previewFrameOffset function
value as a position in the video, given the rate its frames run at.
Implementation
Duration previewFrameOffset(String value, double frameRate) {
final match = _timeCode.firstMatch(value)!;
final frames = int.parse(match.group(4)!);
return Duration(
hours: int.parse(match.group(1)!),
minutes: int.parse(match.group(2)!),
seconds: int.parse(match.group(3)!),
) +
Duration(microseconds: (frames * 1000000 / frameRate).round());
}