1 files changed, 2 insertions, 0 deletions
diff --git a/sub/dec_sub.c b/sub/dec_sub.c
index 79884576b0..cc608c3ca5 100644
--- a/sub/dec_sub.c
+++ b/sub/dec_sub.c
@@ -531,6 +531,8 @@ bool sub_has_get_text(struct dec_sub *sub)
 }
 
 // See sub_get_bitmaps() for locking requirements.
+// It can be called unlocked too, but then only 1 thread must call this function
+// at a time (unless exclusive access is guaranteed).
 char *sub_get_text(struct dec_sub *sub, double pts)
 {
     pthread_mutex_lock(&sub->lock);