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• Making colour of MP4 video consistent in Chrome

  21 septembre 2021, par OneWorld

  I see a difference in the colour of a video between different machines using different browsers. I was wondering what the cause of the difference is ?

  


  I use FFMPEG to create the video. I sent the video to three different people with slightly different machines, and slightly different Chrome versions, to try and see where the differences are.

  


  The FFMPEG output from the video is as follows :-

  


  ffmpeg version 3.2.2-static http://johnvansickle.com/ffmpeg/  Copyright (c) 2000-2016 the FFmpeg developers
  built with gcc 5.4.1 (Debian 5.4.1-4) 20161202
  configuration: --enable-gpl --enable-version3 --enable-static --disable-debug --disable-ffplay --disable-indev=sndio --disable-outdev=sndio --cc=gcc-5 --enable-fontconfig --enable-frei0r --enable-gnutls --enable-gray --enable-libass --enable-libfreetype --enable-libfribidi --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-librtmp --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libvidstab --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxvid --enable-libzimg
  libavutil      55. 34.100 / 55. 34.100
  libavcodec     57. 64.101 / 57. 64.101
  libavformat    57. 56.100 / 57. 56.100
  libavdevice    57.  1.100 / 57.  1.100
  libavfilter     6. 65.100 /  6. 65.100
  libswscale      4.  2.100 /  4.  2.100
  libswresample   2.  3.100 /  2.  3.100
  libpostproc    54.  1.100 / 54.  1.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'red_and_yellow_uat.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf57.56.100
  Duration: 00:00:03.00, start: 0.000000, bitrate: 84 kb/s
    Stream #0:0(und): Video: h264 (Constrained Baseline) (avc1 / 0x31637661), yuv420p(tv, unknown/bt709/bt709), 1080x1080, 81 kb/s, 25 fps, 25 tbr, 12800 tbn, 50 tbc (default)
    Metadata:
      handler_name    : VideoHandler


  


  From the same UAT rendered Video, with screenshots taken in Chrome from person 1, person 2, person 3, and person 4, and using GIMP colour picker on my machine from the screenshots, the results for red, and yellow are as follows.

  


  Person 1:- #A83833  and  #FFCB2E  Chrome Version 92.0.4515.131 (Official Build) (64-bit)
Person 2:- #AB3334  and  #FFCA38  Chrome Version 92.0.4515.107


  


  (Note : these colours Match / are very close to the original).

  


  Both these machines above are 64 bit Ubuntu machines, using Ubuntu 18.04.5 LTS
We both use the gnome screenshot tool in Ubuntu to take the screenshot, which creates an 8bit PNG.

  


  Person 3:-    #B14039  and  #FED303  Chrome Version 93.0.4577.63 (Official Build) (x86_64)
Person 4:-    #B2403A  and  #FFD201  Chrome Version 92.0.4515.159 (Official Build) (x86_64)


  


  Mac screenshots are taken using cmd shift 4, and generate an 8bit PNG file.

  


  Person 3 Machine Spec :-
Machine :- Macbook Pro (2019)
OS : macOS Big Sur Version 11.5.2
Processor :- 2.6Ghz Intel Core i7 processor. 32bit architecture (typing arch in her tty terminal returns i386).
Graphics :- Intel UHD Graphics 630 1536

  


  Person 4 Machine Spec :-
Machine :- Macbook Pro (Retina, 2015)
OS :- MacOS Mojave, Version 10.14.6
Processor :- 2.5GHz, Intel Core i7
Graphics :- AMD Radeon R9, M370X 2 GB Intel Iris Pro 1536 MB

  


  Person 1 screenshot

  


  

  


  Person 2 screenshot

  


  

  


  Person 3 screenshot

  


  

  


  Person 4 screenshot

  


  

  


  Any suggestions anyone has to make these colours consistent would be much appreciated. Would love to know why it happens also ? If anyone can explain ?

  


• ffmpeg and VFR vs fixed

  1er décembre 2017, par B Davidson

  I was changing some music videos from VFR to 30000/1001 using

  ffmpeg.exe -y -i "C:\Temp\Faith Hill - The Way You Love Me.mp4" -c:v libx264 -crf:v 23 -filter:v fps="fps=30000/1001" -c:a ac3 -b:a 256k -ar 48000 "D:\Faith Hill - The Way You Love Me.mkv"

  Using mediainfo, the file still appeared to be VFR and not the expected 29.97
  ffprobe reported 30000/1001 and MPC reported 29.97.
  I contacted mediainfo and was told it is a bug in ffmpeg, so now I am here.

  Read all about it here - https://sourceforge.net/p/mediainfo/discussion/297609/thread/e0ef2ce9/?limit=25

  Any thoughts on the chance of a bug in ffmpeg ??

• Revision 98537 : 3 notices PHP en moins lors de la création d’une Page unique. Le champ ...

  23 juin 2016, par marcimat@… — Log

  3 notices PHP en moins lors de la création d’une Page unique.
  Le champ $erreurchamp_page ? n’est pas toujours présent, tout comme $argcontexte ?page ?.