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);
}
}