test.c

#include <stdlib.h>
#include <stdio.h>
#include <stdbool.h>
#include <errno.h>
#include <unistd.h>
#include <math.h>
#include <getopt.h>
#include <string.h>
#include <wchar.h>
#include <locale.h>

#include <jack/jack.h>
#include <jack/transport.h>

typedef jack_default_audio_sample_t sample_t;


char *client_name;
jack_client_t *client;
jack_port_t *output_port_l;
jack_port_t *output_port_r;
jack_port_t *input_port_l;
jack_port_t *input_port_r;

int process(jack_nframes_t nframes, void *arg) {
        sample_t *outBufferLeft = (sample_t *) jack_port_get_buffer(output_port_l, nframes);
        sample_t *outBufferRight = (sample_t *) jack_port_get_buffer(output_port_r, nframes);
        sample_t *inBufferLeft = (sample_t *) jack_port_get_buffer(input_port_l, nframes);
        sample_t *inBufferRight = (sample_t *) jack_port_get_buffer(input_port_r, nframes);

        memcpy(outBufferLeft, inBufferLeft, sizeof(sample_t) * nframes);
        memcpy(outBufferRight, inBufferRight, sizeof(sample_t) * nframes);

        double total = 0;
        for (int i = 0; i < nframes; i++) {
                total += pow(outBufferLeft[i], 2);
        }
        if (total / nframes > 0.025) {
                printf("\n111111111111111111");
        } else {
                printf("\n000000000000000000");
        }

        return 0;
}

int sample_rate_change() {
        printf("Sample rate has changed! Exiting...\n");
        exit(-1);
}

bool startClient() {
        jack_status_t status;
        while ((client = jack_client_open(client_name, JackNoStartServer, &status)) == 0) {
                fprintf(stderr, "jack server not running?\n");
                //return false;
        }
        printf("Client started\n");
        return true;
}

void createPorts() {
        output_port_l = jack_port_register(client, "lag_out_l", JACK_DEFAULT_AUDIO_TYPE, JackPortIsOutput, 0);
        output_port_r = jack_port_register(client, "lag_out_r", JACK_DEFAULT_AUDIO_TYPE, JackPortIsOutput, 0);
        input_port_l = jack_port_register(client, "lag_in_l", JACK_DEFAULT_AUDIO_TYPE, JackPortIsInput, 0);
        input_port_r = jack_port_register(client, "lag_in_r", JACK_DEFAULT_AUDIO_TYPE, JackPortIsInput, 0);
        printf("Ports created\n");
}

void connectPorts() {
        jack_connect(client, "PulseAudio JACK Sink:front-left", jack_port_name(input_port_l));
        jack_connect(client, "PulseAudio JACK Sink:front-right", jack_port_name(input_port_r));

        jack_connect(client, jack_port_name(output_port_l), "system:playback_1");
        jack_connect(client, jack_port_name(output_port_r), "system:playback_2");

        printf("Ports connected\n");
}

int main(int argc, char *argv[]) {
        client_name = "Visualizer";

        if (!startClient()) {
                return -1;
        }

        createPorts();

        jack_set_process_callback(client, process, 0);

        if (jack_activate(client)) {
                fprintf(stderr, "cannot activate client");
                return 1;
        }
        printf("Jack activated\n");

        connectPorts();

        const char **port_names = jack_get_ports(client, NULL, NULL, 0);
        for (int j = 0; port_names[j] != NULL; j++) {
                printf("%s\n", port_names[j]);
        }

        while (true) {
                sleep(1);
        }
}