Add LibV4L2 capture

Baballonia.sln

@@ -45,6 +45,8 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Baballonia.FastCorruptionDe
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Baballonia.CaptureBin.IO", "src\Baballonia.CaptureBin.IO\Baballonia.CaptureBin.IO.csproj", "{8D298C1C-774E-4BF0-A107-D5D3985C7A9B}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Baballonia.LibV4L2Capture", "src\Baballonia.LibV4L2Capture\Baballonia.LibV4L2Capture.csproj", "{02E9F6A2-A443-491D-93FF-6F002F3C494F}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -120,6 +122,10 @@ Global
 		{8D298C1C-774E-4BF0-A107-D5D3985C7A9B}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{8D298C1C-774E-4BF0-A107-D5D3985C7A9B}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{8D298C1C-774E-4BF0-A107-D5D3985C7A9B}.Release|Any CPU.Build.0 = Release|Any CPU
+		{02E9F6A2-A443-491D-93FF-6F002F3C494F}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{02E9F6A2-A443-491D-93FF-6F002F3C494F}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{02E9F6A2-A443-491D-93FF-6F002F3C494F}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{02E9F6A2-A443-491D-93FF-6F002F3C494F}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
@@ -135,6 +141,7 @@ Global
 		{575BB586-5394-4F94-A178-DF4062EC44A1} = {82C6A0B4-5014-4BE4-9F52-7DC1989134E3}
 		{4B08BDE8-099A-405F-AB71-094E8FC24AB1} = {82C6A0B4-5014-4BE4-9F52-7DC1989134E3}
 		{8D298C1C-774E-4BF0-A107-D5D3985C7A9B} = {82C6A0B4-5014-4BE4-9F52-7DC1989134E3}
+		{02E9F6A2-A443-491D-93FF-6F002F3C494F} = {82C6A0B4-5014-4BE4-9F52-7DC1989134E3}
 	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {8D6643ED-DDC1-4236-9471-024DCCFC81F6}

src/Baballonia.Desktop/Baballonia.Desktop.csproj

@@ -45,6 +45,7 @@
         <PackageReference Include="Project-Babble.OpenCvSharp4.mini.runtime.ubuntu.22.04-arm64" Version="4.11.0.1" Condition="$([MSBuild]::IsOSPlatform('Linux')) And $(RuntimeIdentifier.Contains('arm'))" />
 	    <PackageReference Include="Microsoft.ML.OnnxRuntime" Version="1.22.0" Condition="$([MSBuild]::IsOSPlatform('Linux'))" />
         <PackageReference Include="SkiaSharp.NativeAssets.Linux" Version="3.119.0" Condition="$([MSBuild]::IsOSPlatform('Linux'))" />
+        <ProjectReference Include="..\Baballonia.LibV4L2Capture\Baballonia.LibV4L2Capture.csproj" Condition="$([MSBuild]::IsOSPlatform('Linux'))"/>
     </ItemGroup>
     <ItemGroup>
         <ProjectReference Include="..\Baballonia.CaptureBin.IO\Baballonia.CaptureBin.IO.csproj" />
@@ -131,10 +132,12 @@
 
     <Target Name="CopyModulesToFolder" AfterTargets="AfterBuild">
         <ItemGroup>
+            <ModuleDlls Condition="Exists('$(OutputPath)Baballonia.LibV4L2Capture.dll')" Include="$(OutputPath)Baballonia.LibV4L2Capture.dll" />
             <ModuleDlls Condition="Exists('$(OutputPath)Baballonia.SerialCameraCapture.dll')" Include="$(OutputPath)Baballonia.SerialCameraCapture.dll" />
             <ModuleDlls Condition="Exists('$(OutputPath)Baballonia.OpenCVCapture.dll')" Include="$(OutputPath)Baballonia.OpenCVCapture.dll" />
             <ModuleDlls Condition="Exists('$(OutputPath)Baballonia.IPCameraCapture.dll')" Include="$(OutputPath)Baballonia.IPCameraCapture.dll" />
             <ModuleDlls Condition="Exists('$(OutputPath)Baballonia.VFTCapture.dll')" Include="$(OutputPath)Baballonia.VFTCapture.dll" />
+            <ModuleDlls Condition="Exists('$(OutputPath)Baballonia.LibV4L2Capture.pdb')" Include="$(OutputPath)Baballonia.LibV4L2Capture.pdb" />
             <ModuleDlls Condition="Exists('$(OutputPath)Baballonia.SerialCameraCapture.pdb')" Include="$(OutputPath)Baballonia.SerialCameraCapture.pdb" />
             <ModuleDlls Condition="Exists('$(OutputPath)Baballonia.OpenCVCapture.pdb')" Include="$(OutputPath)Baballonia.OpenCVCapture.pdb" />
             <ModuleDlls Condition="Exists('$(OutputPath)Baballonia.IPCameraCapture.pdb')" Include="$(OutputPath)Baballonia.IPCameraCapture.pdb" />

