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  • Support de tous types de médias

    10 April 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 (...)

  • Supporting all media types

    13 April 2011, by

    Unlike most software and media-sharing platforms, MediaSPIP aims to manage as many different media types as possible. The following are just a few examples from an ever-expanding list of supported formats: images: png, gif, jpg, bmp and more audio: MP3, Ogg, Wav and more video: AVI, MP4, OGV, mpg, mov, wmv and more text, code and other data: OpenOffice, Microsoft Office (Word, PowerPoint, Excel), web (html, CSS), LaTeX, Google Earth and (...)

  • Contribute to a better visual interface

    13 April 2011

    MediaSPIP is based on a system of themes and templates. Templates define the placement of information on the page, and can be adapted to a wide range of uses. Themes define the overall graphic appearance of the site.
    Anyone can submit a new graphic theme or template and make it available to the MediaSPIP community.

On other websites (4054)

  • Re-sampling H264 video to reduce frame rate while maintaining high image quality

    31 March 2016, by BrianTheLion

    Here’s the mplayer output for a video of interest:

    br@carina:/tmp$ mplayer foo.mov 
    
mplayer: Symbol `ff_codec_bmp_tags' has different size in shared object, consider re-linking
    
MPlayer 1.0rc4-4.5.2 (C) 2000-2010 MPlayer Team
    
mplayer: could not connect to socket
    
mplayer: No such file or directory
    
Failed to open LIRC support. You will not be able to use your remote control.
    

    
Playing foo.mov.
    
libavformat file format detected.
    
[lavf] stream 0: video (h264), -vid 0
    
[lavf] stream 1: audio (aac), -aid 0, -alang eng
    
VIDEO:  [H264]  1280x720  24bpp  59.940 fps  2494.2 kbps (304.5 kbyte/s)
    
==========================================================================
    
Opening video decoder: [ffmpeg] FFmpeg's libavcodec codec family
    
Selected video codec: [ffh264] vfm: ffmpeg (FFmpeg H.264)
    
==========================================================================
    
==========================================================================
    
Opening audio decoder: [faad] AAC (MPEG2/4 Advanced Audio Coding)
    
AUDIO: 44100 Hz, 2 ch, s16le, 128.0 kbit/9.07% (ratio: 15999->176400)
    
Selected audio codec: [faad] afm: faad (FAAD AAC (MPEG-2/MPEG-4 Audio))
    
==========================================================================
    
AO: [pulse] 44100Hz 2ch s16le (2 bytes per sample)
    
Starting playback...
    
Movie-Aspect is 1.78:1 - prescaling to correct movie aspect.
    
VO: [vdpau] 1280x720 => 1280x720 Planar YV12

    I’d like to use ffmpeg, mencoder, or some other command-line video transcoder to re-sample this video to a lower framerate without loss of image quality. That is, each frame should remain as crisp as possible.

    Attempts

    ffmpeg -i foo.mov -r 25 -vcodec copy bar.mov
    • The target frame rate — 25fps — is achieved but individual frames are "blocky."
    mencoder -nosound -ovc copy foo.mov -ofps 25 -o bar.mov
    • Videos are effectively un-viewable.

    Help!

    This seems like a simple enough use case. I’m very surprised that obvious things are not working. Is there something wrong with my approach?

  • Re-sampling H264 video to reduce frame rate while maintaining high image quality

    4 March 2019, by BrianTheLion

    Here’s the mplayer output for a video of interest:

    br@carina:/tmp$ mplayer foo.mov 
    
mplayer: Symbol `ff_codec_bmp_tags' has different size in shared object, consider re-linking
    
MPlayer 1.0rc4-4.5.2 (C) 2000-2010 MPlayer Team
    
mplayer: could not connect to socket
    
mplayer: No such file or directory
    
Failed to open LIRC support. You will not be able to use your remote control.
    

    
Playing foo.mov.
    
libavformat file format detected.
    
[lavf] stream 0: video (h264), -vid 0
    
[lavf] stream 1: audio (aac), -aid 0, -alang eng
    
VIDEO:  [H264]  1280x720  24bpp  59.940 fps  2494.2 kbps (304.5 kbyte/s)
    
==========================================================================
    
Opening video decoder: [ffmpeg] FFmpeg's libavcodec codec family
    
Selected video codec: [ffh264] vfm: ffmpeg (FFmpeg H.264)
    
==========================================================================
    
==========================================================================
    
Opening audio decoder: [faad] AAC (MPEG2/4 Advanced Audio Coding)
    
AUDIO: 44100 Hz, 2 ch, s16le, 128.0 kbit/9.07% (ratio: 15999->176400)
    
Selected audio codec: [faad] afm: faad (FAAD AAC (MPEG-2/MPEG-4 Audio))
    
==========================================================================
    
AO: [pulse] 44100Hz 2ch s16le (2 bytes per sample)
    
Starting playback...
    
