Code:
/* %: gcc latproc.c -o latproc -lfftw3f -lasound -lrt -ldl -lm */
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <sched.h>
#include <errno.h>
#include <getopt.h>
#include <alsa/asoundlib.h>
#include <sys/time.h>
#include <math.h>
#include <math.h>
char *pdevice = "hw:1,0";
char *cdevice = "hw:1,0";
snd_pcm_format_t format = SND_PCM_FORMAT_S16_LE;
int rate = 48000;
int channels = 2;
int buffer_size = 0; /* auto */
int period_size = 0; /* auto */
int latency_min ; /* in frames / 2 */
/* latency_min = 32, 64, 128,...., 1024, 2048, 8192, 16384, 32768 */
int latency_max = 32768; /* in frames / 2 */
int block = 1; /* block mode */
int use_poll = 0;
int resample = 1;
unsigned long loop_limit;
snd_output_t *output = NULL;
int doublecomp();
int floatcomp();
///////
double sine_array[480000];
int last_position = 0;
///////
int setparams_stream(snd_pcm_t *handle,
snd_pcm_hw_params_t *params,
const char *id)
{
int err;
unsigned int rrate;
err = snd_pcm_hw_params_any(handle, params);
if (err < 0) {
printf("Broken configuration for %s PCM: no configurations available: %s\n", snd_strerror(err), id);
return err;
}
err = snd_pcm_hw_params_set_rate_resample(handle, params, resample);
if (err < 0) {
printf("Resample setup failed for %s (val %i): %s\n", id, resample, snd_strerror(err));
return err;
}
err = snd_pcm_hw_params_set_access(handle, params, SND_PCM_ACCESS_RW_INTERLEAVED);
if (err < 0) {
printf("Access type not available for %s: %s\n", id, snd_strerror(err));
return err;
}
err = snd_pcm_hw_params_set_format(handle, params, format);
if (err < 0) {
printf("Sample format not available for %s: %s\n", id, snd_strerror(err));
return err;
}
err = snd_pcm_hw_params_set_channels(handle, params, channels);
if (err < 0) {
printf("Channels count (%i) not available for %s: %s\n", channels, id, snd_strerror(err));
return err;
}
rrate = rate;
err = snd_pcm_hw_params_set_rate_near(handle, params, &rrate, 0);
if (err < 0) {
printf("Rate %iHz not available for %s: %s\n", rate, id, snd_strerror(err));
return err;
}
if ((int)rrate != rate) {
printf("Rate doesn't match (requested %iHz, get %iHz)\n", rate, err);
return -EINVAL;
}
return 0;
}
int setparams_bufsize(snd_pcm_t *handle,
snd_pcm_hw_params_t *params,
snd_pcm_hw_params_t *tparams,
snd_pcm_uframes_t bufsize,
const char *id)
{
int err;
snd_pcm_uframes_t periodsize;
snd_pcm_hw_params_copy(params, tparams);
periodsize = bufsize * 2;
err = snd_pcm_hw_params_set_buffer_size_near(handle, params, &periodsize);
if (err < 0) {
printf("Unable to set buffer size %li for %s: %s\n", bufsize * 2, id, snd_strerror(err));
return err;
}
if (period_size > 0)
periodsize = period_size;
else
periodsize /= 2;
err = snd_pcm_hw_params_set_period_size_near(handle, params, &periodsize, 0);
if (err < 0) {
printf("Unable to set period size %li for %s: %s\n", periodsize, id, snd_strerror(err));
return err;
}
return 0;
}
int setparams_set(snd_pcm_t *handle,
snd_pcm_hw_params_t *params,
snd_pcm_sw_params_t *swparams,
const char *id)
{
int err;
snd_pcm_uframes_t val;
err = snd_pcm_hw_params(handle, params);
if (err < 0) {
printf("Unable to set hw params for %s: %s\n", id, snd_strerror(err));
return err;
}
err = snd_pcm_sw_params_current(handle, swparams);
if (err < 0) {
printf("Unable to determine current swparams for %s: %s\n", id, snd_strerror(err));
return err;
}
err = snd_pcm_sw_params_set_start_threshold(handle, swparams, 0x7fffffff);
if (err < 0) {
printf("Unable to set start threshold mode for %s: %s\n", id, snd_strerror(err));
return err;
}
if (!block)
val = 4;
else
snd_pcm_hw_params_get_period_size(params, &val, NULL);
err = snd_pcm_sw_params_set_avail_min(handle, swparams, val);
if (err < 0) {
printf("Unable to set avail min for %s: %s\n", id, snd_strerror(err));
return err;
}
err = snd_pcm_sw_params(handle, swparams);
if (err < 0) {
printf("Unable to set sw params for %s: %s\n", id, snd_strerror(err));
return err;
}
return 0;
}
