TVideoGrabber FAQ - Video capture and media player component for Delphi, C++ Builder

Some codecs are protected against debugging, and this may cause problems when running your application under the control of the debugger.

The symptoms are: preview, recording or playback fails, or just a few frames are displayed, or just a black window appears. Sometime the codec popups automatically a message like this one, and the application is closed immediately.

This problem occurs ONLY when the project is running from the IDE and the debugger is enabled.

To verify that, simply run the .exe of your project out of the IDE. If it works, either you must run your project out of the IDE, either you must disable the integrated debugger to make these tests (Tools | Debugger Options, uncheck "integrated debugging").

This problem has been reported e.g. when trying to play MPEG2 video clips recorded with an Hauppauge PVR (the concerned codec is the InterVideo Video Decoder).

One workaround consists to install a different codec having the same input and output formats, that can play the video clips under a debugger control.

If the stream is a MPEG-2 stream, for debugging purpose you can install third-party MPEG2 decoders, e.g. like:

- the Elecard MPEG2 decoder (note that the evaluation version of this codec shows a nag-screen walking across the video)

- the GPL MPEG2 decoder (download and install MpegDecoder012.msi)

Licensing

How do I remove the nag-screens of the evaluation package?

After purchasing the license, you will receive a download link to the licensed package, that includes the component binaries without nag-screens.
You will have simply to replace the evaluation component binaries by the licensed component binaries as explained in the "readme.txt" file to get the nag-screens removed.

What is the difference between the "without sources" and "with source code" versions?

The "without sources" licensed package looks like the full evaluation package that can be downloaded from our web site, but of course without nag-screens.

The "with source code" package looks like a "without sources" package, but includes additionally the source code of the TVideoGrabber component itself, written in Delphi.

The code of the demo projects included in the package is free of use. The purpose of the demo projects is to show how to implement the component within an application. This code can be reused as needed.

GRAPHICS AND TEXT OVERLAYS

The graphic or text overlays are not refreshed when the video clip is paused

Enable the PlayerRefreshPausedDisplay property.

The graphics or text overlays are displayed during the recording, but when I play the clip they do not appear

- disable the RecordingInNativeFormat property,
- set the FrameGrabber property to fg_BothStreams.

The graphics or text overlays I apply look fine during recording, but they look wrong during playback

Simply check that the frame grabber (or at least the graphics overlays) are disabled during playback.

The frame overlay feature can be applied during recording as well as during playback. Of course, usually, if it is applied during recording, it should not be applied during playback.

If you do not disable the graphics overlay during playback, these operations will be re-applied over the playback frames in the same manner they were during recording, so the frame overlay will be performed 2 times, one time
during recording and one time during playback.

To prevent this problem:
- either disable the frame grabber during playback (but you won't have the
frame capture feature available during playback),
- either check in the OnFrameOverlayUsing... events that you are in a
"recording" state, e.g.:

procedure TfrmMainForm.VideoGrabberFrameOverlayUsingDIB(Sender: TObject;
const FrameInfo: TFrameInfo; DibSection: PDIBSection);
begin
   if VideoGrabber.CurrentState = cs_Recording then begin
      // we perform overlay operations only during recording
   end;
end;

Is it possible to draw over individual frames, e.g. to draw a circle on the 50th video frame?

Yes, this can be done easily from the OnFrameOverlayUsingDC event, e.g.:

procedure TForm1.VideoGrabber1FrameOverlayUsingDC(Sender: TObject;
const FrameInfo: TFrameInfo; Dc: HDC);
const
   BORDER = 10;
var
   OldBrush: LongInt;
   OldPen: LongInt;
   TransparentBrush: HGDIOBJ;
   Pen: HPEN;
begin
   if FrameInfo.FrameNumber < 50 then begin

      // we want a transparent circle background
      TransparentBrush := GetStockObject(NULL_BRUSH);

      // we want to draw a blue circle
      Pen := CreatePen(0, 1, clBlue);

      // we save the current brush and select the new brush
      OldBrush := SelectObject (Dc, TransparentBrush);

      // we save the current pen and select the new pen
      OldPen := SelectObject(Dc, Pen);

      // we draw the blue circle
      Ellipse (Dc, BORDER, BORDER, VideoGrabber1.VideoHeight - BORDER, VideoGrabber1.VideoHeight - BORDER);

      // we restore the current pen
      SelectObject (Dc, OldPen);

      // we restore the current brush
      SelectObject (Dc, OldBrush);

      // we delete our brush
      DeleteObject (TransparentBrush);

      // we delete our pen
      DeleteOBject (Pen);

   end;
end;

When I add my own code in the OnFrameOverlayUsing... events, the program freezes

From these events you should not perform any actions with the potential to block, such as holding a critical section or waiting on another thread. Also, do not call any GDI or USER32.DLL APIs that might cause a window to move.

Important:

Reading or setting properties of VCL components may invoke indirectly these functions, therefore you can have to use intermediary variables or flags to set/retrieve VCL component properties from the OnFrameOverlay... events.

E.g. to read a property of a TListBox from the OnFrameOverlay... event, use an intermediate TStringList variable that will be set when the TListBox.Text property changes, and then read the TStringList variable within the OnFrameOverlay... event.

I need to invert colors only in a part of the video frame

This can be done easily from the OnFrameOverlayUsingDC event by using the following sample code:

procedure TForm1.VideoGrabberFrameOverlayUsingDC(Sender: TObject; Dc: HDC; FrameNumber: Cardinal; FrameTime: Int64; FrameId: Integer);
var
   TempDc: HDc;
begin
   TempDc := CreateCompatibleDc (Dc);
   BitBlt (Dc, 0, VideoGrabber.VideoHeight - 50, VideoGrabber.VideoWidth, VideoGrabber.VideoHeight, TempDc, 0, 0, DSTINVERT);
   DeleteDc (TempDc);
end;

Feel free to contact us at support@datastead.com if you need the same sample code for VB6 or Visual VB and C# .NET.

DISPLAY

When I start preview or I open the player I get a black window (or sometimes white window)

This problem can have 2 origins:

1. the current video render is not compatible:

Try VideoRenderer = vr_VMR7, or VideoRenderer = vr_StandardRenderer

2. the current video subtype may not be supported for the current video size (when a video capture device is used as video source):

In this case try a different VideoSubtype index in the VideoSubtypes list.

How can I dock / undock the component?

