Make webcam handling more stable (fix possible NPE)

Vocaluxe/Base/CWebcam.cs

@@ -49,58 +49,70 @@ namespace Vocaluxe.Base
             return true;
         }
 
+        public static void Close()
+        {
+            if (_Webcam == null)
+                return;
+            _Webcam.Close();
+            _Webcam = null;
+        }
+
         public static bool GetFrame(ref CTexture tex)
         {
-            return _Webcam.GetFrame(ref tex);
+            return _Webcam != null && _Webcam.GetFrame(ref tex);
         }
 
         public static Bitmap GetBitmap()
         {
-            return _Webcam.GetBitmap();
+            return _Webcam == null ? null : _Webcam.GetBitmap();
-        }
-
-        public static void Close()
-        {
-            if (_Webcam != null)
-            {
-                _Webcam.Close();
-                _Webcam = null;
-            }
         }
 
         public static void Pause()
         {
+            if (_Webcam == null)
+                return;
             _Webcam.Pause();
         }
 
         public static void Start()
         {
+            if (_Webcam == null)
+                return;
             _Webcam.Start();
         }
 
         public static void Stop()
         {
+            if (_Webcam == null)
+                return;
             _Webcam.Stop();
         }
 
-        public static void Select(SWebcamConfig c)
+        public static bool Select(SWebcamConfig c)
         {
-            _Webcam.Select(c);
+            return _Webcam != null && _Webcam.Select(c);
+        }
+
+        public static void DeSelect()
+        {
+            if (_Webcam == null)
+                return;
+            _Webcam.DeSelect();
         }
 
         public static SWebcamDevice[] GetDevices()
         {
-            return _Webcam.GetDevices();
+            return _Webcam == null ? null : _Webcam.GetDevices();
         }
 
         public static bool IsDeviceAvailable()
         {
-            return _Webcam.IsDeviceAvailable();
+            return (_Webcam != null) && _Webcam.IsDeviceAvailable();
         }
 
         public static bool IsCapturing()
         {
-            return _Webcam.IsCapturing();
+            return (_Webcam != null) && _Webcam.IsCapturing();
         }
     }
 }

Vocaluxe/Lib/Webcam/CAForgeNet.cs

@@ -15,6 +15,7 @@
 // along with Vocaluxe. If not, see <http://www.gnu.org/licenses/>.
 #endregion
 
+using System;
 using AForge.Video;
 using AForge.Video.DirectShow;
 using System.Collections.Generic;
@@ -31,60 +32,27 @@ namespace Vocaluxe.Lib.Webcam
         private readonly List<SWebcamDevice> _Devices = new List<SWebcamDevice>();
         private bool _Paused;
         private VideoCaptureDevice _Webcam;
-        private FilterInfoCollection _WebcamDevices;
         private SWebcamConfig _Config;
-        private byte[] _Data = new byte[1];
+        private byte[] _Data;
         private static readonly object _MutexData = new object();
         private int _Width, _Height;
-
+        private bool _NewFrameAvailable;
-        public void Close()
+        private bool _IsCapturing;
-        {
-            if (_Webcam == null)
-                return;
-            _Webcam.SignalToStop();
-            _Webcam.WaitForStop();
-            _Webcam.NewFrame -= _OnFrame;
-            _Data = new byte[1];
-        }
-
-        public bool GetFrame(ref CTexture frame)
-        {
-            lock (_MutexData)
-            {
-                if (_Webcam != null && _Width > 0 && _Height > 0 && _Data.Length == _Width * _Height * 4)
-                    CDraw.UpdateOrAddTexture(ref frame, _Width, _Height, _Data);
-            }
-            return false;
-        }
-
-        public Bitmap GetBitmap()
-        {
-            if (_Webcam != null && _Width > 0 && _Height > 0 && _Data.Length == _Height * _Width * 4)
-            {
-                lock (_MutexData)
-                {
-                    var bmp = new Bitmap(_Width, _Height);
-                    BitmapData bitmapdata = bmp.LockBits(new Rectangle(0, 0, _Width, _Height), ImageLockMode.WriteOnly, PixelFormat.Format32bppArgb);
-                    Marshal.Copy(_Data, 0, bitmapdata.Scan0, _Data.Length);
-                    bmp.UnlockBits(bitmapdata);
-                    return bmp;
-                }
-            }
-            return null;
-        }
 
