Recherche avancée

Médias (3)

Mot : - Tags -/collection

Autres articles (112)

  • Personnaliser en ajoutant son logo, sa bannière ou son image de fond

    5 septembre 2013, par

    Certains thèmes prennent en compte trois éléments de personnalisation : l’ajout d’un logo ; l’ajout d’une bannière l’ajout d’une image de fond ;

  • MediaSPIP 0.1 Beta version

    25 avril 2011, par

    MediaSPIP 0.1 beta is the first version of MediaSPIP proclaimed as "usable".
    The zip file provided here only contains the sources of MediaSPIP in its standalone version.
    To get a working installation, you must manually install all-software dependencies on the server.
    If you want to use this archive for an installation in "farm mode", you will also need to proceed to other manual (...)

  • Submit bugs and patches

    13 avril 2011

    Unfortunately a software is never perfect.
    If you think you have found a bug, report it using our ticket system. Please to help us to fix it by providing the following information : the browser you are using, including the exact version as precise an explanation as possible of the problem if possible, the steps taken resulting in the problem a link to the site / page in question
    If you think you have solved the bug, fill in a ticket and attach to it a corrective patch.
    You may also (...)

Sur d’autres sites (13722)

  • FFmpeg dnn_processing with tensorflow backend : difficulties applying a filter on an image

    9 avril 2023, par ArnoBen

    I am trying to perform a video segmentation for background blurring similar to Google Meet or Zoom using FFmpeg, and I'm not very familiar with it.

    


    Google's MediaPipe model is available as a tensorflow .pb file here (using download_hhxwww.sh).

    


    I can load it in python and it works as expected, though I do need to format the input frames : scaling to the model input dimension, adding a batch dimension, dividing the pixel values by 255 to have a range 0-1.

    


    FFmpeg has a filter that can use tensorflow models thanks to dnn_processing, but I'm wondering about these preprocessing steps. I tried to read the dnn_backend_tf.c file in ffmpeg's github repo, but C is not my forte. I'm guessing it adds a batch dimension somewhere otherwise the model wouldn't run, but I'm not sure about the rest.

    


    Here is my current command :

    


    ffmpeg \
    -i $FILE -filter_complex \
    "[0:v]scale=160:96,format=rgb24,dnn_processing=dnn_backend=tensorflow:model=$MODEL:input=input_1:output=segment[masks];[masks]extractplanes=2[mask]" \
    -map "[mask]" output.png


    


      

    • I'm already applying a scaling to match the input dimension.
    • 


    • I wrote this [masks]extractplanes=2[mask] because the model outputs a HxWx2 tensor (background mask and foreground mask) and I want to keep the foreground mask.
    • 


    


    The result I get with this command is the following (input-output) :

    


    Output example

    


    I'm not sure how to interpret the problems in this output. In python I can easily get a nice grayscale output :

    


    enter image description here

    


    I'm trying to obtain something similar with FFmpeg.

    


    Any suggestion or insights to obtain a correct output with FFmpeg would be greatly appreciated.

    


    PS : If I try to apply this on a video file, it hits a Segmentation Fault somewhere before getting any output so I stick with testing on an image for now.

    


  • Révision 20232 : Patch pour que le dump fonctionne avec la version sQlite 3.2.8 utilisee chez l’h...

    6 mars 2013, par Gilles VINCENT

    La methode "IF NOT EXISTS" n’est implementee qu’a partir de la version 3.3.alpha Donc on contourne le probleme lorsque la creation d’une table plante, en utilisant une methode de test de presence de table plus "old school" (on recherche dans sqlite_master tout (...)

  • APPLY Strong to Buffer rule. Quit Switching Bit rates MPEG DASH

    14 juillet 2015, par Vinay

    I am using mpeg dash for adaptive bit rate streaming of video from my server.

