player: add --subs-with-matching-audio option

This allows users to control whether full dialogue subtitles are displayed
with an audio track already in their preferred subtitle language.

Additionally, this improves handling for the forced flag, automatically
selecting between forced and unforced subtitle streams based on the user's
settings and the selected audio.

1 files changed, 16 insertions, 5 deletions

diff --git a/player/loadfile.c b/player/loadfile.c
index 97ae9328f1..f8d5327acf 100644
--- a/player/loadfile.c
+++ b/player/loadfile.c
@@ -453,17 +453,19 @@ static int match_lang(char **langs, char *lang)
  * 1) track is external (no_default cancels this)
  * 1b) track was passed explicitly (is not an auto-loaded subtitle)
  * 2) earlier match in lang list
- * 3a) track is marked forced
- * 3b) track is marked default
+ * 3a) track is marked forced and we're preferring forced tracks
+ * 3b) track is marked non-forced and we're preferring non-forced tracks
+ * 3c) track is marked default
  * 4) attached picture, HLS bitrate
  * 5) lower track number
  * If select_fallback is not set, 5) is only used to determine whether a
  * matching track is preferred over another track. Otherwise, always pick a
  * track (if nothing else matches, return the track with lowest ID).
+ * Forced tracks are preferred when the user prefers not to display subtitles
  */
 // Return whether t1 is preferred over t2
 static bool compare_track(struct track *t1, struct track *t2, char **langs,
-                          struct MPOpts *opts)
+                          int prefer_forced, struct MPOpts *opts)
 {
     if (!opts->autoload_files && t1->is_external != t2->is_external)
         return !t1->is_external;
@@ -477,7 +479,7 @@ static bool compare_track(struct track *t1, struct track *t2, char **langs,
     if (l1 != l2)
         return l1 > l2;
     if (t1->forced_track != t2->forced_track)
-        return t1->forced_track;
+        return prefer_forced ? t1->forced_track : !t1->forced_track;
     if (t1->default_track != t2->default_track)
         return t1->default_track;
     if (t1->attached_picture != t2->attached_picture)
@@ -512,6 +514,10 @@ struct track *select_default_track(struct MPContext *mpctx, int order,
     struct MPOpts *opts = mpctx->opts;
     int tid = opts->stream_id[order][type];
     char **langs = opts->stream_lang[type];
+    int prefer_forced = type != STREAM_SUB ||
+                        (!opts->subs_with_matching_audio &&
+                         mpctx->current_track[0][STREAM_AUDIO] &&
+                         match_lang(langs, mpctx->current_track[0][STREAM_AUDIO]->lang));
     if (tid == -2)
         return NULL;
     bool select_fallback = type == STREAM_VIDEO || type == STREAM_AUDIO;
@@ -528,7 +534,7 @@ struct track *select_default_track(struct MPContext *mpctx, int order,
             continue;
         if (duplicate_track(mpctx, order, type, track))
             continue;
-        if (!pick || compare_track(track, pick, langs, mpctx->opts))
+        if (!pick || compare_track(track, pick, langs, prefer_forced, mpctx->opts))
             pick = track;
     }
     if (pick && !select_fallback && !(pick->is_external && !pick->no_default)
@@ -539,6 +545,9 @@ struct track *select_default_track(struct MPContext *mpctx, int order,
         pick = NULL;
     if (pick && !opts->autoload_files && pick->is_external)
         pick = NULL;
+    if (pick && type == STREAM_SUB && prefer_forced && !pick->forced_track &&
+        opts->subs_rend->forced_subs_only == -1)
+        opts->subs_rend->forced_subs_only_current = 1;
     return pick;
 }
 
@@ -1522,6 +1531,8 @@ static void play_current_file(struct MPContext *mpctx)
     if (reinit_complex_filters(mpctx, false) < 0)
         goto terminate_playback;
 
+    opts->subs_rend->forced_subs_only_current = (opts->subs_rend->forced_subs_only == 1) ? 1 : 0;
+
     for (int t = 0; t < STREAM_TYPE_COUNT; t++) {
         for (int i = 0; i < num_ptracks[t]; i++) {
             struct track *sel = NULL;