2 Replies Latest reply on May 23, 2012 5:50 AM by gaya

    UVC with 2 output ISO streams

    piotr.bocian

       Hi,

         

      is it possible to have UVC devices with 2 output ISO streams but not as composite devices. My goal is to have just 1 device which I can load by DirectShow (for example by Graph Edit) and this device should have 2 the same output pins (capture).

         

       

         

      If so, should it has:

         

      A) 1 Output Terminal with 2 ISO interfaces binded to it or

         

      B) 2 Outpin Terminals with 1 ISO interface each?

         

       

         

      Thanks in advence for your help.

         

       

         

      BTW, is there any USB forum on Internet, where I can put such questions. I know only https://www.usb.org/phpbb/ which is inaccessible because (as far as I know) it was closed about 2 years ago.

        • 1. Re: UVC with 2 output ISO streams
          steve.magnani

          Hi Piotr,

          Since the VS Input Header descriptor only supports one bEndpointAddress I think you would have to present this as two VideoStreaming interfaces, i.e. bInCollection = 2 in the VC Interface Header descriptor.  

          So, you would provide one Output Terminal and two sets of Video Streaming descriptors.

          Even with this, I don't think there's anything preventing the host from doing a probe/commit sequence on the second interface that conflicts with the settings required for the first - unless your interface is such that no configuration is allowed.

          You might try these folks for a more definitive answer:

          uvcdisc@microsoft.com

             

          https://lists.sourceforge.net/lists/listinfo/linux-uvc-devel

          Regards,
          Steve 

          • 2. Re: UVC with 2 output ISO streams
            gaya

             Hi,

               

             

               

            I did not get how you can handle two interfaces using same O/P terminal? If you had two streaming interfaces for one video source, how would you adjust video properties of both the sterams individually? Please excuse, if I did not understand your app well. I think 1O/P terminal must be mapped to 1 IISO interface. Can you please detail your app a bit more.

               

             

               

            Regards,

               

            Gayathri