Deinterlace a live stream with FFGL

  • Hi all,

    Since I can natively capture my live stream from my BlackMagic Intensity with Isadora, the only thing I miss is to deinterlace it.
    I mean deinterlace in vid-gpu mode. I searched a lot on the net in FFGL plugins but didn't find one.

    Any idea ?



  • Tech Staff

    I assume you are capturing as a single video stream.

    So your video is probably alternating frames even and odd.
    You would need to buffer a frame so that you always have a odd and even to combine.
    I believe you can find shaders that combine odd and even textures, so wrapping that up as a FFGL plugin should be possible. That said, I don't know you comfort level with this type of coding...
    So it may be best to add it as a feature request:

  • I'm sorry I do not have the required level to code a FFGL plugin !
    Feature request added..

    I will stick with vid-cpu for the moment.



  • Dear @fifou,

    As noted on this page
    there is no built-in de-interlacing as part of the Blackmagic API, except if you upscale SD to 720p.
    But on that same page, there is a Quartz Composer de-interlacer plugin. Maybe that will give you the performance you need?
    Note that converting from Core Image (Quartz Composer) vid-ci and back to vid-gpu is not very heavy. Give it a try and report back.
    Best Wishes,

  • Thanks a lot Mark,

    I'm trying to do what you said, it works. But I cannot find a way to convert back a vid-ci stream to a vid-GPU. (didn't find some "Image to Texture" actor)
    I need some vid-GPU processing after capture.



  • Ah yes, you're right. There isn't a converter for that.

    Let me just say that we're working some stuff that will allow you to solve your problem, and many others like this. Please be patient and we'll get you the tools you need to do this in relatively short order.
    Best Wishes,

  • Thanks Mark.
    I will stay in vid-CPU mode for the moment.
    But Native BM capture works well.
    I don't need no more the use of Black Syphon -> Isadora. It's great :)

    All the best,