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  • Keeping control of your media in your hands

    13 avril 2011, par

    The vocabulary used on this site and around MediaSPIP in general, aims to avoid reference to Web 2.0 and the companies that profit from media-sharing.
    While using MediaSPIP, you are invited to avoid using words like "Brand", "Cloud" and "Market".
    MediaSPIP is designed to facilitate the sharing of creative media online, while allowing authors to retain complete control of their work.
    MediaSPIP aims to be accessible to as many people as possible and development is based on expanding the (...)

  • Mise à jour de la version 0.1 vers 0.2

    24 juin 2013, par

    Explications des différents changements notables lors du passage de la version 0.1 de MediaSPIP à la version 0.3. Quelles sont les nouveautés
    Au niveau des dépendances logicielles Utilisation des dernières versions de FFMpeg (>= v1.2.1) ; Installation des dépendances pour Smush ; Installation de MediaInfo et FFprobe pour la récupération des métadonnées ; On n’utilise plus ffmpeg2theora ; On n’installe plus flvtool2 au profit de flvtool++ ; On n’installe plus ffmpeg-php qui n’est plus maintenu au (...)

  • 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 (...)

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  • What Every Programmer Should Know

    24 décembre 2012, par Multimedia Mike — General

    During my recent effort to force myself to understand Unicode and modern text encoding/processing, I was reminded that this is something that “every programmer should just know”, an idea that comes up every so often, usually in relation to a subject in which the speaker is already an expert. One of the most absurd examples I ever witnessed was a blog post along the lines of “What every working programmer ought to know about [some very specific niche of enterprise-level Java programming]“. I remember reading through the article and recognizing that I had almost no knowledge of the material. Disturbing, since I am demonstrably a “working programmer”.

    For fun, I queried the googles on the matter of what ever programmer ought to know.

    Specific Topics
    Here is what every programmer should know about : Unicode, time, memory (simple), memory (extremely in-depth), regular expressions, search engine optimization, floating point, security, basic number theory, race conditions, managed C++, VIM commands, distributed systems, object-oriented design, latency numbers, rate monotonic algorithm, merging branches in Mercurial, classes of algorithms, and human names.

    Broader Topics
    20 subjects every programmer should know, 97 things every programmer should know, 12 things every programmer should know, things every programmer should know (27 items), 10 papers every programmer should read at least twice, 10 things every programmer should know for their first job.

    Meanwhile, I remain fond of this xkcd comic whose mouseover text describes all that a person genuinely needs to know. Still, the new year is upon us, a time when people often make commitments to bettering themselves, and it couldn’t hurt (much) to at least skim some of the lists and find out what you never knew that you never knew.

    What About Multimedia ?
    Reading the foregoing (or the titles of the foregoing pieces), I naturally wonder if I should write something about what every programmer should know about multimedia. I think it would look something like a multimedia programming FAQ. These are some items that I can think of :

    1. YUV : The other colorspace (since most programmers are only familiar with RGB and have no idea what to make of the YUV that comes out of most video decoding APIs)
    2. Why you can’t easily seek randomly to any specific frame in a video file (keyframe/interframe discussion and their implications)
    3. Understand your platform before endeavoring to implement multimedia software (modern platforms, particularly mobile platforms, probably provide everything you need in the native APIs and there is likely little reason to compile libavcodec for the platform)
    4. Difference between containers and codecs (longstanding item, but I would argue it’s less relevant these days due to standardization on the MPEG — MP4/H.264/AAC — stack)
    5. What counts as a multimedia standard in this day and age (comparing the foregoing MPEG stack with the WebM/VP8/Vorbis stack)
    6. Trade-offs to consider when engineering a multimedia solution
    7. Optimization doesn’t always work the way you think it does (not everything touted as a massive speed-up in the world of computing — whether it be multithreaded CPUs, GPGPUs, new SIMD instruction sets — will necessarily be applicable to multimedia processing)
    8. A practical guide to legal issues would not be amiss
    9.  ???

    What other items count as “something multimedia-related that every programmer should know” ?

  • ffmpeg to convert mov to flv

    27 octobre 2014, par jeet

    I’m trying to convert a mov video to flv, but keep getting these errors below.
    There are 2 commands I used, both are below.

    ffmpeg -y -i video.mov -deinterlace -acodec copy -r 25 -qmin 3 -qmax 6 video.flv
    

    

    
FFmpeg version SVN-r16573, Copyright (c) 2000-2009 Fabrice Bellard, et al.
    
configuration: --extra-cflags=-fno-common --enable-memalign-hack --enable-pthreads --enable-libmp3lame --enable-libxvid --enable-libvorbis --enable-libtheora --enable-libspeex --enable-libfaac --enable-libgsm --enable-libx264 --enable-libschroedinger --enable-avisynth --enable-swscale --enable-gpl
    
libavutil     49.12. 0 / 49.12. 0
    
libavcodec    52.10. 0 / 52.10. 0
    
libavformat   52.23. 1 / 52.23. 1
    
libavdevice   52. 1. 0 / 52. 1. 0
    
libswscale     0. 6. 1 /  0. 6. 1
    
built on Jan 13 2009 02:57:09, gcc: 4.2.4
    
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'vid\video.mov':
    
Duration: 00:03:16.00, start: 0.000000, bitrate: 398 kb/s
    
Stream #0.0(eng): Video: mpeg4, yuv420p, 800x600 [PAR 1:1 DAR 4:3], 30.00 tb(r)
    
Stream #0.1(eng): Audio: pcm_u8, 8000 Hz, mono, s16, 64 kb/s
    
Output #0, flv, to 'vid\video.flv':
    
Stream #0.0(eng): Video: flv, yuv420p, 800x600 [PAR 1:1 DAR 4:3], q=3-6, 200 kb/s, 25.00 tb(c)
    
Stream #0.1(eng): Audio: pcm_u8, 8000 Hz, mono, s16, 64 kb/s
    
Stream mapping:
    
Stream #0.0 -> #0.0
    
Stream #0.1 -> #0.1
    
[NULL @ 0x1714390]codec not compatible with flv
    
Could not write header for output file #0 (incorrect codec parameters ?)

