Added RTSP camera support

IPCamAppBar.sln.DotSettings

@@ -1,5 +1,9 @@
 <wpf:ResourceDictionary xml:space="preserve" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:s="clr-namespace:System;assembly=mscorlib" xmlns:ss="urn:shemas-jetbrains-com:settings-storage-xaml" xmlns:wpf="http://schemas.microsoft.com/winfx/2006/xaml/presentation">
 	<s:String x:Key="/Default/CodeStyle/Naming/CSharpNaming/Abbreviations/=EOI/@EntryIndexedValue">EOI</s:String>
+	<s:String x:Key="/Default/CodeStyle/Naming/CSharpNaming/Abbreviations/=HTTP/@EntryIndexedValue">HTTP</s:String>
+	<s:String x:Key="/Default/CodeStyle/Naming/CSharpNaming/Abbreviations/=HTTPMJPEG/@EntryIndexedValue">HTTPMJPEG</s:String>
 	<s:String x:Key="/Default/CodeStyle/Naming/CSharpNaming/Abbreviations/=MJPEG/@EntryIndexedValue">MJPEG</s:String>
+	<s:String x:Key="/Default/CodeStyle/Naming/CSharpNaming/Abbreviations/=RTSP/@EntryIndexedValue">RTSP</s:String>
 	<s:String x:Key="/Default/CodeStyle/Naming/CSharpNaming/Abbreviations/=SOI/@EntryIndexedValue">SOI</s:String>
-	<s:String x:Key="/Default/CodeStyle/Naming/CSharpNaming/Abbreviations/=URL/@EntryIndexedValue">URL</s:String></wpf:ResourceDictionary>
+	<s:String x:Key="/Default/CodeStyle/Naming/CSharpNaming/Abbreviations/=URL/@EntryIndexedValue">URL</s:String>
+	<s:String x:Key="/Default/CodeStyle/Naming/CSharpNaming/PredefinedNamingRules/=EnumMember/@EntryIndexedValue">&lt;Policy Inspect="True" Prefix="" Suffix="" Style="AaBb" /&gt;</s:String></wpf:ResourceDictionary>

IPCamAppBar/CameraStream.cs

@@ -1,203 +0,0 @@
-using System;
-using System.Drawing;
-using System.IO;
-using System.Net;
-using System.Threading;
-using System.Threading.Tasks;
-
-namespace IPCamAppBar
-{
-    public class FrameEventArgs : EventArgs
-    {
-        public Image Image { get; set; }
-    }
-
-    public class StreamExceptionEventArgs : EventArgs
-    {
-        public Exception Exception { get; set; }
-    }
-
-
-    public delegate void FrameEvent(object sender, FrameEventArgs args);
-    public delegate void StreamExceptionEvent(object sender, StreamExceptionEventArgs args);
-
-
-    internal abstract class CameraStream : IDisposable
-    {
-        public event FrameEvent Frame;
-        public event StreamExceptionEvent StreamException;
-
-        private readonly CancellationTokenSource cancelTaskTokenSource = new CancellationTokenSource();
-        private Task streamTask;
-        private DataMonitor dataMonitor;
-
-        protected CameraStream()
-        {
-        }
-
-
-        public void Start(string url)
-        {
-            if (streamTask != null)
-                throw new InvalidOperationException("CameraStream already started");
-
-            streamTask = Task.Run(() => Fetch(url, cancelTaskTokenSource.Token));
-        }
-
-
-        public void Dispose()
-        {
-            cancelTaskTokenSource.Cancel();
-
-            try
-            {
-                streamTask?.Wait();
-            }
-            catch (AggregateException e)
-            {
-                if (e.InnerExceptions.Count == 1 && e.InnerExceptions[0] is TaskCanceledException)
-                    return;
-
-                throw;
-            }
-            catch (TaskCanceledException) { }
-        }
-
-
-        private async Task Fetch(string url, CancellationToken cancellationToken)
-        {
-            while (!cancellationToken.IsCancellationRequested)
-            {
-                var uri = new Uri(url);
-                var request = WebRequest.CreateHttp(uri);
-
-                if (!string.IsNullOrEmpty(uri.UserInfo))
-                {
-                    var parts = uri.UserInfo.Split(':');
-                    request.Credentials = new NetworkCredential(parts[0], parts.Length > 1 ? parts[1] : "");
-                }
-
-                request.ReadWriteTimeout = 10;
-
-                try
-                {
-                    HttpWebResponse response;
-
-                    using (cancellationToken.Register(() => request.Abort(), false))
-                    {
-                        response = (HttpWebResponse)await request.GetResponseAsync();
-                        cancellationToken.ThrowIfCancellationRequested();
-                    }
-
-
-                    if (response.StatusCode != HttpStatusCode.OK)
-                        throw new WebException(response.StatusDescription);
-
-                    using (var responseStream = response.GetResponseStream())
-                    {
-                        var dataMonitorCancellationTokenSource = CancellationTokenSource.CreateLinkedTokenSource(cancellationToken);
-                        dataMonitor = new DataMonitor(dataMonitorCancellationTokenSource, TimeSpan.FromSeconds(15));
-
-                        try
-                        { 
-                            await ReadFrames(responseStream, dataMonitorCancellationTokenSource.Token);
-                        }
-                        catch (TaskCanceledException)
-                        {
-                            if (!dataMonitorCancellationTokenSource.IsCancellationRequested)
-                                throw;
-                        }
-                    }
-                }
-                catch (TaskCanceledException)
-                {
-                }
-                catch (Exception e)
-                {
-                    if (cancellationToken.IsCancellationRequested)
-                        break;
-
-                    OnStreamException(new StreamExceptionEventArgs
-                    {
-                        Exception = e
-                    });
-
-                    await Task.Delay(5000, cancellationToken);
-                }
-            }
-        }
-
-
-        protected abstract Task ReadFrames(Stream stream, CancellationToken cancellationToken);
-
-
-        protected virtual void OnFrame(FrameEventArgs args)
-        {
-            dataMonitor.Reset();
-            Frame?.Invoke(this, args);
-        }
-
-
-        protected virtual void OnStreamException(StreamExceptionEventArgs args)
-        {
-            StreamException?.Invoke(this, args);
-        }
-    }
-
-
-    internal static class BufferExtensions
-    {
-        public static int Find(this byte[] buffer, byte[] pattern, int limit = int.MaxValue, int startAt = 0)
-        {
-            var patternIndex = 0;
-            var bufferIndex = 0;
-
-            for (bufferIndex = startAt; bufferIndex < buffer.Length && patternIndex < pattern.Length && bufferIndex < limit; bufferIndex++)
-            {
-                if (buffer[bufferIndex] == pattern[patternIndex])
-                {
-                    patternIndex++;
-                }
-                else
-                {
-                    patternIndex = 0;
-                }
-            }
-
-            if (patternIndex == pattern.Length)
-                return bufferIndex - pattern.Length;
-
-            return -1;
-        }
-    }
-
-
-    internal class DataMonitor
-    {
-        private readonly CancellationTokenSource cancellationTokenSource;
-        private readonly long timeout;
-
-        private readonly Timer timeoutTimer;
-
-
-        public DataMonitor(CancellationTokenSource cancellationTokenSource, TimeSpan timeout)
-        {
-            this.cancellationTokenSource = cancellationTokenSource;
-            this.timeout = (long)timeout.TotalMilliseconds;
-
-            timeoutTimer = new Timer(Tick, null, this.timeout, -1);
-        }
-
-
-        public void Reset()
-        {
-            timeoutTimer.Change(timeout, -1);
-        }
-
-
-        private void Tick(object state)
-        {
-            cancellationTokenSource.Cancel();
-        }
-    }
-}

IPCamAppBar/CameraView.Designer.cs

@@ -28,11 +28,9 @@
         /// </summary>
         private void InitializeComponent()
         {
-            this.components = new System.ComponentModel.Container();
             this.ConnectingLabel = new System.Windows.Forms.Label();
             this.StreamView = new System.Windows.Forms.PictureBox();
             this.IssueLabel = new System.Windows.Forms.Label();
-            this.NoDataTimer = new System.Windows.Forms.Timer(this.components);
             ((System.ComponentModel.ISupportInitialize)(this.StreamView)).BeginInit();
             this.SuspendLayout();
             // 
@@ -73,11 +71,6 @@
             this.IssueLabel.TextAlign = System.Drawing.ContentAlignment.MiddleCenter;
             this.IssueLabel.Visible = false;
             // 
-            // NoDataTimer
-            // 
-            this.NoDataTimer.Interval = 1000;
-            this.NoDataTimer.Tick += new System.EventHandler(this.NoDataTimer_Tick);
-            // 
             // CameraView
             // 
             this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
@@ -98,6 +91,5 @@
         private System.Windows.Forms.Label ConnectingLabel;
         private System.Windows.Forms.PictureBox StreamView;
         private System.Windows.Forms.Label IssueLabel;
-        private System.Windows.Forms.Timer NoDataTimer;
     }
 }

IPCamAppBar/CameraView.cs

@@ -1,64 +1,63 @@
 using System;
 using System.Drawing;
 using System.Drawing.Drawing2D;
+using System.Threading;
+using System.Threading.Tasks;
 using System.Windows.Forms;
-using DateTime = System.DateTime;
+using FastBitmapLib;
+using IPCamLib;
 
 namespace IPCamAppBar
 {
-    public partial class CameraView : UserControl
+    public partial class CameraView : UserControl, IRetryableCameraObserver
     {
-        private DateTime lastFrameTime;
+        private readonly bool overlayDateTime;
+        private Bitmap viewBitmap;
         
-
+        public CameraView(ICamera camera, bool overlayDateTime)
-        public CameraView(string url)
         {
+            this.overlayDateTime = overlayDateTime;
             InitializeComponent();
 
-            var cameraStream = new CameraMJPEGStream();
+            var streamCancellationTokenSource = new CancellationTokenSource();
-            cameraStream.Frame += CameraStreamOnFrame;
+            Task.Run(async () =>
-            cameraStream.StreamException += CameraStreamOnStreamException;
-            cameraStream.Start(url);
-
-            Disposed += (sender, args) =>
             {
-                cameraStream.Dispose();
+                var retryableCamera = new RetryableCamera(camera);
+                await retryableCamera.Fetch(this, streamCancellationTokenSource.Token);
+            });
+            
+            Disposed += (_, _) =>
+            {
+                streamCancellationTokenSource.Cancel();
             };
         }
 
-        private void CameraStreamOnFrame(object sender, FrameEventArgs args)
-        {
-            // The event comes from a background thread, so if needed invoke it on the main thread
-            if (InvokeRequired)
-            {
-                Invoke(new Action(() => { CameraStreamOnFrame(sender, args); }));
-                return;
-            }
 
-            ConnectingLabel.Visible = false;
+        private Bitmap resizedBitmap;
-            StreamView.Visible = true;
-            IssueLabel.Visible = false;
 
-            lastFrameTime = DateTime.Now;
+        public Task OnFrame(Image image)
-            NoDataTimer.Start();
-
-            var viewImage = new Bitmap(Width, Height);
-            using (var graphics = Graphics.FromImage(viewImage))
         {
+            if (overlayDateTime || image is not Bitmap bitmap || image.Width != Width || image.Height != Height)
+            {
+                resizedBitmap ??= new Bitmap(Width, Height);
+                
+                using var graphics = Graphics.FromImage(resizedBitmap);
                 graphics.SmoothingMode = SmoothingMode.AntiAlias;
                 graphics.InterpolationMode = InterpolationMode.HighQualityBicubic;
                 graphics.PixelOffsetMode = PixelOffsetMode.HighQuality;
 
-                graphics.DrawImage(args.Image, 0, 0, viewImage.Width, viewImage.Height);
+                graphics.DrawImage(image, 0, 0, resizedBitmap.Width, resizedBitmap.Height);
 
+                if (overlayDateTime)
+                {
                     using (var path = new GraphicsPath())
                     {
                         path.AddString(
-                        lastFrameTime.ToString("G"), 
+                            DateTime.Now.ToString("G"),
                             FontFamily.GenericSansSerif,
-                        (int)FontStyle.Regular,
+                            (int) FontStyle.Regular,
                             graphics.DpiY * 14 / 72,
-                        Rectangle.Inflate(new Rectangle(0, 0, viewImage.Width, viewImage.Height), -4, -4),
+                            Rectangle.Inflate(new Rectangle(0, 0, resizedBitmap.Width, resizedBitmap.Height), -4, -4),
                             new StringFormat
                             {
                                 Alignment = StringAlignment.Far,
@@ -68,37 +67,73 @@ namespace IPCamAppBar
                         graphics.DrawPath(new Pen(Color.Black, 3), path);
                         graphics.FillPath(Brushes.White, path);
                     }
+                }
 
                 graphics.Flush();
+                bitmap = resizedBitmap;
             }
 
-            var oldImage = StreamView.Image;
+            Invoke(new Action(() => { InvokeFrame(bitmap); }));
-            StreamView.Image = viewImage;
+            return Task.CompletedTask;
-            oldImage?.Dispose();
         }
 
         
-        private void CameraStreamOnStreamException(object sender, StreamExceptionEventArgs args)
+        public Task OnFetch()
         {
-            if (InvokeRequired)
+            Invoke(new Action(InvokeFetch));
+            return Task.CompletedTask;
+        }
+
+
+        public Task OnDisconnected(Exception exception, TimeSpan retryDelay)
         {
-                Invoke(new Action(() => { CameraStreamOnStreamException(sender, args); }));
+            Invoke(new Action(() => { InvokeDisconnected(exception, retryDelay); }));
+            return Task.CompletedTask;
+        }
+
+
+        private void InvokeFrame(Bitmap bitmap)
+        {
+            if (IsDisposed)
                 return;
+
+            ConnectingLabel.Visible = false;
+            StreamView.Visible = true;
+            IssueLabel.Visible = false;
+
+
+            if (viewBitmap == null)
+            {
+                viewBitmap = new Bitmap(Width, Height);
+                StreamView.Image = viewBitmap;
             }
 
-            IssueLabel.Text = args.Exception.Message;
+            using (var fastViewBitmap = viewBitmap.FastLock()) 
+            {
+                fastViewBitmap.CopyRegion(bitmap, new Rectangle(Point.Empty, bitmap.Size), new Rectangle(Point.Empty, viewBitmap.Size));
+            }
+
+            StreamView.Invalidate();
+        }
+        
+        
+        private void InvokeFetch()
+        {
+            if (IsDisposed)
+                return;
+
+            IssueLabel.Text = "Connecting...";
             IssueLabel.Visible = true;
             IssueLabel.BringToFront();
         }
         
         
-        private void NoDataTimer_Tick(object sender, EventArgs e)
+        private void InvokeDisconnected(Exception exception, TimeSpan retryDelay)
         {
-            var timeSinceLastFrame = DateTime.Now - lastFrameTime;
+            if (IsDisposed)
-            if (timeSinceLastFrame.TotalSeconds < 10)
                 return;
 
-            IssueLabel.Text = $@"No data for {(int)timeSinceLastFrame.TotalSeconds} seconds";
+            IssueLabel.Text = (exception?.Message ?? "Camera disconnected") + $", retrying in {retryDelay.TotalSeconds} seconds";
             IssueLabel.Visible = true;
             IssueLabel.BringToFront();
         }

IPCamAppBar/CameraView.resx

@@ -117,7 +117,4 @@
   <resheader name="writer">
     <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
   </resheader>
-  <metadata name="NoDataTimer.TrayLocation" type="System.Drawing.Point, System.Drawing, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
-    <value>17, 17</value>
-  </metadata>
 </root>

IPCamAppBar/Config.cs

@@ -4,7 +4,7 @@ namespace IPCamAppBar
 {
     public class Config
     {
-        public ConfigAppBar AppBar { get; } = new ConfigAppBar();
+        public ConfigAppBar AppBar { get; } = new();
         public List<ConfigCamera> Cameras { get; set; }
     }
 