Movie-Aspect is 1.78:1 - prescaling to correct movie aspect.
    
VO: [vdpau] 1280x720 => 1280x720 Planar YV12

    I’d like to use ffmpeg, mencoder, or some other command-line video transcoder to re-sample this video to a lower framerate without loss of image quality. That is, each frame should remain as crisp as possible.

    Attempts

    ffmpeg -i foo.mov -r 25 -vcodec copy bar.mov
    • The target frame rate — 25fps — is achieved but individual frames are "blocky."
    mencoder -nosound -ovc copy foo.mov -ofps 25 -o bar.mov
    • Videos are effectively un-viewable.

    Help!

    This seems like a simple enough use case. I’m very surprised that obvious things are not working. Is there something wrong with my approach?

  • ffmpeg png to png quality loss

    13 April 2018, by kilo

    I did a python script that managed to unshuffle a shuffled (png) image according to a specific pattern, that python script uses ffmpeg and does 12 encodes to unshuffling it (by cropping a specific part and pasting it over the existing picture).
    As such the same file is re-encoded into a new file each time, which shouldn’t be a problem since i am doing png conversion (lossless, right?), but i still lose quality on it.

    Here are the pictures:

    Notice the loss of quality on the "ONE PUNCH MAN" text. The rest of the picture is, seemingly, literally identical. So the problem seems to be with the colors.

    Here are the ffmpeg commands i ran to get to the output:

    ffmpeg -loglevel panic -y -i "output/001.png" -i "001.png" -qscale:v 2 -filter_complex "[0:v]crop=200:280:200:0[t];[0:v][t]overlay=0:280" "output/001.png"
    
ffmpeg -loglevel panic -y -i "output/001.png" -i "001.png" -qscale:v 2 -filter_complex "[0:v]crop=200:280:400:0[t];[0:v][t]overlay=0:560" "output/001.png"
    
ffmpeg -loglevel panic -y -i "output/001.png" -i "001.png" -qscale:v 2 -filter_complex "[0:v]crop=200:280:600:0[t];[0:v][t]overlay=0:840" "output/001.png"
    
ffmpeg -loglevel panic -y -i "output/001.png" -i "001.png" -qscale:v 2 -filter_complex "[1:v]crop=200:280:0:280[t];[0:v][t]overlay=200:0" "output/001.png"
    
ffmpeg -loglevel panic -y -i "output/001.png" -i "001.png" -qscale:v 2 -filter_complex "[0:v]crop=200:280:400:280[t];[0:v][t]overlay=200:560" "output/001.png"
    
ffmpeg -loglevel panic -y -i "output/001.png" -i "001.png" -qscale:v 2 -filter_complex "[0:v]crop=200:280:600:280[t];[0:v][t]overlay=200:840" "output/001.png"
    
ffmpeg -loglevel panic -y -i "output/001.png" -i "001.png" -qscale:v 2 -filter_complex "[1:v]crop=200:280:0:560[t];[0:v][t]overlay=400:0" "output/001.png"
    
ffmpeg -loglevel panic -y -i "output/001.png" -i "001.png" -qscale:v 2 -filter_complex "[1:v]crop=200:280:200:560[t];[0:v][t]overlay=400:280" "output/001.png"
    
ffmpeg -loglevel panic -y -i "output/001.png" -i "001.png" -qscale:v 2 -filter_complex "[0:v]crop=200:280:600:560[t];[0:v][t]overlay=400:840" "output/001.png"
    
ffmpeg -loglevel panic -y -i "output/001.png" -i "001.png" -qscale:v 2 -filter_complex "[1:v]crop=200:280:0:840[t];[0:v][t]overlay=600:0" "output/001.png"
    
ffmpeg -loglevel panic -y -i "output/001.png" -i "001.png" -qscale:v 2 -filter_complex "[1:v]crop=200:280:200:840[t];[0:v][t]overlay=600:280" "output/001.png"
    
ffmpeg -loglevel panic -y -i "output/001.png" -i "001.png" -qscale:v 2 -filter_complex "[1:v]crop=200:280:400:840[t];[0:v][t]overlay=600:560" "output/001.png"

    Anyone got any idea why is there this quality loss?
    Strangely enough, there is no quality loss when i do it in an entirely different way (crop each square into an individual file, then each of them are put into a 1x2 vstack with the next one, then each of the resulting 1x2 files are vstacked with a second file to make a 1x4 file, then each of those are hstacked to make a 2x4 file, and finally we hstack the two resulting file for the resulting 4x4 output), even though there is more than double the amount of encodes.

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