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authorSebastian Dröge <sebastian.droege@collabora.co.uk>2010-08-28 07:30:18 (GMT)
committer Sebastian Dröge <sebastian.droege@collabora.co.uk>2010-08-28 07:31:59 (GMT)
commit8ca48752fb787ce708c86183b51505cd53d6b5ed (patch) (side-by-side diff)
treec8aca78f4b1d0092befa988d2f6b91068b0199b8
parent8a20878535d34210e36db0f0bee7d1711b57669e (diff)
downloadgstreamer-8ca48752fb787ce708c86183b51505cd53d6b5ed.zip
gstreamer-8ca48752fb787ce708c86183b51505cd53d6b5ed.tar.gz
utils: Add gst_util_fraction_compare() to compare fractions
And use it for the fraction comparisons in gstvalue.c instead of using comparisons by first converting the fractions to double. Should fix bug #628174. API: gst_util_fraction_compare()
Diffstat (more/less context) (ignore whitespace changes)
-rw-r--r--gst/gstutils.c48
-rw-r--r--gst/gstutils.h1
-rw-r--r--gst/gstvalue.c43
3 files changed, 70 insertions, 22 deletions
diff --git a/gst/gstutils.c b/gst/gstutils.c
index f1b52af..265f427 100644
--- a/gst/gstutils.c
+++ b/gst/gstutils.c
@@ -4196,3 +4196,51 @@ gst_util_fraction_add (gint a_n, gint a_d, gint b_n, gint b_d, gint * res_n,
return TRUE;
}
+
+/**
+ * gst_util_fraction_compare:
+ * @a_n: Numerator of first value
+ * @a_d: Denominator of first value
+ * @b_n: Numerator of second value
+ * @b_d: Denominator of second value
+ *
+ * Compares the fractions @a_n/@a_d and @b_n/@b_d and returns
+ * -1 if a < b, 0 if a = b and 1 if a > b.
+ *
+ * Returns: -1 if a < b; 0 if a = b; 1 if a > b.
+ *
+ * Since: 0.10.31
+ */
+gint
+gst_util_fraction_compare (gint a_n, gint a_d, gint b_n, gint b_d)
+{
+ gint64 new_num_1;
+ gint64 new_num_2;
+ gint gcd;
+
+ g_return_val_if_fail (a_d == 0 || b_d == 0, 0);
+
+ /* Simplify */
+ gcd = gst_util_greatest_common_divisor (a_n, a_d);
+ a_n /= gcd;
+ a_d /= gcd;
+
+ gcd = gst_util_greatest_common_divisor (b_n, b_d);
+ b_n /= gcd;
+ b_d /= gcd;
+
+ /* fractions are reduced when set, so we can quickly see if they're equal */
+ if (a_n == b_n && a_d == b_d)
+ return 0;
+
+ /* extend to 64 bits */
+ new_num_1 = ((gint64) a_n) * b_d;
+ new_num_2 = ((gint64) b_n) * a_d;
+ if (new_num_1 < new_num_2)
+ return -1;
+ if (new_num_1 > new_num_2)
+ return 1;
+
+ /* Should not happen because a_d and b_d are not 0 */
+ g_return_val_if_reached (0);
+}
diff --git a/gst/gstutils.h b/gst/gstutils.h
index 82860bb..f91b777 100644
--- a/gst/gstutils.h
+++ b/gst/gstutils.h
@@ -1172,6 +1172,7 @@ void gst_util_fraction_to_double (gint src_n, gint src_d, gdouble *dest);
void gst_util_double_to_fraction (gdouble src, gint *dest_n, gint *dest_d);
gboolean gst_util_fraction_multiply (gint a_n, gint a_d, gint b_n, gint b_d, gint *res_n, gint *res_d);
gboolean gst_util_fraction_add (gint a_n, gint a_d, gint b_n, gint b_d, gint *res_n, gint *res_d);
+gint gst_util_fraction_compare (gint a_n, gint a_d, gint b_n, gint b_d);
/* sink message event
diff --git a/gst/gstvalue.c b/gst/gstvalue.c
index e6595ac..a3c4393 100644
--- a/gst/gstvalue.c
