FF-1811: Fixing blocking issue with reading audio information

AudioNodes/Helpers/IFFmpegHelper.cs

@@ -34,37 +34,40 @@ public class FFmpegHelper(string ffmpeg, string ffprobe) : IFFmpegHelper
     {
         try
         {
-            using (var process = new Process())
+            using var process = new Process();
+            process.StartInfo = new ProcessStartInfo
             {
-                process.StartInfo = new ProcessStartInfo
-                {
-                    FileName = ffmpeg,
-                    UseShellExecute = false,
-                    RedirectStandardOutput = true,
-                    RedirectStandardError = true,
-                    CreateNoWindow = true,
-                    ArgumentList = {
-                        "-hide_banner", 
-                        "-i",
-                        file
-                    }
-                };
-                process.Start();
-
-                bool exited = process.WaitForExit(60000);
-                if (exited == false)
-                {
-                    process.Kill();
-                    string pkOutput = process.StandardError.ReadToEnd()?.EmptyAsNull() ?? process.StandardOutput.ReadToEnd();
-                    return Result<string>.Fail("Process timed out." + Environment.NewLine + pkOutput);
+                FileName = ffmpeg,
+                UseShellExecute = false,
+                RedirectStandardOutput = true,
+                RedirectStandardError = true,
+                CreateNoWindow = true,
+                ArgumentList = {
+                    "-hide_banner", 
+                    "-i",
+                    file
                 }
+            };
 
-                // we use error here, since we're not specify an output file, FFmpeg will report it as an error, but we don't care
-                string output = process.StandardOutput.ReadToEnd();
-                string error = process.StandardError.ReadToEnd();
+            process.Start();
 
-                return output?.EmptyAsNull() ?? error;
+            // Read asynchronously from both output and error streams
+            var outputTask = process.StandardOutput.ReadToEndAsync();
+            var errorTask = process.StandardError.ReadToEndAsync();
+
+            bool exited = process.WaitForExit(60000);
+            if (!exited)
+            {
+                process.Kill();
+                string pkOutput = errorTask.Result.EmptyAsNull() ?? outputTask.Result;
+                return Result<string>.Fail("Process timed out." + Environment.NewLine + pkOutput);
             }
+
+            // Await both the output and error tasks
+            string output = outputTask.Result;
+            string error = errorTask.Result;
+
+            return output?.EmptyAsNull() ?? error;
         }
         catch (Exception ex)
         {
@@ -93,18 +96,24 @@ public class FFmpegHelper(string ffmpeg, string ffprobe) : IFFmpegHelper
                     file
                 }
             };
+
             process.Start();
 
+            // Read asynchronously from both output and error streams
+            var outputTask = process.StandardOutput.ReadToEndAsync();
+            var errorTask = process.StandardError.ReadToEndAsync();
+
             bool exited = process.WaitForExit(60000);
-            if (exited == false)
+            if (!exited)
             {
                 process.Kill();
-                string pkOutput = process.StandardError.ReadToEnd()?.EmptyAsNull() ?? process.StandardOutput.ReadToEnd();
+                string pkOutput = errorTask.Result.EmptyAsNull() ?? outputTask.Result;
                 return Result<string>.Fail("Process timed out." + Environment.NewLine + pkOutput);
             }
 
-            string output = process.StandardOutput.ReadToEnd();
-            string error = process.StandardError.ReadToEnd();
+            // Await both the output and error tasks
+            string output = outputTask.Result;
+            string error = errorTask.Result;
 
             if (string.IsNullOrEmpty(error) == false)
                 return Result<string>.Fail($"Failed reading ffmpeg info: {error}");
@@ -116,4 +125,5 @@ public class FFmpegHelper(string ffmpeg, string ffprobe) : IFFmpegHelper
             return Result<string>.Fail($"An error occurred: {ex.Message}");
         }
     }
+
 } 

