split transport functionality out of simple client, to make it really SIMPLE; copy old simple client to "transport client"; update commentary in both files; use $(top_builddir) rather than .. to refer to libjack

git-svn-id: svn+ssh://jackaudio.org/trunk/jack@3113 0c269be4-1314-0410-8aa9-9f06e86f4224

example-clients/Makefile.am

@@ -1,6 +1,7 @@
 MAINTAINERCLEANFILES    = Makefile.in
 
 bin_PROGRAMS = jack_simple_client \
+	       jack_transport_client \
 	       jack_impulse_grabber \
 	       jack_metro \
 	       jack_showtime \
@@ -17,27 +18,31 @@ AM_CXXFLAGS = -I.. $(JACK_CFLAGS) $(sndfile_cflags)
 
 jack_simple_client_SOURCES = simple_client.c
 jack_simple_client_LDFLAGS = @OS_LDFLAGS@
-jack_simple_client_LDADD = ../libjack/libjack.la
+jack_simple_client_LDADD = $(top_builddir)/libjack/libjack.la
+
+jack_transport_client_SOURCES = transport_client.c
+jack_transport_client_LDFLAGS = @OS_LDFLAGS@
+jack_transport_client_LDADD = $(top_builddir)/libjack/libjack.la
 
 jack_metro_SOURCES = metro.c
 jack_metro_LDFLAGS = @OS_LDFLAGS@
-jack_metro_LDADD = ../libjack/libjack.la
+jack_metro_LDADD = $(top_builddir)/libjack/libjack.la
 
 jack_showtime_SOURCES = showtime.c
 jack_showtime_LDFLAGS = @OS_LDFLAGS@
-jack_showtime_LDADD = ../libjack/libjack.la
+jack_showtime_LDADD = $(top_builddir)/libjack/libjack.la
 
 jack_impulse_grabber_SOURCES = impulse_grabber.c
 jack_impulse_grabber_LDFLAGS = @OS_LDFLAGS@
-jack_impulse_grabber_LDADD = ../libjack/libjack.la
+jack_impulse_grabber_LDADD = $(top_builddir)/libjack/libjack.la
 
 jack_midiseq_SOURCES = midiseq.c
 jack_midiseq_LDFLAGS = @OS_LDFLAGS@
-jack_midiseq_LDADD = ../libjack/libjack.la
+jack_midiseq_LDADD = $(top_builddir)/libjack/libjack.la
 
 jack_midisine_SOURCES = midisine.c
 jack_midisine_LDFLAGS = @OS_LDFLAGS@
-jack_midisine_LDADD = ../libjack/libjack.la
+jack_midisine_LDADD = $(top_builddir)/libjack/libjack.la
 
 #
 # sample in-process client(s)

example-clients/simple_client.c

@@ -1,6 +1,6 @@
 /** @file simple_client.c
  *
- * @brief This simple client demonstrates the basic features of JACK
+ * @brief This simple client demonstrates the most basic features of JACK
  * as they would be used by many applications.
  */
 
@@ -16,41 +16,23 @@ jack_port_t *input_port;
 jack_port_t *output_port;
 jack_client_t *client;
 
-/* a simple state machine for this client */
-volatile enum {
-	Init,
-	Run,
-	Exit
-} client_state = Init;
-
 /**
  * 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.
+ * This client does nothing more than copy data from its input
+ * port to its output port. It will exit when stopped by 
+ * the user (e.g. using Ctrl-C on a unix-ish operating system)
  */
 int
 process (jack_nframes_t nframes, void *arg)
 {
 	jack_default_audio_sample_t *in, *out;
-	jack_transport_state_t ts = jack_transport_query(client, NULL);
-
-	if (ts == JackTransportRolling) {
-
-		if (client_state == Init)
-			client_state = Run;
-
-		in = jack_port_get_buffer (input_port, nframes);
-		out = jack_port_get_buffer (output_port, nframes);
-		memcpy (out, in,
-			sizeof (jack_default_audio_sample_t) * nframes);
-
-	} else if (ts == JackTransportStopped) {
-
-		if (client_state == Run)
-			client_state = Exit;
-	}
+	
+	in = jack_port_get_buffer (input_port, nframes);
+	out = jack_port_get_buffer (output_port, nframes);
+	memcpy (out, in,
+		sizeof (jack_default_audio_sample_t) * nframes);
 