    I have used ffmpeg and MP4Box to generate 4 different quality video files from my source .mp4

    The .mpd file generated has the below code

    <?xml version="1.0"?>

    <mpd xmlns="urn:mpeg:dash:schema:mpd:2011" minbuffertime="PT1.500000S" type="static" mediapresentationduration="PT0H3M1.42S" profiles="urn:mpeg:dash:profile:isoff-on-demand:2011">
    <programinformation moreinformationurl="http://gpac.sourceforge.net">
     
    </programinformation>

    <period duration="PT0H3M1.42S">
     <adaptationset segmentalignment="true" maxwidth="1920" maxheight="1080" maxframerate="24" par="16:9" lang="und" subsegmentstartswithsap="1">
      <representation mimetype="video/mp4" codecs="avc1.64000d" width="320" height="240" framerate="24" sar="1:1" startwithsap="1" bandwidth="375715">
       <baseurl>400_dashinit.mp4</baseurl>
       <segmentbase indexrangeexact="true" indexrange="904-1403">
         <initialization range="0-903"></initialization>
       </segmentbase>
      </representation>
      <representation mimetype="video/mp4" codecs="avc1.640015" width="420" height="270" framerate="24" sar="1:1" startwithsap="1" bandwidth="644824">
       <baseurl>700_dashinit.mp4</baseurl>
       <segmentbase indexrangeexact="true" indexrange="905-1404">
         <initialization range="0-904"></initialization>
       </segmentbase>
      </representation>
      <representation mimetype="video/mp4" codecs="avc1.64001f" width="1024" height="576" framerate="24" sar="1:1" startwithsap="1" bandwidth="1349484">
       <baseurl>1500_dashinit.mp4</baseurl>
       <segmentbase indexrangeexact="true" indexrange="905-1404">
         <initialization range="0-904"></initialization>
       </segmentbase>
      </representation>
      <representation mimetype="video/mp4" codecs="avc1.64001f" width="1280" height="720" framerate="24" sar="1:1" startwithsap="1" bandwidth="2264379">
       <baseurl>2500_dashinit.mp4</baseurl>
       <segmentbase indexrangeexact="true" indexrange="905-1404">
         <initialization range="0-904"></initialization>
       </segmentbase>
      </representation>
      <representation mimetype="video/mp4" codecs="avc1.640028" width="1920" height="1080" framerate="24" sar="1:1" startwithsap="1" bandwidth="3633049">
       <baseurl>4000_dashinit.mp4</baseurl>
       <segmentbase indexrangeexact="true" indexrange="906-1405">
         <initialization range="0-905"></initialization>
       </segmentbase>
      </representation>
     </adaptationset>
    </period>
    </mpd>

    I am using video.js along with dash.js to playback the mpeg dash content on client side. The issue is that the video doesn’t playback perfectly when i simulate network conditions from chrome dev tools.

    It works at times and it doesn’t at others. For ex the stream starts with bit rate of 400kbps and then detects enough bandwidth available so it switches to 2500kbps. Then when i bring down my bandwidth to 400kbps again then the video freezes at some point of time.

    At times the video freezes after few initial seconds of playback when it tries to switch the stream. I think there might be some command line parameter that i am missing while generating my video files via ffmpeg or generating .mpd file via MP4Box.

    below are the commands i use for ffmpeg and MP4Box

    ffmpeg -y -i inputfile -c:a libfdk_aac -ac 2 -ab 128k -c:v libx264 -r 24 – g 24 -b:v 1500k -maxrate 1500k -bufsize 1000k -vf "scale=-1:720" outputfile.mp4


    MP4Box -dash [DURATION] -rap -frag-rap -profile [PROFILE] -out [path/to/outpout.file] [path/to/input1.file] [path/to/input2.file] [path/to/input3.file]

    Also while i am generating .mpd files via MP4Box i am getting below warning in console

    [DASH]: Files have non-proportional track layouts (320x240 vs 420x270) but sample size and aspect ratio match, assuming precision issue
    [DASH]: Files have non-proportional track layouts (320x240 vs 1024x576) but sample size and aspect ratio match, assuming precision issue
    [DASH]: Files have non-proportional track layouts (320x240 vs 1280x720) but sample size and aspect ratio match, assuming precision issue
    [DASH]: Files have non-proportional track layouts (320x240 vs 1920x1080) but sample size and aspect ratio match, assuming precision issue

    Whenever the video stops playing the chrome console has these logs

    Number of times the buffer has run dry: 25
    Apply STRONG to buffer rule.
    Quit switching bit rates.

    I don’t have any clue as to why the buffers run dry and it stops switching the bit rates.

    Anything that is predominantly wrong in the process ?