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Added transform functions between double and fraction.

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Original commit message from CVS:
* gst/gstvalue.c: (gst_value_transform_double_fraction),
(gst_value_transform_fraction_double), (_gst_value_initialize):
* testsuite/caps/Makefile.am:
* testsuite/caps/fraction-convert.c: (check_from_double_convert),
(check_from_fraction_convert), (transform_test), (main):
Added transform functions between double and fraction.
Added testcase to verify transforms
This commit is contained in:
Wim Taymans 2004-07-27 16:45:30 +00:00
parent f8d6750a36
commit 36b41f4666
6 changed files with 336 additions and 0 deletions
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10
ChangeLog
View file

@ -1,3 +1,13 @@
2004-07-27 Wim Taymans <wim@fluendo.com>
* gst/gstvalue.c: (gst_value_transform_double_fraction),
(gst_value_transform_fraction_double), (_gst_value_initialize):
* testsuite/caps/Makefile.am:
* testsuite/caps/fraction-convert.c: (check_from_double_convert),
(check_from_fraction_convert), (transform_test), (main):
Added transform functions between double and fraction.
Added testcase to verify transforms
2004-07-26 Steve Lhomme <steve.lhomme@free.fr>
* win32/GStreamer.vcproj:

94
gst/gstvalue.c
View file

@ -20,6 +20,7 @@
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <math.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
@ -2544,6 +2545,95 @@ gst_value_transform_string_fraction (const GValue * src_value,
gst_value_deserialize_fraction (dest_value, src_value->data[0].v_pointer);
}
#define MAX_TERMS 30
#define MIN_DIVISOR 1.0e-10
#define MAX_ERROR 1.0e-20
/* use continued fractions to transform a double into a fraction,
* see http://mathforum.org/dr.math/faq/faq.fractions.html#decfrac.
* This algorithm takes care of overflows.
*/
static void
gst_value_transform_double_fraction (const GValue * src_value,
GValue * dest_value)
{
gdouble V, F; /* double being converted */
gint N, D; /* will contain the result */
gint A; /* current term in continued fraction */
gint64 N1, D1; /* numerator, denominator of last approx */
gint64 N2, D2; /* numerator, denominator of previous approx */
gint i;
gboolean negative = FALSE;
/* initialize fraction being converted */
F = src_value->data[0].v_double;
if (F < 0.0) {
F = -F;
negative = TRUE;
}
V = F;
/* initialize fractions with 1/0, 0/1 */
N1 = 1;
D1 = 0;
N2 = 0;
D2 = 1;
N = 1;
D = 1;
for (i = 0; i < MAX_TERMS; i++) {
/* get next term */
A = floor (F);
/* get new divisor */
F = F - A;
/* calculate new fraction in temp */
N2 = N1 * A + N2;
D2 = D1 * A + D2;
/* guard against overflow */
if (N2 > G_MAXINT || D2 > G_MAXINT) {
break;
}
N = N2;
D = D2;
/* save last two fractions */
N2 = N1;
D2 = D1;
N1 = N;
D1 = D;
/* quit if dividing by zero or close enough to target */
if (F < MIN_DIVISOR || fabs (V - ((gdouble) N) / D) < MAX_ERROR) {
break;
}
/* Take reciprocal */
F = 1 / F;
}
/* fix for overflow */
if (D == 0) {
N = G_MAXINT;
D = 1;
}
/* fix for negative */
if (negative)
N = -N;
/* will also simplify */
gst_value_set_fraction (dest_value, N, D);
}
static void
gst_value_transform_fraction_double (const GValue * src_value,
GValue * dest_value)
{
dest_value->data[0].v_double = ((double) src_value->data[0].v_int) /
((double) src_value->data[1].v_int);
}
static int
gst_value_compare_fraction (const GValue * value1, const GValue * value2)
{
@ -2817,6 +2907,10 @@ _gst_value_initialize (void)
gst_value_transform_fraction_string);
g_value_register_transform_func (G_TYPE_STRING, GST_TYPE_FRACTION,
gst_value_transform_string_fraction);
g_value_register_transform_func (GST_TYPE_FRACTION, G_TYPE_DOUBLE,
gst_value_transform_fraction_double);
g_value_register_transform_func (G_TYPE_DOUBLE, GST_TYPE_FRACTION,
gst_value_transform_double_fraction);
gst_value_register_intersect_func (G_TYPE_INT, GST_TYPE_INT_RANGE,
gst_value_intersect_int_int_range);

