From 8ab3f8b66dcf2c2471f4dbba5cee21cda06843b7 Mon Sep 17 00:00:00 2001
From: idontwannagoo <35237425+idontwannagoo@users.noreply.github.com>
Date: Sat, 4 Jul 2026 19:55:09 +0800
Subject: [PATCH] options: add secondary-sub-scale

This allows scaling secondary subtitles independently from primary subtitles. The option defaults to 1 like --sub-scale and follows the other secondary-sub-* options by not inheriting from the primary subtitle setting.

Fixes #14989.
---
 DOCS/interface-changes/secondary-sub-scale.txt | 2 ++
 DOCS/man/options.rst                           | 4 ++++
 options/options.c                              | 7 +++++--
 options/options.h                              | 2 +-
 player/command.c                               | 1 +
 sub/sd_ass.c                                   | 3 ++-
 sub/sd_lavc.c                                  | 4 ++--
 7 files changed, 17 insertions(+), 6 deletions(-)
 create mode 100644 DOCS/interface-changes/secondary-sub-scale.txt

diff --git a/DOCS/interface-changes/secondary-sub-scale.txt b/DOCS/interface-changes/secondary-sub-scale.txt
new file mode 100644
index 0000000000..0119db9310
--- /dev/null
+++ b/DOCS/interface-changes/secondary-sub-scale.txt
@@ -0,0 +1,2 @@
+add `--secondary-sub-scale` option
+`--sub-scale` now only affects primary subtitles
diff --git a/DOCS/man/options.rst b/DOCS/man/options.rst
index 0febce1bf8..f14254c6c6 100644
--- a/DOCS/man/options.rst
+++ b/DOCS/man/options.rst
@@ -2518,6 +2518,10 @@ Subtitles
         This affects ASS subtitles as well, and may lead to incorrect subtitle
         rendering. Use with care, or use ``--sub-font-size`` instead.
 