 	return 0;      
 }
@@ -69,26 +51,11 @@ int
 main (int argc, char *argv[])
 {
 	const char **ports;
-	const char *client_name;
+	const char *client_name = "simple";
 	const char *server_name = NULL;
 	jack_options_t options = JackNullOption;
 	jack_status_t status;
-
-	if (argc >= 2) {		/* client name specified? */
-		client_name = argv[1];
-		if (argc >= 3) {	/* server name specified? */
-			server_name = argv[2];
-			options |= JackServerName;
-		}
-	} else {			/* use basename of argv[0] */
-		client_name = strrchr(argv[0], '/');
-		if (client_name == 0) {
-			client_name = argv[0];
-		} else {
-			client_name++;
-		}
-	}
-
+	
 	/* open a client connection to the JACK server */
 
 	client = jack_client_open (client_name, options, &status, server_name);
@@ -183,11 +150,14 @@ main (int argc, char *argv[])
 
 	free (ports);
 
-	/* keep running until the transport stops */
+	/* keep running until stopped by the user */
 
-	while (client_state != Exit) {
-		sleep (1);
-	}
+	sleep (-1);
+
+	/* this is never reached but if the program
+	   had some other way to exit besides being killed,
+	   they would be important to call.
+	*/
 
 	jack_client_close (client);
 	exit (0);

example-clients/transport_client.c

@@ -0,0 +1,197 @@
+/** @file transport_client.c
+ *
+ * @brief This client demonstrates very simple use of the JACK
+ * transport API. Compare it with the simple_client example,
+ * which is even simpler. It also demonstrates taking a client
+ * name and optionally server name from the command line, rather 
+ * than hard-coding either of these names.
+ */
+
+#include <stdio.h>
+#include <errno.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <jack/jack.h>
+
+jack_port_t *input_port;
+jack_port_t *output_port;
+jack_client_t *client;
+
+/* a simple state machine for this client */
+volatile enum {
+	Init,
+	Run,
+	Exit
+} client_state = Init;
+
+/**
+ * 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 *in, *out;
+	jack_transport_state_t ts = jack_transport_query(client, NULL);
+
+	if (ts == JackTransportRolling) {
+
+		if (client_state == Init)
+			client_state = Run;
+
+		in = jack_port_get_buffer (input_port, nframes);
+		out = jack_port_get_buffer (output_port, nframes);
+		memcpy (out, in,
+			sizeof (jack_default_audio_sample_t) * nframes);
+
+	} else if (ts == JackTransportStopped) {
+
+		if (client_state == Run)
+			client_state = Exit;
+	}
+
+	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;
+
+	if (argc >= 2) {		/* client name specified? */
+		client_name = argv[1];
+		if (argc >= 3) {	/* server name specified? */
+			server_name = argv[2];
+			options |= JackServerName;
+		}
+	} else {			/* use basename of argv[0] */
+		client_name = strrchr(argv[0], '/');
+		if (client_name == 0) {
+			client_name = argv[0];
+		} else {
+			client_name++;
+		}
+	}
+
+	/* 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, 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);
+
+	if ((input_port == NULL) || (output_port == 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|JackPortIsOutput);
+	if (ports == NULL) {
+		fprintf(stderr, "no 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);
+	
+	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_port), ports[0])) {
+		fprintf (stderr, "cannot connect output ports\n");
+	}
+
+	free (ports);
+
+	/* keep running until the transport stops */
+
+	while (client_state != Exit) {
+		sleep (1);
+	}
+
+	jack_client_close (client);
+	exit (0);
+}