video: add libvlc_video_get_deinterlace()

Fixes #12884.

include/vlc/libvlc_media_player.h

@@ -2386,6 +2386,24 @@ int libvlc_video_take_snapshot( libvlc_media_player_t *p_mi, unsigned num,
                                 const char *psz_filepath, unsigned int i_width,
                                 unsigned int i_height );
 
+/**
+ * Gets the deinterlacing parameters.
+ *
+ * If \p modep is not NULL, it will be set to a heap-allocated nul-terminated
+ * character string indicating the current deinterlacing algorithm name.
+ * If no algorithm is selected or if allocation fails, it be set to NULL.
+ * The value should be freed with the C run-time's free() function to avoid
+ * leaking.
+ *
+ * \param mpi media player instance
+ * \param modep storage space for hold the mode name (or NULL) [OUT]
+ * \retval -1 deinterlacing is selected automatically
+ * \retval 0 deinterlacing is forcefully disabled
+ * \retval 1 deinterlacing is forcefully enabled
+ */
+LIBVLC_API int libvlc_video_get_deinterlace(libvlc_media_player_t *mp,
+                                            char **modep);
+
 /**
  * Enable or disable deinterlace filter
  *

lib/libvlc.sym

@@ -243,6 +243,7 @@ libvlc_video_get_adjust_int
 libvlc_video_get_aspect_ratio
 libvlc_video_get_size
 libvlc_video_get_cursor
+libvlc_video_get_deinterlace
 libvlc_video_get_logo_int
 libvlc_video_get_marquee_int
 libvlc_video_get_scale

lib/video.c

@@ -536,6 +536,20 @@ int libvlc_video_set_deinterlace( libvlc_media_player_t *p_mi, int deinterlace,
     return 0;
 }
 
+int libvlc_video_get_deinterlace(libvlc_media_player_t *mp, char **modep)
+{
+    int tristate = var_GetInteger(mp, "deinterlace");
+
+    if (modep != NULL) {
+        if (tristate != 0)
+            *modep = var_GetString(mp, "deinterlace-mode");
+        else
+            *modep = NULL;
+    }
+
+    return tristate;
+}
+
 /* ************** */
 /* module helpers */
 /* ************** */