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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-19 00:47:55 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-19 00:47:55 +0000
commit26a029d407be480d791972afb5975cf62c9360a6 (patch)
treef435a8308119effd964b339f76abb83a57c29483 /media/ffvpx/libavutil/rational.c
parentInitial commit. (diff)
downloadfirefox-26a029d407be480d791972afb5975cf62c9360a6.tar.xz
firefox-26a029d407be480d791972afb5975cf62c9360a6.zip
Adding upstream version 124.0.1.upstream/124.0.1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'media/ffvpx/libavutil/rational.c')
-rw-r--r--media/ffvpx/libavutil/rational.c193
1 files changed, 193 insertions, 0 deletions
diff --git a/media/ffvpx/libavutil/rational.c b/media/ffvpx/libavutil/rational.c
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+/*
+ * rational numbers
+ * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/**
+ * @file
+ * rational numbers
+ * @author Michael Niedermayer <michaelni@gmx.at>
+ */
+
+#include "avassert.h"
+#include <limits.h>
+
+#include "common.h"
+#include "mathematics.h"
+#include "rational.h"
+
+int av_reduce(int *dst_num, int *dst_den,
+ int64_t num, int64_t den, int64_t max)
+{
+ AVRational a0 = { 0, 1 }, a1 = { 1, 0 };
+ int sign = (num < 0) ^ (den < 0);
+ int64_t gcd = av_gcd(FFABS(num), FFABS(den));
+
+ if (gcd) {
+ num = FFABS(num) / gcd;
+ den = FFABS(den) / gcd;
+ }
+ if (num <= max && den <= max) {
+ a1 = (AVRational) { num, den };
+ den = 0;
+ }
+
+ while (den) {
+ uint64_t x = num / den;
+ int64_t next_den = num - den * x;
+ int64_t a2n = x * a1.num + a0.num;
+ int64_t a2d = x * a1.den + a0.den;
+
+ if (a2n > max || a2d > max) {
+ if (a1.num) x = (max - a0.num) / a1.num;
+ if (a1.den) x = FFMIN(x, (max - a0.den) / a1.den);
+
+ if (den * (2 * x * a1.den + a0.den) > num * a1.den)
+ a1 = (AVRational) { x * a1.num + a0.num, x * a1.den + a0.den };
+ break;
+ }
+
+ a0 = a1;
+ a1 = (AVRational) { a2n, a2d };
+ num = den;
+ den = next_den;
+ }
+ av_assert2(av_gcd(a1.num, a1.den) <= 1U);
+ av_assert2(a1.num <= max && a1.den <= max);
+
+ *dst_num = sign ? -a1.num : a1.num;
+ *dst_den = a1.den;
+
+ return den == 0;
+}
+
+AVRational av_mul_q(AVRational b, AVRational c)
+{
+ av_reduce(&b.num, &b.den,
+ b.num * (int64_t) c.num,
+ b.den * (int64_t) c.den, INT_MAX);
+ return b;
+}
+
+AVRational av_div_q(AVRational b, AVRational c)
+{
+ return av_mul_q(b, (AVRational) { c.den, c.num });
+}
+
+AVRational av_add_q(AVRational b, AVRational c) {
+ av_reduce(&b.num, &b.den,
+ b.num * (int64_t) c.den +
+ c.num * (int64_t) b.den,
+ b.den * (int64_t) c.den, INT_MAX);
+ return b;
+}
+
+AVRational av_sub_q(AVRational b, AVRational c)
+{
+ return av_add_q(b, (AVRational) { -c.num, c.den });
+}
+
+AVRational av_d2q(double d, int max)
+{
+ AVRational a;
+ int exponent;
+ int64_t den;
+ if (isnan(d))
+ return (AVRational) { 0,0 };
+ if (fabs(d) > INT_MAX + 3LL)
+ return (AVRational) { d < 0 ? -1 : 1, 0 };
+ frexp(d, &exponent);
+ exponent = FFMAX(exponent-1, 0);
+ den = 1LL << (61 - exponent);
+ // (int64_t)rint() and llrint() do not work with gcc on ia64 and sparc64,
+ // see Ticket2713 for affected gcc/glibc versions
+ av_reduce(&a.num, &a.den, floor(d * den + 0.5), den, max);
+ if ((!a.num || !a.den) && d && max>0 && max<INT_MAX)
+ av_reduce(&a.num, &a.den, floor(d * den + 0.5), den, INT_MAX);
+
+ return a;
+}
+
+int av_nearer_q(AVRational q, AVRational q1, AVRational q2)
+{
+ /* n/d is q, a/b is the median between q1 and q2 */
+ int64_t a = q1.num * (int64_t)q2.den + q2.num * (int64_t)q1.den;
+ int64_t b = 2 * (int64_t)q1.den * q2.den;
+
+ /* rnd_up(a*d/b) > n => a*d/b > n */
+ int64_t x_up = av_rescale_rnd(a, q.den, b, AV_ROUND_UP);
+
+ /* rnd_down(a*d/b) < n => a*d/b < n */
+ int64_t x_down = av_rescale_rnd(a, q.den, b, AV_ROUND_DOWN);
+
+ return ((x_up > q.num) - (x_down < q.num)) * av_cmp_q(q2, q1);
+}
+
+int av_find_nearest_q_idx(AVRational q, const AVRational* q_list)
+{
+ int i, nearest_q_idx = 0;
+ for (i = 0; q_list[i].den; i++)
+ if (av_nearer_q(q, q_list[i], q_list[nearest_q_idx]) > 0)
+ nearest_q_idx = i;
+
+ return nearest_q_idx;
+}
+
+uint32_t av_q2intfloat(AVRational q) {
+ int64_t n;
+ int shift;
+ int sign = 0;
+
+ if (q.den < 0) {
+ q.den *= -1;
+ q.num *= -1;
+ }
+ if (q.num < 0) {
+ q.num *= -1;
+ sign = 1;
+ }
+
+ if (!q.num && !q.den) return 0xFFC00000;
+ if (!q.num) return 0;
+ if (!q.den) return 0x7F800000 | (q.num & 0x80000000);
+
+ shift = 23 + av_log2(q.den) - av_log2(q.num);
+ if (shift >= 0) n = av_rescale(q.num, 1LL<<shift, q.den);
+ else n = av_rescale(q.num, 1, ((int64_t)q.den) << -shift);
+
+ shift -= n >= (1<<24);
+ shift += n < (1<<23);
+
+ if (shift >= 0) n = av_rescale(q.num, 1LL<<shift, q.den);
+ else n = av_rescale(q.num, 1, ((int64_t)q.den) << -shift);
+
+ av_assert1(n < (1<<24));
+ av_assert1(n >= (1<<23));
+
+ return sign<<31 | (150-shift)<<23 | (n - (1<<23));
+}
+
+AVRational av_gcd_q(AVRational a, AVRational b, int max_den, AVRational def)
+{
+ int64_t gcd, lcm;
+
+ gcd = av_gcd(a.den, b.den);
+ lcm = (a.den / gcd) * b.den;
+ return lcm < max_den ? av_make_q(av_gcd(a.num, b.num), lcm) : def;
+}