         public bool Init()
         {
-            _WebcamDevices = new FilterInfoCollection(FilterCategory.VideoInputDevice);
+            FilterInfoCollection webcams = new FilterInfoCollection(FilterCategory.VideoInputDevice);
-            foreach (FilterInfo info in _WebcamDevices)
+            foreach (FilterInfo info in webcams)
             {
+                var tmpdev = new VideoCaptureDevice(info.MonikerString);
+                if (tmpdev.VideoCapabilities.Length == 0)
+                    continue;
                 var device = new SWebcamDevice
                     {
                         Name = info.Name,
                         MonikerString = info.MonikerString,
-                        Capabilities = new List<SCapabilities>()
+                        Capabilities = new List<SCapabilities>(tmpdev.VideoCapabilities.Length)
                     };
-                var tmpdev = new VideoCaptureDevice(info.MonikerString);
 
                 foreach (VideoCapabilities capabilities in tmpdev.VideoCapabilities)
                 {
@@ -101,44 +69,188 @@ namespace Vocaluxe.Lib.Webcam
             return true;
         }
 
-        private void _OnFrame(object sender, NewFrameEventArgs e)
+        public void Close()
         {
-            if (_Paused)
+            DeSelect();
+            _Devices.Clear();
+        }
+
+        public void DeSelect()
+        {
+            if (_Webcam == null)
                 return;
+            _Webcam.Stop();
+            _Webcam.NewFrame -= _OnFrame;
+            _IsCapturing = false;
             lock (_MutexData)
             {
-                if (_Width != e.Frame.Width || _Height != e.Frame.Height || _Data.Length != e.Frame.Width * e.Frame.Height * 4)
+                _Data = null;
-                    _Data = new byte[4 * e.Frame.Width * e.Frame.Height];
+                _Webcam = null;
-
-                _Width = e.Frame.Width;
-                _Height = e.Frame.Height;
-                BitmapData bitmapdata = e.Frame.LockBits(new Rectangle(0, 0, _Width, _Height), ImageLockMode.ReadOnly, PixelFormat.Format32bppArgb);
-                Marshal.Copy(bitmapdata.Scan0, _Data, 0, _Data.Length);
-                e.Frame.UnlockBits(bitmapdata);
             }
         }
 
-        public void Pause()
+        #region ConfigSelection
+        private static float _GetScore(int value, int valueRequested)
         {
-            if (_Webcam != null)
+            if (valueRequested <= 0)
-                _Paused = true;
+                return 1;
+            return 1.0f - (float)Math.Abs(value - valueRequested) / Math.Max(value, valueRequested);
+        }
+
+        private static VideoCapabilities _SelectWebcamConfig(VideoCapabilities[] capabilities, SWebcamConfig config)
+        {
+            int configTaken = 0;
+            if (config.Framerate != 0 && config.Height != 0 && config.Width != 0)
+            {
+                float bestMatchScore = 0;
+                for (int i = 0; i < capabilities.Length; i++)
+                {
+                    float score = _GetScore(capabilities[i].AverageFrameRate, config.Framerate);
+                    score += _GetScore(capabilities[i].FrameSize.Height, config.Height);
+                    score += _GetScore(capabilities[i].FrameSize.Width, config.Width);
+                    if (score >= bestMatchScore)
+                    {
+                        // Take the config with the best score, Higher indizes should indicate a better resolution
+                        // so choose the last one with best score if 2 have equal scores
+                        bestMatchScore = score;
+                        configTaken = i;
+                    }
+                }
+            }
+
+            return capabilities[configTaken];
+        }
+        #endregion
+
+        public bool Select(SWebcamConfig config)
+        {
+            //Close old camera connection
+            DeSelect();
+
+            if (_Devices.Count < 1)
+                return false;
+
+            string moniker = _Devices[0].MonikerString;
+            if (config.MonikerString != "")
+            {
+                foreach (SWebcamDevice device in _Devices)
+                {
+                    if (device.MonikerString == config.MonikerString)
+                    {
+                        moniker = device.MonikerString;
+                        break;
+                    }
+                }
+            }
+            _Webcam = new VideoCaptureDevice(moniker);
+
+            _Webcam.VideoResolution = _SelectWebcamConfig(_Webcam.VideoCapabilities, config);
+
+            _Config.Framerate = _Webcam.VideoResolution.AverageFrameRate;
+            _Config.Height = _Webcam.VideoResolution.FrameSize.Height;
+            _Config.Width = _Webcam.VideoResolution.FrameSize.Width;
+            _Config.MonikerString = _Webcam.Source;
+
+            return true;
         }
 
