Label.cs

using System;
using System.Collections.Generic;
using System.IO;
using System.Runtime.CompilerServices;

namespace QuickLook.Plugin.WavLabelViewer;

public class LabelLine
{
    public double Start { get; set; }
    public double End { get; set; }
    public string Text { get; set; }

    public static LabelLine[] LoadFrom(string labelPath)
    {
        var labelLines = new List<LabelLine>();
        var labelText = File.ReadAllText(labelPath);
        string[] labLines = labelText.Split(['\n'], StringSplitOptions.RemoveEmptyEntries);
        foreach (var labLine in labLines)
        {
            var lineSegs = labLine.Split([' '], 3);
            var start = Convert100nSecondToSecond(double.Parse(lineSegs[0]));
            var end = Convert100nSecondToSecond(double.Parse(lineSegs[1]));
            var text = lineSegs[2].TrimEnd();
            labelLines.Add(new LabelLine { Start = start, End = end, Text = text });
        }

        return labelLines.ToArray();
    }

    public const double LAB_100NS_OFFSET = 10_000_000.0;

    [MethodImpl(MethodImplOptions.AggressiveInlining)]
    public static double Convert100nSecondToSecond(double ns) => ns / LAB_100NS_OFFSET;
}