From 45fbd944ebbd7eab3dc897d7de3beae66ca8c03b Mon Sep 17 00:00:00 2001
From: Nikolaj Olsson <nikse.dk@gmail.com>
Date: Sun, 23 Aug 2020 10:43:43 +0200
Subject: [PATCH]  Add new subtitle (dv) format - thx George :)

---
 Changelog.txt                           |   1 +
 libse/SubtitleFormats/DvSubtitle.cs     | 123 ++++++++++++++++++++++++
 libse/SubtitleFormats/SubtitleFormat.cs |   1 +
 3 files changed, 125 insertions(+)
 create mode 100644 libse/SubtitleFormats/DvSubtitle.cs

diff --git a/Changelog.txt b/Changelog.txt
index a76002f27..3a4a21607 100644
--- a/Changelog.txt
+++ b/Changelog.txt
@@ -6,6 +6,7 @@
    * Add new subtitle (Excel) format - thx Jecy
    * Add new subtitle (json) format - thx Maksim
    * Add new subtitle format FCP Xml 1.8 - thx Maria
+   * Add new subtitle (dv) format - thx George
    * Add shortcuts for Tools menu items Split/Append/Join - thx z3us
    * Add shortcuts for "Merge line with same text/time-code" - thx Mike
    * Add shortcuts "Set end and pause" + "Export to PAC" - thx Milenko
diff --git a/libse/SubtitleFormats/DvSubtitle.cs b/libse/SubtitleFormats/DvSubtitle.cs
new file mode 100644
index 000000000..c6b45edf3
--- /dev/null
+++ b/libse/SubtitleFormats/DvSubtitle.cs
@@ -0,0 +1,123 @@
+using System.Collections.Generic;
+using System.Text;
+using System.Text.RegularExpressions;
+
+namespace Nikse.SubtitleEdit.Core.SubtitleFormats
+{
+    public class DvSubtitle : SubtitleFormat
+    {
+        private static readonly Regex LinePattern = new Regex(@"^c 1 \d{8} \d{8} .+", RegexOptions.Compiled);
+
+        public override string Extension => ".dv";
+
+        public override string Name => "DV Subtitle";
+
+        public override bool IsTimeBased => false;
+
+        public override bool IsMine(List<string> lines, string fileName)
+        {
+            var okCount = 0;
+            var errors = 0;
+            foreach (var line in lines)
+            {
+                if (!string.IsNullOrWhiteSpace(line) && line.StartsWith('c') && LinePattern.IsMatch(line))
+                {
+                    okCount++;
+                }
+                else
+                {
+                    errors++;
+                }
+            }
+            return okCount > errors;
+        }
+
+        public override string ToText(Subtitle subtitle, string title)
+        {
+            var sb = new StringBuilder();
+            foreach (var p in subtitle.Paragraphs)
+            {
+                sb.AppendLine($"c 1 {MillisecondsToFrames(p.StartTime.TotalMilliseconds):00000000} {MillisecondsToFrames(p.EndTime.TotalMilliseconds):00000000} {WriteText(p.Text)} 0");
+            }
+            return sb.ToString().Trim();
+        }
+
+        private static string WriteText(string text)
+        {
+            var sb = new StringBuilder();
+            var lines = text.SplitToLines();
+            foreach (var line in lines)
+            {
+                if (sb.Length > 0)
+                {
+                    sb.Append(' ');
+                }
+
+                sb.Append('\'');
+                sb.Append(line);
+                sb.Append('\'');
+            }
+
+            if (lines.Count == 1)
+            {
+                sb.Append(" ''");
+            }
+
+            return sb.ToString();
+        }
+
+        public override void LoadSubtitle(Subtitle subtitle, List<string> lines, string fileName)
+        {
+            _errorCount = 0;
+            foreach (var line in lines)
+            {
+                if (!string.IsNullOrWhiteSpace(line) && line.StartsWith('c') && LinePattern.IsMatch(line))
+                {
+                    var arr = line.Split();
+                    if (long.TryParse(arr[2], out var start) && long.TryParse(arr[3], out var end))
+                    {
+                        var text = ReadText(line.Remove(0, 22));
+                        subtitle.Paragraphs.Add(new Paragraph(text, FramesToMilliseconds(start), FramesToMilliseconds(end)));
+                    }
+                    else
+                    {
+                        _errorCount++;
+                    }
+                }
+                else
+                {
+                    _errorCount++;
+                }
+
+                if (_errorCount > 25)
+                {
+                    return;
+                }
+            }
+
+            subtitle.Renumber();
+        }
+
+        private string ReadText(string input)
+        {
+            var arr = input.TrimEnd('0').Replace("' '", "\n").SplitToLines();
+            var sb = new StringBuilder();
+            for (var index = 0; index < arr.Count; index++)
+            {
+                var line = arr[index].Trim();
+                if (index == 0 && line.StartsWith('\''))
+                {
+                    line = line.Remove(0, 1);
+                }
+                else if (index == arr.Count - 1 && line.EndsWith('\''))
+                {
+                    line = line.Remove(line.Length - 1);
+                }
+
+                sb.AppendLine(line);
+            }
+
+            return sb.ToString().Trim();
+        }
+    }
+}
diff --git a/libse/SubtitleFormats/SubtitleFormat.cs b/libse/SubtitleFormats/SubtitleFormat.cs
index d8e4faf2b..fd6734419 100644
--- a/libse/SubtitleFormats/SubtitleFormat.cs
+++ b/libse/SubtitleFormats/SubtitleFormat.cs
@@ -64,6 +64,7 @@ namespace Nikse.SubtitleEdit.Core.SubtitleFormats
                     new DvdStudioProSpace(),
                     new DvdSubtitle(),
                     new DvdSubtitleSystem(),
+                    new DvSubtitle(),
                     new Ebu(),
                     new Edl(),
                     new Eeg708(),