         public void Start()
         {
             if (_Webcam == null)
                 return;
-            _Webcam.NewFrame -= _OnFrame;
+            if (_IsCapturing)
-            //Subscribe to NewFrame event
+            {
-            _Webcam.NewFrame += _OnFrame;
+                if (_Paused)
-            _Webcam.Start();
+                {
-            _Paused = false;
+                    _Webcam.NewFrame += _OnFrame;
+                    _Paused = false;
+                }
+            }
+            else
+            {
+                //Subscribe to NewFrame event
+                _Webcam.NewFrame += _OnFrame;
+                _Paused = false;
+                _Webcam.Start();
+                _IsCapturing = true;
+            }
+        }
+
+        public void Pause()
+        {
+            if (_Webcam != null && !_Paused)
+            {
+                _Webcam.NewFrame -= _OnFrame;
+                lock (_MutexData) //Make sure all events are finished or not yet startet for consistency
+                {
+                    _Paused = true;
+                }
+            }
         }
 
         public void Stop()
         {
             if (_Webcam != null)
+            {
                 _Webcam.SignalToStop();
+                _Webcam.NewFrame -= _OnFrame;
+                lock (_MutexData) //Make sure all events are finished or not yet startet for consistency
+                {
+                    _IsCapturing = false;
+                }
+            }
+        }
+
+        public bool GetFrame(ref CTexture frame)
+        {
+            lock (_MutexData)
+            {
+                if (_Data != null && _Data.Length == _Width * _Height * 4 && _NewFrameAvailable)
+                {
+                    CDraw.UpdateOrAddTexture(ref frame, _Width, _Height, _Data);
+                    _NewFrameAvailable = false;
+                    return true;
+                }
+                return false;
+            }
+        }
+
+        public Bitmap GetBitmap()
+        {
+            lock (_MutexData)
+            {
+                if (_Data != null && _Data.Length == _Width * _Height * 4)
+                {
+                    var bmp = new Bitmap(_Width, _Height);
+                    BitmapData bitmapdata = bmp.LockBits(new Rectangle(0, 0, _Width, _Height), ImageLockMode.WriteOnly, PixelFormat.Format32bppArgb);
+                    Marshal.Copy(_Data, 0, bitmapdata.Scan0, _Data.Length);
+                    bmp.UnlockBits(bitmapdata);
+                    return bmp;
+                }
+                return null;
+            }
+        }
+
+        private void _OnFrame(object sender, NewFrameEventArgs e)
+        {
+            if (_Paused)
+                return;
+            if (e.Frame.Width == 0 || e.Frame.Height == 0)
+                return;
+            lock (_MutexData)
+            {
+                if (!IsCapturing())
+                    return;
+                if (_Data == null || _Data.Length != e.Frame.Width * e.Frame.Height * 4)
+                    _Data = new byte[e.Frame.Width * e.Frame.Height * 4];
+
+                _Width = e.Frame.Width;
+                _Height = e.Frame.Height;
+                BitmapData bitmapdata = e.Frame.LockBits(new Rectangle(0, 0, _Width, _Height), ImageLockMode.ReadOnly, PixelFormat.Format32bppArgb);
+                Marshal.Copy(bitmapdata.Scan0, _Data, 0, _Data.Length);
+                e.Frame.UnlockBits(bitmapdata);
+                _NewFrameAvailable = true;
+            }
         }
 
         public SWebcamDevice[] GetDevices()
@@ -148,42 +260,12 @@ namespace Vocaluxe.Lib.Webcam
 
         public bool IsDeviceAvailable()
         {
-            return _Devices.Count > 0;
+            return _Webcam != null;
         }
 
