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Autres articles (54)

  • Les autorisations surchargées par les plugins

    27 avril 2010, par

    Mediaspip core
    autoriser_auteur_modifier() afin que les visiteurs soient capables de modifier leurs informations sur la page d’auteurs

  • L’utiliser, en parler, le critiquer

    10 avril 2011

    La première attitude à adopter est d’en parler, soit directement avec les personnes impliquées dans son développement, soit autour de vous pour convaincre de nouvelles personnes à l’utiliser.
    Plus la communauté sera nombreuse et plus les évolutions seront rapides ...
    Une liste de discussion est disponible pour tout échange entre utilisateurs.

  • List of compatible distributions

    26 avril 2011, par

    The table below is the list of Linux distributions compatible with the automated installation script of MediaSPIP. Distribution nameVersion nameVersion number Debian Squeeze 6.x.x Debian Weezy 7.x.x Debian Jessie 8.x.x Ubuntu The Precise Pangolin 12.04 LTS Ubuntu The Trusty Tahr 14.04
    If you want to help us improve this list, you can provide us access to a machine whose distribution is not mentioned above or send the necessary fixes to add (...)

Sur d’autres sites (9878)

  • Revision 9a1d73d036 : Add loop filtering for UV plane On block boundary within a MB when 8x8 block bo

    12 janvier 2013, par Yaowu Xu

    Changed Paths : Modify /vp9/common/vp9_loopfilter_filters.c Modify /vp9/common/x86/vp9_loopfilter_x86.c Add loop filtering for UV plane On block boundary within a MB when 8x8 block boundary only is filtered for Y. Change-Id : (...)

  • Is there a way to (automatically) detect if the channels of a stereo video/audio are out of phase and canceling each other ?

    8 mars 2024, par Rhenan Bartels

    Background

    


    I've encountered an issue while attempting to convert an audio downloaded from a youtube video into a mono .wav format using ffmpeg. Despite using typical conversion commands (code below), the resulting audio is either silent or corrupted, indicating potential stereo channel cancellation.
I tried to load the audio into Python and calculate phase and cross-correlation, but this step uses a lot of memory, especially for a 6-hour-long audio.

    


    Goal

    


    I'm seeking a method, preferably using ffmpeg, to detect if stereo channels are canceling each other out due to phase misalignment. Additionally, I aim to automate the process of phase inversion before converting to mono to ensure the integrity of the resulting audio.

    


    Question :

    


    How can I automatically detect if stereo channels are canceling each other and subsequently invert the phase to ensure successful conversion to mono using ffmpeg ? Any insights, solutions, or alternative approaches would be greatly appreciated.

    


    Steps Taken :

    


      

    1. Downloaded audio from YouTube using yt-dlp.

      2. 


    2. Attempted audio conversion to mono using ffmpeg, resulting in silent or corrupted output.

      3. 


    3. Successfully converted audio to mono by manually inverting the phase of one channel prior to conversion.

      4. 


    


    Download audio from youtube

    


    yt-dlp -f bestaudio https://www.youtube.com/watch?v=s3QB_rJzH08 -o input.webm


    


    Audio conversion

    


    The resulting file is silent or corrupted

    


    ffmpeg -i input.webm  -ac 1 -ar 16000 -c:a pcm_s16le output.wav


    


    Audio conversion to mono .wav with phase inversion

    


    The resulting file has audio

    


    ffmpeg -i input.webm -af "aeval=val(0)|-val(1)" -ac 1 -ar 16000 -c:a pcm_s16le output.wav


    


  • doc/ffserver : move general stream options upwards in the list

    28 novembre 2013, par Stefano Sabatini
    doc/ffserver : move general stream options upwards in the list
    • [DH] doc/ffserver.texi

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