Page 1 of 2 12 LastLast
Results 1 to 15 of 24

Thread: Logitech Brio 4k transmitted with 640x480

  1. #1
    Registered User
    Join Date
    May 2018
    Location
    Austria
    Posts
    11

    Logitech Brio 4k transmitted with 640x480

    Hi,

    we are using a Logitech Brio 4k camera via Scan Converter 3.5. to Wirecast. But the stream runs only with 640x480, when set to Auto.

    Any ideas?

    Thomas

    Windows 10 1709, 64-Bit, only Scan Converter installed
    Last edited by t.kofler; 06-21-2018 at 06:31 AM.

  2. #2
    Registered User
    Join Date
    May 2018
    Location
    Austria
    Posts
    11
    When the resolution is set manually to 1920x1440 then Wirecast can receive 1920x1440. For Auto or any resolution set higher then 1920x1440 Wirecast only receives 640x480.

  3. #3
    Registered User
    Join Date
    Mar 2016
    Location
    NJ
    Posts
    33
    I get the same results with my Brio when sending anything higher than 1920x to vMix. This happens both when trying to ingest it as an NDI feed and when using Virtual Camera (which likely is just forwarding the low res NDI it's receiving from Scan Converter)

  4. #4
    Registered User
    Join Date
    May 2018
    Location
    Austria
    Posts
    11
    Very strange, but got to know I am not alone :-)

    I will open a bug report as suggested here: https://forums.newtek.com/showthread...-documentation
    Maybe you can do the same.

    - - - Updated - - -

    and I also tried NewTek Connect, same results and same behaviour

  5. #5
    Registered User
    Join Date
    Mar 2016
    Location
    Houston TX
    Posts
    32
    I've use Brio with vMix at 4k. Brio delivers an uncompressed YUY2 stream by default. That works fine up to and including 1920x1080. Or perhaps 1440 as you say.

    To achieve 4K/UHD the Brio must be told to use MJPEG encoding to compress the images sent across the USB 3 link. The client app must do this when configuring the webcam.

    You appear to be getting some kind of default result because the app isn't configuring the camera correctly.

    Since it's free you could try using OBS to tinker with the camera settings. You'd at least be able to verify that it does deliver 4K when suitably configured.

  6. #6
    Registered User
    Join Date
    Mar 2016
    Location
    NJ
    Posts
    33
    When setting ScanConverter to accept the Brio at 3840x2160, then using virtual camera...
    Adding an input in vmix with the virtual camera as a source... and choosing MJPEG as the format, I get the following notice in vMix



    AddNewInput.The following are supported:

    1024x576 NTSC 30p UYVY
    1024x576 NTSC 30p YUY2
    1024x-576 NTSC 30p ë6ä
    1024x-576 NTSC 30p Āšw

  7. #7
    Registered User
    Join Date
    May 2018
    Location
    Austria
    Posts
    11
    Alanz, are you able roto use the Brio directly via USB as 4k camera?

  8. #8
    Registered User
    Join Date
    Mar 2016
    Location
    NJ
    Posts
    33
    I have always been able to use the Brio with vMix, however there was a lag. So I am trying to see if NDI can eliminate the lag. The Windows Camera app does not have this lag, but vMix, wirecast and vidblaster do when using the Brio at 4k.

  9. #9
    Registered User
    Join Date
    May 2018
    Location
    Austria
    Posts
    11
    Exact same scenario for us with Wirecast

  10. #10
    Registered User
    Join Date
    May 2018
    Location
    Austria
    Posts
    11
    Got an answer from the NetTek support, which responded really fast and professional.
    Short version: Brio is delivering only fake 4k, thats also the cause of the delay even used locally via USB 3.0

    The reason that these higher resolutions do not work is that these web cameras do not actually support "true" 4k, but instead use a mode that sends compressed frames instead of fill frame video. I have not looked at this exact camera and so do not know the exact codec, but it might well be h264 which is not supported at 4k in the Microsoft DirectShow codecs.
    I am sure that if I buy a camera that I can work out how to get it to put out what is a 4k signal although I am certain that the latency will get high and potentially the framerate will be poor. Most vendors did the exact same marketing gimmick with HD webcams before that became sufficiently affordable that it was possible to get uncompressed hd working ... Even today though many do not really do hd at reasonable frame rates.

  11. #11
    Registered User
    Join Date
    Mar 2016
    Location
    Houston TX
    Posts
    32
    Quote Originally Posted by AlanZ View Post
    When setting ScanConverter to accept the Brio at 3840x2160, then using virtual camera...
    Adding an input in vmix with the virtual camera as a source... and choosing MJPEG as the format, I get the following notice in vMix



    AddNewInput.The following are supported:

    1024x576 NTSC 30p UYVY
    1024x576 NTSC 30p YUY2
    1024x-576 NTSC 30p ë6ä
    1024x-576 NTSC 30p Āšw
    What you're seeing here is that Scan Convertor acting as a virtual webcam does not report to vMix that it's capable of the required settings. Even though the camera supports them natively.

  12. #12
    Registered User
    Join Date
    Mar 2016
    Location
    Houston TX
    Posts
    32
    Quote Originally Posted by AlanZ View Post
    I have always been able to use the Brio with vMix, however there was a lag. So I am trying to see if NDI can eliminate the lag. The Windows Camera app does not have this lag, but vMix, wirecast and vidblaster do when using the Brio at 4k.
    The windows camera app uses NV12 encoding, which is not at all common in webcams. All the other apps use YUY2 or MJPEG.

    I need to find a way to get a vMix trial to run on my desktop. That way i could test this myself. My vMix license does not support 4k.

    Using OBS I just confirmed what you are reporting. Brio delivers 1080p with no unexpected latency. When delivering 2160p there are several frames of delay.

    I suspect that the client app must support NV12 to eliminate the latency.
    Last edited by mjgraves; 06-25-2018 at 11:14 AM.

  13. #13
    Registered User
    Join Date
    Mar 2016
    Location
    NJ
    Posts
    33
    MJ, I wonder if we should do feature requests to these companies to provide NV12 encoding... *if* that's what is letting the Windows Camera app ingest the stream at 4k without lag.

  14. #14
    Registered User
    Join Date
    Mar 2016
    Location
    Houston TX
    Posts
    32
    Quote Originally Posted by AlanZ View Post
    MJ, I wonder if we should do feature requests to these companies to provide NV12 encoding... *if* that's what is letting the Windows Camera app ingest the stream at 4k without lag.
    It's certainly worth asking. My insight into this came from conversation with Rich Neuman, founder of Sub2r who has been developing a modular high-end webcam. when they started on a 4K version they found that no apps supported 4K at full-resolutions and frame rate. Their example videos were made using MS Camera specifically because it supported NV12. Their camera is just now entering production.

    http://www.sub2r.com/

    I've just created a related feature request in the vMix forums.

    https://forums.vmix.com/default.aspx...453&#post55453
    Last edited by mjgraves; 06-25-2018 at 11:30 AM. Reason: add point

  15. #15
    Registered User
    Join Date
    Mar 2016
    Location
    NJ
    Posts
    33
    Thanks, now does anyone think that NDI can also enable the format?

Page 1 of 2 12 LastLast

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •