Is it possible to Capture video and modify it before display in Windows (SOLVED)

[af0815]

This Code was only a small and old testrun in Lazarus for one or two cameras. There are a lot of good information about DirectShow and Pascal in the internet. If you want to dive deeper.

BTW. i have also used gstreamer an windows. But DS was handier.

[Dzandaa]

Hi,
This is a skeleton for a Frame Grabber using DirectX9.

Feel free to correct and improve it.

I don't know how to add some drawings on the Frame ( like lines passing at the center)

and I'm not sure that the correct format is selected.

To be continued.

B->

[af0815]

I don't know how to add some drawings on the Frame ( like lines passing at the center)

So it is better you save the image direct and not to load in a visual component. So you can do postprozessing

Code: Pascal  [Select][+][-]

1. procedure TTst_FormVideoTmp.SnapShot(var bmp:TBitmap);
2. begin
3.   if FilterGraph.Active then begin
4.     SampleGrabber.GetBitmap(bmp);  
5.   end
6. end;
7.  

Here a trigger a snapshot and store it in a Bitmap. This bitmap can i postprocess and show the result the user. I do it in my apps for insert information and store the bitmap on the filesystem.   

[Dzandaa]

Hi,

Thank you again Andreas.

In this version, I Grab Frames in a TBitmap with a Timer, add Cyan Square at 10, 10 30, 30 and display it in a TImage.

For the moment, I use only the first camera (just what I need), but some code must be added when you change the camera number.

I'm sure there are other bugs to correct, but it's a start.

If you change the resolution, you have to stop and start the camera again.

@wadu, try this code and tell me if it works? I only tested it on a Win7 pro 64 bits.


B->

[af0815]

With GraphStudioNext you can see, what parameters you can change if the camera is running. Camera, resolution, mediatypes or pins can not changed in run mode. Other parameter (eg. brigthness,...) can well queried and changed in run mode. And each camera can have another set of parameters. :-)

Some hints from my bookmarks:
A good starting point is https://tutoriels.pecaudchristopher.com/tutoriels_windows/espace_delphi/TutorielDSPACK234Delphi.php and this can be good translated to your language, if you are not speaking french.

https://learn.microsoft.com/de-de/windows/win32/directshow/directshow-system-overview?redirectedfrom=MSDN
https://stackoverflow.com/questions/tagged/dspack

BTW: Actual i use Linux and V4L with Lazarus. So i can also use special cameras, with no standard video or resolution like 20 mpx and more.

[Dzandaa]

Hi,

@Andreas, thank you for the links.

I also use Linux with 5DPO and V4L, it's easier,
I just wanted to know if it was possible to do the same thing in Windows to integrate it into my 3D Scanner, Windows version.

I can select the camera now

Too bad you can't easily use BGRABitmap in

Code: Pascal  [Select][+][-]

1. SampleGrabber.GetBitmap(Picture)

instead of TBitmap.

But it's a start.

Looking now how to change Brightness, etc...

Thank you.

B->

[Dzandaa]

Hi,

The program work fine in Windows 7 64bits Pro
But Crashes in Windows 10 when I try to enumerate the camera formats
with and "invalid typecast":

Code: Pascal  [Select][+][-]

1. procedure TVideoGrabberDX9Form.FillFormats(CameraNum: Integer);
2. var
3.         PinList: TPinList;
4.         Cnt: Integer;
5.         MediaStr : String;
6. begin
7.         if(VideoMediaTypes <> nil) then VideoMediaTypes.Free;
8.         VideoMediaTypes := TEnumMediaType.Create;
9.         try
10.                 VideoDev.SelectGUIDCategory(CLSID_VideoInputDeviceCategory);
11.                 Filter.BaseFilter.Moniker := VideoDev.GetMoniker(CameraNum);
12.                 Filter.FilterGraph := FilterGraph;
13.                 FilterGraph.Active := true;
14.                 PinList := TPinList.Create(Filter as IBaseFilter); // Here error: "Invalid typecast"
15.                 VideoMediaTypes.Assign(PinList.First);
16.                 CBVideoFormats.Clear;
17.                 for Cnt := 0 to Pred(VideoMediaTypes.Count) do
18.                 begin
19.                         MediaStr := VideoMediaTypes.MediaDescription[Cnt];
20.                         CBVideoFormats.Items.Add(MediaStr);
21.                 end;
22.                 if(CBVideoFormats.Items.Count <> 0) then CBVideoFormats.ItemIndex := 0;
23.         finally
24.                 FreeAndNil(PinList);
25.         end;
26. end;  
27.  

Any idea?

Thank you.

B->

[af0815]

Insert a step

Code: Pascal  [Select][+][-]

1. var
2.   MyBF : IBaseFilter;
3.  
4. .....
5.  
6.       MyBF:= Filter as IBaseFilter;
7.       PinList := TPinList.Create(MyBF);
8. ...
9.  

look working here with win10, but only with the extra step.

[Dzandaa]

Hi,

Thank you.

Same error at:

Code: Pascal  [Select][+][-]

1. MyBF = Filter as IBaseFilter;

Invalid typecast

Lazarus 2.2.4
FPC 3.2.2

I HATE Windows !!!

B->

[jamie]

Code: Pascal  [Select][+][-]

1. :=  not =  
2.  

See the quote difference?

Maybe I missed something, too?

[Dzandaa]

Hi,
@jamie:

:=  not = 

The typo was just on the forum, not in the code:

Code: Pascal  [Select][+][-]

1. // *****************************
2. // ***** Get Video Formats *****
3. // *****************************
4. procedure TVideoGrabberDX9Form.FillFormats(CameraNum: Integer);
5. var
6.  PinList: TPinList;
7.  Cnt: Integer;
8.  MediaStr : String;
9.  IBF: IBaseFilter;
10. begin
11.  if(VideoMediaTypes <> nil) then VideoMediaTypes.Free;
12.  VideoMediaTypes := TEnumMediaType.Create;
13.  try
14.   VideoDev.SelectGUIDCategory(CLSID_VideoInputDeviceCategory);
15.   Filter.BaseFilter.Moniker := VideoDev.GetMoniker(CameraNum);
16.   Filter.FilterGraph := FilterGraph;
17.   FilterGraph.Active := true;
18.   IBF := Filter as IBaseFilter;  // Here error: "Invalid typecast"
19.   PinList := TPinList.Create(IBF);
20.   VideoMediaTypes.Assign(PinList.First);
21.   CBVideoFormats.Clear;
22.   for Cnt := 0 to Pred(VideoMediaTypes.Count) do
23.   begin
24.    MediaStr := VideoMediaTypes.MediaDescription[Cnt];
25.    CBVideoFormats.Items.Add(MediaStr);
26.   end;
27.   if(CBVideoFormats.Items.Count <> 0) then CBVideoFormats.ItemIndex := 0;
28.  finally
29.   FreeAndNil(PinList);
30.  end;
31. end;              
32.  
33. B->  
34.  

[Dzandaa]

Hi again,

I also tried on Windows 10 Home 64 Bits with Lazarus 3.4 FPC 3.2.2: same result...
No problem in Windows 7 Pro 64 Bits

Did I miss something?

B->

P.S. DxDiag show DirectX 12

[af0815]

Do you use the DSPack from my Source ?

Here "Lazarus 3.4 (rev lazarus_3_4) FPC 3.2.3 i386-win32-win32/win64" it compiles (and with all Lazarus/fpc Versions on my systems) - but i use only win32 Versions of Lazarus because of some issues with 64Bit Lazarus in older (ancient) Programms.

[Dzandaa]

Hi,

Same problem with cross compiling Win64->Win32

I stop playing with video on Windows. My program works well on Linux, I was hoping it was Linux/Windows portable.
It works on Windows 7 64 Bits.

B->

[VisualLab]

Hi again,

I also tried on Windows 10 Home 64 Bits with Lazarus 3.4 FPC 3.2.2: same result...
No problem in Windows 7 Pro 64 Bits

Did I miss something?

B->

P.S. DxDiag show DirectX 12

DirectShow has not been part of DirectX since at least Windows 7 (if not earlier). I suggest following the advice of af0815. I also used this package, although in Delphi. Anyway, it works quite well.