Here is the sample code to undock the component:

procedure TForm1.btnUndockClick(Sender: TObject);
begin
   VideoGrabber1.Parent := nil;
   VideoGrabber1.Visible := false;
   Videograbber1.Display_Embedded := false; // undock
   VideoGrabber1.Display_AutoSize := True; // disable it to force the width and height specified in Display_SetLocation bloew
   VideoGrabber1.Display_KeepAspectRatio := True; // disable it to adjust the video window to the control window
   VideoGrabber1.Display_SetLocation (10, 10, 320, 240); // 320 and 240 are not used because of AutoSize above
end;

and then to dock it again:

procedure TForm1.btnDockClick(Sender: TObject);
begin
   Videograbber1.Display_Embedded := True;
   VideoGrabber1.Visible := True;
   VideoGrabber1.Parent := MyParentControl;
end;

PREVIEW

By default the control resizes by itself. How can I get full control over the width and height of the control?

Disable the Display_AutoSize and Display_KeepAspectRatio properties.

The full screen preview is not smooth

Try the following:

- set the video renderer to VMR7 or VMR9 (VideoRenderer = vr_VMR7 or VideoRenderer = vr_VMR9)

- disable the frame grabber if not required (set FrameGrabber = fg_Disabled)

I put a TVideoGrabber component on the form, run the project but no video appears

The AutoStartPreview property is disabled by default. You can:
- either enable AutoStartPreview: the preview will start automatically when the form is created, even if it is not yet visible,
- either invoke StartPreview from the OnShow event of the form where TVideoGrabber is located, to start preview only when the form is shown.

My video card is shipped with a custom third-party renderer filter, how can I use it instead of the default video renderers?

Invoke the ThirdPartyFilter_AddToList function before invoking StartPreview, and pass the CLSID of your third-party filter. E.g.:

...
uses ComObj;
...

procedure TfrmMainForm.Button1Click(Sender: TObject);
const
   CLSID_MyRendererFilter: TGUID = '{70e102b0-5556-11ce-97c0-00aa0055595a}';
begin
   if VideoGrabber.ThirdPartyFilter_AddToList (tpf_VideoRenderer, GUIDtoString (CLSID_MyRendererFilter), 'rndr', true, false) > -1 then begin
      ShowMessage ('filter added');
      VideoGrabber.StartPreview;
   end;
end;

Feel free to contact us at support@datastead.com if you don't know how to retrieve the CLSID of your renderer filter.

DV preview appears interlaced in full size

To get it deinterlaced:
- with the frame grabber enabled⁽¹⁾: enable the Video_Deinterlace property,
- with the frame grabber disabled⁽¹⁾: select the VMR7 video renderer.

(1) the frame grabber is disabled when the FrameGrabber property = fg_Disabled

Preview does not restart automatically after changing a property or calling one of the dialogs.

1) the AutoStartPreview does not work:

- when the component is dynamically created at runtime,
- with the "OCX" version,
- when the component is built into a DLL.

In these cases simply invoke StartPreview when running the application.

2) when the component is placed on a Delphi or C++Builder form, you have to enable the AutoRefreshPreview property.

No window transparency when starting preview.

If you do not need to capture frames or draw over frames, disable the frame grabber (FrameGrabber = fg_Disabled), or insert it on the capture stream only or (FrameGrabber = fg_CaptureStream).

The video quality settings are not available for my capture device. When running MainDemo.exe, the "Quality" button is disabled and the "IsVideoQualityAvailable" property returns "false".

If your video capture device has video quality settings and they are not available, it is possible that the driver of your device does not expose the quality properties. If your capture card is based on Btxxx chips (which is the case of 80% of the PCI video capture boards) we suggest you to try this generic WDM driver.

StartPreview fails on a Windows Media Center platform

You may have to stop the Media Center service before invoking StartPreview or StartRecording.

AVI/MPEG RECORDING

In the "stream" dialog my video capture device shows a compression format (e.g. I420). How can I select this format? Is it related to CompressionMode?

It is not related to CompressionMode. The CompressionMode and CompressionType properties are used ONLY to activate the sofware compressors available in the VideoCompressors and AudioCompressors list.

The formats exposed in the "stream" dialog of the video capture devices are considered as "native" formats. They are exposed in the "VideoSubtypes" list and selected with the VideoSubtype index.

So to specify you want to record in one of the native formats of the video device (e.g. I420), proceed as follows (let's suppose your webcam appears in the VideoDevices list as "Creative Webcam (WDM)")

VideoGrabber.VideoDevice = VideoGrabber.VideoDeviceIndex ("Creative Webcam (WDM)")
VideoGrabber.VideoSubtype = VideoGrabber.VideoSubtypeIndex ("I420")
VideoGrabber.RecordingInNativeFormat = true
VideoGrabber.CompressionMode = cm_None
VideoGrabber.StartRecording

Black screen when invoking StartRecording

This problem has been reported when video compression is enabled and the video compressor selected is not suitable.
Be sure that CompressionMode = cm_NoCompression, or that a suitable VideoCompressor is selected in the VideoCompressors list.

When invoking PauseRecording the frame count goes on and on (paused or not)

The pause/resume feature is disabled by default. Enable the RecordingCanPause property before invoking StartRecording.

During recording, can I generate several small video sequences instead of a large video clip?

Yes, during recording (after invoking StartRecording),:

- if you want to let TVideoGrabber generate the new file name automatically according to the AutoFileName propety, set RecordingFileName = "" then invoke RecordToNewFileNow, e.g:
VideoGrabber.recordingFileName = ""
VideoGrabber.RecordToNewFileNow

- if you want to provide your own recording file name, assign to RecordingFileName the file name to use, then invoke RecordToNewFileNow, e.g.:
VideoGrabber.recordingFileName = "c:\myclips\mynewclip.avi"
VideoGrabber.RecordToNewFileNow

The video clip currently recording is immediately closed and a video clip having the new file name starts recording.

You can also use a timer to do new video sequences periodically, e.g. every 5 min.

I assign a value to the RecordingBacktimedFramesCount property, but when I start recording to fill the buffer nothing happens.

First of all, be sure that:
- the "RecordingInNativeFormat" property is disabled,
- the frame grabber is enabled on both streams or on the capture stream (FrameGrabber = fg_BothStreams or fg_CaptureStream).

E.g. if you assign RecordingBacktimedFramesCount = 30, and the video source frame rate is 30 fps, you will get about 1 sec video time shifting.

