diff options
| author | Tristan Schmelcher <tschmelcher@google.com> | 2022-09-26 20:14:09 +0300 |
|---|---|---|
| committer | Michael Niedermayer <michael@niedermayer.cc> | 2022-09-27 01:07:43 +0300 |
| commit | 179830108dbeb1c6b73105ae2234cf04874728b4 (patch) | |
| tree | 6a2e97cb5667d9a322d1bfd1f61082244a786811 /libavfilter/scale_eval.c | |
| parent | 543a46b4b2ff0f02fa85e45d7b7bcda19d3be9b4 (diff) | |
avfilter/scale_eval: Reduce rounding error.
When force_original_aspect_ratio and force_divisible_by are both
used, dimensions are now rounded to the nearest allowed multiple of
force_divisible_by rather than first rounding to the nearest integer and
then rounding in a static direction. This results in less distortion of
the aspect ratio.
Reviewed-by: Thierry Foucu <tfoucu@google.com>
Signed-off-by: Tristan Schmelcher <tschmelcher@google.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
Diffstat (limited to 'libavfilter/scale_eval.c')
| -rw-r--r-- | libavfilter/scale_eval.c | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/libavfilter/scale_eval.c b/libavfilter/scale_eval.c index dfec081e15..75ed503f15 100644 --- a/libavfilter/scale_eval.c +++ b/libavfilter/scale_eval.c @@ -148,14 +148,17 @@ int ff_scale_adjust_dimensions(AVFilterLink *inlink, * dimensions so that it is not divisible by the set factors anymore * unless force_divisible_by is defined as well */ if (force_original_aspect_ratio) { - int tmp_w = av_rescale(h, inlink->w, inlink->h); - int tmp_h = av_rescale(w, inlink->h, inlink->w); + // Including force_divisible_by here rounds to the nearest multiple of it. + int tmp_w = av_rescale(h, inlink->w, inlink->h * (int64_t)force_divisible_by) + * force_divisible_by; + int tmp_h = av_rescale(w, inlink->h, inlink->w * (int64_t)force_divisible_by) + * force_divisible_by; if (force_original_aspect_ratio == 1) { w = FFMIN(tmp_w, w); h = FFMIN(tmp_h, h); if (force_divisible_by > 1) { - // round down + // round down in case provided w or h is not divisible. w = w / force_divisible_by * force_divisible_by; h = h / force_divisible_by * force_divisible_by; } @@ -163,7 +166,7 @@ int ff_scale_adjust_dimensions(AVFilterLink *inlink, w = FFMAX(tmp_w, w); h = FFMAX(tmp_h, h); if (force_divisible_by > 1) { - // round up + // round up in case provided w or h is not divisible. w = (w + force_divisible_by - 1) / force_divisible_by * force_divisible_by; h = (h + force_divisible_by - 1) / force_divisible_by * force_divisible_by; } |