View Full Version : WDM Driver

October 8, 2003, 14:28:20

I would like to use the DFG/1394 to Grab samples from COMP1 & COMP2 analog video inputs. I have develped my own DirectShow filter and would like to connect both input to the two inputpins on my filter. If I load all filters into GraphEdit, I only have one outputpin for the DFG/1394 device.

How do I use both Composite inputs of the DFG/1394 in GraphEdit (or DirectShow).

thnx Pjotr (awaiting registration)

Stefan Geissler
October 8, 2003, 14:57:24

It is not possible to use two cameras parallel on the DFG 1394/1.

If more than one camera is connected to the DFG 1394/1, an application can
use all cameras only in sequence. This done by switching from one input channel to the next. Therefore, the DFG 1394/1 has two composit inputs and one SVHS input.

October 9, 2003, 09:16:42
Hi Stefan,

first of all, thanks for your fast reply.

So it is not possible to use two camera's parallel.
If there are two input connected, I would end up with a framerate of 12.5 fps per input if I switch between both inputs?

And How do I tell the WDM Driver to switdh between the inputs? Is there a API available which lists the 'Video to 1394 Converter' interface, so I can tell it to switch between two inputs in a DirectShow application?

I must say I find it strange I cannot select the input on the propertie page of the WDM Capture Driver.

thnx Pjotr

Stefan Geissler
October 9, 2003, 10:06:05

If the cameras are not synchronized, the grabber chip in the DFG/1394-1 needs up to 100 ms to synchronize, after the input channel has changed. Thus, the frame rate at switching between the input channels is much less than 12,5 hz.

The method "setInputChannel" is used, to change the input channels.
This is a sample code for switching between input channels:

void CDialogSampleDlg::OnTimer(UINT nIDEvent)

if( m_iChannel == 0 )
m_iChannel = 1;
m_iChannel = 0;


October 9, 2003, 16:33:24

Do you know if there is a APi available, listing the CLSID, the IID(s) (Interface GUID(s)) and the methods supported by the Capture filter of the DFG/1394, including libs or .h files.
This way I can implement the filter directly into my DirectShow application without using your library.

thnx Pjotr

Johannes Vogel
October 9, 2003, 18:00:06

The API you are looking for is IC Imaging Control. It is shipped for free together with the converter.

Btw, there is a separate crossbar filter for the converter providing access to the inputs.

Best regards
IC Support

October 9, 2003, 21:29:02

I'll have another look at it. I have just taken a quick look at the API. I'll hope I will find the tools I need.
thnx for the reply