/*************************************************************************** * jack-skeleton * * This program is a skeleton program to use to get data from a Jack * source to process. * * Written: * May 2013 * by Rob Frohne * e-mail: Rob "dot" Frohne "at sign" wallawalla "dot" edu * ****************************************************************************/ /* To build this program, you must have jack audio connection kit installed. * At the command prompt: * $ gcc jack-skeleton.c -ljack -o jack-skeleton */ /* * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ #include #include #include #include #include #include #include #include #include #include #include /* global jack variables. */ jack_client_t *test_client; jack_port_t *audio_input_port_left, *audio_input_port_right; /* To use this command, you need to $ jack-skeleton * assuming those are the options you want. * Options are: * -? for help * -v or --verbose for verbose response. */ /* Flag set by ‘--verbose’. */ static int verbose_flag; // Specify options and their syntax static struct option long_options[] = { /* These options set a flag. */ {"verbose", no_argument, &verbose_flag, 1}, {"brief", no_argument, &verbose_flag, 0}, /* These options don't set a flag. We distinguish them by their indices. */ {"help", no_argument, 0, '?'}, {0, 0, 0, 0} }; /* Close things opened. */ void cleanup(void) { if(test_client != NULL) { jack_deactivate(test_client); jack_client_close(test_client); } } /* This is the function that is called when and if jackd shuts down. */ void jack_shutdown (void *arg) { fprintf (stderr, "JACK shutdown\n"); cleanup(); abort(); } /* This is the callback process that gets data from jack.*/ int process(jack_nframes_t number_of_frames, void *arg) { //Use static variables if you want to save things between calls to // this process. jack_default_audio_sample_t *sample_buffer_left = (jack_default_audio_sample_t *) jack_port_get_buffer(audio_input_port_left, number_of_frames); jack_default_audio_sample_t *sample_buffer_right = (jack_default_audio_sample_t *) jack_port_get_buffer(audio_input_port_right, number_of_frames); jack_nframes_t i; //This is where you get your data in the format that the program using /dev/dsp needs it. for(i = 0; i < number_of_frames; i++){ // This is where you process your data. } return 0; } int main (int argc, char *argv[]){ int error; char * fifo_name = PIPE_NAME; // Iterate over options and handle each one as appropriate int c; // The function getopt_long stores the option index here. int option_index = 0; while ( (c = getopt_long ( argc, argv, "v?f:", long_options, &option_index )) != -1 ) { switch ( c ) { case 0: // If this option set a flag, do nothing else now. if ( long_options[option_index].flag != 0 ) break; case 'v': verbose_flag = 1; break; case '?': default : printf( "Options are: \n" "-v or --verbose for verbose output\n" "Typing EOF (ctrl-D) (ctrl-capitol D, to be exact) will end the program.\n"); exit ( 0 ); } } //Create a new jack client, then make sure everything went ok. test_client = jack_client_open("Test Client",(jack_options_t)(!JackServerName),NULL); if (test_client == 0) { fprintf(stderr,"Cannot connect to the jackd as a client.\n"); cleanup(); return 1; } /* Set up Jack */ //Set up the jack shutdown routine in case we want to do something special on shutdown of jack. jack_on_shutdown (test_client, jack_shutdown, 0); //Create and register new audio input ports. audio_input_port_left = jack_port_register(test_client, "Audio FIFO Port_left", JACK_DEFAULT_AUDIO_TYPE, JackPortIsInput, 0); if (audio_input_port_left == NULL) { fprintf(stderr, "Error: jack_port_register returned NULL for left channel.\n"); cleanup(); return 1; } audio_input_port_right = jack_port_register(test_client, "Audio FIFO Port_right", JACK_DEFAULT_AUDIO_TYPE, JackPortIsInput, 0); if (audio_input_port_right == NULL) { fprintf(stderr, "Error: jack_port_register returned NULL for right channel.\n"); cleanup(); return 1; } //Tell the jackd server what function call when it wants more audio data. if((error = jack_set_process_callback(test_client, process, &pipe_handle)) != 0) { fprintf(stderr, "Jack could not set the callback, (error %i).\n", error); cleanup(); return 1; } //Tell jack it's ok to start asking us for audio data. if((error = jack_activate(test_client)) != 0) { fprintf(stderr, "Jack could not activate the client (error %i).\n", error); cleanup(); return 1; } else if(verbose_flag) fprintf(stderr,"Activated client.\n"); //Connect the ports. if (jack_connect (test_client,"system:capture_1", jack_port_name (audio_input_port_left))) { fprintf (stderr, "cannot connect port: system:capture_1\n"); } else if(verbose_flag) fprintf(stderr, "Connected to port: system:capture_1\n"); if (jack_connect (test_client,"system:capture_2", jack_port_name (audio_input_port_right))) { fprintf (stderr, "cannot connect port: system:capture_2\n"); } else if(verbose_flag) fprintf(stderr, "Connected to port: system:capture_2\n"); while(getchar() != EOF){ //Quit on ctrl-D. } /* Close things opened. */ cleanup(); return 0; }