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  1. Hello, newbie here hope you don't mind

    I've encoding videos using ffmpeg and a supplied avisynth+ script in order to leverage the power of qtgmc for deinterlacing. The results are great, but the encoding performance is a little underwhelming so to speak. I've been trying to enable multithreading but it doesn't seem to have any effect... Here's my script

    LoadPlugin("C:\Program Files (x86)\AviSynth+\plugins64+\ffms2.dll")
    FFMPEGSource2(".\title_t05 (1)-001.mkv")
    SetFilterMTMode("QTGMC", 2)
    QTGMC(preset="Slower", EdiThreads=5)
    The mulithread.avsi script is the one mentionned here
    It doesn't matter if I use 5 or 2 EdiThreads, and Prefetch does not make any difference either. Am I doing something wrong or is this the best performance I can get? I have a i7 8700 cpu by the way, and encoding speed for x264 on veryslow preset is x0.5 versus x2.1 using Handbrake and Decomb on LessSensitive, for comparison.
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  2. How much CPU usage are you getting? And what frame size? With a 1080i source on my i5 2500K I'm seeing over 2 fps with that script and x264 CLI at the veryslow preset, near 100 percent CPU usage. Note that the script alone (no encoding) runs around 7 fps.
    Last edited by jagabo; 15th May 2019 at 18:32.
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  3. I'm seeing 100% cpu usage, but I'm not confident on how optimized that workload is. I am encoding 480i content, and encoding runs at about 30 fps I would say (I don't have the exact figure displayed, only the ratio, how can I see that with ffmpeg?)
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  4. QTGMC is much slower (and much better quality) than any of Handbrake's deinterlacers. Keep in mind that your 0.5x is relative to a 60 fps video, ie, it's encoding at 30 fps. On my old i5 I get around 18 fps using you settings on 480i video. So your 30 fps is in the ballpark of what I'd expect to see out of an i7 8700.
    Last edited by jagabo; 16th May 2019 at 06:07.
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  5. Indeed QTGMC is giving amazing results, so I don't mind waiting a little more. Thank you for your help!
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  6. Even at the "fast" preset it usually looks pretty good.
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