_data {
signed short *samples;
snd_pcm_channel_area_t *areas;
unsigned int period;
};
/////////// CALL BACK STUFF ///////////////////
static void async_capture_callback(snd_async_handler_t *ahandler)
{
snd_pcm_t *handle = snd_async_handler_get_pcm(ahandler);
int err;
short signal[100000];
unsigned int n,i;
while (snd_pcm_avail_update(handle) >= period_size) { // read until data is ready in buffer
err = snd_pcm_readi(handle, (signal), period_size);
if (err < 0) {
printf("Read error: %s\n", snd_strerror(err));
exit(EXIT_FAILURE);
}
if (err != period_size) {
printf("Read error: red %i expected %li\n", err, period_size);
exit(EXIT_FAILURE);
}
for ( n=0; n<period_size; n+=2 ){
for ( i=0; i<MAX_BINS; i++ )
{
q0 = coefs[i] * q1[i] - q2[i] + signal[n];
q2[i] = q1[i];
q1[i] = q0;
}
}
for ( i=0; i<MAX_BINS; i++ )
{
r[i] = (q1[i] * q1[i]) + (q2[i] * q2[i]) - (coefs[i] * q1[i] * q2[i]);
q1[i] = 0.0;
q2[i] = 0.0;
}
out=fopen("./output.txt","a");
for(i=0;i<MAX_BINS;i++) fprintf(out,"%6f ",r[i]);
fprintf(out,"\n");
fclose(out);
}
}
int main(int argc, char *argv[])
{
snd_pcm_t *playback_handle, *capture_handle;
int err;
snd_pcm_hw_params_t *hwparams;
snd_pcm_sw_params_t *swparams;
signed short *frame; // pointer to array of samples
unsigned int chn;
snd_pcm_channel_area_t *areas;
struct async_private_data data;
snd_async_handler_t *chandler, *phandler;
int count;
unsigned int i,j;
snd_pcm_hw_params_alloca(&hwparams);
snd_pcm_sw_params_alloca(&swparams);
printf("SID monitor 2.0 starting work.. \n");
//open and set capture device
if ((err = snd_pcm_open(&capture_handle, device, SND_PCM_STREAM_CAPTURE, 0)) < 0) {
printf("Playback open error: %s\n", snd_strerror(err));
return 0;
}
if ((err = set_hwparams(capture_handle, hwparams, 2)) < 0) {
printf("Setting of hwparams failed: %s\n", snd_strerror(err));
exit(EXIT_FAILURE);
}
if ((err = set_swparams(capture_handle, swparams)) < 0) {
printf("Setting of swparams failed: %s\n", snd_strerror(err));
exit(EXIT_FAILURE);
}
// register capture callback
err = snd_async_add_pcm_handler(&chandler, capture_handle, async_capture_callback, &data); // fill by dummy &data
if (err < 0) {
printf("Unable to register async handler\n");
exit(EXIT_FAILURE);
}
calc_coeffs();
//start capture
if ((err = snd_pcm_prepare (capture_handle)) < 0) {
fprintf (stderr, "cannot prepare audio interface for use (%s)\n",
snd_strerror (err));
exit (1);
}
err = snd_pcm_start(capture_handle);
if (err < 0) {
printf("Start error: %s\n", snd_strerror(err));
exit(EXIT_FAILURE);
}
//wait until all samples aren't transmitted
printf("processing audio input.. \n");
for (i=0; i<5000; i++) usleep( 1000);
snd_pcm_close(capture_handle);
return 0;
}
