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  • Les autorisations surchargées par les plugins

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    Mediaspip core
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  • Encoding and processing into web-friendly formats

    13 avril 2011, par

    MediaSPIP automatically converts uploaded files to internet-compatible formats.
    Video files are encoded in MP4, Ogv and WebM (supported by HTML5) and MP4 (supported by Flash).
    Audio files are encoded in MP3 and Ogg (supported by HTML5) and MP3 (supported by Flash).
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Sur d’autres sites (7478)

  • 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


    


  • 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


    


  • 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 ?

    


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