3 Replies Latest reply on Jan 11, 2017 5:34 AM by angryuser1

    Color distortion in video capture and GPU role in process?

    a_h
      1. Hi.

       

      I have a very sticky problem when doing a live streaming event. I am capturing an RGB 32bit signal (DVI) and we notice that the colors are distorted, despite of the fact that there’s no YCbCr <-> RGB color conversions etc. This is checked visually and using color picker without saving the image (paste to paint).

      When I capture the video using the capture card manufacturer’s own capture window we see that the colors are ok but when using a third party encoding software (Telestream Wirecast, Adobe FMLE, OBS) I see the distortion.

       

      My questions are: what is the role of the GPU in this process / relation between the GPU and encoder software? What is the color processing chart in this capture case over all (trying to find the factor of this behavior)?

      I also noticed that using the older AMD software I can adjust the color slightly, but not reaching the exact values. Still I wonder if in this process it is ok to adjust colors using GPU overall (like in YCbCr to RGB conversion you lose part of the colors and you’re not able to restore them but only twist them to a desired tone).

       

      I have done live streaming for years but now for the first time I’m trying to reach the perfect color precision since our customer has millions of viewers and is demanding a perfection. I’m streaming to YouTube, Twitch, Facebook and our partner CDN. We also know the playback site will distort color in some cases, but we try to minimize it by doing the perfect on our end.

       

      I’m using AMD Radeon R7 200

      Win 7 up-to-date

      Computer: Asus X99-S

      Ram 16GB

      Capture card: Datapath Vision AV-SDI using DVI input

       

      Any help is highly appreciated since I'm not that familiar with the process details.

       

      - A_H

        • Re: Color distortion in video capture and GPU role in process?
          angryuser1

          You should check your 3rd party programs configuration first, like color space (PC uses 0-255 while TV or youtube and some programs by default expect 16-255 if I recall), and color format.

          I believe you can make your GPU send a different signal in Radeon Settings, too. Play around with these and see if it changes anything.

          You said yourself that the card software displays the image correctly, suggesting that it's the 3rd party programs misconfiguration.

          • Re: Color distortion in video capture and GPU role in process?
            angryuser1

            Can you connect a different PC or laptop to see if the issue persists?

            Can  you check if the color settings on source PC and target capture card are the same? Like 16/24/32 bit color etc.

            Have you tried a different cable?

            This whole issue is very weird. Since the card software shows the image correctly, there should be no issues at all. Why do you suspect the graphics card to be the culprit?