@@ -22,13 +22,24 @@ namespace IPCamAppBar
         public int Monitor { get; set; }
         public ConfigSide Side { get; set; }
         public int Size { get; set; }
+        public int Spacing { get; set; }
     }
 
 
+    // ReSharper disable InconsistentNaming
+    public enum ConfigCameraType
+    {
+        HTTPMJPEG,
+        RTSP
+    }
+    // ReSharper restore InconsistentNaming
+
     public class ConfigCamera
     {
+        public ConfigCameraType Type { get; set; }
         public string URL { get; set; }
         public int Width { get; set; }
         public int Height { get; set; }
+        public bool OverlayDateTime { get; set; }
     }
 }

IPCamAppBar/IPCamAppBar.csproj

@@ -12,9 +12,10 @@
     <FileAlignment>512</FileAlignment>
     <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
     <Deterministic>true</Deterministic>
+    <LangVersion>9</LangVersion>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
-    <PlatformTarget>AnyCPU</PlatformTarget>
+    <PlatformTarget>x64</PlatformTarget>
     <DebugSymbols>true</DebugSymbols>
     <DebugType>full</DebugType>
     <Optimize>false</Optimize>
@@ -22,6 +23,7 @@
     <DefineConstants>DEBUG;TRACE</DefineConstants>
     <ErrorReport>prompt</ErrorReport>
     <WarningLevel>4</WarningLevel>
+    <Prefer32Bit>false</Prefer32Bit>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
     <PlatformTarget>AnyCPU</PlatformTarget>
@@ -34,8 +36,11 @@
     <Prefer32Bit>false</Prefer32Bit>
   </PropertyGroup>
   <ItemGroup>
-    <Reference Include="Newtonsoft.Json, Version=12.0.0.0, Culture=neutral, PublicKeyToken=30ad4fe6b2a6aeed, processorArchitecture=MSIL">
+    <Reference Include="FastBitmapLib, Version=2.0.0.0, Culture=neutral, processorArchitecture=MSIL">
-      <HintPath>packages\Newtonsoft.Json.12.0.2\lib\net45\Newtonsoft.Json.dll</HintPath>
+      <HintPath>..\packages\FastBitmapLib.2.0.0\lib\net452\FastBitmapLib.dll</HintPath>
+    </Reference>
+    <Reference Include="Newtonsoft.Json, Version=13.0.0.0, Culture=neutral, PublicKeyToken=30ad4fe6b2a6aeed, processorArchitecture=MSIL">
+      <HintPath>..\packages\Newtonsoft.Json.13.0.1\lib\net45\Newtonsoft.Json.dll</HintPath>
     </Reference>
     <Reference Include="System" />
     <Reference Include="System.Core" />
@@ -51,8 +56,6 @@
   </ItemGroup>
   <ItemGroup>
     <Compile Include="AppBar.cs" />
-    <Compile Include="CameraMJPEGStream.cs" />
-    <Compile Include="CameraStream.cs" />
     <Compile Include="CameraView.cs">
       <SubType>UserControl</SubType>
     </Compile>
@@ -100,5 +103,11 @@
   <ItemGroup>
     <None Include="App.config" />
   </ItemGroup>
+  <ItemGroup>
+    <ProjectReference Include="..\IPCamLib\IPCamLib.csproj">
+      <Project>{FD0886FF-F274-4EFC-8A56-F82A4641C3FD}</Project>
+      <Name>IPCamLib</Name>
+    </ProjectReference>
+  </ItemGroup>
   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
 </Project>

IPCamAppBar/MainForm.cs

@@ -1,9 +1,10 @@
 using System;
-using System.Diagnostics.Contracts;
 using System.IO;
 using System.Linq;
 using System.Reflection;
 using System.Windows.Forms;
+using IPCamLib;
+using IPCamLib.Concrete;
 using Newtonsoft.Json;
 
 namespace IPCamAppBar
@@ -32,6 +33,11 @@ namespace IPCamAppBar
             appBar = new AppBar(Handle);
             appBar.SetPosition(monitor, position, config.AppBar.Size);
 
+            CameraViewContainer.FlowDirection =
+                config.AppBar.Side == ConfigSide.Left || config.AppBar.Side == ConfigSide.Right
+                    ? FlowDirection.TopDown
+                    : FlowDirection.LeftToRight;
+            
             config.Cameras?.ForEach(AddCamera);
         }
 
@@ -71,12 +77,26 @@ namespace IPCamAppBar
         }
 
 
-        private void AddCamera(ConfigCamera camera)
+        private void AddCamera(ConfigCamera configCamera)
         {
-            var view = new CameraView(camera.URL)
+            ICamera camera = configCamera.Type switch
             {
-                Width = camera.Width, 
+                ConfigCameraType.HTTPMJPEG => new HTTPMJPEGStreamCamera(new Uri(configCamera.URL)),
-                Height = camera.Height
+                ConfigCameraType.RTSP => new RTSPStreamCamera(new Uri(configCamera.URL), configCamera.Width, configCamera.Height),
+                _ => throw new ArgumentOutOfRangeException($"Camera type in configuration is not valid: {configCamera.Type}")
+            };
+
+            var margin = new Padding(0);
+            if (CameraViewContainer.FlowDirection == FlowDirection.LeftToRight)
+                margin.Right = config.AppBar.Spacing;
+            else
+                margin.Bottom = config.AppBar.Spacing;
+
+            var view = new CameraView(camera, configCamera.OverlayDateTime)
+            {
+                Width = configCamera.Width, 
+                Height = configCamera.Height,
+                Margin = margin
             };
 
             CameraViewContainer.Controls.Add(view);

IPCamAppBar/config.json

@@ -2,19 +2,24 @@
   "AppBar": {
     "Monitor": 0,
     "Side": "Top",
-    "Size": 480
+    "Size": 480,
+    "Spacing": 2
   },
 
   "Cameras": [
     {
-      "URL": "http://username:password@ipcamera1/videostream.cgi",
+      "Type": "RTSP",
+      "URL": "rtsp://username:password@ipcamera1/",
       "Width": 480,
-      "Height": 360
+      "Height": 360,
+      "OverlayDateTime": false
     },
     {
+      "Type": "HTTPMJPEG",
       "URL": "http://username:password@ipcamera2/videostream.cgi",
       "Width": 480,
-      "Height": 360
+      "Height": 360,
+      "OverlayDateTime": true
     }
   ]
 }

IPCamAppBar/packages.config

@@ -1,4 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <packages>
-  <package id="Newtonsoft.Json" version="12.0.2" targetFramework="net472" />
+  <package id="FastBitmapLib" version="2.0.0" targetFramework="net472" />
+  <package id="Newtonsoft.Json" version="13.0.1" targetFramework="net472" />
 </packages>

IPCamLib/Base/BaseHTTPStreamCamera.cs

@@ -0,0 +1,73 @@
+using System;
+using System.IO;
+using System.Net;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace IPCamLib.Base
+{
+    /// <summary>
+    /// Abstract base class for IP cameras reading an HTTP stream.
+    /// </summary>
+    public abstract class BaseHTTPStreamCamera : ICamera
+    {
+        private readonly Uri streamUri;
+
+
+        /// <param name="streamUri">The URI to the camera stream.
+        /// Can include basic credentials in the standard 'username:password@' format.</param>
+        protected BaseHTTPStreamCamera(Uri streamUri)
+        {
+            this.streamUri = streamUri;
+        }
+
+
+        /// <inheritdoc />
+        public async Task Fetch(ICameraObserver observer, CancellationToken cancellationToken)
+        {
+            var request = WebRequest.CreateHttp(streamUri);
+
+            if (!string.IsNullOrEmpty(streamUri.UserInfo))
+            {
+                var parts = streamUri.UserInfo.Split(':');
+                request.Credentials = new NetworkCredential(parts[0], parts.Length > 1 ? parts[1] : "");
+            }
+
+            request.ReadWriteTimeout = (int)TimeSpan.FromMinutes(1).TotalMilliseconds;
+            try
+            {
+                HttpWebResponse response;
+
+                using (cancellationToken.Register(() => request.Abort(), false))
+                {
+                    response = (HttpWebResponse)await request.GetResponseAsync();
+                    cancellationToken.ThrowIfCancellationRequested();
+                }
+
+
+                if (response.StatusCode != HttpStatusCode.OK)
+                    throw new WebException(response.StatusDescription);
+
+                
+                using var responseStream = response.GetResponseStream();
+                await ReadFrames(observer, responseStream, cancellationToken);
+            }
+            catch (TaskCanceledException)
+            {
+            }
+            finally
+            {
+                request.Abort();
+            }
+        }
+
+
+        /// <summary>
+        /// Implement in concrete descendants to continuously read frames from the HTTP stream.
+        /// </summary>
+        /// <param name="observer">The observer implementation passed to Fetch which should receive the decoded frames.</param>
+        /// <param name="stream">The HTTP response stream.</param>
+        /// <param name="cancellationToken">Stop reading frames when this token is cancelled.</param>
+        protected abstract Task ReadFrames(ICameraObserver observer, Stream stream, CancellationToken cancellationToken);
+    }
+}

IPCamLib/Concrete/HTTPMJPEGStreamCamera.cs

@@ -3,10 +3,16 @@ using System.Drawing;
 using System.IO;
 using System.Threading;
 using System.Threading.Tasks;
+using IPCamLib.Base;
 
-namespace IPCamAppBar
+// ReSharper disable UnusedMember.Global - public API
+
+namespace IPCamLib.Concrete
 {
-    internal class CameraMJPEGStream : CameraStream
+    /// <summary>
+    /// Implements the ICamera interface for IP cameras exposing an MJPEG stream over HTTP.
+    /// </summary>
+    public class HTTPMJPEGStreamCamera : BaseHTTPStreamCamera
     {
         // MJPEG decoding is a variation on https://github.com/arndre/MjpegDecoder
         private static readonly byte[] JpegSOI = { 0xff, 0xd8 }; // start of image bytes
@@ -16,7 +22,17 @@ namespace IPCamAppBar
         private const int MaxBufferSize = 1024 * 1024 * 10;
 
 
-        protected override async Task ReadFrames(Stream stream, CancellationToken cancellationToken)
+        /// <summary>
+        /// Creates a new instance for an IP camera exposing an MJPEG stream over HTTP.
+        /// </summary>
+        /// <inheritdoc />
+        public HTTPMJPEGStreamCamera(Uri streamUri) : base(streamUri)
+        {
+        }
+
+
+        /// <inheritdoc />
+        protected override async Task ReadFrames(ICameraObserver observer, Stream stream, CancellationToken cancellationToken)
         {
             var buffer = new byte[ChunkSize];
             var bufferPosition = 0;
@@ -51,9 +67,13 @@ namespace IPCamAppBar
             }
 
 
-            while (!cancellationToken.IsCancellationRequested)
+            var frameTimeout = TimeSpan.FromMinutes(1);
+            var frameTimeoutCancellationTokenSource = new CancellationTokenSource(frameTimeout);
+            var combinedCancellation = CancellationTokenSource.CreateLinkedTokenSource(cancellationToken, frameTimeoutCancellationTokenSource.Token);
+
+            while (!combinedCancellation.IsCancellationRequested)
             {
-                var bytesRead = await stream.ReadAsync(buffer, bufferPosition, ChunkSize, cancellationToken);
+                var bytesRead = await stream.ReadAsync(buffer, bufferPosition, ChunkSize, combinedCancellation.Token);
                 if (bytesRead == 0)
                     throw new EndOfStreamException();
 
@@ -61,7 +81,7 @@ namespace IPCamAppBar
 
                 if (!startOfImage.HasValue)
                 {
-                    var index = buffer.Find(JpegSOI, bufferPosition);
+                    var index = buffer.IndexOf(JpegSOI, bufferPosition);
                     if (index == -1)
                     {
                         // No start of image yet, we need to buffer more
@@ -72,7 +92,7 @@ namespace IPCamAppBar
                     startOfImage = index;
                 }
 
-                var endOfImage = buffer.Find(JpegEOI, bufferPosition, lastEndOfSearch.GetValueOrDefault(startOfImage.Value));
+                var endOfImage = buffer.IndexOf(JpegEOI, bufferPosition, lastEndOfSearch.GetValueOrDefault(startOfImage.Value));
                 if (endOfImage == -1)
                 {
                     // No start of image yet, we need to buffer more. Keep track of where we were so we don't
@@ -90,21 +110,42 @@ namespace IPCamAppBar
                 }
 
                 endOfImage += JpegEOI.Length;
-                HandleFrame(buffer, startOfImage.Value, endOfImage);
+
+                using (var image = new Bitmap(new MemoryStream(buffer, startOfImage.Value, endOfImage - startOfImage.Value)))
+                {
+                    await observer.OnFrame(image);
+                }
+
                 ResetBuffer(endOfImage);
+                frameTimeoutCancellationTokenSource.CancelAfter(frameTimeout);
+            }
         }
     }
 
 
-        protected void HandleFrame(byte[] buffer, int start, int end)
+    internal static class BufferExtensions
     {
-            using (var image = new Bitmap(new MemoryStream(buffer, start, end - start)))
+        public static int IndexOf(this byte[] buffer, byte[] pattern, int limit = int.MaxValue, int startAt = 0)
         {
-                OnFrame(new FrameEventArgs
+            var patternIndex = 0;
+            int bufferIndex;
+
+            for (bufferIndex = startAt; bufferIndex < buffer.Length && patternIndex < pattern.Length && bufferIndex < limit; bufferIndex++)
             {
-                    Image = image
+                if (buffer[bufferIndex] == pattern[patternIndex])
-                });
+                {
+                    patternIndex++;
                 }
+                else
+                {
+                    patternIndex = 0;
+                }
+            }
+
+            if (patternIndex == pattern.Length)
+                return bufferIndex - pattern.Length;
+
+            return -1;
         }
     }
 }

IPCamLib/Concrete/RTSPStreamCamera.cs

@@ -0,0 +1,113 @@
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.Drawing;
+using System.Net;
+using System.Threading;
+using System.Threading.Tasks;
+using FastBitmapLib;
+using IPCamLib.FFMPEG;
+using RtspClientSharp;
+using RtspClientSharp.RawFrames.Video;
+
+namespace IPCamLib.Concrete
+{
+    /// <summary>
+    /// Implements the ICamera interface for IP cameras exposing an RTSP stream.
+    /// </summary>
+    public class RTSPStreamCamera : ICamera
+    {
+        private readonly Uri streamUri;
+        private readonly Dictionary<FFmpegVideoCodecId, FFmpegVideoDecoder> videoDecodersMap = new();
+        private readonly Bitmap bitmap;
+        private readonly TransformParameters transformParameters;
+
+        /// <param name="streamUri">The URI to the camera stream.
+        /// Can include basic credentials in the standard 'username:password@' format.</param>
+        /// <param name="width">The width of the viewport</param>
+        /// <param name="height">The height of the viewport</param>
+        public RTSPStreamCamera(Uri streamUri, int width, int height)
+        {
+            this.streamUri = streamUri;
+
+            transformParameters = new TransformParameters(RectangleF.Empty, new Size(width, height),
+                ScalingPolicy.Stretch, PixelFormat.Bgra32, ScalingQuality.FastBilinear);
+
+            bitmap = new Bitmap(width, height, System.Drawing.Imaging.PixelFormat.Format32bppArgb);
+            
+            using var fastBitmap = bitmap.FastLock();
+            fastBitmap.Clear(Color.Black);
+        }
+
+
+        /// <inheritdoc />
+        public async Task Fetch(ICameraObserver observer, CancellationToken cancellationToken)
+        {
+            NetworkCredential credentials = null;
+            
+            if (!string.IsNullOrEmpty(streamUri.UserInfo))
+            {
+                var parts = streamUri.UserInfo.Split(':');
+                credentials = new NetworkCredential(parts[0], parts.Length > 1 ? parts[1] : "");
+            }
+            else
+                credentials = new NetworkCredential(null, (string)null);
+
+
+            var connectionParameters = new ConnectionParameters(streamUri, credentials)
+            {
+                RtpTransport = RtpTransportProtocol.TCP
+            };
+            
+            using var rtspClient = new RtspClient(connectionParameters);
+
+            rtspClient.FrameReceived += (_, rawFrame) =>
+            {
+                if (rawFrame is not RawVideoFrame rawVideoFrame)
+                    return;
+
+                var decoder = GetDecoderForFrame(rawVideoFrame);
+                var decodedFrame = decoder.TryDecode(rawVideoFrame);
+
+                if (decodedFrame == null) 
+                    return;
+
+                using (var fastBitmap = bitmap.FastLock())
+                {
+                    decodedFrame.TransformTo(fastBitmap.Scan0, fastBitmap.StrideInBytes, transformParameters);
+                }
+
+                // TODO await
+                observer.OnFrame(bitmap);
+            };
+
+            await rtspClient.ConnectAsync(cancellationToken);
+            await rtspClient.ReceiveAsync(cancellationToken);
+        }
+
+
+
+        private FFmpegVideoDecoder GetDecoderForFrame(RawVideoFrame videoFrame)
+        {
+            var codecId = DetectCodecId(videoFrame);
+            if (videoDecodersMap.TryGetValue(codecId, out var decoder)) 
+                return decoder;
+            
+            decoder = FFmpegVideoDecoder.CreateDecoder(codecId);
+            videoDecodersMap.Add(codecId, decoder);
+
+            return decoder;
+        }
+
+        
+        private static FFmpegVideoCodecId DetectCodecId(RawVideoFrame videoFrame)
+        {
+            return videoFrame switch
+            {
+                RawJpegFrame => FFmpegVideoCodecId.MJPEG,
+                RawH264Frame => FFmpegVideoCodecId.H264,
+                _ => throw new ArgumentOutOfRangeException(nameof(videoFrame))
+            };
+        }
+    }
+}