When you start recording directly by invoking StartRecording without enabling HoldRecording, of course TVideoGrabber does not have any "back-timed" video frame to put in the recorded stream, so it repeats the first video frame in the video clip until the 30 frames buffer is filled, so you will see a "static image" during 1sec, then you will see the back-timed video.

If you want to record the back-timed video immediately, you have to start the recording "held" in preview mode, by enabling HoldRecording before invoking StartRecording.
Then you can release the recording by invoking ResumeRecording, and by this way the back-timed video will start without having a static image at the beginning of the video clip.

How can I record 2 cameras synchronously?

Enable the Synchronized property before invoking StartRecording, e.g.:

VideoGrabber1.Synchronized := True;
VideoGrabber2.Synchronized := True;

VideoGrabber1.VideoDevice := 0; // e.g. index of the 1st camera in the VideoDevices list
VideoGrabber2.VideoDevice := 1; // e.g. index of the 2nd camera in the VideoDevices list

VideoGrabber1.StartRecording;
VideoGrabber2.StartRecording;

// then both recordings will start at the same time

end;

I get an error or a blak window if I start the recording from the IDE, but not if I run the ".exe" out of the IDE

This problem is caused by a third-party filter that is protected against debugging, detects the debugger and generate a "halt" or a "break"

This explain why the problem does not occurs when running the application's ".exe" out of the debugger.

The workaround consists either to avoid testing the recording from the IDE, either to uninstall the third-party filter that causes the problem. Feel free to contact our support team at support@datastead.com if you need help to identify the filter concerned.

I want to record an AVI file encoded in Windows Media 9 format, but the Windows Media Video 9 codec does not appear in the VideoCompressors list.

You need to install the Windows Media Video 9 VCM (wmv9VCMsetup.exe) that you can download from the Microsoft web site here.

WMV (ASF) RECORDING

The ASF recording fails to start

Install the Windows Media Encoder 9 Series encoder pack.

MOTION DETECTION

How can I record only when motion is detected?

Before invoking StartRecording, enable these 3 properties:

- MotionDetector_Enabled
- RecordingOnMotion_Enabled
- RecordingCanPause

E.g.:

...
VideoGrabber.VideoDevice = 2; // e.g. index of your video device in the VideoDevices list
videograbber.MotionDetector_Enabled = True;
VideoGrabber.RecordingOnMotion_Enabled = True;
VideoGrabber.RecordingCanPause = True;
VideoGrabberStartRecording;

FRAME CAPTURE

The frame capture does not work when playing a MPEG2 clip or previewing a MPEG2 stream.

The default MPEG2 codec currently available on your platform is not compatible with the frame grabber.

You can try the InterVideo codec, that is shipped e.g. with the WinDVD player.

If you use e.g. a Hauppauge PVR (hardware-encoded MPEG2) capture device to record the video clips, be sure that the InterVideo MPEG2 decoder for Hauppauge is properly installed, then add the following code before invoking VideoGrabber1.OpenPlayer:

VideoGrabber1.PlayerForcedCodec := 'InterVideo NonCSS Video Decoder for Hauppauge';

This will force TVideoGrabber to use this MPEG2 codec instead of the default one.

Important - this string is case sensitive.
- the InterVideo codec does not like AT ALL the debuggers. If you need to open a MPEG2 clip, or to preview a MPEG2 stream, Be sure to run your app out of the IDE, or disable temporarily the debugger, otherwise you will get a black video window or some unpredictable results.

PLAYER

Does TVideoGrabber support Dolby 5.1 audio playback (AC3)?

Yes, you just need to install an AC3 decoder filter, e.g.: http://sourceforge.net/projects/ac3filter/

When the clip is paused, the overlays are not refreshed (e.g. the mouse free hand drawing included in the demo does not refresh)

Enable the PlayerRefreshPausedDisplay property.

When the clip is playing, how can I know the total duration and/or frame count of the clip?

Create a OpenPlayerOpened event. When this event occurs, the clip has just been opened, so from this event you can read:

- the PlayerDuration property (that gives the time in 100ns units, 1 second = 10000000),

- the PlayerFrameCount property, that gives the total number of frames.

Is it possible to play Quicktime (*.mov) media clips?

Yes, you need to install first a Quicktime decoder codec, e.g. like Quicktime Alternative.

In paused mode, the player frame positioning is not accurate, either by using the PlayerTrackbar, either by using SetPlayerFramePosition or SetPlayerTimePosition.

Check that you are not using the VMR9 to display the video. The VMR9 buffers 3 video frames and this is the usual source of this problem.

Use the VMR7 (same quality), or the standard renderer (VideoRenderer = vr_VMR7 or vr_StandardRenderer).

I want to use only the player, how can I disable features related to the video and audio capture devices?

From the Object Inspector, set VideoDevice = -1 and AudioDevice = -1.

How to connect a trackbar to TVideoGrabber? I added a TTrackBar in the form, but it was not moving when playing a video.

1. put a TTrackbar component on the form where is located TVideoGrabber.
2. click on the TVideoGrabber component, and, from the Object Inspector, locate the "PlayerTrackbar" property, browse it and select the TrackBar component.

and now the trackbar will move automatically according to the current position of the video clip.

When the player is paused and I step forward or backward by using the arrow keys on the trackbar, sometimes frames are reported twice by the OnFrameProgress event.

Set VideoRender = vr_VMR7.

if you update the trackbar position from the OnFrameProgress event, you must test the "InFrameProgressEvent" state in your trackbar's "OnChange" event code to cancel updating the player position in this case.

If this test is not done, when the OnFrameProgress event occurs -> you set a new trackbar position -> the OnChange event occurs -> from this event you update the player position -> an OnFrameProgress event occurs... an so on, this generates random loopbacks and the player trackbar looks jerky when the user moves it.

E.g.:

procedure TForm1.TrackBar1Change(Sender: TObject);
begin
   if not VideoGrabber1.InFrameProgressEvent then begin
      VideoGrabber1.PlayerFramePosition := TrackBar1.Position;
   end;
end;

REENCODING

The reencoding of VOB files fails

It is probable that you do not have a MPEG2 codec on this platform, or that the MPEG2 codec you have is not compatible with TVideoGrabber.

You can install e.g. one of the following codecs:

- the GPL MPEG1/2 decoder
- the Elecard MPEG Player that you can download here. This will install the Elecard MPEG2 decoder, that is compatible with TVideoGrabber.
If you still have problems anyway, contact the support.

