threaded video decoding

src/Video/VideoAV1.cs

@@ -10,19 +10,18 @@ namespace MoonWorks.Video
 
 		public int Width => width;
 		public int Height => height;
-		public double FramesPerSecond => 28.97;
+		public double FramesPerSecond { get; set; }
 		public Dav1dfile.PixelLayout PixelLayout => pixelLayout;
 		public int UVWidth { get; }
 		public int UVHeight { get; }
 
 		private int width;
 		private int height;
-		private double fps;
 		private Dav1dfile.PixelLayout pixelLayout;
 
 		bool IsDisposed;
 
-		public VideoAV1(string filename)
+		public VideoAV1(string filename, double framesPerSecond)
 		{
 			if (!File.Exists(filename))
 			{
@@ -55,6 +54,8 @@ namespace MoonWorks.Video
 			{
 				throw new NotSupportedException("Unrecognized YUV format!");
 			}
+
+			FramesPerSecond = framesPerSecond;
 		}
 
 		protected virtual void Dispose(bool disposing)

src/Video/VideoPlayer.cs

@@ -21,17 +21,26 @@ namespace MoonWorks.Video
 		private Texture vTexture = null;
 		private Sampler LinearSampler;
 
+		private object readLock = new object();
+		private bool frameDataUpdated;
+
+		private IntPtr yDataHandle;
+		private IntPtr uDataHandle;
+		private IntPtr vDataHandle;
+		private uint yDataLength;
+		private uint uvDataLength;
+		private uint yStride;
+		private uint uvStride;
+
 		private int currentFrame;
 
 		private Stopwatch timer;
 		private double lastTimestamp;
 		private double timeElapsed;
 
-		private Stopwatch profilingTimer = new Stopwatch();
-
 		private bool disposed;
 
-		public VideoPlayer(GraphicsDevice graphicsDevice, AudioDevice audioDevice)
+		public VideoPlayer(GraphicsDevice graphicsDevice)
 		{
 			GraphicsDevice = graphicsDevice;
 			if (GraphicsDevice.VideoPipeline == null)
@@ -154,11 +163,6 @@ namespace MoonWorks.Video
 			Video = null;
 		}
 
-		public void Update()
-		{
-			if (Video == null) { return; }
-		}
-
 		public void Render()
 		{
 			if (Video == null || State == VideoState.Stopped)
@@ -172,27 +176,13 @@ namespace MoonWorks.Video
 			int thisFrame = ((int) (timeElapsed / (1000.0 / Video.FramesPerSecond)));
 			if (thisFrame > currentFrame)
 			{
-				profilingTimer.Restart();
+				if (frameDataUpdated)
-				int readResult = Dav1dfile.df_readvideo(
-					Video.Handle,
-					thisFrame - currentFrame,
-					out var yData,
-					out var uData,
-					out var vData,
-					out var yDataLength,
-					out var uvDataLength,
-					out var yStride,
-					out var uvStride
-				);
-				profilingTimer.Stop();
-				System.Console.WriteLine($"Frame decoded in: {profilingTimer.Elapsed.TotalMilliseconds}");
-
-				if (readResult == 1 || currentFrame == -1)
 				{
-					UpdateRenderTexture(yData, uData, vData, yDataLength, uvDataLength, yStride, uvStride);
+					UpdateRenderTexture();
 				}
 
 				currentFrame = thisFrame;
+				System.Threading.Tasks.Task.Run(ReadNextFrame);
 			}
 
 			bool ended = Dav1dfile.df_eos(Video.Handle) == 1;
@@ -217,39 +207,42 @@ namespace MoonWorks.Video
 			}
 		}
 
-		private void UpdateRenderTexture(IntPtr yData, IntPtr uData, IntPtr vData, uint yDataLength, uint uvDataLength, uint yStride, uint uvStride)
+		private void UpdateRenderTexture()
 		{
-			var commandBuffer = GraphicsDevice.AcquireCommandBuffer();
+			lock (readLock)
+			{
+				var commandBuffer = GraphicsDevice.AcquireCommandBuffer();
 
-			commandBuffer.SetTextureDataYUV(
+				commandBuffer.SetTextureDataYUV(
-				yTexture,
+					yTexture,
-				uTexture,
+					uTexture,
-				vTexture,
+					vTexture,
-				yData,
+					yDataHandle,
-				uData,
+					uDataHandle,
-				vData,
+					vDataHandle,
-				yDataLength,
+					yDataLength,
-				uvDataLength,
+					uvDataLength,
-				yStride,
+					yStride,
-				uvStride
+					uvStride
-			);
+				);
 
-			commandBuffer.BeginRenderPass(
+				commandBuffer.BeginRenderPass(
-				new ColorAttachmentInfo(RenderTexture, Color.Black)
+					new ColorAttachmentInfo(RenderTexture, Color.Black)
-			);
+				);
 
-			commandBuffer.BindGraphicsPipeline(GraphicsDevice.VideoPipeline);
+				commandBuffer.BindGraphicsPipeline(GraphicsDevice.VideoPipeline);
-			commandBuffer.BindFragmentSamplers(
+				commandBuffer.BindFragmentSamplers(
-				new TextureSamplerBinding(yTexture, LinearSampler),
+					new TextureSamplerBinding(yTexture, LinearSampler),
-				new TextureSamplerBinding(uTexture, LinearSampler),
+					new TextureSamplerBinding(uTexture, LinearSampler),
-				new TextureSamplerBinding(vTexture, LinearSampler)
+					new TextureSamplerBinding(vTexture, LinearSampler)
-			);
+				);
 
-			commandBuffer.DrawPrimitives(0, 1, 0, 0);
+				commandBuffer.DrawPrimitives(0, 1, 0, 0);
 
-			commandBuffer.EndRenderPass();
+				commandBuffer.EndRenderPass();
 
-			GraphicsDevice.Submit(commandBuffer);
+				GraphicsDevice.Submit(commandBuffer);
+			}
 		}
 
 		private static Texture CreateRenderTexture(GraphicsDevice graphicsDevice, int width, int height)
@@ -276,20 +269,30 @@ namespace MoonWorks.Video
 
 		private void InitializeDav1dStream()
 		{
-			// Grab the first video frame ASAP.
+			System.Threading.Tasks.Task.Run(ReadNextFrame);
-			Dav1dfile.df_readvideo(
-				Video.Handle,
-				1,
-				out var _,
-				out var _,
-				out var _,
-				out var _,
-				out var _,
-				out var _,
-				out var _);
 			currentFrame = -1;
 		}
 
+		private void ReadNextFrame()
+		{
+			lock (readLock)
+			{
+				if (Dav1dfile.df_readvideo(
+					Video.Handle,
+					1,
+					out yDataHandle,
+					out uDataHandle,
+					out vDataHandle,
+					out yDataLength,
+					out uvDataLength,
+					out yStride,
+					out uvStride) == 1
+				) {
+					frameDataUpdated = true;
+				}
+			}
+		}
+
 		protected virtual void Dispose(bool disposing)
 		{
 			if (!disposed)