IPCamLib/FFMPEG/DecodedVideoFrame.cs

@@ -0,0 +1,24 @@
+/*
+ * Source code originally from RtspClientSharp's player example:
+ * https://github.com/BogdanovKirill/RtspClientSharp
+ */
+// ReSharper disable All
+using System;
+
+namespace IPCamLib.FFMPEG
+{
+    internal class DecodedVideoFrame : IDecodedVideoFrame
+    {
+        private readonly Action<IntPtr, int, TransformParameters> _transformAction;
+
+        public DecodedVideoFrame(Action<IntPtr, int, TransformParameters> transformAction)
+        {
+            _transformAction = transformAction;
+        }
+
+        public void TransformTo(IntPtr buffer, int bufferStride, TransformParameters transformParameters)
+        {
+            _transformAction(buffer, bufferStride, transformParameters);
+        }
+    }
+}

IPCamLib/FFMPEG/DecodedVideoFrameParameters.cs

@@ -0,0 +1,47 @@
+/*
+ * Source code originally from RtspClientSharp's player example:
+ * https://github.com/BogdanovKirill/RtspClientSharp
+ */
+// ReSharper disable All
+namespace IPCamLib.FFMPEG
+{
+    internal class DecodedVideoFrameParameters
+    {
+        public int Width { get; }
+
+        public int Height { get; }
+
+        public FFmpegPixelFormat PixelFormat { get; }
+
+        public DecodedVideoFrameParameters(int width, int height, FFmpegPixelFormat pixelFormat)
+        {
+            Width = width;
+            Height = height;
+            PixelFormat = pixelFormat;
+        }
+
+        protected bool Equals(DecodedVideoFrameParameters other)
+        {
+            return Width == other.Width && Height == other.Height && PixelFormat == other.PixelFormat;
+        }
+
+        public override bool Equals(object obj)
+        {
+            if (ReferenceEquals(null, obj)) return false;
+            if (ReferenceEquals(this, obj)) return true;
+            if (obj.GetType() != GetType()) return false;
+            return Equals((DecodedVideoFrameParameters) obj);
+        }
+
+        public override int GetHashCode()
+        {
+            unchecked
+            {
+                var hashCode = Width;
+                hashCode = (hashCode * 397) ^ Height;
+                hashCode = (hashCode * 397) ^ (int) PixelFormat;
+                return hashCode;
+            }
+        }
+    }
+}

IPCamLib/FFMPEG/DecoderException.cs

@@ -0,0 +1,39 @@
+/*
+ * Source code originally from RtspClientSharp's player example:
+ * https://github.com/BogdanovKirill/RtspClientSharp
+ */
+// ReSharper disable All
+using System;
+using System.Runtime.Serialization;
+
+namespace IPCamLib.FFMPEG
+{
+    [Serializable]
+    internal class DecoderException : Exception
+    {
+        //
+        // For guidelines regarding the creation of new exception types, see
+        //    http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpgenref/html/cpconerrorraisinghandlingguidelines.asp
+        // and
+        //    http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dncscol/html/csharp07192001.asp
+        //
+
+        public DecoderException()
+        {
+        }
+
+        public DecoderException(string message) : base(message)
+        {
+        }
+
+        public DecoderException(string message, Exception inner) : base(message, inner)
+        {
+        }
+
+        protected DecoderException(
+            SerializationInfo info,
+            StreamingContext context) : base(info, context)
+        {
+        }
+    }
+}