src/Baballonia.LibV4L2Capture/Baballonia.LibV4L2Capture.csproj

@@ -0,0 +1,14 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <TargetFramework>net8.0</TargetFramework>
+        <ImplicitUsings>enable</ImplicitUsings>
+        <Nullable>enable</Nullable>
+        <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
+    </PropertyGroup>
+
+    <ItemGroup>
+        <ProjectReference Include="..\Baballonia.SDK\Baballonia.SDK.csproj" />
+    </ItemGroup>
+
+</Project>

src/Baballonia.LibV4L2Capture/LibV4L2Capture.cs

@@ -0,0 +1,115 @@
+using System.Runtime.InteropServices;
+using Baballonia.LibV4L2Capture.V4L2;
+using Microsoft.Extensions.Logging;
+using OpenCvSharp;
+using Capture = Baballonia.SDK.Capture;
+
+namespace Baballonia.LibV4L2Capture;
+
+public sealed class LibV4L2Capture(string source, ILogger<LibV4L2Capture> logger) : Capture(source, logger)
+{
+    private Device? _device;
+    private CancellationTokenSource? _cts;
+    private Task? _captureTask;
+
+    public override Task<bool> StartCapture()
+    {
+        try
+        {
+            _device = Device.Connect(Source);
+
+            if (_device == null)
+                return Task.FromResult(false);
+
+            Logger.LogInformation($"Using pixel format: {_device.PixelFormat}");
+
+            _device.StartCapture();
+            IsReady = true;
+        }
+        catch (Exception e)
+        {
+            Logger.LogError(e.ToString());
+            return Task.FromResult(false);
+        }
+
+        _cts = new CancellationTokenSource();
+        var token = _cts.Token;
+
+        _captureTask = Task.Run(() => VideoCapture_UpdateLoop(token), token);
+
+        return Task.FromResult(true);
+    }
+
+    private void DecodeMJPEG(byte[] frame)
+    {
+        Mat mat = Cv2.ImDecode(frame, ImreadModes.Grayscale);
+        SetRawMat(mat);
+    }
+
+    private void DecodeYUYV(byte[] frame, uint width, uint height)
+    {
+        Mat yuyvMat = new Mat((int)height, (int)width, MatType.CV_8UC2);
+        Marshal.Copy(frame, 0, yuyvMat.Data, frame.Length);
+
+        Mat grayMat = new Mat();
+        Cv2.CvtColor(yuyvMat, grayMat, ColorConversionCodes.YUV2GRAY_YUY2);
+        SetRawMat(grayMat);
+    }
+
+    private async Task VideoCapture_UpdateLoop(CancellationToken ct)
+    {
+        while (!ct.IsCancellationRequested && _device != null)
+        {
+            try
+            {
+                if (_device.CaptureFrame(out byte[]? frame))
+                {
+                    if (frame is { Length: > 0 })
+                    {
+                        switch (_device.PixelFormat)
+                        {
+                            case v4l2_pix_fmt.V4L2_PIX_FMT_MJPEG:
+                                DecodeMJPEG(frame);
+                                break;
+                            case v4l2_pix_fmt.V4L2_PIX_FMT_YUYV:
+                                var pix = _device.CurrentFormat.pix;
+                                DecodeYUYV(frame, pix.width, pix.height);
+                                break;
+                            default:
+                                throw new ArgumentOutOfRangeException();
+                        }
+                    }
+                }
+                else
+                {
+                    await Task.Delay(1, ct);
+                }
+            }
+            catch(Exception e)
+            {
+                SetRawMat(new Mat());
+                IsReady = false;
+                Logger.LogError(e.ToString());
+                _device.Dispose();
+                break;
+            }
+        }
+    }
+
+    public override Task<bool> StopCapture()
+    {
+        if (_device is null)
+            return Task.FromResult(false);
+
+        if (_captureTask != null)
+        {
+            _cts?.Cancel();
+            _captureTask.Wait();
+        }
+
+        IsReady = false;
+        _device?.Dispose();
+        _device = null;
+        return Task.FromResult(true);
+    }
+}

src/Baballonia.LibV4L2Capture/LibV4L2CaptureFactory.cs

@@ -0,0 +1,29 @@
+using Baballonia.SDK;
+using Microsoft.Extensions.Logging;
+
+namespace Baballonia.LibV4L2Capture;
+
+public class LibV4L2CaptureFactory : ICaptureFactory
+{
+    private readonly ILoggerFactory _loggerFactory;
+
+    public LibV4L2CaptureFactory(ILoggerFactory loggerFactory)
+    {
+        _loggerFactory = loggerFactory;
+    }
+
+    public Capture Create(string address)
+    {
+        return new LibV4L2Capture(address, _loggerFactory.CreateLogger<LibV4L2Capture>());
+    }
+
+    public bool CanConnect(string address)
+    {
+        return address.StartsWith("/dev/video");
+    }
+
+    public string GetProviderName()
+    {
+        return "Video4Linux2";
+    }
+}