Recherche avancée

Sur d’autres sites (6596)

• RGB to YUV422 conversion with ffmpeg, incorrect colors

  22 janvier 2016, par user3578571

  I’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.

• Rsync a video stream continously and watch it

  13 juin 2017, par Ural

  I am recording a cam on a remote machine in my office. I use ffmpeg for that, and writing to mpegts file.
  I want to copy that stream locally, to have a fresh copy, and watch it simultaneously.
  I don’t know options for rsync to grab a changing (appending) file, so I am using loop for it, and it is very slow.

  while true; do rsync -avz --progress --partial --append remote:~/myvideo.mp4 ~/; done

  For watching, I tried :

  mkfifo /tmp/fifo
  
  tail -f ~/myvideo.mp4 > /tmp/fifo
  
  mplayer /tmp/fifo

  But because rsync is stopping every 5 sec, it is working unstable.

  How to record and stream a remote cam continuously, and use only one network stream for that ?

• Evolution #3610 : Avoir les répertoires plugins/auto par défaut dans la dist

  30 janvier 2018, par RastaPopoulos ♥

  Non pour la création depuis PHP à mon avis, puisque pour création il faut qu’il y ait les droits d’écriture de PHP sur le dossier parent, or "plugins" ne fait pas partie des dossiers sur lesquels la personne qui installe doit mettre des droits d’écriture obligatoire, et ça ne doit pas le devenir d’après moi.

  Seul plugins/auto doit avoir les droits d’écriture normalement. Donc le fournir d’office à l’installation oui pourquoi pas, et aussi l’ajouter à la liste des dossiers qui doivent être "écrivables" lorsqu’il existe (avec tmp, config, local, IMG) afin que lors de l’installation ça le signale si ce n’est pas le cas.