IPCamLib/FFMPEG/FFmpegDecodedVideoScaler.cs

@@ -0,0 +1,140 @@
+/*
+ * Source code originally from RtspClientSharp's player example:
+ * https://github.com/BogdanovKirill/RtspClientSharp
+ */
+// ReSharper disable All
+using System;
+
+namespace IPCamLib.FFMPEG
+{
+    internal class FFmpegDecodedVideoScaler
+    {
+        private const double MaxAspectRatioError = 0.1;
+        private bool _disposed;
+
+        public IntPtr Handle { get; }
+        public int ScaledWidth { get; }
+        public int ScaledHeight { get; }
+        public PixelFormat ScaledPixelFormat { get; }
+
+        private FFmpegDecodedVideoScaler(IntPtr handle, int scaledWidth, int scaledHeight,
+            PixelFormat scaledPixelFormat)
+        {
+            Handle = handle;
+            ScaledWidth = scaledWidth;
+            ScaledHeight = scaledHeight;
+            ScaledPixelFormat = scaledPixelFormat;
+        }
+
+        ~FFmpegDecodedVideoScaler()
+        {
+            Dispose();
+        }
+
+        /// <exception cref="DecoderException"></exception>
+        public static FFmpegDecodedVideoScaler Create(DecodedVideoFrameParameters decodedVideoFrameParameters,
+            TransformParameters transformParameters)
+        {
+            if (decodedVideoFrameParameters == null)
+                throw new ArgumentNullException(nameof(decodedVideoFrameParameters));
+            if (transformParameters == null)
+                throw new ArgumentNullException(nameof(transformParameters));
+
+            int sourceLeft = 0;
+            int sourceTop = 0;
+            int sourceWidth = decodedVideoFrameParameters.Width;
+            int sourceHeight = decodedVideoFrameParameters.Height;
+            int scaledWidth = decodedVideoFrameParameters.Width;
+            int scaledHeight = decodedVideoFrameParameters.Height;
+
+            if (!transformParameters.RegionOfInterest.IsEmpty)
+            {
+                sourceLeft =
+                    (int) (decodedVideoFrameParameters.Width * transformParameters.RegionOfInterest.Left);
+                sourceTop =
+                    (int) (decodedVideoFrameParameters.Height * transformParameters.RegionOfInterest.Top);
+                sourceWidth =
+                    (int) (decodedVideoFrameParameters.Width * transformParameters.RegionOfInterest.Width);
+                sourceHeight =
+                    (int) (decodedVideoFrameParameters.Height * transformParameters.RegionOfInterest.Height);
+            }
+
+            if (!transformParameters.TargetFrameSize.IsEmpty)
+            {
+                scaledWidth = transformParameters.TargetFrameSize.Width;
+                scaledHeight = transformParameters.TargetFrameSize.Height;
+
+                ScalingPolicy scalingPolicy = transformParameters.ScalePolicy;
+
+                float srcAspectRatio = (float) sourceWidth / sourceHeight;
+                float destAspectRatio = (float) scaledWidth / scaledHeight;
+
+                if (scalingPolicy == ScalingPolicy.Auto)
+                {
+                    float relativeChange = Math.Abs(srcAspectRatio - destAspectRatio) / srcAspectRatio;
+
+                    scalingPolicy = relativeChange > MaxAspectRatioError
+                        ? ScalingPolicy.RespectAspectRatio
+                        : ScalingPolicy.Stretch;
+                }
+
+                if (scalingPolicy == ScalingPolicy.RespectAspectRatio)
+                {
+                    if (destAspectRatio < srcAspectRatio)
+                        scaledHeight = sourceHeight * scaledWidth / sourceWidth;
+                    else
+                        scaledWidth = sourceWidth * scaledHeight / sourceHeight;
+                }
+            }
+
+            PixelFormat scaledPixelFormat = transformParameters.TargetFormat;
+            FFmpegPixelFormat scaledFFmpegPixelFormat = GetFFmpegPixelFormat(scaledPixelFormat);
+            FFmpegScalingQuality scaleQuality = GetFFmpegScaleQuality(transformParameters.ScaleQuality);
+
+            int resultCode = FFmpegVideoPInvoke.CreateVideoScaler(sourceLeft, sourceTop, sourceWidth, sourceHeight,
+                decodedVideoFrameParameters.PixelFormat,
+                scaledWidth, scaledHeight, scaledFFmpegPixelFormat, scaleQuality, out var handle);
+
+            if (resultCode != 0)
+                throw new DecoderException(@"An error occurred while creating scaler, code: {resultCode}");
+
+            return new FFmpegDecodedVideoScaler(handle, scaledWidth, scaledHeight, scaledPixelFormat);
+        }
+
+        public void Dispose()
+        {
+            if (_disposed)
+                return;
+
+            _disposed = true;
+            FFmpegVideoPInvoke.RemoveVideoScaler(Handle);
+            GC.SuppressFinalize(this);
+        }
+
+        private static FFmpegScalingQuality GetFFmpegScaleQuality(ScalingQuality scalingQuality)
+        {
+            if (scalingQuality == ScalingQuality.Nearest)
+                return FFmpegScalingQuality.Point;
+            if (scalingQuality == ScalingQuality.Bilinear)
+                return FFmpegScalingQuality.Bilinear;
+            if (scalingQuality == ScalingQuality.FastBilinear)
+                return FFmpegScalingQuality.FastBilinear;
+            if (scalingQuality == ScalingQuality.Bicubic)
+                return FFmpegScalingQuality.Bicubic;
+
+            throw new ArgumentOutOfRangeException(nameof(scalingQuality));
+        }
+
+        private static FFmpegPixelFormat GetFFmpegPixelFormat(PixelFormat pixelFormat)
+        {
+            if (pixelFormat == PixelFormat.Bgra32)
+                return FFmpegPixelFormat.BGRA;
+            if (pixelFormat == PixelFormat.Grayscale)
+                return FFmpegPixelFormat.GRAY8;
+            if (pixelFormat == PixelFormat.Bgr24)
+                return FFmpegPixelFormat.BGR24;
+
+            throw new ArgumentOutOfRangeException(nameof(pixelFormat));
+        }
+    }
+}

IPCamLib/FFMPEG/FFmpegVideoDecoder.cs

@@ -0,0 +1,129 @@
+/*
+ * Source code originally from RtspClientSharp's player example:
+ * https://github.com/BogdanovKirill/RtspClientSharp
+ */
+// ReSharper disable All
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using RtspClientSharp.RawFrames.Video;
+
+namespace IPCamLib.FFMPEG
+{
+    internal class FFmpegVideoDecoder
+    {
+        private readonly IntPtr _decoderHandle;
+        private readonly FFmpegVideoCodecId _videoCodecId;
+
+        private DecodedVideoFrameParameters _currentFrameParameters =
+            new DecodedVideoFrameParameters(0, 0, FFmpegPixelFormat.None);
+
+        private readonly Dictionary<TransformParameters, FFmpegDecodedVideoScaler> _scalersMap =
+            new Dictionary<TransformParameters, FFmpegDecodedVideoScaler>();
+
+        private byte[] _extraData = new byte[0];
+        private bool _disposed;
+
+        private FFmpegVideoDecoder(FFmpegVideoCodecId videoCodecId, IntPtr decoderHandle)
+        {
+            _videoCodecId = videoCodecId;
+            _decoderHandle = decoderHandle;
+        }
+
+        ~FFmpegVideoDecoder()
+        {
+            Dispose();
+        }
+
+        public static FFmpegVideoDecoder CreateDecoder(FFmpegVideoCodecId videoCodecId)
+        {
+            int resultCode = FFmpegVideoPInvoke.CreateVideoDecoder(videoCodecId, out IntPtr decoderPtr);
+
+            if (resultCode != 0)
+                throw new DecoderException(
+                    $"An error occurred while creating video decoder for {videoCodecId} codec, code: {resultCode}");
+
+            return new FFmpegVideoDecoder(videoCodecId, decoderPtr);
+        }
+
+        public unsafe IDecodedVideoFrame TryDecode(RawVideoFrame rawVideoFrame)
+        {
+            fixed (byte* rawBufferPtr = &rawVideoFrame.FrameSegment.Array[rawVideoFrame.FrameSegment.Offset])
+            {
+                int resultCode;
+
+                if (rawVideoFrame is RawH264IFrame rawH264IFrame)
+                {
+                    if (rawH264IFrame.SpsPpsSegment.Array != null &&
+                        !_extraData.SequenceEqual(rawH264IFrame.SpsPpsSegment))
+                    {
+                        if (_extraData.Length != rawH264IFrame.SpsPpsSegment.Count)
+                            _extraData = new byte[rawH264IFrame.SpsPpsSegment.Count];
+
+                        Buffer.BlockCopy(rawH264IFrame.SpsPpsSegment.Array, rawH264IFrame.SpsPpsSegment.Offset,
+                            _extraData, 0, rawH264IFrame.SpsPpsSegment.Count);
+
+                        fixed (byte* initDataPtr = &_extraData[0])
+                        {
+                            resultCode = FFmpegVideoPInvoke.SetVideoDecoderExtraData(_decoderHandle,
+                                (IntPtr)initDataPtr, _extraData.Length);
+
+                            if (resultCode != 0)
+                                throw new DecoderException(
+                                    $"An error occurred while setting video extra data, {_videoCodecId} codec, code: {resultCode}");
+                        }
+                    }
+                }
+
+                resultCode = FFmpegVideoPInvoke.DecodeFrame(_decoderHandle, (IntPtr)rawBufferPtr,
+                    rawVideoFrame.FrameSegment.Count,
+                    out int width, out int height, out FFmpegPixelFormat pixelFormat);
+
+                if (resultCode != 0)
+                    return null;
+
+                if (_currentFrameParameters.Width != width || _currentFrameParameters.Height != height ||
+                    _currentFrameParameters.PixelFormat != pixelFormat)
+                {
+                    _currentFrameParameters = new DecodedVideoFrameParameters(width, height, pixelFormat);
+                    DropAllVideoScalers();
+                }
+
+                return new DecodedVideoFrame(TransformTo);
+            }
+        }
+
+        public void Dispose()
+        {
+            if (_disposed)
+                return;
+
+            _disposed = true;
+            FFmpegVideoPInvoke.RemoveVideoDecoder(_decoderHandle);
+            DropAllVideoScalers();
+            GC.SuppressFinalize(this);
+        }
+
+        private void DropAllVideoScalers()
+        {
+            foreach (var scaler in _scalersMap.Values)
+                scaler.Dispose();
+
+            _scalersMap.Clear();
+        }
+
+        private void TransformTo(IntPtr buffer, int bufferStride, TransformParameters parameters)
+        {
+            if (!_scalersMap.TryGetValue(parameters, out FFmpegDecodedVideoScaler videoScaler))
+            {
+                videoScaler = FFmpegDecodedVideoScaler.Create(_currentFrameParameters, parameters);
+                _scalersMap.Add(parameters, videoScaler);
+            }
+
+            int resultCode = FFmpegVideoPInvoke.ScaleDecodedVideoFrame(_decoderHandle, videoScaler.Handle, buffer, bufferStride);
+
+            if (resultCode != 0)
+                throw new DecoderException($"An error occurred while converting decoding video frame, {_videoCodecId} codec, code: {resultCode}");
+        }
+    }
+}

