From 1723f8a9d200bed5e225ba640411d06782cca8ca Mon Sep 17 00:00:00 2001
From: nanahi <130121847+na-na-hi@users.noreply.github.com>
Date: Wed, 18 Dec 2024 01:08:10 -0500
Subject: [PATCH] sd_ass: fix fix_margins calculation

Saving old playresx method is incorrect after the first
configure after the subtitle is loaded.

Fixes: f862d3b6cd66abee98f2af21c36255ef7361cb80
---
 sub/sd_ass.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/sub/sd_ass.c b/sub/sd_ass.c
index 3aef76c911c4c..4f9cd3eb48eeb 100644
--- a/sub/sd_ass.c
+++ b/sub/sd_ass.c
@@ -617,9 +617,10 @@ static void configure_ass(struct sd *sd, struct mp_osd_res *dim,
         if (override_playres) {
             int vidw = dim->w - (dim->ml + dim->mr);
             int vidh = dim->h - (dim->mt + dim->mb);
-            int old_playresx = track->PlayResX;
             track->PlayResX = track->PlayResY * (double)vidw / MPMAX(vidh, 1);
-            double fix_margins = track->PlayResX / (double)old_playresx;
+            // ffmpeg and mpv use a default PlayResX of 384 when it is not known,
+            // this comes from VSFilter.
+            double fix_margins = track->PlayResX / (double)MP_ASS_FONT_PLAYRESX;
             for (int n = 0; n < track->n_styles; n++) {
                 track->styles[n].MarginL = lrint(track->styles[n].MarginL * fix_margins);
                 track->styles[n].MarginR = lrint(track->styles[n].MarginR * fix_margins);