ytdl_hook: add ytdl-prefer-srv3 option

Author: afishhh

DOCS/man/options.rst

@@ -1039,6 +1039,15 @@ Program Behavior
 ``--ytdl-extract-chapters=<yes|no>``
     Enable chapter extracting from youtube-dl video description (default: yes).
 
+``--ytdl-prefer-srv3=<yes|no>``
+    Allow youtube-dl to download srv3 subtitles and prefer them over other formats.
+    Only available if mpv was compiled with subrandr enabled.
+    (default: no)
+
+    This will prepend `srv3/` to the default allowed ytdl `--sub-format`s.
+    Preferring srv3 will make YouTube subtitles display more accurately but
+    ignore most of the various `--sub-*` options that override styling.
+
 ``--js-memory-report=<yes|no>``
     Enable memory reporting for javascript scripts in the stats overlay.
     This is disabled by default because it has an overhead and increases

options/options.c

@@ -557,6 +557,9 @@ static const m_option_t mp_opts[] = {
     {"ytdl-format", OPT_STRING(lua_ytdl_format)},
     {"ytdl-raw-options", OPT_KEYVALUELIST(lua_ytdl_raw_options)},
     {"ytdl-extract-chapters", OPT_BOOL(lua_ytdl_extract_chapters)},
+#if HAVE_SUBRANDR
+    {"ytdl-prefer-srv3", OPT_BOOL(lua_ytdl_prefer_srv3)},
+#endif
     {"load-stats-overlay", OPT_BOOL(lua_load_stats),
         .flags = UPDATE_BUILTIN_SCRIPTS},
     {"load-console", OPT_BOOL(lua_load_console),

options/options.h

@@ -177,6 +177,7 @@ typedef struct MPOpts {
     char *lua_ytdl_format;
     char **lua_ytdl_raw_options;
     bool lua_ytdl_extract_chapters;
+    bool lua_ytdl_prefer_srv3;
     bool lua_load_stats;
     bool lua_load_console;
     int lua_load_auto_profiles;

player/lua/ytdl_hook.lua

@@ -908,12 +908,13 @@ local function run_ytdl_hook(url)
 
     local format = mp.get_property("options/ytdl-format")
     local raw_options = mp.get_property_native("options/ytdl-raw-options")
+    local prefer_srv3 = mp.get_property_native("options/ytdl-prefer-srv3")
     local allsubs = true
     local proxy = nil
     local use_playlist = false
     local wanted_sub_formats = "ass/srt/best"
 
-    if has_subrandr then
+    if prefer_srv3 then
         wanted_sub_formats = "srv3/" .. wanted_sub_formats
     end