Commit 8b94094253 for ffmpeg
commit 8b940942533aa4e1282092dc03a09bc760d0b234
Author: Kacper Michajłow <kasper93@gmail.com>
Date: Wed Sep 30 00:10:42 2026 +0200
avutil/rational: fix the sign handling in av_q2intfloat()
The sign was shifted into bit 31 of an int and INT_MIN was negated as an
int, both undefined. Negate in int64_t and keep the sign as the bit
itself. A negative value over zero now gives a negative infinity, the
sign of an infinity was read from the numerator after it had been made
positive.
Signed-off-by: Kacper Michajłow <kasper93@gmail.com>
diff --git a/libavutil/rational.c b/libavutil/rational.c
index fdb1da7f48..d2a92fdda8 100644
--- a/libavutil/rational.c
+++ b/libavutil/rational.c
@@ -152,37 +152,37 @@ int av_find_nearest_q_idx(AVRational q, const AVRational* q_list)
}
uint32_t av_q2intfloat(AVRational q) {
- int64_t n;
+ int64_t n, num = q.num, den = q.den;
int shift;
- int sign = 0;
+ uint32_t sign = 0;
- if (q.den < 0) {
- q.den *= -1;
- q.num *= -1;
+ if (den < 0) {
+ den = -den;
+ num = -num;
}
- if (q.num < 0) {
- q.num *= -1;
- sign = 1;
+ if (num < 0) {
+ num = -num;
+ sign = 1U << 31;
}
- if (!q.num && !q.den) return 0xFFC00000;
- if (!q.num) return 0;
- if (!q.den) return 0x7F800000 | (q.num & 0x80000000);
+ if (!num && !den) return 0xFFC00000;
+ if (!num) return 0;
+ if (!den) return sign | 0x7F800000;
- 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 = 23 + av_log2(den) - av_log2(num);
+ if (shift >= 0) n = av_rescale(num, 1LL<<shift, den);
+ else n = av_rescale(num, 1, 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);
+ if (shift >= 0) n = av_rescale(num, 1LL<<shift, den);
+ else n = av_rescale(num, 1, den << -shift);
av_assert1(n < (1<<24));
av_assert1(n >= (1<<23));
- return sign<<31 | (150-shift)<<23 | (n - (1<<23));
+ return sign | (150-shift)<<23 | (n - (1<<23));
}
AVRational av_gcd_q(AVRational a, AVRational b, int max_den, AVRational def)