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  • Multilang : améliorer l’interface pour les blocs multilingues

    18 février 2011, par

    Multilang est un plugin supplémentaire qui n’est pas activé par défaut lors de l’initialisation de MediaSPIP.
    Après son activation, une préconfiguration est mise en place automatiquement par MediaSPIP init permettant à la nouvelle fonctionnalité d’être automatiquement opérationnelle. Il n’est donc pas obligatoire de passer par une étape de configuration pour cela.

  • Les tâches Cron régulières de la ferme

    1er décembre 2010, par

    La gestion de la ferme passe par l’exécution à intervalle régulier de plusieurs tâches répétitives dites Cron.
    Le super Cron (gestion_mutu_super_cron)
    Cette tâche, planifiée chaque minute, a pour simple effet d’appeler le Cron de l’ensemble des instances de la mutualisation régulièrement. Couplée avec un Cron système sur le site central de la mutualisation, cela permet de simplement générer des visites régulières sur les différents sites et éviter que les tâches des sites peu visités soient trop (...)

  • Soumettre améliorations et plugins supplémentaires

    10 avril 2011

    Si vous avez développé une nouvelle extension permettant d’ajouter une ou plusieurs fonctionnalités utiles à MediaSPIP, faites le nous savoir et son intégration dans la distribution officielle sera envisagée.
    Vous pouvez utiliser la liste de discussion de développement afin de le faire savoir ou demander de l’aide quant à la réalisation de ce plugin. MediaSPIP étant basé sur SPIP, il est également possible d’utiliser le liste de discussion SPIP-zone de SPIP pour (...)

Sur d’autres sites (13520)

  • How to optimize ffmpeg w/ x264 for multiple bitrate output files

    10 octobre 2013, par Jonesy

    The goal is to create multiple output files that differ only in bitrate from a single source file. The solutions for this that were documented worked, but had inefficiencies. The solution that I discovered to be most efficient was not documented anywhere that I could see. I am posting it here for review and asking if others know of additional optimizations that can be made.

    Source file       MPEG-2 Video (Letterboxed) 1920x1080 @>10Mbps
    
                  MPEG-1 Audio @ 384Kbps
    
Destiation files  H264 Video 720x400 @ multiple bitrates
    
                  AAC Audio @ 128Kbps
    
Machine           Multi-core Processor

    The video quality at each bitrate is important so we are running in 2-Pass mode with the 'medium' preset

    VIDEO_OPTIONS_P2 = -vcodec libx264 -preset medium -profile:v main -g 72 -keyint_min 24 -vf scale=720:-1,crop=720:400

    The first approach was to encode them all in parallel processes

    ffmpeg -y -i $INPUT_FILE $AUDIO_OPTIONS_P2 $VIDEO_OPTIONS_P2 -b:v 250k -threads auto -f mp4 out-250.mp4 &
ffmpeg -y -i $INPUT_FILE $AUDIO_OPTIONS_P2 $VIDEO_OPTIONS_P2 -b:v 500k -threads auto -f mp4 out-500.mp4 &
ffmpeg -y -i $INPUT_FILE $AUDIO_OPTIONS_P2 $VIDEO_OPTIONS_P2 -b:v 700k -threads auto -f mp4 out-700.mp4 &

    The obvious inefficiencies are that the source file is read, decoded, scaled, and cropped identically for each process. How can we do this once and then feed the encoders with the result ?

    The hope was that generating all the encodes in a single ffmpeg command would optimize-out the duplicate steps.

    ffmpeg -y -i $INPUT_FILE \
    
$AUDIO_OPTIONS_P2 $VIDEO_OPTIONS_P2 -b:v 250k -threads auto -f mp4 out-250.mp4 \
    
$AUDIO_OPTIONS_P2 $VIDEO_OPTIONS_P2 -b:v 500k -threads auto -f mp4 out-500.mp4 \
    
$AUDIO_OPTIONS_P2 $VIDEO_OPTIONS_P2 -b:v 700k -threads auto -f mp4 out-700.mp4

    However, the encoding time was nearly identical to the previous multi-process approach. This leads me to believe that all the steps are again being performed in duplicate.

    To force ffmpeg to read, decode, and scale only once, I put those steps in one ffmpeg process and piped the result into another ffmpeg process that performed the encoding. This improved the overall processing time by 15%-20%.

