/** @file simple_client.c * * @brief This is very simple client that demonstrates the basic * features of JACK as they would be used by many applications. */ #include #include #include #include #include #include jack_port_t *input_port; jack_port_t *output_port; /** * The process callback for this JACK application. * It is called by JACK at the appropriate times. */ int process (jack_nframes_t nframes, void *arg) { jack_default_audio_sample_t *out = (jack_default_audio_sample_t *) jack_port_get_buffer (output_port, nframes); jack_default_audio_sample_t *in = (jack_default_audio_sample_t *) jack_port_get_buffer (input_port, nframes); memcpy (out, in, sizeof (jack_default_audio_sample_t) * nframes); return 0; } /** * This is the shutdown callback for this JACK application. * It is called by JACK if the server ever shuts down or * decides to disconnect the client. */ void jack_shutdown (void *arg) { exit (1); } int main (int argc, char *argv[]) { jack_client_t *client; const char **ports; if (argc < 2) { fprintf (stderr, "usage: jack_simple_client \n"); return 1; } /* try to become a client of the JACK server */ if ((client = jack_client_new (argv[1])) == 0) { fprintf (stderr, "jack server not running?\n"); return 1; } /* tell the JACK server to call `process()' whenever there is work to be done. */ jack_set_process_callback (client, process, 0); /* tell the JACK server to call `jack_shutdown()' if it ever shuts down, either entirely, or if it just decides to stop calling us. */ jack_on_shutdown (client, jack_shutdown, 0); /* display the current sample rate. */ printf ("engine sample rate: %" PRIu32 "\n", jack_get_sample_rate (client)); /* create two ports */ input_port = jack_port_register (client, "input", JACK_DEFAULT_AUDIO_TYPE, JackPortIsInput, 0); output_port = jack_port_register (client, "output", JACK_DEFAULT_AUDIO_TYPE, JackPortIsOutput, 0); /* tell the JACK server that we are ready to roll */ if (jack_activate (client)) { fprintf (stderr, "cannot activate client"); return 1; } /* connect the ports. Note: you can't do this before the client is activated, because we can't allow connections to be made to clients that aren't running. */ if ((ports = jack_get_ports (client, NULL, NULL, JackPortIsPhysical|JackPortIsOutput)) == NULL) { fprintf(stderr, "Cannot find any physical capture ports\n"); exit(1); } if (jack_connect (client, ports[0], jack_port_name (input_port))) { fprintf (stderr, "cannot connect input ports\n"); } free (ports); if ((ports = jack_get_ports (client, NULL, NULL, JackPortIsPhysical|JackPortIsInput)) == NULL) { fprintf(stderr, "Cannot find any physical playback ports\n"); exit(1); } if (jack_connect (client, jack_port_name (output_port), ports[0])) { fprintf (stderr, "cannot connect output ports\n"); } free (ports); /* Since this is just a toy, run for a few seconds, then finish */ sleep (10); jack_client_close (client); exit (0); }