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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 use shell script to make video from multiple images and one audio with specific timestamps for each image [closed]

  3 juin 2024, par Trojosh

  I have an audio file and I have 15 images. I would like to make a video from these 15 still images. Each image may appear for different number of seconds.
E.g. Image 1,2,3 will take 3 seconds each but image 4 may take 40 seconds because it is more complex.

  


  How can I use a shell script that uses ffmpeg to specify timestamp for each image and add audio to the same.

  


  Also note that the sum of timestamps of all images = running time of the audio.

  


  I looked at this question and image2 filter option from the official documentation but no luck in producing such a video

  


• avcodec/tta : Limit decoder to 16 channels

  28 juin 2019, par Michael Niedermayer

  avcodec/tta : Limit decoder to 16 channels
  libtta 2.3 has a limit of 6 channels, so 16 is substantially above the "official" already
  Fixes : OOM
  
  Fixes : 15249/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_TTA_fuzzer-5643988125614080
  Found-by : continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
  
  Signed-off-by : Michael Niedermayer <michael@niedermayer.cc>
  

  • [DH] libavcodec/tta.c