    INPUT_STREAM="ffmpeg -i $INPUT_FILE -vf scale=720:-1,crop=720:400 -threads auto -f yuv4mpegpipe -"
    

    
$INPUT_STREAM | ffmpeg -y -f yuv4mpegpipe -i - \
    
$AUDIO_OPTIONS_P2 $VIDEO_OPTIONS_P2 -b:v 250k -threads auto out-250.mp4 \
    
$AUDIO_OPTIONS_P2 $VIDEO_OPTIONS_P2 -b:v 500k -threads auto out-500.mp4 \
    
$AUDIO_OPTIONS_P2 $VIDEO_OPTIONS_P2 -b:v 700k -threads auto out-700.mp4

    Does anyone see potential problems with doing it this way, or know of a better method ?

  • How to optimize ffmpeg w/ x264 for multiple bitrate output files

    10 octobre 2013, par Jonesy

    The goal is to create multiple output files that differ only in bitrate from a single source file. The solutions for this that were documented worked, but had inefficiencies. The solution that I discovered to be most efficient was not documented anywhere that I could see. I am posting it here for review and asking if others know of additional optimizations that can be made.

    Source file       MPEG-2 Video (Letterboxed) 1920x1080 @>10Mbps
    
                  MPEG-1 Audio @ 384Kbps
    
Destiation files  H264 Video 720x400 @ multiple bitrates
    
                  AAC Audio @ 128Kbps
    
Machine           Multi-core Processor

    The video quality at each bitrate is important so we are running in 2-Pass mode with the 'medium' preset

    VIDEO_OPTIONS_P2 = -vcodec libx264 -preset medium -profile:v main -g 72 -keyint_min 24 -vf scale=720:-1,crop=720:400

    The first approach was to encode them all in parallel processes

    ffmpeg -y -i $INPUT_FILE $AUDIO_OPTIONS_P2 $VIDEO_OPTIONS_P2 -b:v 250k -threads auto -f mp4 out-250.mp4 &
ffmpeg -y -i $INPUT_FILE $AUDIO_OPTIONS_P2 $VIDEO_OPTIONS_P2 -b:v 500k -threads auto -f mp4 out-500.mp4 &
ffmpeg -y -i $INPUT_FILE $AUDIO_OPTIONS_P2 $VIDEO_OPTIONS_P2 -b:v 700k -threads auto -f mp4 out-700.mp4 &

    The obvious inefficiencies are that the source file is read, decoded, scaled, and cropped identically for each process. How can we do this once and then feed the encoders with the result ?

    The hope was that generating all the encodes in a single ffmpeg command would optimize-out the duplicate steps.

    ffmpeg -y -i $INPUT_FILE \
    
$AUDIO_OPTIONS_P2 $VIDEO_OPTIONS_P2 -b:v 250k -threads auto -f mp4 out-250.mp4 \
    
$AUDIO_OPTIONS_P2 $VIDEO_OPTIONS_P2 -b:v 500k -threads auto -f mp4 out-500.mp4 \
    
$AUDIO_OPTIONS_P2 $VIDEO_OPTIONS_P2 -b:v 700k -threads auto -f mp4 out-700.mp4

    However, the encoding time was nearly identical to the previous multi-process approach. This leads me to believe that all the steps are again being performed in duplicate.

    To force ffmpeg to read, decode, and scale only once, I put those steps in one ffmpeg process and piped the result into another ffmpeg process that performed the encoding. This improved the overall processing time by 15%-20%.

    INPUT_STREAM="ffmpeg -i $INPUT_FILE -vf scale=720:-1,crop=720:400 -threads auto -f yuv4mpegpipe -"
    

    
$INPUT_STREAM | ffmpeg -y -f yuv4mpegpipe -i - \
    
$AUDIO_OPTIONS_P2 $VIDEO_OPTIONS_P2 -b:v 250k -threads auto out-250.mp4 \
    
$AUDIO_OPTIONS_P2 $VIDEO_OPTIONS_P2 -b:v 500k -threads auto out-500.mp4 \
    
$AUDIO_OPTIONS_P2 $VIDEO_OPTIONS_P2 -b:v 700k -threads auto out-700.mp4

    Does anyone see potential problems with doing it this way, or know of a better method ?

  • Are there any resources listing current codecs and formats not supported by FFmpeg ?

    4 mars 2020, par Alexander Swann

    We are building a service where we do not know what format/codec a video uploaded by a user is in. Due to the nature of the application, we expect input video formats to be very fragmented, diverse and niche. We are currently using FFmpeg to transcode input formats to a consistent output (e.g. mp4).

    Due to the above scenario, I would like to establish a general list of what formats and codecs are not currently supported by FFmpeg. This is so I can research other open source video transcoding tools which I can utilise to fill in the gaps and allow our service to be more reliable for the user.

    Are there resources online that can help at least get a general idea of what might not be supported by FFmpeg ?

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