CODECS

MPEG Layer-3 codec and concurrent recordings

The Microsoft's MPEG-3 codec (that appears in the AudioCompressors list as "MPEG Layer-3") does not support concurrent recording.
E.g. you can't use 2 TVideoGrabber components that record with MP3 compression in the same application.

If you need to do that, use the Elecard MP3 "Lame Audio Encoder" instead.
You can download it here (download the lame_dshow.zip package, "MPEG Layer III Audio Encoder")

Does TVideoGrabber include a MPEG-2 decoder?

TVideoGrabber does not include any codec. You must install separately a third-party MPEG2 decoder, e.g. like the GPL MPEG1/2 decoder.

The following DVD packs (recommended by Microsoft) include MPEG2 decoders.

Note:
if you have a video capture board, check if it shipped with a DVD player software (e.g. WinDVD, PowerDVD, etc...).
By installing the DVD Player software, a licensed MPEG2 decoder will be automatically installed.
Several of these DVD players are shipped with the InterVideo MPEG2 decoder. This codec works well with TVideoGrabber but does not support running from the IDE.

Explorer crashes when opening a DivX video

This is a conflict between the DivX and XVid codecs. The method to fix the problem is described here.

*.VRO files fail to play

You need to install the PANASONIC DV codec. Search for "Panasonic VFW DV codec" on Google.

MULTIPLE CAMERAS

I can't preview 2 DV cameras concurrently. Either only one camera is previewing at the same time, either my test project crashes

First step, if you are using Windows XP SP2, apply the Microsoft update fix KB885222 and make a new test.

If the problem remains, verify that the 2 DV cameras can run concurrently out of TVideoGrabber. Proceed as follows:

- close any application that could keep the DV cameras in use,

- open Windows Explorer

- click on "My Computer"

- you should see your 2 DV cameras at the end of the list, double-click on the 1st DV camera to run its preview

- open and 2nd instance of Windows Explorer

- click on "My Computer"

- double-click on the 2nd DV camera to run its preview

- now by switching from an explorer window to the other, you should see both devices previewing concurrently.

If this does not work, the origin of the problem is Windows XP SP2 that does not supports concurrent DV devices on the same IEEE1394 bus.

In this case, the workaround consists to install an additional IEEE1394 PCI card (cheap), and to connect the 2nd DV camera to this card.

If this still does not work, feel free to contact our support team at support@datastead.com

Does TVideoGrabber handle multiple cameras ? Can I perform network streaming with more than one camera ?

Yes, you can, by the following ways:

1) ONE TVIDEOGRABBER COMPONENT BY VIDEO INPUT:
If you have a "true inputs" card (one input = one video chip), e.g. like the IEI IVC200G, that has 4 inputs and 4 ouputs.

Simply put 4 TVideoGrabber components on the form, and assign each "VideoDevice" property respectively to each input (0, 1, 2 and 3).

In this case you have to assign an unique network port to each "ASFNetworkPort" property of the TVideoGrabber components, so you will have 4 network streaming URLs with 4 different network ports.
Of course you have to open each network port on the router or firewall, if any.

2) A SINGLE TVIDEOGRABBER component handles one card having 4 or 16 multiplexed inputs: the multiplexed inputs are switched periodically and automatically by TVideoGrabber, that lets you display them in a "mosaic layout" mode, in which TVideoGrabber shows the whole 4 or 16 inputs into the same larger video window.

This mode is activated simply by setting the "MultiplexedRole" property to mr_MultiplexedMosaic4 or mr_MultiplexedMosaic16.

In this case you can stream the 4 or the 16 inputs simultaneously in a single video window and a single network stream (in this case you need only one network port for 4 or 16 channels).

3) A master TVIDEOGRABBER component handles one card having 4 or 16 multiplexed inputs, and each input is distributed to one TVideoGrabber slave component.
This is the master/slave mode, where a "master" TVideoGrabber component distributes each of the 4 or 16 inputs to 4 or 16 TVideoGrabber "slaves" components. Each slave component can be used as a normal TVideoGrabber component, that receives the video frames from one of the inputs of the master component.

This mode is described in the user guide, and you can find 2 Delphi demo projects in the "MultiplexedInputs" folder included in the package.

I have a standard 4 inputs card, I need some sample code to get 2 inputs previewing in 2 separated TVideoGrabber components.

You need to work in "master/slave" mode: one master TVideoGrabber component distributes the inputs to up to 4 TVideoGrabber slaves components.

E.g.:

procedure TForm1.Button1Click(Sender: TObject);
begin
   VideoGrabber1 := TVideoGrabber.Create (Self);
   VideoGrabber2 := TVideoGrabber.Create (Self);
   VideoGrabber3 := TVideoGrabber.Create (Self);

// select the video device index in the VideoDevices list
VideoGrabber1.VideoDevice := 0;

// VideoGrabber1 will be the "master" component
VideoGrabber1.MultiplexedRole := mr_MultiplexedMaster;

// VideoGrabber2 will be the 1st "slave" component
VideoGrabber2.MultiplexedRole := mr_MultiplexedSlave;

   // VideoGrabber3 will be the 2nd "slave" component
   VideoGrabber3.MultiplexedRole := mr_MultiplexedSlave;

   // VideoGrabber2 will receive the input #2 from VideoGrabber1
   VideoGrabber1.AssociateMultiplexedSlave (2, VideoGrabber2.UniqueID);

   // VideoGrabber2 will receive the input #3 from VideoGrabber1
   VideoGrabber1.AssociateMultiplexedSlave (3, VideoGrabber3.UniqueID);

   VideoGrabber1.Parent := Form1;
   VideoGrabber2.Parent := Form1;
   VideoGrabber3.Parent := Form1;

   VideoGrabber1.Left := 10;
   VideoGrabber2.Left := 10;
   VideoGrabber3.Left := 10;

   VideoGrabber1.Top := 10;
   VideoGrabber2.Top := 300;
   VideoGrabber3.Top := 600;

   VideoGrabber1.StartPreview;
end;

If you need e.g. 4 video inputs add a VideoGrabber4 and a VideoGrabber5 component, and put them the same code than the VideoGrabber2 and VideoGrabber3 have (select the desired inputs when invoking AssociateMultiplexedSlave).

If you need more explanations feel free to contact our support team.

When using a video card with 4 multiplexed inputs, the video is jumping in multiplexed mode (master/slave or mosaļc)

Set the frame rate to 6 (fps).

