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CHli
May 15, 2006, 09:49:52
Hi,

First I'm sorry to post in this section since my question is not directly related to the Imaging Control API, but I couldn't find anywhere else to ask on this forum.

We recently bought a "Video to 1394 Converter" and in our application we create the DirectShow graph manually. It is composed like that :

"Video to 1394 Crossbar" --> "Video to 1394 Converter" --> "SampleGrabber" --> "Null Renderer"

For that we are using the DirectShowLib a .Net wrapper to access the DirectShow COM interfaces.

But when setting the "Capture Pin" parameters of the "Video to 1394 Converter" we can set the picture size, the framerate but the color space remain unchanged.

I tried directly with Graphedit :

- Add the "Video to 1394 Converter" filter
- Set RGB8 to it's Capture Pin
- "Render Pin" on it's capture Pin

Graphedit then add a "Color Space Converter" and a "Video Renderer" and begin to capture with... RGB32 colorspace :(

Is it a known limitation ?

Thank you and have a nice day.

Christophe

Stefan Geissler
May 15, 2006, 10:33:09
Christophe,

Please excuse, i am not expierenced in DirectShow itself. I assume, the problem is the color format that is used in the sample grabber. It seems to use RGB32 by default. Thus, DirectShow will insert the Color Space Converter to convert the video format exported by the DFG/1394 to the RGB32 format of the sample grabber. I suggest to check, whether you can force the sample grabber to accept other video formats too. If i am right, the source code of the sample grabber is available in the DirectX SDK. With this you can enhance it to accept other video formats too. This should not be so hard.

CHli
May 15, 2006, 10:56:41
Ok thanks for the quick answer. I'll give it a try.


Edit :

In my code I was already setting the SampleGrabber input pin to "Whatever get configured on the Video to 1394 Converter capture pin" so that was not the problem.

The issue was that I was connecting the filters and then I was setting the capture Pin and grabber video formats. Doing this before connecting them did the trick.

Thanks for the fast support, it gave me some idea to resolve this problem.

Bye

akram
October 20, 2010, 13:11:37
This character string encapsulates operating-system dependent directions as to how to find, open and configure the video stream. In order to assist you in determining a set of parameters, the functions arVideoDispOption(); or ar2VideoDispOption(); are designed to output some help text. The text is reproduced here for your convenience.