         public bool IsCapturing()
         {
-            return _Webcam.IsRunning;
+            return _IsCapturing && !_Paused;
-        }
-
-        public bool Select(SWebcamConfig config)
-        {
-            //Close old camera connection
-            Close();
-
-            if (_WebcamDevices == null)
-                return false;
-            if (_WebcamDevices.Count < 1)
-                return false;
-
-            //No MonikerString found, try first webcam
-            _Webcam = config.MonikerString == "" ? new VideoCaptureDevice(_WebcamDevices[0].MonikerString) : new VideoCaptureDevice(config.MonikerString);
-
-            if (_Webcam == null)
-                return false;
-
-            if (config.Framerate != 0 && config.Height != 0 && config.Width != 0)
-            {
-                //_Webcam.DesiredFrameRate = config.Framerate;
-                //_Webcam.DesiredFrameSize = new Size(config.Width, config.Height);
-            }
-
-            _Config.Framerate = _Webcam.SnapshotResolution.AverageFrameRate;
-            _Config.Height = _Webcam.SnapshotResolution.FrameSize.Height;
-            _Config.Width = _Webcam.SnapshotResolution.FrameSize.Width;
-            _Config.MonikerString = _Webcam.Source;
-
-            return true;
         }
 
         public SWebcamConfig GetConfig()

Vocaluxe/Lib/Webcam/IWebcam.cs

@@ -46,19 +46,33 @@ namespace Vocaluxe.Lib.Webcam
     interface IWebcam
     {
         bool Init();
+        void Close();
 
         void Start();
         void Pause();
         void Stop();
-        void Close();
 
+        /// <summary>
+        ///     Gets last captured frame. Returns true if frame was updated<br />
+        ///     Note that this will invalidate the last frame and not return it again with this function
+        /// </summary>
+        /// <param name="frame"></param>
+        /// <returns></returns>
         bool GetFrame(ref CTexture frame);
+
+        /// <summary>
+        ///     Gets the last captured frame as a bitma
+        /// </summary>
+        /// <param name="frame"></param>
+        /// <returns>Null if no frame was captured, the bitmap otherwise</returns>
         Bitmap GetBitmap();
+
         SWebcamConfig GetConfig();
         SWebcamDevice[] GetDevices();
         bool IsDeviceAvailable();
         bool IsCapturing();
 
         bool Select(SWebcamConfig webcamConfig);
+        void DeSelect();
     }
 }

Vocaluxe/Screens/CScreenOptionsVideo.cs

@@ -154,8 +154,8 @@ namespace Vocaluxe.Screens
 
         public override bool UpdateGame()
         {
-            CWebcam.GetFrame(ref _WebcamTexture);
+            if (CWebcam.GetFrame(ref _WebcamTexture))
-            _Statics[_StaticWebcamOutput].Texture = _WebcamTexture;
+                _Statics[_StaticWebcamOutput].Texture = _WebcamTexture;
             _SelectSlides[_SelectSlideVideosToBackground].Selection = (int)CConfig.VideosToBackground;
             return true;
         }
@@ -170,7 +170,7 @@ namespace Vocaluxe.Screens
         public override void OnClose()
         {
             base.OnClose();
-            CWebcam.Close();
+            CWebcam.Stop();
         }
 
         public override void OnShow()
@@ -189,25 +189,20 @@ namespace Vocaluxe.Screens
             {
                 if (devices != null && devices.Length > 0)
                 {
-                    _DeviceNr = 0;
-                    _CapabilityNr = 0;
-                    _GetFirstConfiguredWebcamDevice(ref _DeviceNr, ref _CapabilityNr);
-
                     foreach (SWebcamDevice d in devices)
                         _SelectSlides[_SelectSlideWebcamDevices].AddValue(d.Name);
-                    _SelectSlides[_SelectSlideWebcamDevices].Selection = _DeviceNr;
 
