[FFmpeg-devel] [PATCH] avfilter/vf_scale: overwrite the width and eight expressions with the original values

[James Almer]

Instead of the potentially adjusted ones. Otherwise, if config_props() is
called again and if using force_original_aspect_ratio, the already adjusted
values could be altered again.

Example command line
scale=size=1920x1000:force_original_aspect_ratio=decrease:force_divisible_by=2

user value 1920x1000 -> 1920x798 on init_dict() -> 1918x798 on frame
change when eval_mode == EVAL_MODE_INIT, which after e645a1ddb9 could be at the
very first frame.

Signed-off-by: James Almer <jamrial at gmail.com>
---
 libavfilter/vf_scale.c | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/libavfilter/vf_scale.c b/libavfilter/vf_scale.c
index 996f7aaa5b..2b12cf283c 100644
--- a/libavfilter/vf_scale.c
+++ b/libavfilter/vf_scale.c
@@ -491,19 +491,19 @@ static int config_props(AVFilterLink *outlink)
     if ((ret = scale_eval_dimensions(ctx)) < 0)
         goto fail;
 
-    ff_scale_adjust_dimensions(inlink, &scale->w, &scale->h,
+    outlink->w = scale->w;
+    outlink->h = scale->h;
+
+    ff_scale_adjust_dimensions(inlink, &outlink->w, &outlink->h,
                                scale->force_original_aspect_ratio,
                                scale->force_divisible_by);
 
-    if (scale->w > INT_MAX ||
-        scale->h > INT_MAX ||
-        (scale->h * inlink->w) > INT_MAX ||
-        (scale->w * inlink->h) > INT_MAX)
+    if (outlink->w > INT_MAX ||
+        outlink->h > INT_MAX ||
+        (outlink->h * inlink->w) > INT_MAX ||
+        (outlink->w * inlink->h) > INT_MAX)
         av_log(ctx, AV_LOG_ERROR, "Rescaled value for width or height is too big.\n");
 
-    outlink->w = scale->w;
-    outlink->h = scale->h;
-
     /* TODO: make algorithm configurable */
 
     scale->input_is_pal = desc->flags & AV_PIX_FMT_FLAG_PAL;
@@ -718,9 +718,9 @@ static int scale_frame(AVFilterLink *link, AVFrame *in, AVFrame **frame_out)
             goto scale;
 
         if (scale->eval_mode == EVAL_MODE_INIT) {
-            snprintf(buf, sizeof(buf)-1, "%d", outlink->w);
+            snprintf(buf, sizeof(buf) - 1, "%d", scale->w);
             av_opt_set(scale, "w", buf, 0);
-            snprintf(buf, sizeof(buf)-1, "%d", outlink->h);
+            snprintf(buf, sizeof(buf) - 1, "%d", scale->h);
             av_opt_set(scale, "h", buf, 0);
 
             ret = scale_parse_expr(ctx, NULL, &scale->w_pexpr, "width", scale->w_expr);
-- 
2.37.2