private void prevChunkButton_Click(object sender, EventArgs e)
{
var difference = endFrameNumericUpDown.Value - startFrameNumericUpDown.Value;
if (startFrameNumericUpDown.Value - difference < 1)
{
startFrameNumericUpDown.Value = 1;
endFrameNumericUpDown.Value = 1 + difference;
}
else
{
endFrameNumericUpDown.Value = startFrameNumericUpDown.Value - 1;
startFrameNumericUpDown.Value = endFrameNumericUpDown.Value - difference;
}
}