-                    foreach (SCapabilities c in devices[_DeviceNr].Capabilities)
+                    int devNr;
-                        _SelectSlides[_SelectSlideWebcamCapabilities].AddValue(c.Width + " x " + c.Height + " @ " + c.Framerate + " FPS ");
+                    int capNr;
-                    _Config.MonikerString = devices[_SelectSlides[_SelectSlideWebcamDevices].Selection].MonikerString;
+                    if (_GetFirstConfiguredWebcamDevice(out devNr, out capNr))
-                    _Config.Width = devices[_SelectSlides[_SelectSlideWebcamDevices].Selection].Capabilities[_SelectSlides[_SelectSlideWebcamCapabilities].Selection].Width;
+                    {
-                    _Config.Height = devices[_SelectSlides[_SelectSlideWebcamDevices].Selection].Capabilities[_SelectSlides[_SelectSlideWebcamCapabilities].Selection].Height;
+                        _SelectSlides[_SelectSlideWebcamDevices].Selection = devNr;
-                    _Config.Framerate =
+                        _OnDeviceEvent();
-                        devices[_SelectSlides[_SelectSlideWebcamDevices].Selection].Capabilities[_SelectSlides[_SelectSlideWebcamCapabilities].Selection].Framerate;
+                        _SelectSlides[_SelectSlideWebcamCapabilities].Selection = capNr;
-                    CWebcam.Close();
+                        _OnCapabilitiesEvent();
-                    CWebcam.Select(CConfig.WebcamConfig);
+
-                    CWebcam.Start();
+                        ssVisible = true;
-                    ssVisible = true;
+                    }
                 }
             }
             catch (Exception e)
@@ -239,7 +234,6 @@ namespace Vocaluxe.Screens
             {
                 _SelectSlides[_SelectSlideWebcamCapabilities].Clear();
                 _DeviceNr = _SelectSlides[_SelectSlideWebcamDevices].Selection;
-                _CapabilityNr = 0;
 
                 SWebcamDevice d = CWebcam.GetDevices()[_DeviceNr];
                 for (int i = 0; i < d.Capabilities.Count; i++)
@@ -247,16 +241,8 @@ namespace Vocaluxe.Screens
                     _SelectSlides[_SelectSlideWebcamCapabilities].AddValue(d.Capabilities[i].Width + " x " + d.Capabilities[i].Height +
                                                                            " @ " + d.Capabilities[i].Framerate + "FPS");
                 }
-                _SelectSlides[_SelectSlideWebcamCapabilities].Selection = 0;
+                _CapabilityNr = -1;
-
+                _OnCapabilitiesEvent();
-                _Config.MonikerString = d.MonikerString;
-                _Config.Width = d.Capabilities[_SelectSlides[_SelectSlideWebcamCapabilities].Selection].Width;
-                _Config.Height = d.Capabilities[_SelectSlides[_SelectSlideWebcamCapabilities].Selection].Height;
-                _Config.Framerate = d.Capabilities[_SelectSlides[_SelectSlideWebcamCapabilities].Selection].Framerate;
-
-                CWebcam.Close();
-                CWebcam.Select(_Config);
-                CWebcam.Start();
             }
         }
 
@@ -266,24 +252,27 @@ namespace Vocaluxe.Screens
             {
                 _CapabilityNr = _SelectSlides[_SelectSlideWebcamCapabilities].Selection;
 
-                SWebcamDevice d = CWebcam.GetDevices()[_SelectSlides[_SelectSlideWebcamDevices].Selection];
+                SWebcamDevice d = CWebcam.GetDevices()[_DeviceNr];
                 _Config.MonikerString = d.MonikerString;
-                _Config.Width = d.Capabilities[_SelectSlides[_SelectSlideWebcamCapabilities].Selection].Width;
+                _Config.Width = d.Capabilities[_CapabilityNr].Width;
-                _Config.Height = d.Capabilities[_SelectSlides[_SelectSlideWebcamCapabilities].Selection].Height;
+                _Config.Height = d.Capabilities[_CapabilityNr].Height;
-                _Config.Framerate = d.Capabilities[_SelectSlides[_SelectSlideWebcamCapabilities].Selection].Framerate;
+                _Config.Framerate = d.Capabilities[_CapabilityNr].Framerate;
 
-                CWebcam.Close();
                 CWebcam.Select(_Config);
                 CWebcam.Start();
             }
         }
 
