sys/oss/: Rate probing test app.

Original commit message from CVS:
* sys/oss/Makefile.am:
* sys/oss/oss_probe.c: (main), (probe_check), (add_range),
(check_rate), (add_rate):  Rate probing test app.

2 files changed, 241 insertions, 0 deletions

diff --git a/sys/oss/Makefile.am b/sys/oss/Makefile.am
index e8995bc5..5480bb7e 100644
--- a/sys/oss/Makefile.am
+++ b/sys/oss/Makefile.am
@@ -14,3 +14,10 @@ noinst_HEADERS = gstosssink.h	\
 		gstosssrc.h	\
 		gstosselement.h\
 		gstossmixer.h
+
+noinst_PROGRAMS = oss_probe
+
+oss_probe_SOURCES = oss_probe.c
+oss_probe_CFLAGS = $(GLIB_CFLAGS)
+oss_probe_LDADD = $(GLIB_LIBS)
+
diff --git a/sys/oss/oss_probe.c b/sys/oss/oss_probe.c
new file mode 100644
index 00000000..dca158a9
--- /dev/null
+++ b/sys/oss/oss_probe.c
@@ -0,0 +1,234 @@
+
+#include <sys/soundcard.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/ioctl.h>
+#include <glib.h>
+
+typedef struct _Probe Probe;
+struct _Probe
+{
+  int fd;
+  int format;
+  int n_channels;
+  GArray *rates;
+};
+
+typedef struct _Range Range;
+struct _Range
+{
+  int min;
+  int max;
+};
+
+static gboolean probe_check (Probe * probe);
+static int check_rate (Probe * probe, int irate);
+static GList *add_range (GList * list, int min, int max);
+static void add_rate (GArray * array, int rate);
+
+int
+main (int argc, char *argv[])
+{
+  int fd;
+  int n;
+  int *rates;
+  int i;
+  Probe *probe;
+
+  fd = open ("/dev/dsp", O_RDWR);
+  if (fd < 0) {
+    perror ("/dev/dsp");
+    exit (1);
+  }
+
+  probe = g_new0 (Probe, 1);
+  probe->fd = fd;
+  probe->format = AFMT_S16_LE;
+  probe->n_channels = 2;
+
+  probe_check (probe);
+  for (i = 0; i < probe->rates->len; i++) {
+    g_print ("%d\n", g_array_index (probe->rates, int, i));
+  }
+
+#if 0
+  probe = g_new0 (Probe, 1);
+  probe->fd = fd;
+  probe->format = AFMT_S16_LE;
+  probe->n_channels = 1;
+
+  probe_check (probe);
+  for (i = 0; i < probe->rates->len; i++) {
+    g_print ("%d\n", g_array_index (probe->rates, int, i));
+  }
+
+  probe = g_new0 (Probe, 1);
+  probe->fd = fd;
+  probe->format = AFMT_U8;
+  probe->n_channels = 2;
+
+  probe_check (probe);
+  for (i = 0; i < probe->rates->len; i++) {
+    g_print ("%d\n", g_array_index (probe->rates, int, i));
+  }
+
+  probe = g_new0 (Probe, 1);
+  probe->fd = fd;
+  probe->format = AFMT_U8;
+  probe->n_channels = 1;
+
+  probe_check (probe);
+  for (i = 0; i < probe->rates->len; i++) {
+    g_print ("%d\n", g_array_index (probe->rates, int, i));
+  }
+#endif
+
+  return 0;
+}
+
+static gboolean
+probe_check (Probe * probe)
+{
+  GList *item;
+  Range *range;
+  GList *new_ranges;
+  GList *ranges;
+  int i;
+  int min, max;
+  int exact_rates = 0;
+  gboolean checking_exact_rates = TRUE;
+  int n_checks = 0;
+
+  probe->rates = g_array_new (FALSE, FALSE, sizeof (int));
+
+  min = check_rate (probe, 1000);
+  add_rate (probe->rates, min);
+  n_checks++;
+  max = check_rate (probe, 100000);
+  add_rate (probe->rates, max);
+  n_checks++;
+  ranges = add_range (NULL, min + 1, max - 1);
+
+  for (i = 0; i < 20; i++) {
+    new_ranges = NULL;
+
+    if (ranges == NULL) {
+      g_print ("no more ranges, probe complete\n");
+      g_print ("n_checks = %d\n", n_checks);
+
+      return TRUE;
+    }
+    for (item = ranges; item; item = item->next) {
+      int min1;
+      int max1;
+      int mid;
+      int mid_ret;
+
+      range = item->data;
+
+      g_print ("checking [%d,%d]\n", range->min, range->max);
+
+      mid = (range->min + range->max) / 2;
+      mid_ret = check_rate (probe, mid);
+      n_checks++;
+
+      if (mid == mid_ret && checking_exact_rates) {
+        exact_rates++;
+        if (exact_rates > 100) {
+          g_print ("got 100 exact rates, assuming all are exact\n");
+          return 0;
+        }
+      } else {
+        checking_exact_rates = FALSE;
+      }
+
+      add_rate (probe->rates, mid_ret);
+
+#if 1
+      /* Assume that the rate is arithmetically rounded to the nearest
+       * supported rate. */
+      if (mid < mid_ret) {
+        min1 = mid - (mid_ret - mid);
+        max1 = mid_ret + 1;
+      } else {
+        min1 = mid_ret - 1;
+        max1 = mid + (mid - mid_ret);
+      }
+#else
+      /* Assume that the rate is not rounded past a supported rate */
+      if (mid < mid_ret) {
+        min1 = mid - 1;
+        max1 = mid_ret + 1;
+      } else {
+        min1 = mid_ret - 1;
+        max1 = mid + 1;
+      }
+#endif
+
+      if (range->min < min1) {
+        new_ranges = add_range (new_ranges, range->min, min1);
+      }
+      if (max1 < range->max) {
+        new_ranges = add_range (new_ranges, max1, range->max);
+      }
+    }
+
+    /* leak ranges */
+
+    ranges = new_ranges;
+  }
+
+  return 0;
+}
+
+static GList *
+add_range (GList * list, int min, int max)
+{
+  Range *range = g_new0 (Range, 1);
+
+  range->min = min;
+  range->max = max;
+
+  return g_list_append (list, range);
+}
+
+static int
+check_rate (Probe * probe, int irate)
+{
+  int rate;
+  int format;
+  int n_channels;
+
+  rate = irate;
+  format = probe->format;
+  n_channels = probe->n_channels;
+
+  ioctl (probe->fd, SNDCTL_DSP_SETFMT, &format);
+  ioctl (probe->fd, SNDCTL_DSP_CHANNELS, &n_channels);
+  ioctl (probe->fd, SNDCTL_DSP_SPEED, &rate);
+
+  g_print ("rate %d -> %d\n", irate, rate);
+
+  if (rate == irate - 1 || rate == irate + 1) {
+    rate = irate;
+  }
+  return rate;
+}
+
+static void
+add_rate (GArray * array, int rate)
+{
+  int i;
+  int val;
+
+  for (i = 0; i < array->len; i++) {
+    val = g_array_index (array, int, i);
+
+    if (val == rate)
+      return;
+  }
+  g_print ("supported rate: %d\n", rate);
+  g_array_append_val (array, rate);
+}