IPCamLib/FFMPEG/FFmpegVideoPInvoke.cs

@@ -0,0 +1,66 @@
+/*
+ * Source code originally from RtspClientSharp's player example:
+ * https://github.com/BogdanovKirill/RtspClientSharp
+ */
+// ReSharper disable All
+using System;
+using System.Runtime.InteropServices;
+
+namespace IPCamLib.FFMPEG
+{
+    internal enum FFmpegVideoCodecId
+    {
+        MJPEG = 7,
+        H264 = 27
+    }
+
+    [Flags]
+    internal enum FFmpegScalingQuality
+    {
+        FastBilinear = 1,
+        Bilinear = 2,
+        Bicubic = 4,
+        Point = 0x10,
+        Area = 0x20,
+    }
+
+    internal enum FFmpegPixelFormat
+    {
+        None = -1,
+        BGR24 = 3,
+        GRAY8 = 8,
+        BGRA = 28
+    }
+
+    internal static class FFmpegVideoPInvoke
+    {
+        private const string LibraryName = "libffmpeghelper.dll";
+
+        [DllImport(LibraryName, EntryPoint = "create_video_decoder", CallingConvention = CallingConvention.Cdecl)]
+        public static extern int CreateVideoDecoder(FFmpegVideoCodecId videoCodecId, out IntPtr handle);
+
+        [DllImport(LibraryName, EntryPoint = "remove_video_decoder", CallingConvention = CallingConvention.Cdecl)]
+        public static extern void RemoveVideoDecoder(IntPtr handle);
+
+        [DllImport(LibraryName, EntryPoint = "set_video_decoder_extradata",
+            CallingConvention = CallingConvention.Cdecl)]
+        public static extern int SetVideoDecoderExtraData(IntPtr handle, IntPtr extradata, int extradataLength);
+
+        [DllImport(LibraryName, EntryPoint = "decode_video_frame", CallingConvention = CallingConvention.Cdecl)]
+        public static extern int DecodeFrame(IntPtr handle, IntPtr rawBuffer, int rawBufferLength, out int frameWidth,
+            out int frameHeight, out FFmpegPixelFormat framePixelFormat);
+
+        [DllImport(LibraryName, EntryPoint = "scale_decoded_video_frame", CallingConvention = CallingConvention.Cdecl)]
+        public static extern int ScaleDecodedVideoFrame(IntPtr handle, IntPtr scalerHandle, IntPtr scaledBuffer,
+            int scaledBufferStride);
+
+        [DllImport(LibraryName, EntryPoint = "create_video_scaler", CallingConvention = CallingConvention.Cdecl)]
+        public static extern int CreateVideoScaler(int sourceLeft, int sourceTop, int sourceWidth, int sourceHeight,
+            FFmpegPixelFormat sourcePixelFormat,
+            int scaledWidth, int scaledHeight, FFmpegPixelFormat scaledPixelFormat, FFmpegScalingQuality qualityFlags,
+            out IntPtr handle);
+
+        [DllImport(LibraryName, EntryPoint = "remove_video_scaler", CallingConvention = CallingConvention.Cdecl)]
+        public static extern void RemoveVideoScaler(IntPtr handle);
+    }
+}

IPCamLib/FFMPEG/IDecodedVideoFrame.cs

@@ -0,0 +1,14 @@
+/*
+ * Source code originally from RtspClientSharp's player example:
+ * https://github.com/BogdanovKirill/RtspClientSharp
+ */
+// ReSharper disable All
+using System;
+
+namespace IPCamLib.FFMPEG
+{
+    internal interface IDecodedVideoFrame
+    {
+        void TransformTo(IntPtr buffer, int bufferStride, TransformParameters transformParameters);
+    }
+}

IPCamLib/FFMPEG/PixelFormat.cs

@@ -0,0 +1,14 @@
+/*
+ * Source code originally from RtspClientSharp's player example:
+ * https://github.com/BogdanovKirill/RtspClientSharp
+ */
+// ReSharper disable All
+namespace IPCamLib.FFMPEG
+{
+    internal enum PixelFormat
+    {
+        Grayscale,
+        Bgr24,
+        Bgra32,
+    }
+}

IPCamLib/FFMPEG/ScalingPolicy.cs

@@ -0,0 +1,14 @@
+/*
+ * Source code originally from RtspClientSharp's player example:
+ * https://github.com/BogdanovKirill/RtspClientSharp
+ */
+// ReSharper disable All
+namespace IPCamLib.FFMPEG
+{
+    internal enum ScalingPolicy
+    {
+        Auto,
+        Stretch,
+        RespectAspectRatio
+    }
+}

IPCamLib/FFMPEG/ScalingQuality.cs

@@ -0,0 +1,15 @@
+/*
+ * Source code originally from RtspClientSharp's player example:
+ * https://github.com/BogdanovKirill/RtspClientSharp
+ */
+// ReSharper disable All
+namespace IPCamLib.FFMPEG
+{
+    internal enum ScalingQuality
+    {
+        Nearest,
+        Bilinear,
+        FastBilinear,
+        Bicubic
+    }
+}

IPCamLib/FFMPEG/TransformParameters.cs

@@ -0,0 +1,59 @@
+/*
+ * Source code originally from RtspClientSharp's player example:
+ * https://github.com/BogdanovKirill/RtspClientSharp
+ */
+// ReSharper disable All
+using System.Drawing;
+
+namespace IPCamLib.FFMPEG
+{
+    internal class TransformParameters
+    {
+        public RectangleF RegionOfInterest { get; }
+
+        public Size TargetFrameSize { get; }
+
+        public ScalingPolicy ScalePolicy { get; }
+
+        public PixelFormat TargetFormat { get; }
+
+        public ScalingQuality ScaleQuality { get; }
+
+        public TransformParameters(RectangleF regionOfInterest, Size targetFrameSize, ScalingPolicy scalePolicy,
+            PixelFormat targetFormat, ScalingQuality scaleQuality)
+        {
+            RegionOfInterest = regionOfInterest;
+            TargetFrameSize = targetFrameSize;
+            TargetFormat = targetFormat;
+            ScaleQuality = scaleQuality;
+            ScalePolicy = scalePolicy;
+        }
+
+        protected bool Equals(TransformParameters other)
+        {
+            return RegionOfInterest.Equals(other.RegionOfInterest) &&
+                   TargetFrameSize.Equals(other.TargetFrameSize) &&
+                   TargetFormat == other.TargetFormat && ScaleQuality == other.ScaleQuality;
+        }
+
+        public override bool Equals(object obj)
+        {
+            if (ReferenceEquals(null, obj)) return false;
+            if (ReferenceEquals(this, obj)) return true;
+            if (obj.GetType() != GetType()) return false;
+            return Equals((TransformParameters) obj);
+        }
+
+        public override int GetHashCode()
+        {
+            unchecked
+            {
+                var hashCode = RegionOfInterest.GetHashCode();
+                hashCode = (hashCode * 397) ^ TargetFrameSize.GetHashCode();
+                hashCode = (hashCode * 397) ^ (int) TargetFormat;
+                hashCode = (hashCode * 397) ^ (int) ScaleQuality;
+                return hashCode;
+            }
+        }
+    }
+}