NETWORK STREAMING

Do you have examples of video and audio streaming?

SAMPLE CODE (server side)

Streaming a live video source (video only):

   VideoGrabber1.VideoDevice := 0;
VideoGrabber1.NetworkStreaming := ns_ASFDirectNetworkStreaming;
VideoGrabber1.NetworkStreamingType := nst_VideoStreaming;
VideoGrabber1.ASFNetworkPort := 10500;
VideoGrabber1.StartPreview;

Streaming a live video source (audio + video):

   VideoGrabber1.VideoDevice := 0;
VideoGrabber1.AudioDevice := 0;
VideoGrabber1.NetworkStreaming := ns_ASFDirectNetworkStreaming;
VideoGrabber1.NetworkStreamingType := nst_AudioVideoStreaming;
VideoGrabber1.ASFNetworkPort := 10500;
VideoGrabber1.StartPreview;

Streaming a video clip:

   VideoGrabber1.VideoSource := vs_VideoFileOrURL;
VideoGrabber1.VideoSource_FileOrUrl := " replace by the file path to your video clip"
VideoGrabber1.NetworkStreaming := ns_ASFDirectNetworkStreaming;
VideoGrabber1.NetworkStreamingType := nst_AudioVideoStreaming;
VideoGrabber1.ASFNetworkPort := 10500;
VideoGrabber1.StartPreview;

SAMPLE CODE (client side)

Note: to view the streaming on the client, you need to open the server URL, that is built as follows: mms:// IP : port
E.g. if the server IP is 192.168.0.123 and the streaming port is 10500 the URL will be mms://192.168.0.123:10500

To know the IP address of the server:
   - either run IPConfig on the server to show it,
   - either use the OnDirectNetworkStreamingHostUrl event (on the server) that returns directly the URL to open in the client when starting the preview or recording (HostUrl parameter).

   VideoGrabber1.VideoSource := vs_VideoFileOrURL;
VideoGrabber1.VideoSource_FileOrUrl := 'mms://192.168.0.123:10500';
VideoGrabber1.StartPreview;

The network streaming fails to start on a Windows 2000 platform

Install the Windows Media Encoder 9 Series encoder pack.

Could you explain me how to setup my computer that is running TVideoGrabber and watch the live video stream by using another computer over the network ?

This example explains how to stream a webcam to the network.

Let's call the computer that sends the video stream the "master", and the computer that watches the live video over the network the "client".

First of all, on the "master" side you need a free IP port of your choise (let's say for this example 8805), and to be sure that this port is opened on the firewall settings of the XP control panel, and on the firewall of your router or DSL modem, if any. See the (*) comment below.

1) Make a quick test by running MainDemo.exe included in the package. Proceed as follows:

a) on the "master" computer:
- run MainDemo.Exe
- go to the "network streaming" tab
- in the "network streaming" groupbox, click on "direct network streaming"
- in the "direct ASF network streaming:" groupbox, enter 8805 in the "Port" edit field"
- go to the "video source" tab, and click "Start preview"
- in the memo field on the left, write down the "streaming url:" that appears, e.g. mms://64.21.142.209:8805. See the (*) comment below.

b) on the "client" computer:

You can use either TVideoGrabber or directly the Windows Media Player to view the live network stream.

With the Windows Media Player, click "file | Open URL", and enter the streaming URL of the "master" computer, e.g. mms://64.21.142.209:8805

With TVideoGrabber:

- run MainDemo.exe,
- select "video file or URL" as video source,
- in the "video source = file or url" edit field, enter the streaming URL of the "master" computer, e.g. mms://64.21.142.209:8805

2) The TVideoGrabber properties and functions programming is:

a) on the "master" computer:
- set the NetworkStreaming property of TVideoGrabber to ns_ASFDirectNetworkStreaming
- set the ASFNetworkPort property to 8805,
- invoke StartPreview to start previewing the live video, this will also start sending the video to the network
- the streaming URL to use on the "client" computer is returned by the DirectNetworkStreamingHostUrl event (host URL parameter) when the network streaming starts, e.g. mms://64.21.142.209:8805

b) on the "client" computer (if you use TVideoGrabber to view the live network streaming),
- set VideoSource = vs_VideoFileOrURL,
- set VideoSource_FileOrUrl = e.g. mms://64.21.142.209:8805,
- invoke StartPreview

(*) if the IP address of the "master" computer that runs TVideoGrabber is a non-routable local IP address (e.g. that begins by 192.... or by 10...), you must setup a port forwarding (of the local IP address of your computer) for the 8805 port on the NAT of your router or DSL modem.
In this case the real IP address to use by the "client" over the internet will be the current IP address of your router or DSL modem on the port 8805, e.g. if your router or DSL modem IP is 64.21.142.209, the client URL to open will be mms://64.21.142.209:8805.

How can I get live network streaming WITH AUDIO in preview mode?

Enable the AudioDeviceRendering property before invoking StartPreview, otherwise the audio section is not binded to the graph.

When I enable the live network streaming under Windows 98 or Windows ME preview and/or recording fails.

The problem will be fixed by installing the Windows Media Format 9 Series SDK that can be downloaded from: https://wmlicense.smdisp.net/ei0u439/91ac29746/download.asp

First of all, you need to choose a free TCP port for each TVideoGrabber component running at the same time.

Choose a port number you want to open. Any free port number can be used, to avoid conflicts choose it above 6000 (and below 65535). E.g. let's choose for this example 8800.

Assign this value to the ASFNetworkPort property of the TVideoGrabber component.

Then create on your router/firewall a NAT routing on this port e.g. for the TCP port 8800 to the local address of your computer running TVideoGrabber (e.g. 192.168.0.122 in this example).

As your IP address changes every day, you need to use a dynamically DNS name, e.g. from http://www.dyndns.org. Ccreate a Dynamic DNS account, and you will get a dynamic domain name, e.g. mydomainname.ath.cx.

This dynamic DNS must be refreshed periodically to your current IP address, and for that you have to install an update client that will refresh periodically your IP address at dyndns.org, look at http://www.dyndns.org/services/dns/dyndns/ -> "Update Clients", you will find several recommended client softwares.

Then give to your clients on the internet the dynamic dns address on the corresponding port, e.g.:

mms://mydomainname.ath.cx:8800

Now, how does it work?

Let's say that today your IP adress assigned by your ISP is 64.88.121.102, and let's say this address has been updated by your update client at www.dyndns.org.

