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Autres articles (42)

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    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" (...)

  • Encoding and processing into web-friendly formats

    13 avril 2011, par

    MediaSPIP automatically converts uploaded files to internet-compatible formats.
    Video files are encoded in MP4, Ogv and WebM (supported by HTML5) and MP4 (supported by Flash).
    Audio files are encoded in MP3 and Ogg (supported by HTML5) and MP3 (supported by Flash).
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Sur d’autres sites (6184)

  • how to write image with yuv420 format data with PIL or something like that

    16 avril 2021, par nathan wu

    I have a video with yuv420p pixel format. 
At first I tried to read each frame's bytes of it using pipe and pixel format as rgb24. And I used PIL to make image of it.
However, the frames read with format of rgb24 seem to lose a little bit of quality.

    



    Here is the command of reading frame with rgb24 pixel format :

    



        ffmpeg -y -i input.mp4 -vcodec rawvideo -pix_fmt rgb24 -an -r 25 -f rawvideo pipe:1
    frame_data = self.process.stdout.read(1920*1080*3)


    



    Then I tried to read it with yuv420p pixel format.

    



        ffmpeg -y -i input.mp4 -vcodec rawvideo -pix_fmt yuv420p -an -r 25 -f rawvideo pipe:1
    frame_data = self.process.stdout.read(1920*1080*3/2)


    



    One single frame includes half of the bytes of rgb24 frame. It is 3110400 bytes within a 1920*1080 yuv420p frame. I tossed these data into PIL :

    



        Image.frombytes('YCbCr', (1920, 1080), frame_data)


    



    but PIL raise an error of not enough image data.
I looked up the modes that PIL support to write from bytes, none of it is 12_bit pixels.
I also tried to transform the yuv data into rgb data, but it took a lot more time than before when is a long video to process.

    



    Am I doing something wrong ? Is there any way to write an image with raw yuv data without any transform ??

    


  • how to make a video from timeline position data ?

    5 décembre 2013, par Brad

    So I have timeline position data available to me as a JSON object where a object is being moved around a screen. I want to be able to make a video using that information. How would you suggest going about doing that ? (Ubuntu or OSX environment).

  • Trying to decode/convert raw AAC data from a recording that stopped abruptly [closed]

    30 août 2023, par Gonzalo Leon

    I made a very long recording with an application in my cellphone that used AAC but its battery died after 13 hours (although it was plugged in). The file can't be played since the file structure is incorrect, but I know the information is there. The bitrate of the recorder is 100kbps, the sample rate 16000Hz and the file format is QuickTime.

    


    ¿Is there a way to play or decode easily the data in the 'mdat' atom ?.

    


    Please help, this recording is very important for me. Thanks.

    


    I read the documentation of atoms in the QuickTime page and tried to fix the file structure without success so far. I also extracted de raw data from the 'mdat' atom with Python and tried to convert it to WAV using ffmpeg but it didn't work.

    


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