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Thomas G. Liesner
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 Posted: Wed May 10, 2006 8:15 am Post subject: Simpliest way to just grab a single picture from a videosour |
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Hello!
I'm programming with Delphi for many years, but mostly data-driven
applications. Now i need to capture a picture from any installed
video-source.
DSPack is now installed and the demo-app "PlayCap" is _nearly_ what i
need. In my case i need a 'silent' solution which means - no window with
the current camerastream visible, only capture the current picture on
command and retrieve it as data without any visual feedback.
If i set VideoWindow to invisible the camerastream i doesn't care and is
visible, if i comment out "VideoWindow.QueryInterface(IBaseFilter,
DestFilter);" a separate window with the videostream opens.
Can someone give me hints how the silent way goes?
And it's bit annoying that if i run it in the IDE i get a protection
error because of the running debugger.
TIA,
Thomas G. Liesner
--
---------------- Neue Hamster-stable 2.1.0.11 seit 28.03.2006 -----------------
Ich suche eine neue Vollzeitarbeitsstelle als Softwareentwickler (Schwerpunkt
Windows) entweder im weiteren Umkreis von Münster (Westfalen) oder in Heim-
arbeit. Details: http://www.tglsoft.de <mailto:jobsuche (AT) tglsoft (DOT) de> |
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KimB
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| Posted: Wed May 10, 2006 12:14 pm Post subject: Re: Simpliest way to just grab a single picture from a video |
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Thomas G. Liesner wrote:
| Quote: | Hello!
I'm programming with Delphi for many years, but mostly data-driven
applications. Now i need to capture a picture from any installed
video-source.
DSPack is now installed and the demo-app "PlayCap" is _nearly_ what i
need. In my case i need a 'silent' solution which means - no window with
the current camerastream visible, only capture the current picture on
command and retrieve it as data without any visual feedback.
If i set VideoWindow to invisible the camerastream i doesn't care and is
visible, if i comment out "VideoWindow.QueryInterface(IBaseFilter,
DestFilter);" a separate window with the videostream opens.
Can someone give me hints how the silent way goes?
And it's bit annoying that if i run it in the IDE i get a protection
error because of the running debugger.
TIA,
Thomas G. Liesner
|
Maybe try TSamplegrabber.getbitmap instead of TVideowindow.getbitmap
hth
KimB |
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Thomas G. Liesner
Guest
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| Posted: Wed May 10, 2006 2:14 pm Post subject: Re: Simpliest way to just grab a single picture from a video |
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KimB schrieb:
| Quote: | Maybe try TSamplegrabber.getbitmap instead of TVideowindow.getbitmap
|
That's what i'm doing - but without playing the source the samplegrabber
grabs nothing and if i play it wants to render visually.
My current hack (for a solution it's not pretty enough):
procedure TVideoForm.FormCreate(Sender: TObject);
var
i: integer;
Device: TMenuItem;
begin
VideoWindow := TVideoWindow.Create(self);
VideoWindow.parent := TForm.Create(self);
VideoWindow.FilterGraph := FilterGraph;
SysDev:= TSysDevEnum.Create(CLSID_VideoInputDeviceCategory);
if SysDev.CountFilters > 0 then
...
end;
procedure TVideoForm.OnSelectDevice(sender: TObject);
var
CaptureGraph: ICaptureGraphBuilder2;
SourceFilter, SampleFilter, DestFilter: IBaseFilter;
begin
FilterGraph.ClearGraph;
FilterGraph.Active := false;
Filter.BaseFilter.Moniker := SysDev.GetMoniker(TMenuItem(Sender).tag);
FilterGraph.Active := true;
FilterGraph.QueryInterface(ICaptureGraphBuilder2, CaptureGraph);
Filter.QueryInterface(IBaseFilter, SourceFilter);
SampleGrabber.QueryInterface(IBaseFilter, SampleFilter);
VideoWindow.QueryInterface(IBaseFilter, DestFilter);
CaptureGraph.RenderStream(nil, nil, SourceFilter,
SampleFilter, DestFilter);
FilterGraph.Play;
CaptureGraph := nil;
SourceFilter := nil;
SampleFilter := nil;
DestFilter := nil;
end;
procedure TVideoForm.SnapShotClick(Sender: TObject);
Var pic: TPicture;
begin
pic := TPicture.create;
SampleGrabber.GetBitmap(pic.Bitmap);
pic.SaveToFile('test.bmp')
end;
So the videostream is rendered to an invisble form and for the grabbing
no visual component is needed anymore.
Not nice, but a working base for what i habe to implement.
Any hints what i can eleminate in the source without elemenating the
possibility to capture are welcome...
So long,
Thomas G. Liesner
--
---------------- Neue Hamster-stable 2.1.0.11 seit 28.03.2006 -----------------
Ich suche eine neue Vollzeitarbeitsstelle als Softwareentwickler (Schwerpunkt
Windows) entweder im weiteren Umkreis von Münster (Westfalen) oder in Heim-
arbeit. Details: http://www.tglsoft.de <mailto:jobsuche (AT) tglsoft (DOT) de> |
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Warrick Wilson
Guest
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| Posted: Wed May 10, 2006 4:15 pm Post subject: Re: Simpliest way to just grab a single picture from a video |
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"Thomas G. Liesner" <tgl (AT) gmx (DOT) de> wrote in message
news:e3svcn.21g.1 (AT) news (DOT) tglsoft.de...
| Quote: | KimB schrieb:
Maybe try TSamplegrabber.getbitmap instead of TVideowindow.getbitmap
That's what i'm doing - but without playing the source the samplegrabber
grabs nothing and if i play it wants to render visually.
My current hack (for a solution it's not pretty enough):
|
I recall seeing something about this on the www.progdigy.com forums - that's
where the DSPack users hang out. Instead of a TVideoWindow, use a
NullRenderer. But check first in those forums for the correct answer, and
possibly some sample code. |
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