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Autres articles (76)

  • Websites made ​​with MediaSPIP

    2 mai 2011, par

    This page lists some websites based on MediaSPIP.

  • Creating farms of unique websites

    13 avril 2011, par

    MediaSPIP platforms can be installed as a farm, with a single "core" hosted on a dedicated server and used by multiple websites.
    This allows (among other things) : implementation costs to be shared between several different projects / individuals rapid deployment of multiple unique sites creation of groups of like-minded sites, making it possible to browse media in a more controlled and selective environment than the major "open" (...)

  • Other interesting software

    13 avril 2011, par

    We don’t claim to be the only ones doing what we do ... and especially not to assert claims to be the best either ... What we do, we just try to do it well and getting better ...
    The following list represents softwares that tend to be more or less as MediaSPIP or that MediaSPIP tries more or less to do the same, whatever ...
    We don’t know them, we didn’t try them, but you can take a peek.
    Videopress
    Website : http://videopress.com/
    License : GNU/GPL v2
    Source code : (...)

Sur d’autres sites (7776)

  • ffmpeg ensure video and audio track syncronization

    15 août 2012, par Ulterior

    I have been using ffmpeg for some time, mostly in windows enviroment, and now trying to implement video recording on embedded machine. What is most challenging so far is to syncronize audio and video tracks, mostly due to variable video frame rate I have to deal with.

    So I set up a variable frame rate mp4 container and calculate pts value according to the maximum frame rate and high frequency timer, this looks to be working ok.

    Now, when I add audio frames I calculate pts just as a counter of audio frames and longer videos tend to drift the audio track to signifant amount of time, so the lipsync is no longer valid.

    Does anybody has worked on recording videos from the variable frame rate setups and has a tip what medicine to apply - reseting audio buffer each frame, calculating pts for audio differently, etc ? Currently audio frames are pushed into container without waiting for video frames and do not account on them in any way.

  • Changing gamma_r & g in video filter eq (ffmpeg) causes decrease in vmaf score ?

    14 août 2019, par Billo Binder

    I am using ffmpeg video filter

    -vf eq=contrast=1.1:brightness=0:saturation=1:gamma=1:gamma_r=0.99:gamma_g=0.98:gamma_b=1.1

    to reduce red & green colors in a video. But this causes reduction in vmaf scores but increase in ssim scores and I don’t understand why ?

    Original Scores :

    • aggregateVMAF="98.0557"
    • aggregateSSIM="0.977389"
    • aggregateMS_SSIM="0.982315"
    • poolMethod="mean".

    Modified scores :

    • aggregateVMAF="87.0124"
    • aggregateSSIM="0.991839"
    • aggregateMS_SSIM="0.984841"
    • poolMethod="mean".

    Also eq=contrast=1.1 causes boost in vmaf score.

    How do i interpret this...i mean can i ignore change in vmaf as ssim is high ?

    Original Score i got using video filter at default :

    -vf eq=contrast=1.1:brightness=0:saturation=1:gamma=1:gamma_r=1:gamma_g=1:gamma_b=1

    Other Details :

    Distorted 720p video was upscaled using :

    ffmpeg -i dist.mkv -map 0:0 -map 0:1 -vf scale=1920x1080:flags=lanczos -c:v h264_nvenc -preset lossless -profile:v high -level 4.1 -crf 0 -c:a copy output_1080p.mkv

    i mean can i discard low vmaf score & finalize the encode because ssim is high ot there is some other filter which will not hamper vmaf score and reduce greenish effect ?

  • lavc/vvcdec : ensure slices contain nonzero CTUs

    26 janvier, par Nuo Mi
    lavc/vvcdec : ensure slices contain nonzero CTUs

    fixes https://github.com/ffvvc/tests/tree/main/fuzz/passed/000323.bit
    

    Co-authored-by : Frank Plowman <post@frankplowman.com>
    • [DH] libavcodec/vvc/ps.c

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