IPCamLib/ICamera.cs

@@ -0,0 +1,38 @@
+using System.Drawing;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace IPCamLib
+{
+    /// <summary>
+    /// Receives frames from an ICamera.
+    /// </summary>
+    public interface ICameraObserver
+    {
+        /// <summary>
+        /// Called when a frame has been decoded from an ICamera.
+        /// </summary>
+        /// <param name="image">The decoded image.</param>
+        Task OnFrame(Image image);
+    }
+    
+    
+    /// <summary>
+    /// Abstracts an IP camera stream.
+    /// </summary>
+    public interface ICamera
+    {
+        /// <summary>
+        /// Starts receiving frames.
+        /// </summary>
+        /// <remarks>
+        /// The implementation should continue receiving frames until it is disconnected (if streaming),
+        /// a request fails (if polling) or the cancellationToken is cancelled. Reconnecting is done by
+        /// the caller which will call Fetch again. Do not keep connection-specific state between calls to Fetch.
+        /// Running on a separate thread is also handled by the caller, the returning Task should not complete until disconnected.
+        /// </remarks>
+        /// <param name="observer">The observer implementation to receive frames.</param>
+        /// <param name="cancellationToken">A CancellationToken which will stop the camera stream when cancelled.</param>
+        Task Fetch(ICameraObserver observer, CancellationToken cancellationToken);
+    }
+}

IPCamLib/IPCamLib.csproj

@@ -12,6 +12,7 @@
     <TargetFrameworkVersion>v4.7.2</TargetFrameworkVersion>
     <FileAlignment>512</FileAlignment>
     <Deterministic>true</Deterministic>
+    <LangVersion>9</LangVersion>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
     <DebugSymbols>true</DebugSymbols>
@@ -21,6 +22,9 @@
     <DefineConstants>DEBUG;TRACE</DefineConstants>
     <ErrorReport>prompt</ErrorReport>
     <WarningLevel>4</WarningLevel>
+    <DocumentationFile>bin\Debug\IPCamLib.xml</DocumentationFile>
+    <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
+    <PlatformTarget>x64</PlatformTarget>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
     <DebugType>pdbonly</DebugType>
@@ -29,10 +33,13 @@
     <DefineConstants>TRACE</DefineConstants>
     <ErrorReport>prompt</ErrorReport>
     <WarningLevel>4</WarningLevel>
+    <DocumentationFile>bin\Release\IPCamLib.xml</DocumentationFile>
+    <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
   </PropertyGroup>
   <ItemGroup>
     <Reference Include="System" />
     <Reference Include="System.Core" />
+    <Reference Include="System.Drawing" />
     <Reference Include="System.Xml.Linq" />
     <Reference Include="System.Data.DataSetExtensions" />
     <Reference Include="Microsoft.CSharp" />
@@ -41,7 +48,61 @@
     <Reference Include="System.Xml" />
   </ItemGroup>
   <ItemGroup>
+    <Compile Include="Base\BaseHTTPStreamCamera.cs" />
+    <Compile Include="Concrete\HTTPMJPEGStreamCamera.cs" />
+    <Compile Include="Concrete\RTSPStreamCamera.cs" />
+    <Compile Include="FFMPEG\DecodedVideoFrame.cs" />
+    <Compile Include="FFMPEG\DecodedVideoFrameParameters.cs" />
+    <Compile Include="FFMPEG\DecoderException.cs" />
+    <Compile Include="FFMPEG\FFmpegDecodedVideoScaler.cs" />
+    <Compile Include="FFMPEG\FFmpegVideoDecoder.cs" />
+    <Compile Include="FFMPEG\FFmpegVideoPInvoke.cs" />
+    <Compile Include="FFMPEG\IDecodedVideoFrame.cs" />
+    <Compile Include="FFMPEG\PixelFormat.cs" />
+    <Compile Include="FFMPEG\ScalingPolicy.cs" />
+    <Compile Include="FFMPEG\ScalingQuality.cs" />
+    <Compile Include="FFMPEG\TransformParameters.cs" />
+    <Compile Include="RetryableCamera.cs" />
+    <Compile Include="ICamera.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
   </ItemGroup>
+  <ItemGroup>
+    <PackageReference Include="FastBitmapLib">
+      <Version>2.0.0</Version>
+    </PackageReference>
+    <PackageReference Include="RtspClientSharp">
+      <Version>1.3.3</Version>
+    </PackageReference>
+  </ItemGroup>
+  <ItemGroup>
+    <Content Include="avcodec-58.dll">
+      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
+    </Content>
+    <Content Include="avdevice-58.dll">
+      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
+    </Content>
+    <Content Include="avfilter-7.dll">
+      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
+    </Content>
+    <Content Include="avformat-58.dll">
+      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
+    </Content>
+    <Content Include="avutil-56.dll">
+      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
+    </Content>
+    <Content Include="libffmpeghelper.dll">
+      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
+    </Content>
+    <Content Include="postproc-55.dll">
+      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
+    </Content>
+    <Content Include="swresample-3.dll">
+      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
+    </Content>
+    <Content Include="swscale-5.dll">
+      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
+    </Content>
+  </ItemGroup>
+  <ItemGroup />
   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
 </Project>

IPCamLib/IPCamLib.csproj.DotSettings

@@ -0,0 +1,2 @@
+<wpf:ResourceDictionary xml:space="preserve" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:s="clr-namespace:System;assembly=mscorlib" xmlns:ss="urn:shemas-jetbrains-com:settings-storage-xaml" xmlns:wpf="http://schemas.microsoft.com/winfx/2006/xaml/presentation">
+	<s:Boolean x:Key="/Default/CodeInspection/NamespaceProvider/NamespaceFoldersToSkip/=x64/@EntryIndexedValue">True</s:Boolean></wpf:ResourceDictionary>

IPCamLib/RetryableCamera.cs

@@ -0,0 +1,82 @@
+using System;
+using System.Threading;
+using System.Threading.Tasks;
+
+// ReSharper disable UnusedMember.Global - public API
+
+namespace IPCamLib
+{
+    /// <summary>
+    /// Receives frames from an ICamera as well as status updates.
+    /// </summary>
+    public interface IRetryableCameraObserver : ICameraObserver
+    {
+        /// <summary>
+        /// Called when a new Fetch attempt has started.
+        /// </summary>
+        Task OnFetch();
+
+        /// <summary>
+        /// Called when the stream was disconnected.
+        /// </summary>
+        /// <param name="exception">Contains the exception, if any occured. Null for graceful disconnects and timeouts.</param>
+        /// <param name="retryDelay">The delay until the next Fetch is attempted.</param>
+        Task OnDisconnected(Exception exception, TimeSpan retryDelay);
+    }
+    
+    
+    /// <summary>
+    /// Implements retry logic for an ICamera instance.
+    /// </summary>
+    public class RetryableCamera
+    {
+        private readonly ICamera camera;
+
+
+        /// <summary>
+        /// Creates a new instance of a RetryableCamera.
+        /// </summary>
+        /// <param name="camera">The camera instance to fetch from.</param>
+        public RetryableCamera(ICamera camera)
+        {
+            this.camera = camera;
+        }
+
+
+        /// <summary>
+        /// Starts receiving frames and will retry when disconnected.
+        /// </summary>
+        /// <param name="observer">The observer implementation to receive frames and status updates.</param>
+        /// <param name="cancellationToken">A CancellationToken which will stop the camera stream when cancelled.</param>
+        public async Task Fetch(IRetryableCameraObserver observer, CancellationToken cancellationToken)
+        {
+            while (!cancellationToken.IsCancellationRequested)
+            {
+                // TODO incremental back-off?
+                var retryDelay = TimeSpan.FromSeconds(5);
+                var exception = false;
+                
+                try
+                {
+                    await observer.OnFetch();
+                    await camera.Fetch(observer, cancellationToken);
+                }
+                catch (TaskCanceledException)
+                {
+                    // Empty by design
+                }
+                catch (Exception e)
+                {
+                    await observer.OnDisconnected(e, retryDelay);
+                    exception = true;
+                }
+                
+                
+                if (!exception && !cancellationToken.IsCancellationRequested)
+                    await observer.OnDisconnected(null, retryDelay);
+
+                await Task.Delay(retryDelay, cancellationToken);
+            }
+        }
+    }
+}