- your clients will connect to mms://mydomainname.ath.cx:8800
- the client's computer will get automatically the IP address from dyndns.org, so it will connect to mms://64.88.121.102:8800
- finally your router/firewall will receive the connection and send it to the corresponding local ip address at mms://192.168.0.122:8800.

MOTION DETECTION

How can record to AVI only when motion occurs?

Use the set of "RecordingOnMotion_..." properties.

E.g.:

...
// activate the motion detection
VideoGrabber1->MotionDetector_Enabled = true;

// activate the recording only when motion occurs
VideoGrabber1->RecordingOnMotion_Enabled = true;

// pause recording each time motion detection stops for 2 seconds
VideoGrabber1->RecordingOnMotion_NoMotionPauseDelayMs = 2000;

// minimal motion sensitivity that activates the recording
VideoGrabber1->RecordingOnMotion_MotionThreshold = 0.001;

VideoGrabber1->StartRecording();
...

AUDIO

The AudioInputLevel property has no effect on the speaker volume

a) if your video capture device is a DV device, it is normal. Use the general AudioVolume property to control the audio output level.

b) if the audio out (e.g. of your TV card) is connected to the line-in or microphone input, the audio goes through the general mixer, independently of TVideoGrabber, and this explains why the AudioMute and AudioInputLevel properties of TVideoGrabber don't seem to act on the audio input level, although they do. Proceed as follow:

1. open the control panel, go to the volume audio control ("advanced" button), and disable the corresponding input in the audio control panel,
2. in TVideoGrabber, for the AudioInputLevel property to work, be sure to disable the "AudioMute" property, and to select an input (e.g. line or microphone), and not the mixer.

No audio rendering or recording with ATI cards

Upgrade to the latest version of the ATI driver.

GENERAL

How can I capture 2 cameras synchroneously?

- put 2 TVideoGrabber components on a form
- assign the VideoDevice of each component respectively to the index of each camera in the VideoDevices list
- enable the "Synchronized" property on each component.
- then invoke StartPreview or StartRecording.

E.g.:

procedure TForm1.Button1Click(Sender: TObject);
begin
VideoGrabber1.Synchronized := true;
VideoGrabber2.Synchronized := true;

VideoGrabber1.StartPreview;
VideoGrabber2.StartPreview;
end;

Preview, recording or playback fail to start

First of all, try the Codecs and debugging solution.

Such problems have been reported after installing third-party codecs, and they have been fixed by reinstalling the latest version of the DirectX runtime. You can download it here.

If the problem remains after, feel free to contact us at support@datastead.com.

Error when opening mpeg clips. Nothing is displayed.

1. the codec required by your clip is probably not installed on your platform. To check that, try to open the clip with the Windows Media Player.
- if the media player reports an error, try to find and install the required codec.
- if the media player downloads and install automatically the codec, and then, plays the clip, try again to open the clip with TVideoGrabber.

2. errors when opening clips are often caused by bugs in third-party codecs. Try to open the clip in the Windows Media Player. If the clip don't work in the WMP as well, and you have an additional codec installed, remove it and try again.

INTERACTIONS WITH THIRD-PARTY APPLICATIONS

When TVideoGrabber is displaying the video, I can't start my application, that reports an error saying the hardware display is not available

The problem occurs because the overlay mixer (that uses hardware acceleration) is used by TVideoGrabber (when VideoRenderer = vr_Default or vr_OverlayRenderer).

So it can't be used by another app when the TVideoGrabber is displaying the video.

To let the overlay mixer available for other applications while TVideoGrabber, set VideoRenderer with another value, e.g. vr_VMR7, vr_VM9 or vr_StandardRenderer.

INSTALL

Invoking regsvr32.exe on Vista returns "DLLRegisterServer failed with error code 0x80004005"

On Vista platforms, regsvr32.exe must be ran as Administrator to be able to register the OCX on the platform.

Therefore the user that installs the TVideoGrabber OCX must have the administrator rights.

- if you invoke regsvr32.exe directly from your install program, right-click on your install program and click "run as Administrator".

- if you run directly Register.cmd or Unregister.cmd, right-click on the .cmd file and click "run as Administrator".

Visual C# .NET

How can I use TVideoGrabber with Visual C# .NET?

First of all, be sure that the Vidgrab_NET.OCX control is registered:

- unzip the TVideoGrabber package in a folder of your choice,
- copy vidgrab_NET.OCX in a folder of your choice
- register vidgrab_NET.OCX by invoking regsvr32, e.g. "regsvr32 c:\vidgrab\vidgrab_NET.ocx'

- run Visual Studio .NET
- click on File | New | Project
- select the "Visual C#" folder, and click on "Windows Application"
- right-click on the ToolBox, click "Add/Remove items"
- select the "COM Components" tab
- browse the list, and near the end check the "VideoGrabberNET control" component, click "OK"
- now the TVideoGrabber component appears in the ToolBox, select it and place it on the form (wait a few seconds before the control appears)
- select the "Windows Form" toolbox, select a button and place it on the form,
- double click on the button, and put this code in the button1_click event: "axVideoGrabberX1.StartPreview();"

- now start the project, click on the button and you should get the preview running.

How can I create a user control including TVideoGrabber with Visual C# .NET?

First of all, be sure that the OCX control is registered: unzip the TVideoGrabber package in a folder of your choice, then click on regVGX.cmd in the ActiveX subfolder.

1. create the user control

- run Visual Studio .NET
- click on File | New | Project
- select the "Visual C#" folder, and click on "Windows Control Library" (let's assume it will be named "WindowsControlLibrary1")

- right-click on the ToolBox, click "Add/Remove items"
- select the "COM Components" tab
- browse the list, and near the end check the "VideoGrabberX Control" component, click "OK"
- now the TVideoGrabber component appears in the ToolBox, select it and place it on the user contol (it can take a few seconds before the control appears)
- select the "Windows Form" toolbox, select a button and place it on the user control,
- double click on the button, and put this code in the button1_click event: "axVideoGrabberX1.StartPreview();"
- now save the project, build the solution, then close the solution.

