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Autres articles (36)

  • Gestion générale des documents

    13 mai 2011, par

    MédiaSPIP ne modifie jamais le document original mis en ligne.
    Pour chaque document mis en ligne il effectue deux opérations successives : la création d’une version supplémentaire qui peut être facilement consultée en ligne tout en laissant l’original téléchargeable dans le cas où le document original ne peut être lu dans un navigateur Internet ; la récupération des métadonnées du document original pour illustrer textuellement le fichier ;
    Les tableaux ci-dessous expliquent ce que peut faire MédiaSPIP (...)

  • Des sites réalisés avec MediaSPIP

    2 mai 2011, par

    Cette page présente quelques-uns des sites fonctionnant sous MediaSPIP.
    Vous pouvez bien entendu ajouter le votre grâce au formulaire en bas de page.

  • HTML5 audio and video support

    13 avril 2011, par

    MediaSPIP uses HTML5 video and audio tags to play multimedia files, taking advantage of the latest W3C innovations supported by modern browsers.
    The MediaSPIP player used has been created specifically for MediaSPIP and can be easily adapted to fit in with a specific theme.
    For older browsers the Flowplayer flash fallback is used.
    MediaSPIP allows for media playback on major mobile platforms with the above (...)

Sur d’autres sites (5737)

  • How to use ffmpeg to encode mp4 to mov

    28 juin 2021, par user1526912

    I trying to use ffmpeg to encode a video for the first time. Can anyone tell me the exact command to encode a video in the following format :

    



    Music Video HD Source Profile

    



    ● Apple ProRes 422 (HQ)
● VBR expected at 220 Mbps
● HD encoded dimensions accepted to support square pixel aspect ratios (PASP) :
Encoded PASP Converted to ProRes From
1920 x 1080 1:1 HDCAM SR, D5, ATSC
1280 x 720 1:1 ATSC progressive

    



    ● HD encoded dimensions accepted to support non-square pixel aspect ratios (this allows you to send HD video in the native dimensions of your best original source, for example in HD broadcast dimensions*) :

    



    Encoded PASP Converted to ProRes From
1440 x 1080 1:1.33333 XDCAM-HD, HDCAM
1280 x 1080 1:1.5 DVCProHD interlaced
960 x 720 1:1.33333 DVCProHD progressive

    



    Native frame rate of original source :

    



    ● 29.97 interlaced frames per second for video sourced
● 24 or 25 progressive frames per second for film sourced
● 23.976 progressive frames for inverse telecine sourced from film
● Telecine materials will not be accepted

    



    ● HD source may be delivered matted : letterbox, pillarbox, or windowbox.

    



    Music Video Audio Source Profile

    



    Stereo
● MPEG-1 layer II stereo
● 384 kpbs
● 48Khz
● Included in the same file as the delivered video

    


  • How to use ffmpeg to encode mp4 to mov

    19 avril 2017, par user1526912

    I trying to use ffmpeg to encode a video for the first time. Can anyone tell me the exact command to encode a video in the following format :

    Music Video HD Source Profile

    ● Apple ProRes 422 (HQ)
    ● VBR expected at 220 Mbps
    ● HD encoded dimensions accepted to support square pixel aspect ratios (PASP) :
    Encoded PASP Converted to ProRes From
    1920 x 1080 1:1 HDCAM SR, D5, ATSC
    1280 x 720 1:1 ATSC progressive

    ● HD encoded dimensions accepted to support non-square pixel aspect ratios (this allows you to send HD video in the native dimensions of your best original source, for example in HD broadcast dimensions*) :

    Encoded PASP Converted to ProRes From
    1440 x 1080 1:1.33333 XDCAM-HD, HDCAM
    1280 x 1080 1:1.5 DVCProHD interlaced
    960 x 720 1:1.33333 DVCProHD progressive

    Native frame rate of original source :

    ● 29.97 interlaced frames per second for video sourced
    ● 24 or 25 progressive frames per second for film sourced
    ● 23.976 progressive frames for inverse telecine sourced from film
    ● Telecine materials will not be accepted

    ● HD source may be delivered matted : letterbox, pillarbox, or windowbox.

    Music Video Audio Source Profile

    Stereo
    ● MPEG-1 layer II stereo
    ● 384 kpbs
    ● 48Khz
    ● Included in the same file as the delivered video

  • Multiple nVidia GPU transcoding (NOT computing) bottleneck

    11 décembre 2018, par Daniel Cantarin

    I’m doing some nVidia multi-GPU testing. However, this tests are not on the computing field but transcoding, using nvenc/nvdec.

    I have a setup with 3 Quadro GPUs (max 4 on this motherboard), and running some transcoding jobs using ffmpeg.

    Thing is, up to 8 jobs everything is fine, with tolerable GPU and CPU stats.
    But when reaching the 9th job, the nVidia cards metrics start to fall down. Whats troublesome is this : it doesn’t matter the job distribution. That is, if I send 8 jobs to GPU0, and 1 job to GPU1, is the same as 4-5, or 4-4-1, or 0-4-5, etc.

    What I see beggining on the 9th job is :

    1. CPU gets to about 60% usage (30% up to 8th jobs) and doesn’t go up much after adding more jobs.
    2. DECODING metrics falls from about 75% (when single card has 8 jobs) to about 20%.
    3. Every card behaves the same when this problem starts, no matter how many jobs they have.

    And the last strange thing I see : when that problem happens, and I kill all the jobs, the cards keep working for a while (sometimes even minutes).

    All this points to some bottleneck somewhere on the motherboard. Maybe the PCIe bus, maybe some CPU subsystem, I’m not sure. It also points to some buffering happening somewhere. I’m using the usual popular tools to see high-level metrics and curves (top/htop, nvidia-smi, nvtop, etc).

    My question : does anybody knows some common bottlenecks regarding multi-GPU setups that could lead to a problem like this ?

    Any tip would be nice.

    Thanks in advance.

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