Added workaround for problem with overlaid subtitles in MKV.

kmcclive · Sep 3, 2019 · 5bbad73 · 5bbad73
1 parent a4a3040
commit 5bbad73
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Showing 2 changed files with 70 additions and 1 deletion.
diff --git a/Tricycle.Media.FFmpeg.Tests/FFmpegArgumentGeneratorTests.cs b/Tricycle.Media.FFmpeg.Tests/FFmpegArgumentGeneratorTests.cs
@@ -332,6 +332,57 @@ public void GeneratesArgumentsForTonemapJob()
             Assert.AreEqual(expected, actual);
         }
 
+        [TestMethod]
+        public void GeneratesArgumentsForMkvSubtitleJob()
+        {
+            var job = new TranscodeJob()
+            {
+                Format = ContainerFormat.Mkv,
+                OutputFileName = "output.mkv",
+                SourceInfo = new MediaInfo()
+                {
+                    FileName = "input.m4v",
+                    Duration = new TimeSpan(0, 1, 42, 37, 610),
+                    Streams = new StreamInfo[]
+                    {
+                        new VideoStreamInfo()
+                        {
+                            Index = 0,
+                            Dimensions = new Dimensions(3840, 2160),
+                            DynamicRange = DynamicRange.Standard
+                        },
+                        new StreamInfo()
+                        {
+                            Index = 1,
+                            StreamType = StreamType.Subtitle
+                        }
+                    }
+                },
+                Streams = new OutputStream[]
+                {
+                    new VideoOutputStream()
+                    {
+                        SourceStreamIndex = 0,
+                        Format = VideoFormat.Avc,
+                        DynamicRange = DynamicRange.Standard,
+                        Quality = 20
+                    }
+                },
+                Subtitles = new SubtitlesConfig()
+                {
+                    SourceStreamIndex = 1
+                }
+            };
+
+            var actual = _generator.GenerateArguments(job);
+            string expected = "-hide_banner -y -canvas_size 3840x2160 -i \"input.m4v\" -f matroska -t 1:42:37.610 " +
+                "-map 0:0 -c:v:0 libx264 -preset medium -crf 20 " +
+                "-filter_complex [0:1][0:0]'scale2ref[sub][ref];[ref][sub]overlay' " +
+                "\"output.mkv\"";
+
+            Assert.AreEqual(expected, actual);
+        }
+
         [TestMethod]
         public void GenerateArgumentsRespectsConfig()
         {

diff --git a/Tricycle.Media.FFmpeg/FFmpegArgumentGenerator.cs b/Tricycle.Media.FFmpeg/FFmpegArgumentGenerator.cs
@@ -109,6 +109,13 @@ public string GenerateArguments(TranscodeJob job)
             AppendFormat(argBuilder, job.Format);
             AppendDelimiter(argBuilder);
 
+            // This is a workaround for subtitle overlays with MKV reporting an incorrect duration
+            if (job.Format == ContainerFormat.Mkv && subtitlesIndex.HasValue)
+            {
+                AppendDuration(argBuilder, job.SourceInfo.Duration);
+                AppendDelimiter(argBuilder);
+            }
+
             try
             {
                 AppendStreamMap(argBuilder, job.SourceInfo, job.Streams, subtitlesIndex);
@@ -197,6 +204,11 @@ void AppendFormat(StringBuilder builder, ContainerFormat format)
             builder.Append($"-f {container}");
         }
 
+        void AppendDuration(StringBuilder builder, TimeSpan duration)
+        {
+            builder.Append($"-t {duration:h':'mm':'ss'.'fff}");
+        }
+
         void AppendStreamMap(StringBuilder builder,
                              MediaInfo sourceInfo,
                              IList<OutputStream> streams,
@@ -404,6 +416,8 @@ void AppendVideoStream(StringBuilder builder,
                 AppendVideoOverlayFilter(filterBuilder);
             }
 
+            bool setSampleAspectRatio = false;
+
             if ((outputStream.CropParameters != null) &&
                 ((outputStream.CropParameters.Size.Width < sourceStream.Dimensions.Width) ||
                  (outputStream.CropParameters.Size.Height < sourceStream.Dimensions.Height)))
@@ -414,6 +428,8 @@ void AppendVideoStream(StringBuilder builder,
                 }
 
                 AppendVideoCropFilter(filterBuilder, outputStream.CropParameters);
+
+                setSampleAspectRatio = true;
             }
 
             if (outputStream.ScaledDimensions.HasValue &&
@@ -425,9 +441,11 @@ void AppendVideoStream(StringBuilder builder,
                 }
 
                 AppendVideoScaleFilter(filterBuilder, outputStream.ScaledDimensions.Value);
+
+                setSampleAspectRatio = true;
             }
 
-            if (filterBuilder.Length > 0)
+            if (setSampleAspectRatio)
             {
                 AppendListDelimiter(filterBuilder);
                 AppendVideoSampleAspectRatioFilter(filterBuilder);