+``--secondary-sub-scale=<0-100>``
+    Factor for the secondary subtitle font size. This is similar to
+    ``--sub-scale`` but for secondary subtitles (default: 1).
+
 ``--sub-scale-signs=<yes|no>``
     When set to yes, also apply ``--sub-scale`` to typesetting (or "signs").
     When this is set to no, ``--sub-scale`` is only applied to dialogue. The
diff --git a/options/options.c b/options/options.c
index bab7e324ca..7ddc532ffc 100644
--- a/options/options.c
+++ b/options/options.c
@@ -316,7 +316,6 @@ const struct m_sub_options mp_subtitle_sub_opts = {
         {"sub-gauss", OPT_FLOAT(sub_gauss), M_RANGE(0.0, 3.0)},
         {"sub-gray", OPT_BOOL(sub_gray)},
         {"sub-ass", OPT_BOOL(ass_enabled), .flags = UPDATE_SUB_HARD},
-        {"sub-scale", OPT_FLOAT(sub_scale), M_RANGE(0, 100)},
         {"sub-scale-signs", OPT_BOOL(sub_scale_signs)},
         {"sub-line-spacing", OPT_FLOAT(sub_line_spacing), M_RANGE(-1000, 1000)},
         {"sub-ass-line-spacing", OPT_REPLACED("sub-line-spacing")},
@@ -366,7 +365,6 @@ const struct m_sub_options mp_subtitle_sub_opts = {
         .sub_scale_with_window = true,
         .ass_prune_delay = -1.0,
         .teletext_page = 0,
-        .sub_scale = 1,
         .ass_vsfilter_color_compat = 1,
         .ass_use_video_data = 2,
         .ass_video_aspect = 0,
@@ -385,6 +383,8 @@ const struct m_sub_options mp_subtitle_shared_sub_opts = {
         {"secondary-sub-delay", OPT_DOUBLE(sub_delay[1])},
         {"sub-pos", OPT_FLOAT(sub_pos[0]), M_RANGE(0.0, 150.0)},
         {"secondary-sub-pos", OPT_FLOAT(sub_pos[1]), M_RANGE(0.0, 150.0)},
+        {"sub-scale", OPT_FLOAT(sub_scale[0]), M_RANGE(0, 100)},
+        {"secondary-sub-scale", OPT_FLOAT(sub_scale[1]), M_RANGE(0, 100)},
         {"sub-visibility", OPT_BOOL(sub_visibility[0])},
         {"secondary-sub-visibility", OPT_BOOL(sub_visibility[1])},
         {"sub-ass-override", OPT_CHOICE(ass_style_override[0],
@@ -408,6 +408,8 @@ const struct m_sub_options mp_subtitle_shared_sub_opts = {
         .sub_visibility[0] = true,
         .sub_visibility[1] = true,
         .sub_pos[0] = 100,
+        .sub_scale[0] = 1,
+        .sub_scale[1] = 1,
         .ass_style_override[0] = ASS_STYLE_OVERRIDE_SCALE,
         .ass_style_override[1] = ASS_STYLE_OVERRIDE_STRIP,
     },
@@ -1190,6 +1192,7 @@ static const struct MPOpts mp_default_opts = {
         "secondary-sid",
         "secondary-sub-delay",
         "secondary-sub-pos",
+        "secondary-sub-scale",
         "secondary-sub-ass-override",
         "secondary-sub-visibility",
         "ab-loop-a",
diff --git a/options/options.h b/options/options.h
index d7b9542e27..c9484967e4 100644
--- a/options/options.h
+++ b/options/options.h
@@ -110,7 +110,6 @@ struct mp_subtitle_opts {
     bool sub_scale_with_window;
     bool ass_scale_with_window;
     struct osd_style_opts *sub_style;
-    float sub_scale;
     bool sub_scale_signs;
     float sub_gauss;
     bool sub_gray;
@@ -141,6 +140,7 @@ struct mp_subtitle_opts {
 struct mp_subtitle_shared_opts {
     double sub_delay[2];
     float sub_pos[2];
+    float sub_scale[2];
     bool sub_visibility[2];
     int ass_style_override[2];
 };
diff --git a/player/command.c b/player/command.c
index 32a756f9cb..a0dccf4a37 100644
--- a/player/command.c
+++ b/player/command.c
@@ -5098,6 +5098,7 @@ static const struct property_osd_display {
       "${?secondary-sub-visibility==yes:visible${?secondary-sid==no: (but no secondary subtitles selected)}}"},
     {"sub-forced-events-only", "Forced sub only"},
     {"sub-scale", "Sub Scale"},
+    {"secondary-sub-scale", "Secondary sub scale"},
     {"sub-ass-use-video-data", "Subtitle using video properties"},
     {"sub-ass-video-aspect-override", "Subtitle aspect override"},
     {"sub-ass-override", "ASS subtitle style override"},
diff --git a/sub/sd_ass.c b/sub/sd_ass.c
index 50d900e490..db4d67daca 100644
--- a/sub/sd_ass.c
+++ b/sub/sd_ass.c
@@ -539,6 +539,7 @@ static void configure_ass(struct sd *sd, struct mp_osd_res *dim,
     bool set_scale_with_window = false;
     bool set_scale_by_window = true;
     bool total_override = false;
+
     // With forced overrides, apply the --sub-* specific options
     if (converted || shared_opts->ass_style_override[sd->order] == ASS_STYLE_OVERRIDE_FORCE) {
         set_scale_with_window = opts->sub_scale_with_window;
@@ -555,7 +556,7 @@ static void configure_ass(struct sd *sd, struct mp_osd_res *dim,
         set_hinting = opts->sub_hinting;
     }
     if (total_override || shared_opts->ass_style_override[sd->order] == ASS_STYLE_OVERRIDE_SCALE) {
-        set_font_scale = opts->sub_scale;
+        set_font_scale = shared_opts->sub_scale[sd->order];
     }
     if (set_scale_with_window) {
         set_font_scale *= dim->h / MPMAX(get_libass_scale_height(dim, set_use_margins), 1);
diff --git a/sub/sd_lavc.c b/sub/sd_lavc.c
index 5cbc6d0a21..5096648c60 100644
--- a/sub/sd_lavc.c
+++ b/sub/sd_lavc.c
@@ -526,11 +526,11 @@ static struct sub_bitmaps *get_bitmaps(struct sd *sd, struct mp_osd_res d,
 
     osd_rescale_bitmaps(res, w, h, d, video_par);
 
-    if (opts->sub_scale != 1.0 && shared_opts->ass_style_override[sd->order]) {
+    if (shared_opts->sub_scale[sd->order] != 1.0 && shared_opts->ass_style_override[sd->order]) {
         for (int n = 0; n < res->num_parts; n++) {
             struct sub_bitmap *sub = &res->parts[n];
 
-            float shit = (opts->sub_scale - 1.0f) / 2;
+            float shit = (shared_opts->sub_scale[sd->order] - 1.0f) / 2;
 
             // Fortunately VO isn't supposed to give a FUCKING FUCK about
             // whether the sub might e.g. go outside of the screen.