Imported Upstream version 4.2-build2006upstream/4.2-build2006upstream

1 files changed, 232 insertions, 0 deletions

diff --git a/tutorials/sndkit/tests/iosync.c b/tutorials/sndkit/tests/iosync.c
new file mode 100644
index 0000000..fc9aa52
--- /dev/null
+++ b/tutorials/sndkit/tests/iosync.c
@@ -0,0 +1,232 @@
+/*
+ * Purpose: Measuring the hardware level latencies.
+ * Copyright (C) 4Front Technologies, 2002-2004. Released under GPLv2/CDDL.
+ *
+ * Description:
+ * This simple program was once used to measure internal latencies of some
+ * sound cards. It was written in great hurry so don't use it as a program
+ * template. Error checking is completely inadequate.
+ *
+ * This program requires that the output of the sound card is connected
+ * to the line in of the same card.
+ *
+ * The program will play a short spike and then measure how many "silent "
+ * samples there are in the input before the spike is seen. You can
+ * get the delay in seconds by dividing this sample count by the
+ * sample rate.
+ *
+ * This is the total delay value that includes both the output and input
+ * delays. There is no way to estimate how large part of it is caused by
+ * input or output.
+ */
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <fcntl.h>
+#include <soundcard.h>
+#ifdef _AIX
+#include <sys/select.h>
+#endif
+
+int frag_size = 0;
+static int pos = 0;
+
+static int
+open_device (char *name, int mode)
+{
+  int tmp, fd;
+
+  int frag = 0x0020000b;	/* 32 fragments of 2^11=2048 bytes */
+
+  if ((fd = open (name, mode, 0)) == -1)
+    {
+      perror (name);
+      exit (-1);
+    }
+
+/*
+ * WARNING!!!!!!!!!!!
+ *
+ * The following code makes ioctl calls without verifying that the
+ * result was OK. Don't do this at home.
+ */
+  if (ioctl (fd, SNDCTL_DSP_SETFRAGMENT, &frag) == -1)
+    perror ("SNDCTL_DSP_SETFRAGMENT");
+
+  tmp = 1;
+  if (ioctl (fd, SNDCTL_DSP_CHANNELS, &tmp) == -1)
+    perror ("SNDCTL_DSP_CHANNELS");
+
+  tmp = AFMT_S16_NE;
+  if (ioctl (fd, SNDCTL_DSP_SETFMT, &tmp) == -1)
+    perror ("SNDCTL_DSP_SETFMT");
+
+  tmp = 48000;
+  if (ioctl (fd, SNDCTL_DSP_SPEED, &tmp) == -1)	/* And #channels & #bits if required */
+    perror ("SNDCTL_DSP_SPEED");
+
+  if (ioctl (fd, SNDCTL_DSP_GETBLKSIZE, &frag_size) == -1)
+    perror ("SNDCTL_DSP_GETBLKSIZE");
+
+  tmp = 0;
+  if (ioctl (fd, SNDCTL_DSP_SETTRIGGER, &tmp) == -1)
+    perror ("SNDCTL_DSP_SETTRIGGER");
+/*
+ * WARNING!!!!!!!!!!!
+ *
+ * The above code makes ioctl calls without verifying that the
+ * result was OK. Don't do this at home.
+ */
+
+  return fd;
+}
+
+static void
+gen_spike (short *buf)
+{
+  int i, p;
+
+  for (i = 0; i < 30; i++)
+    {
+      p = (i / 4) % 3;
+      buf[i] = (p - 1) * 8 * 1024;
+    }
+}
+
+static void
+check_buf (short *buf, int l)
+{
+  int i;
+
+  for (i = 0; i < l; i++)
+    {
+      int v;
+
+      v = buf[i];
+      if (v < 0)
+	v = -v;
+      if (v > 4096)
+	printf ("%d = %d\n", pos, v);
+      pos++;
+    }
+}
+
+int
+main (int argc, char *argv[])
+{
+  int fd_in, fd_out;
+  char *name_in = "/dev/dsp", *name_out = NULL;
+
+  int tmp;
+  int have_data = 0;
+
+  char buf[128 * 1024];
+
+  int n, l;
+
+  fd_set reads, writes;
+
+  if (argc > 1)
+    name_in = argv[1];
+  if (argc > 2)
+    name_out = argv[2];
+
+  if (name_out != NULL)
+    {
+      fd_in = open_device (name_in, O_RDONLY);
+      fd_out = open_device (name_out, O_WRONLY);
+    }
+  else
+    {
+      fd_in = fd_out == open_device (name_in, O_RDWR);
+    }
+
+  memset (buf, 0, frag_size);
+  gen_spike ((short *) buf);
+  write (fd_out, buf, frag_size);
+
+  if (fd_out != fd_in)
+    {
+      tmp = PCM_ENABLE_INPUT;
+      ioctl (fd_in, SNDCTL_DSP_SETTRIGGER, &tmp);
+      tmp = PCM_ENABLE_OUTPUT;
+      ioctl (fd_out, SNDCTL_DSP_SETTRIGGER, &tmp);
+    }
+  else
+    {
+      tmp = PCM_ENABLE_INPUT | PCM_ENABLE_OUTPUT;
+      ioctl (fd_in, SNDCTL_DSP_SETTRIGGER, &tmp);
+    }
+
+  while (1)
+    {
+      struct timeval time;
+
+      FD_ZERO (&reads);
+      FD_ZERO (&writes);
+
+      FD_SET (fd_out, &writes);
+      FD_SET (fd_in, &reads);
+
+      time.tv_sec = 0;
+      time.tv_usec = 100000;
+      if ((l = select (fd_out + 1, &reads, &writes, NULL, &time)) == -1)
+	{
+	  perror ("select");
+	  exit (-1);
+	}
+      if (l == 0)
+	printf ("Timeout ");
+
+      if (FD_ISSET (fd_in, &reads))
+	{
+	  struct audio_buf_info info;
+
+	  if (ioctl (fd_in, SNDCTL_DSP_GETISPACE, &info) == -1)
+	    {
+	      perror ("select");
+	      exit (-1);
+	    }
+
+	  n = info.bytes;
+	  if (n <= 0)
+	    {
+	      printf ("Error: NREAD=%d\n", n);
+	      exit (-1);
+	    }
+
+	  l = read (fd_in, buf, n);
+	  if (l > 0)
+	    have_data = 1;
+	  else
+	    perror ("read");
+	  check_buf ((short *) buf, l / 2);
+	}
+
+      if (FD_ISSET (fd_out, &writes))
+	{
+	  int i;
+
+	  struct audio_buf_info info;
+
+	  if (ioctl (fd_out, SNDCTL_DSP_GETOSPACE, &info) == -1)
+	    {
+	      perror ("select");
+	      exit (-1);
+	    }
+
+	  n = info.bytes;
+
+	  /* printf("Write %d", l); */
+	  l = n;
+	  memset (buf, 0, l);
+	  if (write (fd_out, buf, l) == l);
+	  have_data = 0;
+	}
+    }
+
+  exit (0);
+}