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  • Création définitive du canal

    12 mars 2010, par

    Lorsque votre demande est validée, vous pouvez alors procéder à la création proprement dite du canal. Chaque canal est un site à part entière placé sous votre responsabilité. Les administrateurs de la plateforme n’y ont aucun accès.
    A la validation, vous recevez un email vous invitant donc à créer votre canal.
    Pour ce faire il vous suffit de vous rendre à son adresse, dans notre exemple "http://votre_sous_domaine.mediaspip.net".
    A ce moment là un mot de passe vous est demandé, il vous suffit d’y (...)

  • 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 (...)

  • De l’upload à la vidéo finale [version standalone]

    31 janvier 2010, par

    Le chemin d’un document audio ou vidéo dans SPIPMotion est divisé en trois étapes distinctes.
    Upload et récupération d’informations de la vidéo source
    Dans un premier temps, il est nécessaire de créer un article SPIP et de lui joindre le document vidéo "source".
    Au moment où ce document est joint à l’article, deux actions supplémentaires au comportement normal sont exécutées : La récupération des informations techniques des flux audio et video du fichier ; La génération d’une vignette : extraction d’une (...)

Sur d’autres sites (10895)

  • How to fetch pixel value at specifc x, y from vid1, vid2 in ffmpeg xfade custom transition expression

    25 janvier 2021, par jsaluja

    I am using xfade with transition=custom, and trying to build expression.
I am referring to official documentation https://ffmpeg.org/ffprobe-all.html#xfade

    


    Per my understanding, expression should return pixel value of merged video

    


    I built a few custom transitions using expressions that return some combination of A, B

    


    For eg.,

    


    "custom:expr='if(gt(P, abs(X/W - 0.5)), A, B)'"
"custom:expr='lerp(A, B, 1 - P)'"


    


    For the next set of transitions, I want to fetch the pixel values from source, target video at specific positions, and combine them in my expressions

    


    I tried using a0(X, Y), b0(X, Y) etc inside of

    


    xfade=transition=custom:expr='r....


    


    I ran into exceptions with ffmpeg complaining it doesn't understand the expression.

    


    Can someone clarify, how i can fetch pixel values as specific position from source, target video and combine them in expression ?

    


  • Gstreamer video increases latency with decreased FPS

    19 novembre 2024, par Ri Di

    I am using RPI 5 to stream the video :

    


    rpicam-vid -t 0 --camera 0 --nopreview --mode 2304:1296:10:P --codec yuv420 
           --width 640 --height 360 --framerate 10 --rotation 0 
           --autofocus-mode manual --inline --listen -o - | 
     ffmpeg -f rawvideo -pix_fmt yuv420p -s:v 640x360 -r 10 -i /dev/stdin 
            -c:v libx264 -preset ultrafast -tune zerolatency -maxrate 300k 
            -bufsize 50k -g 30000 -f mpegts tcp://192.168.0.147:1234


    


    View it with :

    


    gst-launch-1.0 -v tcpserversrc host=0.0.0.0 port=1234 ! queue ! 
    tsdemux ! h264parse ! avdec_h264 ! videorate ! video/x-raw,framerate=10/1 !  
    videoconvert ! autovideosink sync=false


    


    Problem is that with 10 FPS I get around 2s of latency ! While 56 or 120 FPS results in below 300ms latency.

    


    Is the problem in sender or reader side ? Or both ?

    


    I am not planning to use the 10 FPS, its only for demonstration of problem. But I would like to get lower latency at 56 FPS - just like at 120 FPS (around 80-100 ms difference) or maybe even better, as it seems to get lower with higher FPS.

    


    Maybe there is some kind of buffering parameter which holds frames ?

    


    (of course, when testing with higher FPS I change both numbers in sender and the one in reader command. The camera is v3 RPI official)

    


    Also I'd like to mention that same thing happens with ffplay :

    


    ffplay -i -probesize 3000 tcp://0.0.0.0:1234/?listen


    


  • Gstreamer video increases latency with decresed FPS

    19 novembre 2024, par Ri Di

    I am using RPI 5 to stream the video :

    


    rpicam-vid -t 0 --camera 0 --nopreview --mode 2304:1296:10:P --codec yuv420 --width 640 --height 360 --framerate 10 --rotation 0 --autofocus-mode manual --inline --listen -o - | ffmpeg -f rawvideo -pix_fmt yuv420p -s:v 640x360 -r 10 -i /dev/stdin -c:v libx264 -preset ultrafast -tune zerolatency -maxrate 300k -bufsize 50k -g 30000 -f mpegts tcp://192.168.0.147:1234


    


    View it with :

    


    gst-launch-1.0 -v tcpserversrc host=0.0.0.0 port=1234 ! queue ! tsdemux ! h264parse ! avdec_h264 ! videorate ! video/x-raw,framerate=10/1 ! videoconvert ! autovideosink sync=false


    


    Problem is that with 10 FPS I get around 2s of latency ! While 56 or 120 FPS results in below 300ms latency.

    


    Is the problem in sender or reader side ? Or both ?

    


    I am not planning to use the 10 FPS, its only for demonstration of problem. But I would like to get lower latency at 56 FPS - just like at 120 FPS (around 80-100 ms difference) or maybe even better, as it seems to get lower with higher FPS.

    


    Maybe there is some kind of buffering parameter which holds frames ?

    


    (of course, when testing with higher FPS I change both numbers in sender and the one in reader command. The camera is v3 RPI official)

    


    Also I'd like to mention that same thing happens with ffplay :

    


    ffplay -i -probesize 3000 tcp://0.0.0.0:1234/?listen


    


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