private string GetSubtitleExpression (SubtitleFormat format, SubtitleProperties subtitleProperties, FileProperties fileProperties) { if (format.Mode == SubtitleMode.Both) { if (fileProperties.TimingMode == TimingMode.Times) return format.SubtitleOutTimesMode; else return format.SubtitleOutFramesMode; } else { if (format.SubtitleOut != null) return format.SubtitleOut; else return format.GetDynamicSubtitleOut(subtitleProperties); } }