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Autres articles (52)

  • Websites made ​​with MediaSPIP

    2 mai 2011, par

    This page lists some websites based on MediaSPIP.

  • Creating farms of unique websites

    13 avril 2011, par

    MediaSPIP platforms can be installed as a farm, with a single "core" hosted on a dedicated server and used by multiple websites.
    This allows (among other things) : implementation costs to be shared between several different projects / individuals rapid deployment of multiple unique sites creation of groups of like-minded sites, making it possible to browse media in a more controlled and selective environment than the major "open" (...)

  • Submit enhancements and plugins

    13 avril 2011

    If you have developed a new extension to add one or more useful features to MediaSPIP, let us know and its integration into the core MedisSPIP functionality will be considered.
    You can use the development discussion list to request for help with creating a plugin. As MediaSPIP is based on SPIP - or you can use the SPIP discussion list SPIP-Zone.

Sur d’autres sites (8703)

  • Repair mpeg files using ffmpeg

    27 février 2014, par rsdrsd

    I have a bunch of mpeg files which are some how invalid or incorrect. I can play the files in different media players but when I upload the files and they should automagically be converted. It takes a very long time to create screenshots and it creates about 10000 screenshots instead of the 50 to be expected. The command is part of an automatic conversion app. With mp4 and other files it works great but whit mpeg it doesn't work as expected. The creation of screenshots eats up all memory and processor power.

    For creating screenshots I have tried the following :

        ffmpeg -y -i /input/file.mpeg -f image2 -aspect 16:9 -bt 20M -vsync passthrough -vf select='isnan(prev_selected_t)+gte(t-prev_selected_t\,10)' /output/file-%05d.jpg

    this just creates 2 screenshots while I expect 50 or so. The following command :

        ffmpeg -y -i /input/file.mpeg -f image2 -vf fps=fps=1/10 -aspect 16:9 -vsync passthrough -bt 20M /output/file-%05d.jpg

    gave me errors about buffers :

        ffmpeg version N-39361-g1524b0f Copyright (c) 2000-2014 the FFmpeg developers
    
      built on Feb 26 2014 23:46:40 with gcc 4.4.7 (GCC) 20120313 (Red Hat 4.4.7-4)
    
      configuration: --prefix=/home/example/ffmpeg_build --extra-cflags=-I/home/example/ffmpeg_build/include --extra-ldflags=-L/home/example/ffmpeg_build/lib --bindir=/home/example/bin --extra-libs=-ldl --enable-gpl --enable-nonfree --enable-libfdk_aac --enable-libmp3lame --enable-libopus --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libfreetype --enable-libspeex --enable-libtheora
    
      libavutil      52. 66.100 / 52. 66.100
    
      libavcodec     55. 52.102 / 55. 52.102
    
      libavformat    55. 33.100 / 55. 33.100
    
      libavdevice    55. 10.100 / 55. 10.100
    
      libavfilter     4.  2.100 /  4.  2.100
    
      libswscale      2.  5.101 /  2.  5.101
    
      libswresample   0. 18.100 /  0. 18.100
    
      libpostproc    52.  3.100 / 52.  3.100
    
    [mp3 @ 0x200d7c0] Header missing
    
    [mpegts @ 0x2008a60] DTS discontinuity in stream 0: packet 6 with DTS 34185, packet 7 with DTS 8589926735
    
    [mpegts @ 0x2008a60] Invalid timestamps stream=0, pts=7157, dts=8589932741, size=150851
    
    Input #0, mpegts, from '/home/example/app/uploads/21.mpeg':
    
      Duration: 00:03:14.75, start: 0.213000, bitrate: 26112 kb/s
    
      Program 1
    
Stream #0:0[0x3e9]: Video: mpeg2video (Main) ([2][0][0][0] / 0x0002), yuv420p(tv), 1440x1080 [SAR 4:3 DAR 16:9], max. 25000 kb/s, 29.97 fps, 60 tbr, 90k tbn, 59.94 tbc
    
Stream #0:1[0x3ea]: Audio: mp2 ([3][0][0][0] / 0x0003), 48000 Hz, stereo, s16p, 384 kb/s
    
    [swscaler @ 0x1ff9860] deprecated pixel format used, make sure you did set range correctly
    
    Output #0, image2, to '/home/example/app/uploads/21-%05d.jpg':
    
      Metadata:
    
encoder         : Lavf55.33.100
    
Stream #0:0: Video: mjpeg, yuvj420p, 1440x1080 [SAR 4:3 DAR 16:9], q=2-31, 200 kb/s, 90k tbn, 0.10 tbc
    
    Stream mapping:
    
      Stream #0:0 -> #0:0 (mpeg2video -> mjpeg)
    
    Press [q] to stop, [?] for help
    
    [mpegts @ 0x2008a60] Invalid timestamps stream=0, pts=7157, dts=8589932741, size=150851
    
    [output stream 0:0 @ 0x1ff2ba0] 100 buffers queued in output stream 0:0, something may be wrong.
    
    [output stream 0:0 @ 0x1ff2ba0] 1000 buffers queued in output stream 0:0, something may be wrong.

    and it creates about 10000 screenshots while I expect 50.

    Now I have read some where on how to repair some broken files. For this I have the following command :

        ffmpeg -y -i input.mpeg -codec:v copy -codec:a copy output.mpeg

    This however creates a file somewhat smaller, but if I run the same command on the output again, I would expect that it creates the same file, but the following command

        ffmpeg -y -i output.mpeg -codec:v copy -codec:a copy output2.mpeg

    returns a file which is much smaller and runs for only a few seconds while the original was about 3 minutes.

    If I run the "repair" commands for a not broken mpeg it results the first time I run the command in a much smaller file. With ffprobe I checked what changed but the only thing that changes is MPEG-TS to MPEG-PS.

    If I run the command over an mp4 file it results in exactly the same file as expected. Does someone have a clue of what is going wrong. It is boggling me now for about two days and I really have no clue. Or does someone have a good suggestion on how to extract screenshots every 10 seconds without creating too much screenshots and eating up all memory and processor power.

  • lavu/tx : invert permutation lookups

    27 février 2021, par Lynne
    lavu/tx : invert permutation lookups

    out[lut[i]] = in[i] lookups were 4.04 times(!) slower than
    
out[i] = in[lut[i]] lookups for an out-of-place FFT of length 4096.
    

    The permutes remain unchanged for anything but out-of-place monolithic
    
FFT, as those benefit quite a lot from the current order (it means
    
there's only 1 lookup necessary to add to an offset, rather than
    
a full gather).
    

    The code was based around non-power-of-two FFTs, so this wasn't
    
benchmarked early on.
    • [DH] libavutil/tx.c
    • [DH] libavutil/tx_priv.h
    • [DH] libavutil/tx_template.c

  • Piwik awarded Gold Prize at Open Source Software World Challenge

    22 décembre 2014, par Matthieu Aubry — About

    We are excited to announce that Piwik has been awarded the Gold Prize in the Open Source Software World Challenge 2014 !

    Winning this award is a testament to the positive impacts of the Piwik platform worldwide. Every day dozens of new people are embracing Piwik to power their web and mobile analytics which gives them full control over their data.

    Every member of the Piwik community, from core developer to beginning user, should be proud to be part of this momentum : congratulations to us all !

    The Open Source World Challenge is the annual competition hosted by the Ministry of Science, ICT and Future Planning of Korea. This competition is mainly intended to promote open source software and expand various exchanges among open source software developers worldwide.

    Piwik Awards

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