VideoNodes/FfmpegBuilderNodes/Subtitle/FfmpegBuilderSubtitleBurnIn.cs

@@ -0,0 +1,68 @@
+// using FileFlows.VideoNodes.FfmpegBuilderNodes.Models;
+//
+// namespace FileFlows.VideoNodes.FfmpegBuilderNodes;
+//
+// /// <summary>
+// /// FFmpeg Builder flow element that burns in a subtitle
+// /// </summary>
+// public class FfmpegBuilderSubtitleBurnIn: TrackSelectorFlowElement<FfmpegBuilderSubtitleBurnIn>
+// {
+//     /// <inheritdoc />
+//     public override string HelpUrl => "https://fileflows.com/docs/plugins/video-nodes/ffmpeg-builder/subtitle-burn-in";
+//     /// <inheritdoc />
+//     public override string Icon => "fas fa-fire";
+//     /// <inheritdoc />
+//     public override int Outputs => 2;
+//
+//     /// <inheritdoc />
+//     public override int Execute(NodeParameters args)
+//     {
+//         // Select a single subtitle track to burn in
+//         var subtitleTrack = Model.SubtitleStreams.FirstOrDefault(track =>
+//             !track.Deleted && StreamMatches(track));
+//
+//         if (subtitleTrack == null)
+//         {
+//             args.Logger?.ILog("No matching subtitle track found to burn in.");
+//             return 2; // No matching track, exit
+//         }
+//
+//         args.Logger?.ILog($"Burning in subtitle track: {subtitleTrack}");
+//
+//         // Build FFmpeg command for burning in the subtitle
+//         string subtitleFilter = BuildSubtitleFilter(subtitleTrack);
+//         if (string.IsNullOrEmpty(subtitleFilter))
+//         {
+//             args.Logger?.ILog("Failed to build subtitle filter for FFmpeg.");
+//             return 2; // Failed to create subtitle filter
+//         }
+//
+//         Model.VideoStreams[0].Filter.Add(subtitleFilter);  // Add the subtitle filter to the FFmpeg filter chain
+//         subtitleTrack.Deleted = true; 
+//
+//         return 1;
+//     }
+//
+//     /// <summary>
+//     /// Builds the FFmpeg filter string for burning in the selected subtitle track.
+//     /// </summary>
+//     /// <param name="subtitleTrack">The subtitle track to burn in.</param>
+//     /// <returns>FFmpeg filter string for burning in the subtitle.</returns>
+//     private string BuildSubtitleFilter(FfmpegSubtitleStream subtitleTrack)
+//     {
+//         // For different subtitle codecs, we need different filter formats
+//         if (subtitleTrack.Codec.ToLowerInvariant() is "subrip" or "srt" or "ass")
+//         {
+//             // FFmpeg filter for SRT subtitles
+//             if (int.TryParse(subtitleTrack.Stream.IndexString.Split(':')[0], out int index) == false)
+//                 return null;
+//             if (index < 0 || index > Model.InputFiles.Count)
+//                 return null;
+//             
+//             return $"subtitles={Model.InputFiles[index].FileName}:{subtitleTrack.Stream.TypeIndex}";
+//         }
+//     
+//         // Unsupported subtitle format
+//         return null;
+//     }
+// }

VideoNodes/Tests/FfmpegBuilderTests/FFmpegBuilder_SubtitleBurnInTests.cs

@@ -0,0 +1,67 @@
+// #if(DEBUG)
+//
+// using FileFlows.VideoNodes.FfmpegBuilderNodes;
+// using Microsoft.VisualStudio.TestTools.UnitTesting;
+// using VideoNodes.Tests;
+//
+// namespace FileFlows.VideoNodes.Tests.FfmpegBuilderTests;
+//
+// /// <summary>
+// /// Tests the subtitle burning in
+// /// </summary>
+// [TestClass]
+// public class FFmpegBuilder_SubtitleBurnInTests : VideoTestBase
+// {
+//     NodeParameters args;
+//
+//     /// <summary>
+//     /// Sets up the test environment before each test.
+//     /// Initializes video parameters and executes the video file setup.
+//     /// </summary>
+//     private void InitVideo(string file)
+//     {
+//         args = GetVideoNodeParameters(file);
+//         VideoFile vf = new VideoFile();
+//         vf.PreExecute(args);
+//         vf.Execute(args);
+//
+//         FfmpegBuilderStart ffStart = new();
+//         ffStart.PreExecute(args);
+//         Assert.AreEqual(1, ffStart.Execute(args));
+//     }
+//
+//     /// <summary>
+//     /// Burn In
+//     /// </summary>
+//     [TestMethod]
+//     public void BurnIn()
+//     {
+//         InitVideo(VideoSubtitles);
+//
+//         var ffSubtitleBurnIn = new FfmpegBuilderSubtitleBurnIn()
+//         {
+//             CustomTrackSelection = true,
+//             TrackSelectionOptions = new()
+//             {
+//                 new("Language", "English")
+//             }
+//         };
+//
+//         ffSubtitleBurnIn.PreExecute(args);
+//         ffSubtitleBurnIn.Execute(args);
+//
+//         var ffRemoveSubtitles = new FfmpegBuilderAudioTrackRemover();
+//         ffRemoveSubtitles.RemoveAll = true;
+//         ffRemoveSubtitles.StreamType = "Subtitle";
+//         ffRemoveSubtitles.PreExecute(args);
+//         ffRemoveSubtitles.Execute(args);
+//
+//         var ffExecutor = new FfmpegBuilderExecutor();
+//         ffExecutor.PreExecute(args);
+//         int result = ffExecutor.Execute(args);
+//
+//         Assert.AreEqual(1, result);
+//     }
+// }
+//
+// #endif