-        private void _GetFirstConfiguredWebcamDevice(ref int device, ref int capabilities)
+        private bool _GetFirstConfiguredWebcamDevice(out int device, out int capabilities)
         {
             SWebcamDevice[] devices = CWebcam.GetDevices();
 
             if (devices == null)
-                return;
+            {
+                device = -1;
+                capabilities = -1;
+                return false;
+            }
 
             for (int i = 0; i < devices.Length; i++)
             {
@@ -296,10 +285,13 @@ namespace Vocaluxe.Screens
                     {
                         device = i;
                         capabilities = j;
-                        return;
+                        return true;
                     }
                 }
             }
+            device = 0;
+            capabilities = 0;
+            return true;
         }
     }
 }

Vocaluxe/Screens/CScreenProfiles.cs

@@ -141,13 +141,13 @@ namespace Vocaluxe.Screens
                         }
                         else if (_Buttons[_ButtonDelete].Selected)
                             _DeleteProfile();
-                        else if (_Buttons[_ButtonWebcam].Selected && CWebcam.IsDeviceAvailable())
+                        else if (_Buttons[_ButtonWebcam].Selected)
                             _OnWebcam();
-                        else if (_Buttons[_ButtonSaveSnapshot].Selected && CWebcam.IsDeviceAvailable())
+                        else if (_Buttons[_ButtonSaveSnapshot].Selected)
                             _OnSaveSnapshot();
-                        else if (_Buttons[_ButtonDiscardSnapshot].Selected && CWebcam.IsDeviceAvailable())
+                        else if (_Buttons[_ButtonDiscardSnapshot].Selected)
                             _OnDiscardSnapshot();
-                        else if (_Buttons[_ButtonTakeSnapshot].Selected && CWebcam.IsDeviceAvailable())
+                        else if (_Buttons[_ButtonTakeSnapshot].Selected)
                             _OnTakeSnapshot();
                         break;
 
@@ -235,13 +235,13 @@ namespace Vocaluxe.Screens
                     CProfiles.SetActive(_SelectSlides[_SelectSlideProfiles].ValueIndex,
                                         (EOffOn)_SelectSlides[_SelectSlideActive].Selection);
                 }
-                else if (_Buttons[_ButtonWebcam].Selected && CWebcam.IsDeviceAvailable())
+                else if (_Buttons[_ButtonWebcam].Selected)
                     _OnWebcam();
-                else if (_Buttons[_ButtonSaveSnapshot].Selected && CWebcam.IsDeviceAvailable())
+                else if (_Buttons[_ButtonSaveSnapshot].Selected)
                     _OnSaveSnapshot();
-                else if (_Buttons[_ButtonDiscardSnapshot].Selected && CWebcam.IsDeviceAvailable())
+                else if (_Buttons[_ButtonDiscardSnapshot].Selected)
                     _OnDiscardSnapshot();
-                else if (_Buttons[_ButtonTakeSnapshot].Selected && CWebcam.IsDeviceAvailable())
+                else if (_Buttons[_ButtonTakeSnapshot].Selected)
                     _OnTakeSnapshot();
             }
 
@@ -270,15 +270,16 @@ namespace Vocaluxe.Screens
 
                 int avatarID = CProfiles.GetAvatarID(_SelectSlides[_SelectSlideProfiles].ValueIndex);
                 _SelectSlides[_SelectSlideAvatars].SetSelectionByValueIndex(avatarID);
-                if (CWebcam.IsDeviceAvailable() && CWebcam.IsCapturing())
+                if (_Snapshot == null)
                 {
-                    if (_Snapshot == null)
+                    if (CWebcam.IsCapturing())
-                        CWebcam.GetFrame(ref _WebcamTexture);
+                    {
-
+                        if (CWebcam.GetFrame(ref _WebcamTexture))
-                    _Statics[_StaticAvatar].Texture = _WebcamTexture;
+                            _Statics[_StaticAvatar].Texture = _WebcamTexture;
+                    }
+                    else
+                        _Statics[_StaticAvatar].Texture = CProfiles.GetAvatarTexture(avatarID);
                 }
-                else
-                    _Statics[_StaticAvatar].Texture = CProfiles.GetAvatarTexture(avatarID);
             }
 
