Merge pull request #596 from rosenbjerg/add-metadata-builder-class

Add metadata builder class

FFMpegCore.Test/VideoTest.cs

@@ -82,6 +82,40 @@ public class VideoTest
         Assert.IsTrue(success);
     }
 
+    [TestMethod]
+    [Timeout(BaseTimeoutMilliseconds, CooperativeCancellation = true)]
+    public async Task Video_MetadataBuilder()
+    {
+        using var outputFile = new TemporaryFile($"out{VideoType.Mp4.Extension}");
+
+        await FFMpegArguments
+            .FromFileInput(TestResources.WebmVideo)
+            .AddMetaData(FFMetadataBuilder.Empty()
+                .WithTag("title", "noname")
+                .WithTag("artist", "unknown")
+                .WithChapter("Chapter 1", 1.1)
+                .WithChapter("Chapter 2", 1.23))
+            .OutputToFile(outputFile, false, opt => opt
+                .WithVideoCodec(VideoCodec.LibX264))
+            .CancellableThrough(TestContext.CancellationToken)
+            .ProcessAsynchronously();
+
+        var analysis = await FFProbe.AnalyseAsync(outputFile, cancellationToken: TestContext.CancellationToken);
+        Assert.IsTrue(analysis.Format.Tags!.TryGetValue("title", out var title));
+        Assert.IsTrue(analysis.Format.Tags!.TryGetValue("artist", out var artist));
+        Assert.AreEqual("noname", title);
+        Assert.AreEqual("unknown", artist);
+
+        Assert.HasCount(2, analysis.Chapters);
+        Assert.AreEqual("Chapter 1", analysis.Chapters.First().Title);
+        Assert.AreEqual(1.1, analysis.Chapters.First().Duration.TotalSeconds);
+        Assert.AreEqual(1.1, analysis.Chapters.First().End.TotalSeconds);
+
+        Assert.AreEqual("Chapter 2", analysis.Chapters.Last().Title);
+        Assert.AreEqual(1.23, analysis.Chapters.Last().Duration.TotalSeconds);
+        Assert.AreEqual(1.1 + 1.23, analysis.Chapters.Last().End.TotalSeconds);
+    }
+
     [TestMethod]
     [Timeout(BaseTimeoutMilliseconds, CooperativeCancellation = true)]
     public void Video_ToH265_MKV_Args()

FFMpegCore/FFMetadataInputArgument.cs

@@ -0,0 +1,62 @@
+using System.Text;
+
+namespace FFMpegCore;
+
+public class FFMetadataBuilder
+{
+    private Dictionary<string, string> Tags { get; } = new();
+    private List<FFMetadataChapter> Chapters { get; } = [];
+
+    public static FFMetadataBuilder Empty()
+    {
+        return new FFMetadataBuilder();
+    }
+
+    public FFMetadataBuilder WithTag(string key, string value)
+    {
+        Tags.Add(key, value);
+        return this;
+    }
+
+    public FFMetadataBuilder WithChapter(string title, long durationMs)
+    {
+        Chapters.Add(new FFMetadataChapter(title, durationMs));
+        return this;
+    }
+
+    public FFMetadataBuilder WithChapter(string title, double durationSeconds)
+    {
+        Chapters.Add(new FFMetadataChapter(title, Convert.ToInt64(durationSeconds * 1000)));
+        return this;
+    }
+
+    public string GetMetadataFileContent()
+    {
+        var sb = new StringBuilder();
+        sb.AppendLine(";FFMETADATA1");
+
+        foreach (var tag in Tags)
+        {
+            sb.AppendLine($"{tag.Key}={tag.Value}");
+        }
+
+        long totalDurationMs = 0;
+        foreach (var chapter in Chapters)
+        {
+            sb.AppendLine("[CHAPTER]");
+            sb.AppendLine("TIMEBASE=1/1000");
+            sb.AppendLine($"START={totalDurationMs}");
+            sb.AppendLine($"END={totalDurationMs + chapter.DurationMs}");
+            sb.AppendLine($"title={chapter.Title}");
+            totalDurationMs += chapter.DurationMs;
+        }
+
+        return sb.ToString();
+    }
+
+    private class FFMetadataChapter(string title, long durationMs)
+    {
+        public string Title { get; } = title;
+        public long DurationMs { get; } = durationMs;
+    }
+}

FFMpegCore/FFMpeg/FFMpegArguments.cs

@@ -109,6 +109,11 @@ public sealed class FFMpegArguments : FFMpegArgumentsBase
         return WithInput(new MetaDataArgument(content), addArguments);
     }
 
+    public FFMpegArguments AddMetaData(FFMetadataBuilder metaDataBuilder, Action<FFMpegArgumentOptions>? addArguments = null)
+    {
+        return WithInput(new MetaDataArgument(metaDataBuilder.GetMetadataFileContent()), addArguments);
+    }
+
     public FFMpegArguments AddMetaData(IReadOnlyMetaData metaData, Action<FFMpegArgumentOptions>? addArguments = null)
     {
         return WithInput(new MetaDataArgument(MetaDataSerializer.Instance.Serialize(metaData)), addArguments);