    ﻿using System;
    using System.Collections.Generic;
    using System.Text;
    using System.Text.RegularExpressions;

    namespace Nikse.SubtitleEdit.Core.SubtitleFormats
    {
        public class Titra : SubtitleFormat
        {
            //* 1 : 01:01:31:19 01:01:33:04 22c
            private static readonly Regex RegexTimeCodes = new Regex(@"^\* \d+ :\t\d\d:\d\d:\d\d:\d\d\t\d\d:\d\d:\d\d:\d\d\t\d+c", RegexOptions.Compiled);

            public override string Extension => ".txt";

            public override string Name => "Titra";

            private static int GetMaxCharsForDuration(double durationSeconds)
            {
                return (int)Math.Round(15.7 * durationSeconds);
            }

            public override string ToText(Subtitle subtitle, string title)
            {
                var sb = new StringBuilder();
                sb.AppendLine(@"TVS - TITRA FILM

    Titre VO :   L'heure d'été
    Titre VST :
    Création :   23/10/2009 - 16:31
    Révision :   26/10/2009 - 17:48
    Langue VO :  Français
    Langue VST : Espagnol
    Bobine :     e01

    BEWARE : No more than 40 characters ON A LINE
    ATTENTION : Pas plus de 40 caractères PAR LIGNE

    ");
                const string writeFormat = "* {0} :\t{1}\t{2}\t{3}{4}{5}";
                int index = 0;
                foreach (Paragraph p in subtitle.Paragraphs)
                {
                    index++;
                    var text = HtmlUtil.RemoveHtmlTags(p.Text, true);
                    sb.AppendLine(string.Format(writeFormat, index, EncodeTimeCode(p.StartTime), EncodeTimeCode(p.EndTime), GetMaxCharsForDuration(p.Duration.TotalSeconds) + "c", Environment.NewLine, text));
                    sb.AppendLine();
                    if (!text.Contains(Environment.NewLine))
                        sb.AppendLine();
                }
                return sb.ToString();
            }

            private static string EncodeTimeCode(TimeCode time)
            {
                //00:03:15:22 (last is frame)
                return time.ToHHMMSSFF();
            }

            public override void LoadSubtitle(Subtitle subtitle, List<string> lines, string fileName)
            {
                //00:03:15:22 00:03:23:10 This is line one.
                //This is line two.
                Paragraph p = null;
                _errorCount = 0;
                subtitle.Paragraphs.Clear();
                foreach (string line in lines)
                {
                    if (RegexTimeCodes.IsMatch(line))
                    {
                        try
                        {
                            var arr = line.Split('\t');
                            string start = arr[1];
                            string end = arr[2];

                            string[] startParts = start.Split(SplitCharColon, StringSplitOptions.RemoveEmptyEntries);
                            string[] endParts = end.Split(SplitCharColon, StringSplitOptions.RemoveEmptyEntries);
                            if (startParts.Length == 4 && endParts.Length == 4)
                            {
                                p = new Paragraph(DecodeTimeCodeFramesFourParts(startParts), DecodeTimeCodeFramesFourParts(endParts), string.Empty);
                                subtitle.Paragraphs.Add(p);
                            }
                        }
                        catch
                        {
                            _errorCount += 10;
                        }
                    }
                    else if (string.IsNullOrWhiteSpace(line))
                    {
                        // skip these lines
                    }
                    else if (p != null)
                    {
                        if (string.IsNullOrEmpty(p.Text))
                            p.Text = line;
                        else
                            p.Text = p.Text + Environment.NewLine + line;
                    }
                    else
                    {
                        _errorCount++;
                    }
                }

                subtitle.Renumber();
            }

        }
    }

↑ V3095 The 'line' object was used before it was verified against null. Check lines: 72, 89.