1 files changed, 126 insertions, 0 deletions
diff --git a/tutorials/sndkit/tests/multich32.c b/tutorials/sndkit/tests/multich32.c
new file mode 100644
index 0000000..ab39297
--- /dev/null
+++ b/tutorials/sndkit/tests/multich32.c
@@ -0,0 +1,126 @@
+/*
+ * Multi channel audio test.
+ *
+ * This program is intended to test playback of 16 bit samples using 4 or more
+ * channels at 48000 Hz. The program plays sine wave pulses sequentially on
+ * channels 0 to N-1.
+ *
+ * Arguments:
+ *
+ * 1:	Number of channelts (default is 8).
+ * 2:	Audio device (/dev/dsp by default).
+ * 3-N: Options
+ * 	  -b	Bypass virtual mixer
+ * 	  -r	Raw mode (disables automatic sample rate/format conversions)
+ */
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/ioctl.h>
+#include <soundcard.h>
+
+static int sinedata[48] = {
+
+  0, 4276, 8480, 12539, 16383, 19947, 23169, 25995,
+  28377, 30272, 31650, 32486, 32767, 32486, 31650, 30272,
+  28377, 25995, 23169, 19947, 16383, 12539, 8480, 4276,
+  0, -4276, -8480, -12539, -16383, -19947, -23169, -25995,
+  -28377, -30272, -31650, -32486, -32767, -32486, -31650, -30272,
+  -28377, -25995, -23169, -19947, -16383, -12539, -8480, -4276
+};
+
+int
+main (int argc, char *argv[])
+{
+  char *dev = "/dev/dsp";
+  int fd, l, i, n = 0, ch, p = 0, phase = 0, arg, channels, srate, thisch = 0;
+  int tick = 0;
+  int nch = 8;
+  int bypass_vmix=0;
+  int disable_format_conversions=0;
+
+  int buf[32*1024];
+
+  if (argc > 1)
+    if (sscanf (argv[1], "%d", &nch) != 1)
+      nch = 2;
+
+  if (argc > 2)
+    dev = argv[2];
+
+  for (i=3;i<argc;i++)
+  if (argv[i][0]=='-')
+  switch (argv[i][1])
+  {
+  case 'b': /* Bypass virtual mixer */
+	  bypass_vmix = O_EXCL;
+	  break;
+
+  case 'r': /* Use raw mode (disable automatic format conversions) */
+	  disable_format_conversions=1;
+	  break;
+  }
+
+  if ((fd = open (dev, O_WRONLY|bypass_vmix, 0)) == -1)
+    {
+      perror (dev);
+      exit (-1);
+    }
+
+  if (disable_format_conversions)
+     {
+  	arg=0;
+  	ioctl(fd, SNDCTL_DSP_COOKEDMODE, &arg);
+     }
+
+  arg = nch;
+  if (ioctl (fd, SNDCTL_DSP_CHANNELS, &arg) == -1)
+    perror ("SNDCTL_DSP_CHANNELS");
+  channels = arg;
+  fprintf (stderr, "Channels %d\n", arg);
+
+  arg = AFMT_S32_NE;
+  if (ioctl (fd, SNDCTL_DSP_SETFMT, &arg) == -1)
+    perror ("SNDCTL_DSP_SETFMT");
+  fprintf (stderr, "Format %x\n", arg);
+
+  arg = 48000;
+  if (ioctl (fd, SNDCTL_DSP_SPEED, &arg) == -1)
+    perror ("SNDCTL_DSP_SPEED");
+  printf ("Using sampling rate %d\n", arg);
+  srate = arg;
+
+  while (1)
+    {
+      for (ch = 0; ch < channels; ch++)
+	{
+	  if (ch == thisch)
+	    {
+	      buf[p] = sinedata[phase]<<16;
+	      phase = (phase + 1 + (ch / 2)) % 48;
+	      if (phase == 0 && tick > 10 * channels)
+		{
+		  thisch = (thisch + 1) % channels;
+		  tick = 0;
+		}
+	    }
+	  else
+	    buf[p] = 0;
+
+	  p++;
+
+	  if (p >= sizeof (buf) / 4)
+	    {
+	      if (write (fd, buf, p * 4) != p * 4)
+		perror ("write");
+	      p = 0;
+	      tick++;
+
+	    }
+	}
+      n++;
+    }
+
+  exit (0);
+}