player: add forced choice to subs-with-matching-audio

fe875083b3 confused things a bit and made
--no-subs-with-matching-audio actually mean what it says: no subtitles
if the languages match. However, the option actually meant no non-forced
subtitles not no subtitles at all. This isn't really intuitive so
instead of changing the behavior back to the old way (we already have a
release since then), add a third option "forced" which is equivalent to
the old meaning of --no-subs-with-matching audio. Fixes #13151.

DOCS/interface-changes.rst

@@ -37,6 +37,7 @@ Interface changes
     - rename key `MP_KEY_BACK` to `MP_KEY_GO_BACK`
     - add `--sub-filter-sdh-enclosures` option
     - added the `mp.input` scripting API to query the user for textual input
+    - add `forced` choice to `subs-with-matching-audio`
  --- mpv 0.37.0 ---
     - `--save-position-on-quit` and its associated commands now store state files
       in %LOCALAPPDATA% instead of %APPDATA% directory by default on Windows.

DOCS/man/options.rst

@@ -135,11 +135,13 @@ Track Selection
     Note that if ``--lavfi-complex`` is set before playback is started, the
     referenced tracks are always selected.
 
-``--subs-with-matching-audio=<yes|no>``
-    When autoselecting a subtitle track, select a full/non-forced one even if the selected
-    audio stream matches your preferred subtitle language (default: yes). If this option is
-    set to ``no``, a non-forced subtitle track that matches the audio language will never be
-    autoselected by mpv regardless of the value of ``--slang`` or ``--subs-fallback``.
+``--subs-with-matching-audio=<yes|forced|no>``
+    When autoselecting a subtitle track, select it even if the selected audio
+    stream matches you preferred subtitle language (default: yes). If this
+    option is set to ``no``, then no subtitle track that matches the audio
+    language will ever be autoselected by mpv regardless of ``--slang`` or
+    ``subs-fallback``. If set to ``forced``, then only forced subtitles
+    will be selected.
 
 ``--subs-match-os-language=<yes|no>``
     When autoselecting a subtitle track, select the track that matches the language of your OS

options/options.c

@@ -585,7 +585,8 @@ static const m_option_t mp_opts[] = {
     {"slang", OPT_STRINGLIST(stream_lang[STREAM_SUB])},
     {"vlang", OPT_STRINGLIST(stream_lang[STREAM_VIDEO])},
     {"track-auto-selection", OPT_BOOL(stream_auto_sel)},
-    {"subs-with-matching-audio", OPT_BOOL(subs_with_matching_audio)},
+    {"subs-with-matching-audio", OPT_CHOICE(subs_with_matching_audio, {"no", 0},
+        {"forced", 1}, {"yes", 2})},
     {"subs-match-os-language", OPT_BOOL(subs_match_os_language)},
     {"subs-fallback", OPT_CHOICE(subs_fallback, {"no", 0}, {"default", 1}, {"yes", 2})},
     {"subs-fallback-forced", OPT_CHOICE(subs_fallback_forced, {"no", 0},
@@ -984,7 +985,7 @@ static const struct MPOpts mp_default_opts = {
                      [STREAM_VIDEO] = -2,
                      [STREAM_SUB] = -2, }, },
     .stream_auto_sel = true,
-    .subs_with_matching_audio = true,
+    .subs_with_matching_audio = 2,
     .subs_match_os_language = true,
     .subs_fallback = 1,
     .subs_fallback_forced = 1,

options/options.h

@@ -279,7 +279,7 @@ typedef struct MPOpts {
     int stream_id[2][STREAM_TYPE_COUNT];
     char **stream_lang[STREAM_TYPE_COUNT];
     bool stream_auto_sel;
-    bool subs_with_matching_audio;
+    int subs_with_matching_audio;
     bool subs_match_os_language;
     int subs_fallback;
     int subs_fallback_forced;

player/loadfile.c

@@ -673,9 +673,12 @@ struct track *select_default_track(struct MPContext *mpctx, int order,
     if (pick && !forced_pick && sub && (!match_lang(langs, pick->lang) || os_langs) && !sub_fallback)
         pick = NULL;
     // Handle this after matching langs and selecting a fallback.
-    if (pick && sub && (!opts->subs_with_matching_audio && audio_matches))
+    if (pick && sub && ((!opts->subs_with_matching_audio && audio_matches) ||
+        (opts->subs_with_matching_audio == 1 && audio_matches && !forced_pick)))
+    {
         pick = NULL;
-    // Handle edge cases if we picked a track that doesn't match the --subs-fallback-force value
+    }
+    // Handle edge cases if we picked a track that doesn't match the --subs-fallback-forced value
     if (pick && sub && ((!pick->forced_track && opts->subs_fallback_forced == 2) ||
         (pick->forced_track && !opts->subs_fallback_forced)))
     {