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Accurately timing image updates (video playback)

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  • M Offline
    M Offline
    mikoro
    wrote on last edited by
    #1

    I'm using FFmpeg to read frames from a video, doing some processing, and then showing the video on a form.

    Let's say I have a 59.97 fps video. I'd need to update the image on the form every 16.68 ms to have a correct looking output.

    At the moment I'm just using QTimer, which isn't very accurate and only allows integers for the timeout. And I'm using a label with setPixmap to display the video frames :)

    1. Can I time the playback more accurately somehow?
    2. What is the best way to display fast changing image data on a form?
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    • JKSHJ Offline
      JKSHJ Offline
      JKSH
      Moderators
      wrote on last edited by
      #2

      Hi, and welcome to the Qt Dev Net!

      What is your main goal?

      To experiment with FFmpeg? Or,

      To apply effects to your video?

      If it's 2, I recommend using high-level video manipulation functions like "QML shader effects":http://qt-project.org/doc/qt-5/qml-qtquick-shadereffect.html instead of low-level FFmpeg code. Here's a demo: https://www.youtube.com/watch?v=P4kv-AoAJ-Q

      Qt Doc Search for browsers: forum.qt.io/topic/35616/web-browser-extension-for-improved-doc-searches

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