1
tests/old/testsuite/caps/Makefile.am
View file

@ -10,6 +10,7 @@ tests_pass = \
union \
string-conversions \
fixed \
fraction-convert \
fraction-multiply-and-zero \
intersect2 \
caps \

115
tests/old/testsuite/caps/fraction-convert.c Normal file
View file

@ -0,0 +1,115 @@
/* GStreamer
*
* fraction-convert.c: test for GstFraction transform
*
* Copyright (C) <2004> Thomas Vander Stichele <thomas at apestaart dot org>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#include <math.h>
#include <gst/gst.h>
#include <glib.h>
static void
check_from_double_convert (gdouble value, gint nom, gint denom, gdouble prec)
{
GValue value1 = { 0 };
GValue value2 = { 0 };
gdouble check;
g_value_init (&value1, G_TYPE_DOUBLE);
g_value_init (&value2, GST_TYPE_FRACTION);
g_value_set_double (&value1, value);
g_value_transform (&value1, &value2);
g_print ("%s = %s\n",
gst_value_serialize (&value1), gst_value_serialize (&value2));
g_assert (gst_value_get_fraction_numerator (&value2) == nom);
g_assert (gst_value_get_fraction_denominator (&value2) == denom);
g_value_transform (&value2, &value1);
g_print ("%s = %s\n",
gst_value_serialize (&value2), gst_value_serialize (&value1));
check = g_value_get_double (&value1);
g_assert (fabs (value - check) <= prec);
}
static void
check_from_fraction_convert (gint nom, gint denom, gdouble prec)
{
GValue value1 = { 0 };
GValue value2 = { 0 };
gdouble value;
g_value_init (&value1, GST_TYPE_FRACTION);
g_value_init (&value2, G_TYPE_DOUBLE);
gst_value_set_fraction (&value1, nom, denom);
g_value_transform (&value1, &value2);
value = g_value_get_double (&value2);
g_assert (fabs (value - ((gdouble) nom) / denom) < prec);
g_print ("%s = %s, %2.50lf as double\n",
gst_value_serialize (&value1), gst_value_serialize (&value2), value);
g_value_transform (&value2, &value1);
g_print ("%s = %s\n",
gst_value_serialize (&value2), gst_value_serialize (&value1));
value = g_value_get_double (&value2);
g_assert (gst_value_get_fraction_numerator (&value1) == nom);
g_assert (gst_value_get_fraction_denominator (&value1) == denom);
g_value_unset (&value2);
g_value_unset (&value1);
}
static void
transform_test (void)
{
check_from_fraction_convert (30000, 1001, 1.0e-12);
check_from_fraction_convert (1, G_MAXINT, 1.0e-12);
check_from_fraction_convert (G_MAXINT, 1, 1.0e-12);
check_from_double_convert (0.0, 0, 1, 1.0e-12);
check_from_double_convert (1.0, 1, 1, 1.0e-12);
check_from_double_convert (-1.0, -1, 1, 1.0e-12);
check_from_double_convert (M_PI, 1881244168, 598818617, 1.0e-12);
check_from_double_convert (-M_PI, -1881244168, 598818617, 1.0e-12);
check_from_double_convert (G_MAXDOUBLE, G_MAXINT, 1, G_MAXDOUBLE);
check_from_double_convert (G_MINDOUBLE, 0, 1, G_MAXDOUBLE);
check_from_double_convert (-G_MAXDOUBLE, -G_MAXINT, 1, G_MAXDOUBLE);
check_from_double_convert (-G_MINDOUBLE, 0, 1, G_MAXDOUBLE);
check_from_double_convert (((gdouble) G_MAXINT) + 1, G_MAXINT, 1,
G_MAXDOUBLE);
check_from_double_convert (((gdouble) G_MININT) - 1, G_MININT + 1, 1,
G_MAXDOUBLE);
check_from_double_convert (G_MAXINT - 1, G_MAXINT - 1, 1, 0);
check_from_double_convert (G_MININT + 1, G_MININT + 1, 1, 0);
}
int
main (int argc, char *argv[])
{
gst_init (&argc, &argv);
transform_test ();
return 0;
}

1
testsuite/caps/Makefile.am
View file

@ -10,6 +10,7 @@ tests_pass = \
union \
string-conversions \
fixed \
fraction-convert \
fraction-multiply-and-zero \
intersect2 \
caps \

115
testsuite/caps/fraction-convert.c Normal file
View file

@ -0,0 +1,115 @@
/* GStreamer
*
* fraction-convert.c: test for GstFraction transform
*
* Copyright (C) <2004> Thomas Vander Stichele <thomas at apestaart dot org>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#include <math.h>
#include <gst/gst.h>
#include <glib.h>
static void
check_from_double_convert (gdouble value, gint nom, gint denom, gdouble prec)
{
GValue value1 = { 0 };
GValue value2 = { 0 };
gdouble check;
g_value_init (&value1, G_TYPE_DOUBLE);
g_value_init (&value2, GST_TYPE_FRACTION);
g_value_set_double (&value1, value);
g_value_transform (&value1, &value2);
g_print ("%s = %s\n",
gst_value_serialize (&value1), gst_value_serialize (&value2));
g_assert (gst_value_get_fraction_numerator (&value2) == nom);
g_assert (gst_value_get_fraction_denominator (&value2) == denom);
g_value_transform (&value2, &value1);
g_print ("%s = %s\n",
gst_value_serialize (&value2), gst_value_serialize (&value1));
check = g_value_get_double (&value1);
g_assert (fabs (value - check) <= prec);
}
static void
check_from_fraction_convert (gint nom, gint denom, gdouble prec)
{
GValue value1 = { 0 };
GValue value2 = { 0 };
gdouble value;
g_value_init (&value1, GST_TYPE_FRACTION);
g_value_init (&value2, G_TYPE_DOUBLE);
gst_value_set_fraction (&value1, nom, denom);
g_value_transform (&value1, &value2);
value = g_value_get_double (&value2);
g_assert (fabs (value - ((gdouble) nom) / denom) < prec);
g_print ("%s = %s, %2.50lf as double\n",
gst_value_serialize (&value1), gst_value_serialize (&value2), value);
g_value_transform (&value2, &value1);
g_print ("%s = %s\n",
gst_value_serialize (&value2), gst_value_serialize (&value1));
value = g_value_get_double (&value2);
g_assert (gst_value_get_fraction_numerator (&value1) == nom);
g_assert (gst_value_get_fraction_denominator (&value1) == denom);
g_value_unset (&value2);
g_value_unset (&value1);
}
static void
transform_test (void)
{
check_from_fraction_convert (30000, 1001, 1.0e-12);
check_from_fraction_convert (1, G_MAXINT, 1.0e-12);
check_from_fraction_convert (G_MAXINT, 1, 1.0e-12);
check_from_double_convert (0.0, 0, 1, 1.0e-12);
check_from_double_convert (1.0, 1, 1, 1.0e-12);
check_from_double_convert (-1.0, -1, 1, 1.0e-12);
check_from_double_convert (M_PI, 1881244168, 598818617, 1.0e-12);
check_from_double_convert (-M_PI, -1881244168, 598818617, 1.0e-12);
check_from_double_convert (G_MAXDOUBLE, G_MAXINT, 1, G_MAXDOUBLE);
check_from_double_convert (G_MINDOUBLE, 0, 1, G_MAXDOUBLE);
check_from_double_convert (-G_MAXDOUBLE, -G_MAXINT, 1, G_MAXDOUBLE);
check_from_double_convert (-G_MINDOUBLE, 0, 1, G_MAXDOUBLE);
check_from_double_convert (((gdouble) G_MAXINT) + 1, G_MAXINT, 1,
G_MAXDOUBLE);
check_from_double_convert (((gdouble) G_MININT) - 1, G_MININT + 1, 1,
G_MAXDOUBLE);
check_from_double_convert (G_MAXINT - 1, G_MAXINT - 1, 1, 0);
check_from_double_convert (G_MININT + 1, G_MININT + 1, 1, 0);
}
int
main (int argc, char *argv[])
{
gst_init (&argc, &argv);
transform_test ();
return 0;
}