Recherche avancée

Sur d’autres sites (12688)

• FFMPEG scaling video disable viewing it while process is not ended, for video transcoding on the fly

  5 juillet 2022, par Lucas F

  Good day all,

  


  I'm working on a video player with 1080p original video files, and I would like to change their resolution on the fly :

  


  Actually I host all my original video files under a web mp4 1080p format, and I would like to be able to offer 720p, 480p, etc ... qualities.

  


  So I started to look for tutorials about video transcoding on the fly and I found the FFMPEG tool.

  


  I'm actually using the following command to scale videos - to 720p for e.g. :

  


  ffmpeg -i input.mp4 -vf scale=-1:720 output.mp4


  


  The problem is, once FFMPEG starts scaling it, I have to wait the end of the process before being able to play the video. Do you know if there is any parameter for this command to allow playing the video while it's under scaling ?

  


  Or any workaround that can help me doing this ?

  


  Thank you in advance for your help !

  


  EDIT

  


  Now I found how to access readable content while transcoding (by transcoding to fragmented MP4) :

  


  ffmpeg -i input.mp4 -vf scale=-2:720 -movflags +frag_keyframe+separate_moof+omit_tfhd_offset+empty_moov output.mp4


  


  But my problem is when opening the video it comes as an "ended" video of the current transcoded data.

  


  So if video lasts 1min and is half transcoded, I'll see only 30s, it will not load more data, once the rest is transcoded.

  


• nomenclature #3324 : Déplacer les fonctions typographiques dans un plugin séparé

  29 octobre 2014, par Fil Up

  Quelques autres améliorations à faire (pas très difficile, mais pointilleux : faire des cas tests).

  1. toujours rendre les espaces insécables (même en anglais) quand l’espace est déjà présente (a ! => a !)

  2. en français-français, ajouter les espaces insécables, mais pas en français-suisse (enfin, différemment)
  http://fr.wikipedia.org/wiki/Comparatif_des_différents_codes_typographiques_francophones#Diff.C3.A9rences_entre_les_typographies_fran.C3.A7aise_et_suisse

  3. remplacer les insécables qui vont bien par des fines (en option avec réglage ou define). Le code est déjà fait, il suffit de l’intégrer (avec les tests idoines) cf. http://core.spip.org/issues/1461

• parallel ffmpeg filter complex pipelines

  3 septembre 2021, par Paul Eppner

  Is there a possibility to run ffmpeg filter_complex filter in parallel pipelines ?
On the page http://trac.ffmpeg.org/wiki/Creating%20multiple%20outputs you can find an example under the heading "One filtering instance per each output". However, the filters mentioned there (boxblur,negate,yadif) are executed one after the other, although they could also all be executed simultaneously. I have quite complex filters and therefore long delays when the filters are executed one after the other.

  


  I hope there is another solution.
Cheers

  


  ---

  


  A few hours later I realised that the delay was probably not due to the pipeline, but to the analysis of the imports. However, I then only use the video and audio of the 1st stream. nevertheless, the delay time is then enormously high. Are there any ideas on how I can prevent this delay ?

  


      -i "rtmp://127.0.0.1:1935/$app/$name-de" \
    -i "rtmp://127.0.0.1:1935/$app/$name-en" \
    -i "rtmp://127.0.0.1:1935/$app/$name-fr" \
    -i "rtmp://127.0.0.1:1935/$app/$name-es" \
    -i "rtmp://127.0.0.1:1935/$app/$name-it" \
    -i "rtmp://127.0.0.1:1935/$app/$name-de" \
    -i "rtmp://127.0.0.1:1935/$app/$name-en" \
    -i "rtmp://127.0.0.1:1935/$app/$name-fr" \
    -i "rtmp://127.0.0.1:1935/$app/$name-es" \
    -i "rtmp://127.0.0.1:1935/$app/$name-it" \
    -i "rtmp://127.0.0.1:1935/$app/$name-de" \
    -i "rtmp://127.0.0.1:1935/$app/$name-en" \
    -i "rtmp://127.0.0.1:1935/$app/$name-fr" \
    -i "rtmp://127.0.0.1:1935/$app/$name-es" \
    -i "rtmp://127.0.0.1:1935/$app/$name-it" \
    -vsync -1 \
    -map 0:v -c:v:0 copy \
    -map 0:a \
    -c:a aac -ar 48000 \...```