Add NTSC Support for FFmpegNativeEncoder

Util/Audio/AudioSyncCalculator.cs

@@ -16,6 +16,7 @@ namespace ADOFAIRenderer.Util.Audio
             _sampleRate = sampleRate;
             _fpsRational = RationalUtil.Double2MaxPrecisionInt(fps);
 
+            // NTSC
             if (Math.Abs(fps - 29.97) < 0.001) _fpsRational = (30000, 1001);
             if (Math.Abs(fps - 59.94) < 0.001) _fpsRational = (60000, 1001);
             if (Math.Abs(fps - 23.976) < 0.001 || Math.Abs(fps - 23.98) < 0.001) _fpsRational = (24000, 1001);