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Autres articles (79)
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MediaSPIP version 0.1 Beta
16 avril 2011, parMediaSPIP 0.1 beta est la première version de MediaSPIP décrétée comme "utilisable".
Le fichier zip ici présent contient uniquement les sources de MediaSPIP en version standalone.
Pour avoir une installation fonctionnelle, il est nécessaire d’installer manuellement l’ensemble des dépendances logicielles sur le serveur.
Si vous souhaitez utiliser cette archive pour une installation en mode ferme, il vous faudra également procéder à d’autres modifications (...) -
MediaSPIP 0.1 Beta version
25 avril 2011, parMediaSPIP 0.1 beta is the first version of MediaSPIP proclaimed as "usable".
The zip file provided here only contains the sources of MediaSPIP in its standalone version.
To get a working installation, you must manually install all-software dependencies on the server.
If you want to use this archive for an installation in "farm mode", you will also need to proceed to other manual (...) -
Amélioration de la version de base
13 septembre 2013Jolie sélection multiple
Le plugin Chosen permet d’améliorer l’ergonomie des champs de sélection multiple. Voir les deux images suivantes pour comparer.
Il suffit pour cela d’activer le plugin Chosen (Configuration générale du site > Gestion des plugins), puis de configurer le plugin (Les squelettes > Chosen) en activant l’utilisation de Chosen dans le site public et en spécifiant les éléments de formulaires à améliorer, par exemple select[multiple] pour les listes à sélection multiple (...)
Sur d’autres sites (14999)
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ffmpeg-python extracting frames from camera in batches
28 juin 2021, par AlterWhen I read frames from my camera using ffmpeg-python, the frames appear to come in batches of 4- why is this, and how can I change it ?


I would like to get one frame at a time... I'm also hoping to avoid faking the frame times using the
-r
option



In the image above, I'm recording at 30fps. The 120ms pause followed by 3 quick frames suggests that the frames are coming in batches of 4.


Partial code


reader = (ffmpeg
 .input('/dev/video0', framerate=fps)
 .output('pipe:', format='rawvideo', pix_fmt='rgb24')
 .run_async(pipe_stdout=True))
 
while True:
 start = time.time_ns()
 frame = reader.stdout.read(width * height * 3)
 logger.debug(f'frame read time: {(time.time_ns() - start)/1e6}ms')
 # Do something else
 logger.debug(f'frame capture loop: {(time.time_ns() - start)/1e6}ms')



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Merge commit ’f046c3b5ac36848cce824b008e0347c621523041’
3 juillet 2015, par Michael NiedermayerMerge commit ’f046c3b5ac36848cce824b008e0347c621523041’
* commit ’f046c3b5ac36848cce824b008e0347c621523041’ :
lavc : Move deprecation warning disabling to files including the table
lavc : Disable deprectation warnings coming from options tableMerged-by : Michael Niedermayer <michaelni@gmx.at>
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RGB to YUV422 conversion with ffmpeg, incorrect colors
22 janvier 2016, par user3578571I’m trying to convert an 8bit RGB uncompressed to an mpeg2 mxf file (xdcam 422 HD 1080 50i) which is YUV422. With info from the FFMpeg docs and various websites i made the following command :
./ffmpeg -y -i test_lines.mov -pix_fmt yuv422p -vcodec mpeg2video -non_linear_quant 1 -flags +ildct+ilme -top 1 -dc 10 -intra_vlc 1 -qmax 2 -vtag xd5c -rc_max_vbv_use 1 -rc_min_vbv_use 1 -g 12 -b:v 50000k -minrate 50000k -maxrate 50000k -bufsize 8000k -acodec pcm_s24le -ar 48000 -bf 2 -ac 2 lines_HD.mxf
This gave me a result with the colors much brighter than the original.
So i tried adding the options
-color_range 1 -colorspace 1 -color_primaries 1 -color_trc 1
but this didn’t seem to do anything.After adding
colormatrix=bt601:bt709
i got a way better image, but slightly darker than the original and it also feels weird specifying this option cause the source is also in the REC709 colorspace, so why specify it differently ?Next i regenerated my source image to an YUV codec (prores) and rerun FFMpeg on it with the colors coming out just fine. Therefore i think it has to be an RGB -> YUV problem.
Does somebody have an idea how to this properly ? I can provide screenshots of the different results on a videoscope as soon as i’m back at the office, if anybody is interested.Last, i know there are various topics touching this subject but either they go way over my head FFmpeg wise or bring me to the stage where i already am.