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Médias (1)

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Autres articles (73)

  • Support de tous types de médias

    10 avril 2011

    Contrairement à beaucoup de logiciels et autres plate-formes modernes de partage de documents, MediaSPIP a l’ambition de gérer un maximum de formats de documents différents qu’ils soient de type : images (png, gif, jpg, bmp et autres...) ; audio (MP3, Ogg, Wav et autres...) ; vidéo (Avi, MP4, Ogv, mpg, mov, wmv et autres...) ; contenu textuel, code ou autres (open office, microsoft office (tableur, présentation), web (html, css), LaTeX, Google Earth) (...)

  • Automated installation script of MediaSPIP

    25 avril 2011, par

    To overcome the difficulties mainly due to the installation of server side software dependencies, an "all-in-one" installation script written in bash was created to facilitate this step on a server with a compatible Linux distribution.
    You must have access to your server via SSH and a root account to use it, which will install the dependencies. Contact your provider if you do not have that.
    The documentation of the use of this installation script is available here.
    The code of this (...)

  • Publier sur MédiaSpip

    13 juin 2013

    Puis-je poster des contenus à partir d’une tablette Ipad ?
    Oui, si votre Médiaspip installé est à la version 0.2 ou supérieure. Contacter au besoin l’administrateur de votre MédiaSpip pour le savoir

Sur d’autres sites (5806)

  • Synchronization between camera video and inertial sensor data

    14 janvier 2013, par Dima Bobby

    I need to :

    write an Android real-time data logging application employing camera video and polling other sensor (accelerometer, gyro, compass) data at high rates e.g. 50 Hz and writing this information into file. As these data will later be used for navigation, precise synchronization between different data is extremely important.

    What I have done :

    implemented sensor polling in native code, so that less Java execution overhead is employed. Nonetheless, camera encoding is still in Java, for this I tried MediaRecorder and MediaCodec. In both cases data from inertial sensors and camera are not synchronized between each other, there is a varying delay of about 400ms and this is inacceptible. Moreover, I am pretty sure that encoding is HW accelerated. Now, to reach my goal I am considering about going for native implementation of video encoding using either OpenCV or FFMPEG (native code is expected to be more efficient).

    EDIT : I have even tried saving the image uncompressed as pgm file, but this way the image data get really huge in size and the FPS is really low, so we are losing data. I suspect that file writing process is the bottleneck in this case. Is there an efficient way to save raw data to file achieving high FPS ?

    Any hints what I should go for to achieve my goal ? I am using Android Jelly Bean with Asus Transformer TF700 Infinity.

    Regards,
    Dmitriy

  • avcodec : do not use AVFrame accessor

    22 avril 2017, par Muhammad Faiz
    avcodec : do not use AVFrame accessor

    Reviewed-by : wm4 <nfxjfg@googlemail.com>
    
Signed-off-by : Muhammad Faiz <mfcc64@gmail.com>
    • [DH] libavcodec/ac3dec.c
    • [DH] libavcodec/cpia.c
    • [DH] libavcodec/crystalhd.c
    • [DH] libavcodec/cuvid.c
    • [DH] libavcodec/decode.c
    • [DH] libavcodec/encode.c
    • [DH] libavcodec/exr.c
    • [DH] libavcodec/gifdec.c
    • [DH] libavcodec/mjpegdec.c
    • [DH] libavcodec/pngdec.c
    • [DH] libavcodec/proresdec2.c
    • [DH] libavcodec/rawdec.c
    • [DH] libavcodec/tiff.c
    • [DH] libavcodec/videotoolboxenc.c
    • [DH] libavcodec/webp.c

  • swresample : add exact_rational option

    12 juin 2016, par Muhammad Faiz
    swresample : add exact_rational option

    give high quality resampling
    
as good as with linear_interp=on
    
as fast as without linear_interp=on
    
tested visually with ffplay
    
ffplay -f lavfi "aevalsrc=’sin(10000*t*t)’, aresample=osr=48000, showcqt=gamma=5"
    
ffplay -f lavfi "aevalsrc=’sin(10000*t*t)’, aresample=osr=48000:linear_interp=on, showcqt=gamma=5"
    
ffplay -f lavfi "aevalsrc=’sin(10000*t*t)’, aresample=osr=48000:exact_rational=on, showcqt=gamma=5"
    

    slightly speed improvement
    
for fair comparison with -cpuflags 0
    
audio.wav is 1 hour 44100 stereo 16bit wav file
    
ffmpeg -i audio.wav -af aresample=osr=48000 -f null -
    
        old         new
    
real    13.498s     13.121s
    
user    13.364s     12.987s
    
sys      0.131s      0.129s
    

    linear_interp=on
    
        old         new
    
real    23.035s     23.050s
    
user    22.907s     22.917s
    
sys      0.119s     0.125s
    

    exact_rational=on
    
real    12.418s
    
user    12.298s
    
sys      0.114s
    

    possibility to decrease memory usage if soft compensation is ignored
    

    Signed-off-by : Muhammad Faiz <mfcc64@gmail.com>
    • [DH] libswresample/arm/resample_init.c
    • [DH] libswresample/options.c
    • [DH] libswresample/resample.c
    • [DH] libswresample/resample.h
    • [DH] libswresample/resample_template.c
    • [DH] libswresample/soxr_resample.c
    • [DH] libswresample/swresample.c
    • [DH] libswresample/swresample_internal.h
    • [DH] libswresample/version.h
    • [DH] libswresample/x86/resample_init.c

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