    Second command :

    ffmpeg -y -i video.mov -deinterlace -ar 44100 -r 25 -qmin 3 -qmax 6 video.flv

    Audio resampler only works with 16 bits per sample, patch welcome.

    With a newer version of ffmpeg :

    ffmpeg version N-49610-gc2dd5a1 Copyright (c) 2000-2013 the FFmpeg developers
    
built on Feb  5 2013 13:20:59 with gcc 4.7.2 (GCC)
    
configuration: --enable-gpl --enable-version3 --disable-w32threads --enable-avisynth --enable-bzlib --enable-fontconfig --enable-frei0r --enable-gnutls --enable-libass --enable-libbluray --enable-libcaca --enable-libfreetype --enable-libgsm --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-librtmp --enable-libschroedinger --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libtwolame --enable-libvo-aacenc --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libxavs --enable-libxvid --enable-zlib
    
  libavutil      52. 17.101 / 52. 17.101
    
  libavcodec     54. 91.100 / 54. 91.100
    
  libavformat    54. 61.104 / 54. 61.104
    
  libavdevice    54.  3.103 / 54.  3.103
    
  libavfilter     3. 35.101 /  3. 35.101
    
  libswscale      2.  2.100 /  2.  2.100
    
  libswresample   0. 17.102 /  0. 17.102
    
  libpostproc    52.  2.100 / 52.  2.100
    
Guessed Channel Layout for  Input Stream #0.1 : mono
    
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'vid\video.mov':
    
  Metadata:
    
    major_brand     : qt  
    
    minor_version   : 512
    
    compatible_brands: qt  
    
    creation_time   : 1970-01-01 00:00:00
    
  Duration: 00:02:50.39, start: 0.000000, bitrate: 370 kb/s
    
    Stream #0:0(eng): Video: mpeg4 (Simple Profile) (mp4v / 0x7634706D), yuv420p, 1366x768 [SAR 1:1 DAR 683:384], 308 kb/s, 11.50 fps, 11.50 tbr, 23 tbn, 23 tbc
    
    Metadata:
    
      creation_time   : 1970-01-01 00:00:00
    
      handler_name    : DataHandler
    
    Stream #0:1(eng): Audio: pcm_u8 (raw  / 0x20776172), 8000 Hz, mono, u8, 64 kb/s
    
    Metadata:
    
      creation_time   : 1970-01-01 00:00:00
    
      handler_name    : DataHandler
    
[flv @ 026347a0] FLV does not support sample rate 8000, choose from (44100, 22050, 11025)
    
Output #0, flv, to 'vid\video.flv':
    
  Metadata:
    
    major_brand     : qt  
    
    minor_version   : 512
    
compatible_brands: qt  
    
    encoder         : Lavf54.61.104
    
    Stream #0:0(eng): Video: flv1 ([2][0][0][0] / 0x0002), yuv420p, 1366x768 [SAR 1:1 DAR 683:384], q=2-31, 200 kb/s, 1k tbn, 11.50 tbc
    
    Metadata:
    
      creation_time   : 1970-01-01 00:00:00
    
      handler_name    : DataHandler
    
    Stream #0:1(eng): Audio: mp3 ([2][0][0][0] / 0x0002), 8000 Hz, mono, s16p
    
    Metadata:
    
      creation_time   : 1970-01-01 00:00:00
    
      handler_name    : DataHandler
    
Stream mapping:
    
  Stream #0:0 -> #0:0 (mpeg4 -> flv)
    
  Stream #0:1 -> #0:1 (pcm_u8 -> libmp3lame)
    
Could not write header for output file #0 (incorrect codec parameters ?): Invalid data found when processing input

    1 more thing please :
    If I use this newer version of ffmpeg to create a video with the below command, I get a video with a very hazy display.
    It’s like a few black dots on a blank screen :

    ffmpeg -i img%d.png -i audio.wav -acodec copy output.mov

    what could be the reason for this display ?

  • ERROR : libvpx decoder version must be >=0.9.1 [closed]

    22 novembre 2013, par Baseem Najjar

    Heyo !
    I'm trying to install ffmpeg on my server using the following tutorial :
    https://ffmpeg.org/trac/ffmpeg/wiki/UbuntuCompilationGuideLucid
    When I reach the ffmpeg part and run the ./configure command it gives the following error :

    ERROR: libvpx decoder version must be >=0.9.1

    I must mention that my server has Ubunto 10.10 64bit
    I'm a total newbie in linux so please take it into consideration :)
    Thanks a lot !

    Following LordNeckBeard solution, I got the following error after the checkinstall :

    root@348588:~/libvpx# sudo checkinstall --pkgname=libvpx --pkgversion="$(date +%Y%m%d%H%M)-git" --backup=no--default --deldoc=yes
    

    
checkinstall 1.6.2, Copyright 2009 Felipe Eduardo Sanchez Diaz Duran
    
           This software is released under the GNU GPL.
    

    

    
no--default is an invalid value for --backup
    

    
Use --help or -h to get more information

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