first beep

.gitignore

@@ -1,3 +1,7 @@
+# mon machin a moi
+ 
+audio/t
+
 # ---> C
 # Prerequisites
 *.d

audio/Makefile

@@ -0,0 +1,11 @@
+
+CC      = gcc
+CCOPT   = -Wall -g -DDEBUG_LEVEL=1
+LIBS    = -lao -lsndfile -lm
+
+ao_output.o:       ao_output.c Makefile
+	$(CC) ${CCOPT} -c $<
+
+t:	t.c ao_output.o Makefile
+	$(CC) ${CCOPT} $< ao_output.o ${LIBS} -o $@
+

audio/ao_output.c

@@ -0,0 +1,91 @@
+/*
+ *      NcLooper        fonctions audio
+ */
+
+#include  <stdio.h>
+#include  <unistd.h>
+#include  <string.h>
+#include  <fcntl.h>
+#include  <math.h>
+
+#include <ao/ao.h>
+#include <sndfile.h>
+
+#include  "ao_output.h"
+
+/* --------------------------------------------------------------------- */
+
+static ao_device	*device;	/*  never alone with a singleton */
+
+/* --------------------------------------------------------------------- */
+int init_ao_output(int smplrate)
+{
+int			default_driver;
+ao_sample_format	format;
+
+#if DEBUG_LEVEL
+fprintf(stderr, ">>> %s ( %d )\n", __func__, smplrate);
+#endif
+
+ao_initialize();
+
+default_driver = ao_default_driver_id();
+#if DEBUG_LEVEL
+fprintf(stderr, "%s : ao default driver #%d\n", __func__, default_driver);
+#endif
+
+memset(&format, 0, sizeof(format));
+format.bits = 16;
+format.channels = 2;
+format.rate = smplrate;
+format.byte_format = AO_FMT_LITTLE;
+
+device = ao_open_live(default_driver, &format, NULL);
+if (device == NULL) {
+        fprintf(stderr, "Error opening AO device.\n");
+        return -1;
+        }
+
+
+return 0;
+}
+/* --------------------------------------------------------------------- */
+int close_ao_output(void)
+{
+
+ao_close(device);
+ao_shutdown();
+
+device = NULL;
+
+return 0;
+}
+/* --------------------------------------------------------------------- */
+int play_some_stuff(int notused)
+{
+int			i, sample;
+char			*buffer;
+float			freq = 440.0;
+
+#define NB_SAMPLES	44100
+
+if (NULL == device) {
+	fprintf(stderr, "%s : please call 'init_ao_output' first\n",
+					__func__);
+	exit(1);
+	}
+
+buffer = calloc(NB_SAMPLES*2, sizeof(short));
+
+for (i = 0; i < NB_SAMPLES; i++) {
+	sample = (int)(0.75 * 32768.0 *
+		sin(2 * M_PI * freq * ((float) i/44100)));
+
+	/* Put the same stuff in left and right channel */
+	buffer[4*i] = buffer[4*i+2] = sample & 0xff;
+	buffer[4*i+1] = buffer[4*i+3] = (sample >> 8) & 0xff;
+	}
+ao_play(device, buffer, NB_SAMPLES);
+
+return 0;
+}

audio/ao_output.h

@@ -0,0 +1,10 @@
+
+/* generic output */
+
+int init_ao_output(int smplrate);
+int close_ao_output(void);
+
+
+/* tests functions */
+
+int play_some_stuff(int notused);

audio/t.c

@@ -0,0 +1,30 @@
+/*
+ *      NcLooper        test des fonctions audio
+ */
+ 
+#include  <stdio.h>
+
+#include  "ao_output.h"
+
+/* --------------------------------------------------------------------- */
+
+/* --------------------------------------------------------------------- */
+
+int main(int argc, char *argv[])
+{
+int             foo;
+
+
+foo = init_ao_output(44100);
+fprintf(stderr, "AO init    -> %d\n", foo);
+
+foo = play_some_stuff(0);
+fprintf(stderr, "play stuff -> %d\n", foo);
+
+foo = close_ao_output();
+fprintf(stderr, "AO close   -> %d\n", foo);
+
+
+return 0;
+}
+/* --------------------------------------------------------------------- */