<html> <head> <meta http-equiv="content-type" content="text/html; charset=utf-8"> </head> <body bgcolor="#FFFFFF" text="#000000"> Hi! In reference to <a class="moz-txt-link-freetext" href="https://github.com/jackaudio/example-clients">https://github.com/jackaudio/example-clients</a>: I saw the code as part of a question on Stackoverflow (<a class="moz-txt-link-freetext" href="http://stackoverflow.com/q/29748082/6544953">http://stackoverflow.com/q/29748082/6544953</a>). Would it be possible to include the source code below as an example? <ul> <li>There's already a midi controlled synth application in that repo (midisine.c). But I feel the example demonstrates in a clearer way how to send audio to the sound card's stereo output, because it just uses audio data, not audio data plus midi handling. </li> <li>There's also the simple client example (simple_client.c), but that one (effectively) handles bi-directional audio data streaming. This client just sends audio data which makes it clearer how to use data output (and, by implication, data input).</li> </ul> Long story in short - this example is clearer to n00bs (like me). Thank you for your consideration! <blockquote type="cite"> <pre style="" class="default prettyprint prettyprinted"><code>/** @file simple_client.c * * @brief This simple client demonstrates the basic features of JACK * as they would be used by many applications. */ #include <stdio.h> #include <errno.h> #include <stdlib.h> #include <string.h> #include <math.h> #include <signal.h> #ifndef WIN32 #include <unistd.h> #endif #include <jack/jack.h> jack_port_t *output_port1, *output_port2; jack_client_t *client; #ifndef M_PI #define M_PI (3.14159265) #endif #define TABLE_SIZE (200) typedef struct { float sine[TABLE_SIZE]; int left_phase; int right_phase; } paTestData; static void signal_handler(int sig) { jack_client_close(client); fprintf(stderr, "signal received, exiting ...\n"); exit(0); } /** * The process callback for this JACK application is called in a * special realtime thread once for each audio cycle. * * This client follows a simple rule: when the JACK transport is * running, copy the input port to the output. When it stops, exit. */ int process(jack_nframes_t nframes, void *arg) { jack_default_audio_sample_t *out1, *out2; paTestData *data = (paTestData*)arg; int i; out1 = (jack_default_audio_sample_t*)jack_port_get_buffer(output_port1, nframes); out2 = (jack_default_audio_sample_t*)jack_port_get_buffer(output_port2, nframes); for (i = 0; i<nframes; i++) { out1[i] = data->sine[data->left_phase]; // left out2[i] = data->sine[data->right_phase]; // right data->left_phase += 1; if (data->left_phase >= TABLE_SIZE) data->left_phase -= TABLE_SIZE; data->right_phase += 10; // higher pitch so we can distinguish left and right. if (data->right_phase >= TABLE_SIZE) data->right_phase -= TABLE_SIZE; } return 0; } /** * JACK calls this shutdown_callback 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[]) { const char **ports; const char *client_name; const char *server_name = NULL; jack_options_t options = JackNullOption; jack_status_t status; paTestData data; int i; /*if (argc >= 2) { // client name specified? client_name = argv[1]; if (argc >= 3) { // server name specified? server_name = argv[2]; int my_option = JackNullOption | JackServerName; options = (jack_options_t)my_option; } } else { // use basename of argv[0] client_name = strrchr(argv[0], '/'); if (client_name == 0) { client_name = argv[0]; } else { client_name++; } }*/ client_name = "mytest"; for (i = 0; i<TABLE_SIZE; i++) { data.sine[i] = 0.2 * (float)sin(((double)i / (double)TABLE_SIZE) * M_PI * 2.); } data.left_phase = data.right_phase = 0; // open a client connection to the JACK server client = jack_client_open(client_name, options, &status, server_name); if (client == NULL) { fprintf(stderr, "jack_client_open() failed, " "status = 0x%2.0x\n", status); if (status & JackServerFailed) { fprintf(stderr, "Unable to connect to JACK server\n"); } exit(1); } if (status & JackServerStarted) { fprintf(stderr, "JACK server started\n"); } if (status & JackNameNotUnique) { client_name = jack_get_client_name(client); fprintf(stderr, "unique name `%s' assigned\n", client_name); } // tell the JACK server to call `process()' whenever //there is work to be done. jack_set_process_callback(client, process, &data); // 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); // create two ports output_port1 = jack_port_register(client, "output1", JACK_DEFAULT_AUDIO_TYPE, JackPortIsOutput, 0); output_port2 = jack_port_register(client, "output2", JACK_DEFAULT_AUDIO_TYPE, JackPortIsOutput, 0); if ((output_port1 == NULL) || (output_port2 == NULL)) { fprintf(stderr, "no more JACK ports available\n"); exit(1); } //Tell the JACK server that we are ready to roll. Our // process() callback will start running now. if (jack_activate(client)) { fprintf(stderr, "cannot activate client"); exit(1); } // Connect the ports. You can't do this before the client is // activated, because we can't make connections to clients // that aren't running. Note the confusing (but necessary) // orientation of the driver backend ports: playback ports are // "input" to the backend, and capture ports are "output" from // it. ports = jack_get_ports(client, NULL, NULL, JackPortIsPhysical | JackPortIsInput); if (ports == NULL) { fprintf(stderr, "no physical playback ports\n"); exit(1); } if (jack_connect(client, jack_port_name(output_port1), ports[0])) { fprintf(stderr, "cannot connect output ports\n"); } if (jack_connect(client, jack_port_name(output_port2), ports[1])) { fprintf(stderr, "cannot connect output ports\n"); } jack_free(ports); // install a signal handler to properly quits jack client #ifdef WIN32 signal(SIGINT, signal_handler); signal(SIGABRT, signal_handler); signal(SIGTERM, signal_handler); #else signal(SIGQUIT, signal_handler); signal(SIGTERM, signal_handler); signal(SIGHUP, signal_handler); signal(SIGINT, signal_handler); #endif // keep running until the Ctrl+C while (1) { #ifdef WIN32 Sleep(1000); #else sleep(1); #endif } jack_client_close(client); exit(0); }</code></pre> </blockquote> </body> </html>