Use FFMPEG to check for mastering display metadata, for enabling Disp…

…lay-P3 primaries

Ref: mpv-player/mpv#9620

iina/VideoView.swift

@@ -301,7 +301,20 @@ extension VideoView {
       return false;
     }
 
-    guard let primaries = mpv.getString(MPVProperty.videoParamsPrimaries), let gamma = mpv.getString(MPVProperty.videoParamsGamma) else { return false }
+    guard var primaries = mpv.getString(MPVProperty.videoParamsPrimaries), var gamma = mpv.getString(MPVProperty.videoParamsGamma) else { return false }
+
+    // Because MPV won't check for mastering display metadata, we have to check it ourselves
+    // TODO: Supports multi-track video source. Maps MPV `player.info.vid` to FFMPEG `streamIndex`
+    if primaries == "bt.2020" && !player.info.isNetworkResource && player.info.videoTracks.count == 1 {
+      if let path = mpv.getString(MPVProperty.path), let colorspaceData = FFmpegController.getColorSpaceMetadata(forFile: path) {
+        if let _primaries = colorspaceData["primaries"] as? String {
+          primaries = _primaries
+        }
+        if let _gamma = colorspaceData["color-trc"] as? String {
+          gamma = _gamma
+        }
+      }
+    }
 
     var name: CFString? = nil;
     switch primaries {