2. create a project including the user control

- click on File | New | Project
- select the "Visual C#" folder, and click on "Windows Application" (let's assume it will be named "WindowsApplication1")

- in the solution explorer, right-click on "References" and click on "Add Reference"
- open the "WindowsControlLibrary1\Bin\Debug" folder, select "WindowsControlLibrary1.dll", then click "OK"

- right-click on the ToolBox, click "Add/Remove items"
- select the ".NET Framework Components" tab
- click on the "browse" button, and open the "WindowsControlLibrary1\Bin\Debug" folder, then select "WindowsControlLibrary1.dll", the "UserControl1" control should appear and be checked in the list
- click "OK", and now "UserControl1" should appear in the ToolBox in the "My User Controls" list
- click on "UserControl1" and put it on the form
- save the project
- start the project, click on the button and you should get the preview running.

How can I assign a new font to the TextOverlay_Font property?

Use the ToHfont().ToInt32(), function of the Font object.

E.g.:

Font NewFont = new Font("Courier New", 14);
axVideoGrabberNET1.TextOverlay_Font = NewFont.ToHfont().ToInt32();
axVideoGrabberNET1.TextOverlay_Enabled = true;
axVideoGrabberNET1.StartPreview();

I get the "Error 1 Cannot implicitly convert type 'int' to ..." message when assigning an int value to a TVideoGrabber property.

Use Convert.ToInt32. E.g.:

int MyVideoDeviceIndex;

MyVideoDeviceIndex = 1;
axVideoGrabberNET1.VideoDevice = Convert.ToInt32 (MyVideoDeviceIndex);

How can I retrieve the RGB values of a pixel on the current video frame?

Start from the following sample code in the OnFrameOverlayUsingDC event (e.g. to get the pixel at the 10, 15 position):

private void axVideoGrabberNET1_OnFrameOverlayUsingDC(object sender, Axvidgrab_NET.IVideoGrabberNETEvents_OnFrameOverlayUsingDCEvent e)
{
   Color RGBColor = System.Drawing.Color.FromArgb (axVideoGrabberNET1.GetRGBPixelAt(10, 15));
   textBoxR.Text = RGBColor.R.ToString();
   textBoxG.Text = RGBColor.G.ToString();
   textBoxB.Text = RGBColor.B.ToString();
}

VISUAL C++ 6

I get an error when building or running my VC++ project after upgrading the vidgrab_VC6.ocx library

To upgrade a VC++ project from an earlier version, proceed as follows:

- exit VC++

- unregister the old ocx (e.g. "regsvr32 /u c:\vidgrab\vidgrab_vc6.ocx")

- overwrite the old vidgrab_vc6.ocx with the new vidgrab_vc6.ocx file

- register the new vidgrab_vc6.ocx (e.g."regsvr32 c:\vidgrab\vidgrab_vc6.ocx")

- in your VC++ project's folder, overwrite the videograbbervc6.cpp and videograbbervc6.h by the new ones included in the "VC6\Interfaces" folder of the new package

- run VC++, open the project

- open the form on which is located the TVideoGrabber component

- select the TVideoGrabber component

- cut the TVideoGrabber component (Ctrl + X)

- paste the TVideoGrabber component (Ctrl + V)

- save and full rebuild the vc++ project.

I do not find in the OCX several properties and functions that are listed in the user guide

Some properties does not appear when browsing the component because they are not "published" (their values are not stored).

However they can be assigned or read programmatically without problem.

VISUAL BASIC 6

I can't open the Visual Basic MainDemo project because the FM20.OCX (FM20.DLL) controls are not installed

This library is NOT REDISTRIBUABLE, however it is shipped with the Microsoft ActiveX Control Pad, that you can freely download and install.

The Control Pad install package (SETUPPAD.EXE) must be downloaded from:
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnaxctrl/html/cpad.asp

I invoke TVideoGrabber between a main form and child forms, and I get an error when exiting or closing a child form

Proceed as follows:

- in your main form, create a public boolean:

Public CanUnload As Boolean

- in the FormLoad, set it to false:

Private Sub Form_Load()
   CanUnload = False
   ...
end Sub

then create a FormUnload event in the main form that set it to true when the main form is destroyed:

Private Sub Form_Unload(Cancel As Integer)
   CanUnload = True
   ...
End Sub

then for each of the child forms, create a Form_Unload event as follows:

Private Sub Form_Unload(Cancel As Integer)
   If Not MainForm.CanUnload Then
      Hide
      Cancel = True
   End If
End Sub

This prevents destroying the child form if the main form is not being destroyed.

DELPHI AND C++BUILDER

I installed the trial version of C++Builder. I installed the component without problem, placed it on a form, but when I run my project I get an error.

The origin of this problem is the "use dynamic RTL" option that is enabled by default. Proceed as follows:

- go to Project | Options | Linker (ilink32) | Linking, and uncheck "use dynamic RTL"

How can I choose between creating a project's ".exe" that contains the full TVideoGrabber library, or a small project's ".exe" than links to the TVideoGrabber library?

a) to create a project's ".exe" that contains the full TVideoGrabber library,
- go to Project | Options | Packages, uncheck "Build with runtime packages"
- rebuild your project

b) to create a small project's ".exe that links to the TVideoGrabber library:
- go to Project | Options | Packages, check "Build with runtime packages".
- rebuild your project
- then you will have to copy the TVidGrab.bpl file in the folder where is located your Project's ".exe" file, or in the Windows\System32 folder.

I get an error "the procedure entry point ... procedure$qri ... could not be located in library Vcl40.bpl" error when I try to install TVideoGrabber on the component palette.

TVideoGrabber has been compiled with the latest update packs applied on Delphi and C++Builder, and the latest Borland update packs have not been applied on your Delphi or C++Builder compiler.

This problem has been reported mainly with Delphi 4, on which you need to apply "d4upd2.exe" on the "CD" install.

visit the following pages at Borland to download and apply the latest update packs:

Delphi : http://info.borland.com/devsupport/delphi/downloads/index.html
C++Builder : http://info.borland.com/devsupport/bcppbuilder/

I installed the component as explained in the readme.txt. When I compile my project I get a Fatal Error " Cant't find TVidgrab.lib or TVidgrab.bpi" message.

This is a Delphi or C++Builder common "search path" problem. According to your Delphi or C++Builder version, check the following points:

go to Tools | Environment Options | Library, and check that you have ;$(DELPHI)\Imports (for Delphi) or ;$(BCB)\Imports (for C++Builder) in the Library path, otherwise add it at the end of the edit field;
go to Project | Options | Packages, check "Build with runtime package", go to the end of the packages list, remove ";TVidGrab", and then uncheck "Build with runtime package".

If the problem remains contact us at support@datastead.com.

How must I configure C++Builder to make an .exe that does not require TVidGrab.bpl at runtime?

