[FFmpeg-cvslog] avfilter/f_ebur128: multiply in integer first, before dividing in float

[Hendrik Leppkes]

ffmpeg | branch: master | Hendrik Leppkes <h.leppkes at gmail.com> | Tue Apr  5 22:37:22 2022 +0200| [cd96211ace22224e27d00ed8bf92955e48ebff73] | committer: Hendrik Leppkes

avfilter/f_ebur128: multiply in integer first, before dividing in float

Restores the order of operations from before 15a1104, which reduces
errors from floating point calculations, and fixes FATE on mingw64.

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=cd96211ace22224e27d00ed8bf92955e48ebff73
---

 libavfilter/f_ebur128.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/libavfilter/f_ebur128.c b/libavfilter/f_ebur128.c
index 1b1bcf1bff..a036aa0c86 100644
--- a/libavfilter/f_ebur128.c
+++ b/libavfilter/f_ebur128.c
@@ -768,7 +768,7 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *insamples)
 
                     /* get lower loudness to consider */
                     n = 0;
-                    nb_pow = LRA_LOWER_PRC * 0.01 * nb_powers + 0.5;
+                    nb_pow = LRA_LOWER_PRC * nb_powers * 0.01 + 0.5;
                     for (i = gate_hist_pos; i < HIST_SIZE; i++) {
                         n += ebur128->i3000.histogram[i].count;
                         if (n >= nb_pow) {
@@ -779,7 +779,7 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *insamples)
 
                     /* get higher loudness to consider */
                     n = nb_powers;
-                    nb_pow = LRA_HIGHER_PRC * 0.01 * nb_powers + 0.5;
+                    nb_pow = LRA_HIGHER_PRC * nb_powers * 0.01 + 0.5;
                     for (i = HIST_SIZE - 1; i >= 0; i--) {
                         n -= FFMIN(n, ebur128->i3000.histogram[i].count);
                         if (n < nb_pow) {