             return true;
@@ -310,22 +311,36 @@ namespace Vocaluxe.Screens
 
         private void _OnTakeSnapshot()
         {
-            _Buttons[_ButtonSaveSnapshot].Visible = true;
+            if (!CWebcam.IsDeviceAvailable())
-            _Buttons[_ButtonDiscardSnapshot].Visible = true;
+            {
-            _Buttons[_ButtonWebcam].Visible = false;
+                CDraw.RemoveTexture(ref _WebcamTexture);
-            _Buttons[_ButtonTakeSnapshot].Visible = false;
+                _Snapshot = null;
-            _Snapshot = CWebcam.GetBitmap();
+                _Buttons[_ButtonSaveSnapshot].Visible = false;
+                _Buttons[_ButtonDiscardSnapshot].Visible = false;
+                _Buttons[_ButtonTakeSnapshot].Visible = false;
+                _Buttons[_ButtonWebcam].Visible = false;
+            }
+            else
+            {
+                CWebcam.Stop(); //Do this first to get consistent frame and bitmap
+                _Snapshot = CWebcam.GetBitmap();
+                if (CWebcam.GetFrame(ref _WebcamTexture))
+                    _Statics[_StaticAvatar].Texture = _WebcamTexture;
+                _Buttons[_ButtonSaveSnapshot].Visible = true;
+                _Buttons[_ButtonDiscardSnapshot].Visible = true;
+                _Buttons[_ButtonTakeSnapshot].Visible = false;
+                _Buttons[_ButtonWebcam].Visible = false;
+            }
         }
 
         private void _OnDiscardSnapshot()
         {
-            CWebcam.Stop();
-            CDraw.RemoveTexture(ref _WebcamTexture);
             _Snapshot = null;
+            CDraw.RemoveTexture(ref _WebcamTexture);
             _Buttons[_ButtonSaveSnapshot].Visible = false;
             _Buttons[_ButtonDiscardSnapshot].Visible = false;
             _Buttons[_ButtonTakeSnapshot].Visible = false;
-            _Buttons[_ButtonWebcam].Visible = true;
+            _Buttons[_ButtonWebcam].Visible = CWebcam.IsDeviceAvailable();
         }
 
         private void _OnSaveSnapshot()
@@ -339,13 +354,12 @@ namespace Vocaluxe.Screens
             _Snapshot.Save(filename, ImageFormat.Png);
 
             _Snapshot = null;
-            CWebcam.Stop();
             CDraw.RemoveTexture(ref _WebcamTexture);
 
             _Buttons[_ButtonSaveSnapshot].Visible = false;
             _Buttons[_ButtonDiscardSnapshot].Visible = false;
             _Buttons[_ButtonTakeSnapshot].Visible = false;
-            _Buttons[_ButtonWebcam].Visible = true;
+            _Buttons[_ButtonWebcam].Visible = CWebcam.IsDeviceAvailable();
 
             int id = CProfiles.NewAvatar(filename);
             CProfiles.SetAvatar(_SelectSlides[_SelectSlideProfiles].ValueIndex, id);
@@ -354,9 +368,13 @@ namespace Vocaluxe.Screens
 
         private void _OnWebcam()
         {
+            if (!CWebcam.IsDeviceAvailable())
+            {
+                _Buttons[_ButtonWebcam].Visible = false;
+                return;
+            }
             _Snapshot = null;
             CWebcam.Start();
-            CWebcam.GetFrame(ref _WebcamTexture);
             _Buttons[_ButtonSaveSnapshot].Visible = false;
             _Buttons[_ButtonDiscardSnapshot].Visible = false;
             _Buttons[_ButtonTakeSnapshot].Visible = true;

Vocaluxe/Screens/CScreenSing.cs

@@ -235,7 +235,7 @@ namespace Vocaluxe.Screens
                     case Keys.W:
                         if (CWebcam.IsDeviceAvailable())
                         {
-                            _Webcam = !_Webcam;
+                            _Webcam = !CWebcam.IsCapturing();
                             if (_Webcam)
                                 CWebcam.Start();
                             else
@@ -756,7 +756,7 @@ namespace Vocaluxe.Screens
             CParty.FinishedSinging();
 
             if (_Webcam)
-                CWebcam.Close();
+                CWebcam.Stop();
         }
 
         private int _FindCurrentLine(CVoice voice, CSongLine[] lines, CSong song)