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  1. Hi. Could someone help figure this out please? I'm trying to convert an interlaced dvd video to progressive with the avisynth commandline at the bottom-through VirtualDub2, but the rendered video creates random dropped frames in the beginning, or at fadeins/outs. I have no clue what's wrong..

    SetFilterMTMode ("QTGMC", 2)
    FFMPEGSource2("cut.mkv")
    AssumeTFF()
    LoadDll("...\fftw-3.3.5-dll64\fftw3.dll")
    QTGMC(preset="Fast", EdiThreads=3, TR0=2, TR1=2, TR2=1, Rep0=1, Rep1=0, Rep2=4, DCT=5, ThSCD1=300, ThSCD2=110, SourceMatch=3, Lossless=1, Sharpness=0, Sbb=0, NoiseProcess=0, GrainRestore=0.0, NoiseRestore=0, StabilizeNoise=false, NoiseTR=0, NoiseDeint="bob")
    Prefetch(8)
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  2. "cut.mkv"... Is that something losslessly cut from a larger file? With an interframe, out of order, open GOP codec? It may have orphaned frames from the prior GOP at the start. Those orphaned frames cannot be restored. Different decoders will do different things with them. Some will just skip them. Some may repeat the first frame of the next GOP in their place. Some will display garbage.
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  3. Originally Posted by jagabo View Post
    "cut.mkv"... Is that something losslessly cut from a larger file? With an interframe, out of order, open GOP codec? It may have orphaned frames from the prior GOP at the start. Those orphaned frames cannot be restored. Different decoders will do different things with them. Some will just skip them. Some may repeat the first frame of the next GOP in their place. Some will display garbage.
    Sorry, I don't understand some of the things you mentioned, but the file is losslessly cut with Videoredo.
    Even when using the original, uncut file, it still looks stuttery after rendering it with this script, even though the framerate shows as 50fps. Pretty interesting that VirtualDub2+Avisynth creates stuttering, but not Hybrid. But I dislike like how Hybrid makes the image look, so i prefer not to use it.
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  4. Member
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    Have you tried it without the prefetch(8) in case the problem
    is related to the multi-threading?
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  5. Originally Posted by davexnet View Post
    Have you tried it without the prefetch(8) in case the problem
    is related to the multi-threading?
    Ok now we're talking. Without that line the stuttering is gone. I didn't know what most of the commands mean, so i left it there. Next time i'll test out everything before asking. Thank you very much!
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  6. prefetch(N) causes AviSynt+ to use multithreading with N threads (the default is to use a single thread, ie, no multithreading). The use of multiple threads is usually much faster (the whole reason we have multicore CPUs) but it can cause frames to be read out of order, which may be causing FFMPEGSource2("cut.mkv") to read the wrong frames at times (many source filters are not always frame accurate on random seeks).

    Instead of removing the prefetch command, you might try using PreRoll(X). That may help FFMPEGSource2() be frame accurate without slowing down the processing.

    http://avisynth.nl/index.php/Preroll

    Or try a higher value than 2 with SetFilterMTMode ("QTGMC", 2).
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