int setparams(snd_pcm_t *phandle, snd_pcm_t *chandle, int *bufsize)
{
int err, last_bufsize = *bufsize;
snd_pcm_hw_params_t *pt_params, *ct_params; /* templates with rate, format and channels */
snd_pcm_hw_params_t *p_params, *c_params;
snd_pcm_sw_params_t *p_swparams, *c_swparams;
snd_pcm_uframes_t p_size, c_size, p_psize, c_psize;
unsigned int p_time, c_time;
unsigned int val;
snd_pcm_hw_params_alloca(&p_params);
snd_pcm_hw_params_alloca(&c_params);
snd_pcm_hw_params_alloca(&pt_params);
snd_pcm_hw_params_alloca(&ct_params);
snd_pcm_sw_params_alloca(&p_swparams);
snd_pcm_sw_params_alloca(&c_swparams);
if ((err = setparams_stream(phandle, pt_params, "playback")) < 0) {
printf("Unable to set parameters for playback stream: %s\n", snd_strerror(err));
exit(0);
}
if ((err = setparams_stream(chandle, ct_params, "capture")) < 0) {
printf("Unable to set parameters for playback stream: %s\n", snd_strerror(err));
exit(0);
}
if (buffer_size > 0) {
*bufsize = buffer_size;
goto __set_it;
}
__again:
if (buffer_size > 0)
return -1;
if (last_bufsize == *bufsize)
*bufsize += 4;
last_bufsize = *bufsize;
if (*bufsize > latency_max)
return -1;
__set_it:
if ((err = setparams_bufsize(phandle, p_params, pt_params, *bufsize, "playback")) < 0) {
printf("Unable to set sw parameters for playback stream: %s\n", snd_strerror(err));
exit(0);
}
if ((err = setparams_bufsize(chandle, c_params, ct_params, *bufsize, "capture")) < 0) {
printf("Unable to set sw parameters for playback stream: %s\n", snd_strerror(err));
exit(0);
}
snd_pcm_hw_params_get_period_size(p_params, &p_psize, NULL);
if (p_psize > (unsigned int)*bufsize)
*bufsize = p_psize;
snd_pcm_hw_params_get_period_size(c_params, &c_psize, NULL);
if (c_psize > (unsigned int)*bufsize)
*bufsize = c_psize;
snd_pcm_hw_params_get_period_time(p_params, &p_time, NULL);
snd_pcm_hw_params_get_period_time(c_params, &c_time, NULL);
if (p_time != c_time)
goto __again;
snd_pcm_hw_params_get_buffer_size(p_params, &p_size);
if (p_psize * 2 < p_size) {
snd_pcm_hw_params_get_periods_min(p_params, &val, NULL);
if (val > 2) {
printf("playback device does not support 2 periods per buffer\n");
exit(0);
}
goto __again;
}
snd_pcm_hw_params_get_buffer_size(c_params, &c_size);
if (c_psize * 2 < c_size) {
snd_pcm_hw_params_get_periods_min(c_params, &val, NULL);
if (val > 2 ) {
printf("capture device does not support 2 periods per buffer\n");
exit(0);
}
goto __again;
}
if ((err = setparams_set(phandle, p_params, p_swparams, "playback")) < 0) {
printf("Unable to set sw parameters for playback stream: %s\n", snd_strerror(err));
exit(0);
}
if ((err = setparams_set(chandle, c_params, c_swparams, "capture")) < 0) {
printf("Unable to set sw parameters for playback stream: %s\n", snd_strerror(err));
exit(0);
}
if ((err = snd_pcm_prepare(phandle)) < 0) {
printf("Prepare error: %s\n", snd_strerror(err));
exit(0);
}
snd_pcm_dump(phandle, output);
snd_pcm_dump(chandle, output);
fflush(stdout);
return 0;
}
long readbuf(snd_pcm_t *handle, short *buf, long len, size_t *frames, size_t *max)
{
long r=0,hitung=0;
int frame_bytes = (snd_pcm_format_width(format) / 8) * channels;
do {
printf("hitung= %ld; len= %ld; r= %ld\n",hitung++,len,r);
r = snd_pcm_readi(handle, buf, len);
if (r > 0) {
buf += r * frame_bytes;
len -= r;
*frames += r;
if ((long)*max < r)
*max = r;
}
printf("hitung= %ld; len= %ld; r= %ld\n",hitung++,len,r);
} while (r >= 1 && len > 0);
return r;
}
long writebuf(snd_pcm_t *handle, short *buf, long len, size_t *frames)
{
long r;
while (len > 0) {
r = snd_pcm_writei(handle, buf, len);
if (r == -EAGAIN)
continue;
if (r < 0)
return r;
buf += r * 4;
len -= r;
*frames += r;
}
return 0;
}
void pan_v2(short *buffer, int r, double a) {
int i;
int latency_max = 32768;
int buflen=latency_max/32; //default: 32 for latency 512
double depth = 1.0, xbuf;
double LVOL = 0;
double RVOL = 0;
LVOL = 1-a; //Modulator signal value 0 = center panning
RVOL = 1+a; //Modulator signal value 0 = center panning