+++ b/gst/gstvalue.c
@@ -1106,10 +1106,9 @@ gst_value_collect_fraction_range (GValue * value, guint n_collect_values,
if (collect_values[3].v_int == 0)
return g_strdup_printf ("passed '0' as second denominator for `%s'",
G_VALUE_TYPE_NAME (value));
- if ((((gdouble) collect_values[0].v_int) /
- ((gdouble) collect_values[1].v_int)) >=
- (((gdouble) collect_values[2].v_int) /
- ((gdouble) collect_values[3].v_int)))
+ if (gst_util_fraction_compare (collect_values[0].v_int,
+ collect_values[1].v_int, collect_values[2].v_int,
+ collect_values[3].v_int) >= 0)
return g_strdup_printf ("range start is not smaller than end for `%s'",
G_VALUE_TYPE_NAME (value));
@@ -1175,9 +1174,8 @@ gst_value_set_fraction_range (GValue * value, const GValue * start,
g_return_if_fail (GST_VALUE_HOLDS_FRACTION_RANGE (value));
g_return_if_fail (GST_VALUE_HOLDS_FRACTION (start));
g_return_if_fail (GST_VALUE_HOLDS_FRACTION (end));
- g_return_if_fail (((gdouble) start->data[0].v_int) /
- ((gdouble) start->data[1].v_int) <
- ((gdouble) end->data[0].v_int) / ((gdouble) end->data[1].v_int));
+ g_return_if_fail (gst_util_fraction_compare (start->data[0].v_int,
+ start->data[1].v_int, end->data[0].v_int, end->data[1].v_int) < 0);
vals = (GValue *) value->data[0].v_pointer;
if (vals == NULL) {
@@ -1210,9 +1208,8 @@ gst_value_set_fraction_range_full (GValue * value,
g_return_if_fail (value != NULL);
g_return_if_fail (denominator_start != 0);
g_return_if_fail (denominator_end != 0);
- g_return_if_fail (((gdouble) numerator_start) /
- ((gdouble) denominator_start) <
- ((gdouble) numerator_end) / ((gdouble) denominator_end));
+ g_return_if_fail (gst_util_fraction_compare (numerator_start,
+ denominator_start, numerator_end, denominator_end) < 0);
g_value_init (&start, GST_TYPE_FRACTION);
g_value_init (&end, GST_TYPE_FRACTION);
@@ -3910,9 +3907,7 @@ gst_value_compare_fraction (const GValue * value1, const GValue * value2)
{
gint n1, n2;
gint d1, d2;
-
- gint64 new_num_1;
- gint64 new_num_2;
+ gint ret;
n1 = value1->data[0].v_int;
n2 = value2->data[0].v_int;
@@ -3923,18 +3918,22 @@ gst_value_compare_fraction (const GValue * value1, const GValue * value2)
if (n1 == n2 && d1 == d2)
return GST_VALUE_EQUAL;
- /* extend to 64 bits */
- new_num_1 = ((gint64) n1) * d2;
- new_num_2 = ((gint64) n2) * d1;
- if (new_num_1 < new_num_2)
+ if (d1 == 0 && d2 == 0)
+ return GST_VALUE_UNORDERED;
+ else if (d1 == 0)
+ return GST_VALUE_GREATER_THAN;
+ else if (d2 == 0)
return GST_VALUE_LESS_THAN;
- if (new_num_1 > new_num_2)
+
+ ret = gst_util_fraction_compare (n1, d1, n2, d2);
+ if (ret == -1)
+ return GST_VALUE_LESS_THAN;
+ else if (ret == 1)
return GST_VALUE_GREATER_THAN;
- /* new_num_1 == new_num_2 implies that both denominators must have
- * been 0, beause otherwise simplification would have caught the
- * equivalence */
- return GST_VALUE_UNORDERED;
+ /* Equality can't happen here because we check for that
+ * first already */
+ g_return_val_if_reached (GST_VALUE_UNORDERED);
}
/*********