Ensure frame size is cached per subscription

bonsai-rx · Jul 14, 2023 · 5eb4cd3 · 5eb4cd3
1 parent 177e84a
commit 5eb4cd3
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Showing 2 changed files with 13 additions and 8 deletions.
diff --git a/Bonsai.Vision/VideoWriter.cs b/Bonsai.Vision/VideoWriter.cs
@@ -14,8 +14,7 @@ namespace Bonsai.Vision
     [Description("Writes a sequence of images into a compressed AVI file.")]
     public class VideoWriter : FileSink<IplImage, VideoWriterDisposable>
     {
-        Size writerFrameSize;
-        static readonly object SyncRoot = new object();
+        static readonly object SyncRoot = new();
 
         /// <summary>
         /// Gets or sets a value specifying the four-character code of the codec
@@ -54,11 +53,10 @@ protected override VideoWriterDisposable CreateWriter(string fileName, IplImage
             var frameSize = FrameSize.Width > 0 && FrameSize.Height > 0 ? FrameSize : input.Size;
             var fourCCText = FourCC;
             var fourCC = fourCCText.Length != 4 ? 0 : OpenCV.Net.VideoWriter.FourCC(fourCCText[0], fourCCText[1], fourCCText[2], fourCCText[3]);
-            writerFrameSize = frameSize;
             lock (SyncRoot)
             {
                 var writer = new OpenCV.Net.VideoWriter(fileName, fourCC, FrameRate, frameSize, input.Channels > 1);
-                return new VideoWriterDisposable(writer, Disposable.Create(() =>
+                return new VideoWriterDisposable(writer, frameSize, Disposable.Create(() =>
                 {
                     lock (SyncRoot)
                     {
@@ -79,9 +77,9 @@ protected override VideoWriterDisposable CreateWriter(string fileName, IplImage
         /// </param>
         protected override void Write(VideoWriterDisposable writer, IplImage input)
         {
-            if (input.Width != writerFrameSize.Width || input.Height != writerFrameSize.Height)
+            if (input.Width != writer.FrameSize.Width || input.Height != writer.FrameSize.Height)
             {
-                var resized = new IplImage(new Size(writerFrameSize.Width, writerFrameSize.Height), input.Depth, input.Channels);
+                var resized = new IplImage(writer.FrameSize, input.Depth, input.Channels);
                 CV.Resize(input, resized, ResizeInterpolation);
                 input = resized;
             }

diff --git a/Bonsai.Vision/VideoWriterDisposable.cs b/Bonsai.Vision/VideoWriterDisposable.cs
@@ -1,6 +1,7 @@
 using System;
 using System.Reactive.Disposables;
 using System.Threading;
+using OpenCV.Net;
 
 namespace Bonsai.Vision
 {
@@ -11,16 +12,22 @@ public sealed class VideoWriterDisposable : ICancelable, IDisposable
     {
         IDisposable resource;
 
-        internal VideoWriterDisposable(OpenCV.Net.VideoWriter writer, IDisposable disposable)
+        internal VideoWriterDisposable(OpenCV.Net.VideoWriter writer, Size frameSize, IDisposable disposable)
         {
             Writer = writer ?? throw new ArgumentNullException(nameof(writer));
+            FrameSize = frameSize;
             resource = disposable;
         }
 
         /// <summary>
         /// Gets the reference to the disposable video writer instance.
         /// </summary>
-        public OpenCV.Net.VideoWriter Writer { get; private set; }
+        public OpenCV.Net.VideoWriter Writer { get; }
+
+        /// <summary>
+        /// Gets the size of individual video frames.
+        /// </summary>
+        public Size FrameSize { get; }
 
         /// <summary>
         /// Gets a value indicating whether the video writer has been disposed.