- go to Project | Options | Packages, check "Build with runtime package", go to the end of the packages list, remove ";TVidGrab", and then uncheck "Build with runtime package".

- go to Project | Options | Linker, uncheck "use dynamic RTL".

- rebuild the project.

I loaded up the demo for TVideoGrabber in Delphi 6 Trial or Delphi 7 Trial and tried to build it. I am getting and error at address nnnnnnn in module dccn0.dll read of address nnnnnnnn.

The trial version comes with a different DCU format than the real one. TVideoGrabber or other third-party components can't be used in the trial.

Exception error CPU window occurs when running the project from the IDE, but not out of the IDE:

If you see "breakpoint" labels in the CPU window, this problem is commonly caused by debug statements left in of some codecs (like Voxware audio codecs) that stops the program by sending unwanted "int 3" breakpoints to the Delphi or C++Builder debugger. This problem occurs when TVideoGrabber enumerates the codecs.

This has absolutely no consequences on the application, but is annoying debug the project from the IDE.

To avoid this problem, an option has been added to disable the codecs enumeration when running the project from the IDE. To use this option, add an initialization section at the bottom of your TVideoGrabber's form as following:
...
initialization
CodecsDisabledFromIDE := true;
finalization
end.

However, the codecs can't be used by TVideoGrabber if this option is enabled and Delphi or C++Builder is running. If you need to test your project with compression filters, disable this option and press "F9" at run time as many times as necessary, then enable the option again when you have finished testing the codecs.

VIDEO CAPTURE DEVICES

Hauppauge PVR: problems with video and/or audio rendering during preview, recording or playback

Verify that the Hauppauge Video Decoder 5 codecs are installed.
They can be downloaded from the Hauppauge support page here.

I am calling the VideoDevices list from the OnDeviceArrivalOrRemoval event. When I turn a video device on, the VideoDevices list is updated, but when I turn it off it is not removed from the list.

This is normal, in order to prevent the complexity of having to manage the shifted indexes of the video captures whose indexes are above the index of the device currently removed (because VideoDevice selects the current video device in the VideoDevices list).

When TVideoGrabber is running, the rules are the following:

1. when a device is turned on, the device is added at the bottom of the VideoDevices list. The OnDeviceArrivalOrRemoval event occurs. Its IsDeviceArrival parameter reports "true", and its DeviceIndex parameter reports the index of the video device added in the list.

2. when a device is turned off, the device remains in the VideoDevices list. The OnDeviceArrivalOrRemoval event occurs. Its IsDeviceArrival parameter reports "false", and its DeviceIndex parameter reports the index of the video device turned off.

3. if a device turned off (case 2 above) is turned on again, the VideoDevices list does not change. The OnDeviceArrivalOrRemoval event occurs. Its IsDeviceArrival parameter reports "true", and its DeviceIndex parameter reports the index the video device had when it was turned off.

You can retrieve current the state of any video capture devices (connected or not) by testing IsVideoDeviceConnected (DeviceIndex).

E.g. IsVideoDeviceConnected (3) will return "true" if the device having the index 3 in the VideoDevices list is active and "false" if the device has been turned off.

How to use TVideoGrabber with 4 cameras?

This depends on the video capture devices you plan to use.

1) you can use a PCI card with 4 inputs/ouputs, (4 TVideoGrabber components will be used separately), e.g. like the IEI IVC200:
http://www.ieiworld.com/en/product_IPC.asp?model=IVC-200G

2) you can use several webcams (one webcam per TVideoGrabber component, this is equivalent to the 1) solution above

3) you can use one PCI card with 4 inputs and one multiplexed output, e.g. like the IEI IVC 100, or the PICO 2000 DRV card used with this generic driver.

For the 1) and 2) solutions, use several TVideoGrabber components as sources. You can record each component separately, or you can mix the TVideoGrabber source components in a destination TVideoGrabber component as shown in the "MixedVideoSources" demo project included in the package.

For the 3) solution:
- you can use a 4 inputs layout (you can test that by running MainDemo.exe, in the "video sources tab", check "enable 4 inputs layout")
- you can use the master/slaves method (one TVideoGrabber component as master, that distributes the 4 inputs to 4 TVideoGrabber slaves components. This solution is shown in the "Multiplexed Inputs" demo projects included in the evaluation package.

Black video window with a Sony HDR-FX1

Search the menu of the camcorder for the I-link (firewire) mode, and turn it on.

Logitech webcams: how can I disable the face tracking feature?

1. update to the latest version of the Logitech driver that you can download from:

2. invoke SetCameraControl (cc_tilt, false, false, 0) before invoking StartPreview

Note: to re-enable the face tracking invoke SetCameraControl (cc_tilt, true, false, 0).

Avermedia EZMaker USB 2.0: can't set the analog video standard and video input

Unfortunately the driver of this device does not expose the required interfaces.

Provideo PV326C / PV326CH

You need to install the V1.3.30425 SDK.
After installing the driver, be sure to run the "setup.exe" located in the "Filter" folder of the SDK.

Hauppauge WinTV USB: no AVI audio capture

The driver is not the same if you capture the WinTV audio directly through USB or if you use an audio cable to connect the WinTV USB audio out to your audio card input.
Upgrade to the right version of the Hauppauge WinTV USB driver here.

NVIDIA Video Capture driver: incorrect video windows

This is a bug of the driver. Go to the NVidia support drivers page and upgrade to the NVidia driver v41.07 or higher.

Pinnacle systems MovieBox USB or MovieBox Deluxe USB

Use only the following video sizes:

352x288 in PAL
352x240 in NTSC

IDS Falcon: not all the video capture device features are available programmatically.

Use this generic WDM driver instead of the driver shipped with the card.

Typhoon WebShot USB 300K: black frame capture or jerkey display

Enable the FixFlickerOrBlackCapture property.

SAMPLE CAPTURE

Is it possible to access the compressed video data buffer from TVideoGrabber?

Yes, the video samples are returned by the OnRawVideoSample event.

In this event the data frame buffer is returned by the pSampleBuffer pointer.

Note: the RawSampleCaptureLocation must be set to rl_AfterCompression before invoking StartRecording.

applications

License Agreement

Copyright © 2002-2007 Datastead Sarl. All rights reserved.
Delphi™ and C++Builder™ are trademarks of Borland Corporation. DirectX™ is a trademark of Microsoft Corporation.
All other trademarks are the sole property of their respective owners.