Recherche avancée

Médias (1)

Mot : - Tags -/wave

Autres articles (58)

  • Dépôt de média et thèmes par FTP

    31 mai 2013, par

    L’outil MédiaSPIP traite aussi les média transférés par la voie FTP. Si vous préférez déposer par cette voie, récupérez les identifiants d’accès vers votre site MédiaSPIP et utilisez votre client FTP favori.
    Vous trouverez dès le départ les dossiers suivants dans votre espace FTP : config/ : dossier de configuration du site IMG/ : dossier des média déjà traités et en ligne sur le site local/ : répertoire cache du site web themes/ : les thèmes ou les feuilles de style personnalisées tmp/ : dossier de travail (...)

  • Les thèmes de MediaSpip

    4 juin 2013

    3 thèmes sont proposés à l’origine par MédiaSPIP. L’utilisateur MédiaSPIP peut rajouter des thèmes selon ses besoins.
    Thèmes MediaSPIP
    3 thèmes ont été développés au départ pour MediaSPIP : * SPIPeo : thème par défaut de MédiaSPIP. Il met en avant la présentation du site et les documents média les plus récents ( le type de tri peut être modifié - titre, popularité, date) . * Arscenic : il s’agit du thème utilisé sur le site officiel du projet, constitué notamment d’un bandeau rouge en début de page. La structure (...)

  • Création définitive du canal

    12 mars 2010, par

    Lorsque votre demande est validée, vous pouvez alors procéder à la création proprement dite du canal. Chaque canal est un site à part entière placé sous votre responsabilité. Les administrateurs de la plateforme n’y ont aucun accès.
    A la validation, vous recevez un email vous invitant donc à créer votre canal.
    Pour ce faire il vous suffit de vous rendre à son adresse, dans notre exemple "http://votre_sous_domaine.mediaspip.net".
    A ce moment là un mot de passe vous est demandé, il vous suffit d’y (...)

Sur d’autres sites (6980)

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

    31 mars 2016, par 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 mars 2019, par 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 avril 2018, par 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.

Navigation