for (i=0;i<buflen;i++) {
if(i%2==0) /* Left channel */ {
xbuf= (double)buffer[i]*(double)(LVOL);
buffer[i]=(int16_t)(xbuf);
}
else /* Right channel */ {
xbuf= (double)buffer[i]*(double)(RVOL);
buffer[i]=(int16_t)(xbuf);
}
}
}
int main()
{
snd_pcm_t *phandle, *chandle;
short *buffer;
int err, latency, morehelp;
snd_timestamp_t p_tstamp, c_tstamp;
ssize_t r;
size_t frames_in, frames_out, in_max;
int effect = 0;
morehelp = 0;
//////////////////////////////////////////////// Generating the Sine Array
double target_frequency = 0.5; //Target Frequency
double converted_frequency = 250.0*target_frequency; //for some reason 1 Hz = 250
double dpi;
int sampling_rate = 48000.0;
double pi = M_PI;
double temp_value = 0;
dpi = (2.0*pi)*(converted_frequency/sampling_rate);
for(int i=i;i<48000;i++) {
temp_value = (double)sin(dpi*(double)i);
sine_array[i] = (double)temp_value;
}
//////////////////////////////////////////////////////////////////////////
printf("\n\n");
printf(
"Tip #1 (usable latency with large periods, non-blocking mode, good CPU usage,\n"
" superb xrun prevention):\n"
" latency -m 8192 -M 8192 -t 1 -p\n"
"Tip #2 (superb latency, non-blocking mode, but heavy CPU usage):\n"
" latency -m 128 -M 128\n"
);
printf("\n");
latency_min = 512; //Fixed latency setting
err = snd_output_stdio_attach(&output, stdout, 0);
if (err < 0) {
printf("Output failed: %s\n", snd_strerror(err));
return 0;
}
latency = latency_min - 4;
/*--------------------------------- penting ----------------------*/
buffer = malloc((latency_max * snd_pcm_format_width(format) / 8) * 2);
/*----------------------------------------------------------------*/
printf("Playback device is %s\n", pdevice);
printf("Capture device is %s\n", cdevice);
printf("Parameters are %iHz, %s, %i channels, %s mode\n",
rate, snd_pcm_format_name(format), channels, block ? "blocking" : "non-blocking");
printf("Poll mode: %s\n", use_poll ? "yes" : "no");
if ((err = snd_pcm_open(&phandle, pdevice, SND_PCM_STREAM_PLAYBACK, block ? 0 : SND_PCM_NONBLOCK)) < 0) {
printf("Playback open error: %s\n", snd_strerror(err));
return 0;
}
if ((err = snd_pcm_open(&chandle, cdevice, SND_PCM_STREAM_CAPTURE, block ? 0 : SND_PCM_NONBLOCK)) < 0) {
printf("Record open error: %s\n", snd_strerror(err));
return 0;
}
while (1) {
frames_in = frames_out = 0;
if (setparams(phandle, chandle, &latency) < 0)
break;
if ((err = snd_pcm_link(chandle, phandle)) < 0) {
printf("Streams link error: %s\n", snd_strerror(err));
exit(0);
}
if (snd_pcm_format_set_silence(format, buffer, latency*channels) < 0) {
fprintf(stderr, "silence error\n");
break;
}
if (writebuf(phandle, buffer, latency, &frames_out) < 0) {
fprintf(stderr, "write error\n");
break;
}
if (writebuf(phandle, buffer, latency, &frames_out) < 0) {
fprintf(stderr, "write error\n");
break;
}
if ((err = snd_pcm_start(chandle)) < 0) {
printf("Go error: %s\n", snd_strerror(err));
exit(0);
}
in_max = 0;
int lp = 0;
double a = 0;
double depth = 1.0;
short audio_buffer_out[480000] = {0};
FILE *f;
while (1) {
r = readbuf(chandle, buffer, latency, &frames_in, &in_max); /* capture audio from mic */
a = sine_array[lp];
pan_v2(buffer,r,a); //Apply Panning
audio_buffer_out[lp] = buffer; //Save data from ALSA buffer
writebuf(phandle, buffer, r, &frames_out); //output panned audio from ALSA buffer
if(lp == 1000) {
printf("\nWriting to raw file\n");
f = fopen("./pan_output.raw","wb");
if(f==NULL) {
printf("\nfile error\n");
exit(1);
}
fwrite(&audio_buffer_out,sizeof(short),1,f);
fclose(f);
printf("Done\n");
exit(0);
}
lp++; //Modulator Signal Array Index
printf("Sine Array Index: %d\n",lp);
}
printf("Hardware sync\n");
snd_pcm_drop(chandle);
snd_pcm_nonblock(phandle, 0);
snd_pcm_drain(phandle);
snd_pcm_nonblock(phandle, !block ? 1 : 0);
snd_pcm_unlink(chandle);
snd_pcm_hw_free(phandle);
snd_pcm_hw_free(chandle);
}
snd_pcm_close(phandle);
snd_pcm_close(chandle);
return 0;
}
Writing raw audio file from ALSA audio buffer
