Added two example application on the use of libfluidsynth

fluidsynth/doc/fluidsynth_fx.c

@@ -0,0 +1,139 @@
+/* FluidSynth FX - An example of using effects with fluidsynth
+ *
+ * This code is in the public domain.
+ *
+ * To compile:
+ *   gcc -g -O -o fluidsynth_fx fluidsynth_fx.c -lfluidsynth
+ *
+ * To run
+ *   fluidsynth_fx soundfont gain
+ *
+ * [Peter Hanappe]
+ */
+
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <fluidsynth.h>
+
+
+/* The structure with the effects data. This example simple applies a
+ * linear gain the to synthesizer output. */
+struct fx_data_t {
+	fluid_synth_t* synth;
+	float gain;
+} fx_data_t;
+
+/* This function implements the callback function of the audio driver
+ * (see new_fluid_audio_driver2 below). The data argument is a pointer
+ * to your private data structure. 'len' is the number of samples in
+ * the buffers. 'nin' and 'nout' are the number of input and output
+ * audio buffers. 'in' and 'out' are an array of float buffers with
+ * the samples. The audio driver fills the 'in' buffers the incoming
+ * audio. The 'out' buffers should be filled by your function. The
+ * 'out' buffers will be sent to the audio output of the sound card.
+ *
+ * IMPORTANT NOTE: The API was designed to be generic but none of the
+ * audio drivers currently handles audio input. Either 'nin' will be
+ * zero, or the buffers will be filled with zero samples.
+ */
+int fx_function(void* data, int len, 
+		int nin, float** in, 
+		int nout, float** out)
+{
+	struct fx_data_t* fx_data = (struct fx_data_t*) data;
+	int i, k;
+	float* out_i;
+
+	/* Call the synthesizer to fill the output buffers with its
+	 * audio output. */
+	if (fluid_synth_process(fx_data->synth, len, nin, in, nout, out) != 0) {
+		/* Some error occured. Very unlikely to happen, though. */
+		return -1;
+	}
+
+	/* Apply your effects here. In this example, the gain is
+	 * applied to all the output buffers. */
+	for (i = 0; i < nout; i++) {
+		out_i = out[i];
+		for (k = 0; k < len; k++) {
+			out_i[k] *= fx_data->gain;
+		}
+	}
+
+	return 0;
+}
+
+
+int main(int argc, char** argv) 
+{
+	fluid_settings_t* settings;
+	fluid_synth_t* synth = NULL;
+	fluid_audio_driver_t* adriver = NULL;
+	int err = 0;
+	struct fx_data_t fx_data;
+
+	if (argc != 3) {
+		fprintf(stderr, "Usage: fluidsynth_simple [soundfont] [gain]\n");
+		return 1;
+	}
+
+	/* Create the settings object. This example uses the default
+	 * values for the settings. */
+	settings = new_fluid_settings();
+	if (settings == NULL) {
+		fprintf(stderr, "Failed to create the settings\n");
+		err = 2;
+		goto cleanup;
+	}
+  
+	/* Create the synthesizer */
+	synth = new_fluid_synth(settings);
+	if (synth == NULL) {
+		fprintf(stderr, "Failed to create the synthesizer\n");
+		err = 3;
+		goto cleanup;
+	}
+
+	/* Load the soundfont */
+	if (fluid_synth_sfload(synth, argv[1], 1) == -1) {
+		fprintf(stderr, "Failed to load the SoundFont\n");
+		err = 4;
+		goto cleanup;
+	}
+
+	/* Fill in the data of the effects unit */
+	fx_data.synth = synth;
+	fx_data.gain = atof(argv[2]);
+
+	/* Create the audio driver. As soon as the audio driver is
+	 * created, the synthesizer can be played. */
+	adriver = new_fluid_audio_driver2(settings, fx_function, (void*) &fx_data);
+	if (adriver == NULL) {
+		fprintf(stderr, "Failed to create the audio driver\n");
+		err = 5;
+		goto cleanup;
+	}
+
+	/* Play a note */
+	fluid_synth_noteon(synth, 0, 60, 100);
+
+	printf("Press \"Enter\" to stop: ");
+	fgetc(stdin);
+	printf("done\n");
+
+	
+ cleanup:
+	
+	if (adriver) {
+		delete_fluid_audio_driver(adriver);
+	}
+	if (synth) {
+		delete_fluid_synth(synth);
+	}
+	if (settings) {
+		delete_fluid_settings(settings);
+	}
+	
+	return err;
+}

fluidsynth/doc/fluidsynth_simple.c

@@ -0,0 +1,84 @@
+/* FluidSynth Simple - An example of using fluidsynth
+ *
+ * This code is in the public domain.
+ *
+ * To compile:
+ *   gcc -g -O -o fluidsynth_simple fluidsynth_simple.c -lfluidsynth
+ *
+ * To run
+ *   fluidsynth_simple soundfont
+ *
+ * [Peter Hanappe]
+ */
+
+
+#include <stdio.h>
+#include <fluidsynth.h>
+
+int main(int argc, char** argv) 
+{
+	fluid_settings_t* settings;
+	fluid_synth_t* synth = NULL;
+	fluid_audio_driver_t* adriver = NULL;
+	int err = 0;
+
+	if (argc != 2) {
+		fprintf(stderr, "Usage: fluidsynth_simple [soundfont]\n");
+		return 1;
+	}
+
+	/* Create the settings object. This example uses the default
+	 * values for the settings. */
+	settings = new_fluid_settings();
+	if (settings == NULL) {
+		fprintf(stderr, "Failed to create the settings\n");
+		err = 2;
+		goto cleanup;
+	}
+  
+	/* Create the synthesizer */
+	synth = new_fluid_synth(settings);
+	if (synth == NULL) {
+		fprintf(stderr, "Failed to create the synthesizer\n");
+		err = 3;
+		goto cleanup;
+	}
+
+	/* Load the soundfont */
+	if (fluid_synth_sfload(synth, argv[1], 1) == -1) {
+		fprintf(stderr, "Failed to load the SoundFont\n");
+		err = 4;
+		goto cleanup;
+	}
+
+	/* Create the audio driver. As soon as the audio driver is
+	 * created, the synthesizer can be played. */
+	adriver = new_fluid_audio_driver(settings, synth);
+	if (adriver == NULL) {
+		fprintf(stderr, "Failed to create the audio driver\n");
+		err = 5;
+		goto cleanup;
+	}
+
+	/* Play a note */
+	fluid_synth_noteon(synth, 0, 60, 100);
+
+	printf("Press \"Enter\" to stop: ");
+	fgetc(stdin);
+	printf("done\n");
+
+	
+ cleanup:
+	
+	if (adriver) {
+		delete_fluid_audio_driver(adriver);
+	}
+	if (synth) {
+		delete_fluid_synth(synth);
+	}
+	if (settings) {
+		delete_fluid_settings(settings);
+	}
+	
+	return err;
+}