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• time progress bar does not scale by sec in FFMPEG chopped mp4 in iOS and Android devices

  10 juillet 2017, par Xi Xiao

  I have used the below command to cut out a 44sec length video. The result video can be found here.

  ffmpeg -i friends.mkv -ss 00:15:30.0 -t 44 -vf scale=640:360  video.mp4

  One odd issue appears from the generated video.mp4.

  when playing it in iphone 7 and huawei honor8 android, the time progress bar does not scale by second.

  What I mean is, for example, the video can start to play either from 0 second or 6 second. But, if I drag the progress bar to time between 0 - 6, such as 4, the video player will jump to 0 and play, instead of playing from 4 second.

  When I use Javascript to setTime for 2 second for html5 video player, it does not work either, i.e. the player will play from 0 second instead of 2. Code is as below :

  var vid = document.getElementById("video1");
  
  vid.currentTime = 2;
  
  vid.play();

  screenshot made in iphone 7

  I stop the video, try set the progress bar between 0 and 6 as in screenshot. When I click play, the player will play from 0.

  

  In what devices have I tested it ?

  • This issue appears in iphone 7, huawei honor8 android phone.
  • This issue does not appear in PC browser, nor in ipad.

  At last, I suspect that the issue roots from video codec, but had no success to locate the keyword to explain my issue and google the solution.

• FFMPEG concatenate multiply files with various extensions and properties

  28 juillet 2022, par KRUK

  I'm trying to create a movie on Windows using ffmpeg from files that are from different devices and in different extensions (.mp4, .mov). Is there any way to combine any file extensions into one final movie that will play properly ?

  


  I'm thinking of such an approach, to first normalize all files to the same format (What is the recommended final format ?) and only then combine them into a final file.

  


  I am experimenting with this approach :

  


  ffmpeg -i [input.anyFormatX] outputX.mp4


  


  and then

  


  ffmpeg -f concat -i [List of files] output.mp4


  


  But unfortunately this does not work for all files, should pay attention to the codecs or maybe some other intermediate format ? The biggest problem appears with files recorded with Iphone and in extension .mov. After the first stage, these videos look overburnt, as if they have a lot of raised brightness, how to correct this ?

  


  Do you know perhaps any generic solution, which would allow the assembly of videos from different devices (including Iphone) and with different parameters such as frame rate or resolution ?

  


• avfilter/vf_format : re-use AVFilterFormats for pix_fmt parsing

  21 octobre 2023, par Niklas Haas

  avfilter/vf_format : re-use AVFilterFormats for pix_fmt parsing
  Rewrite the format parsing code to make it more easily generalizable. In
  
  particular, `invert_formats` does not depend on the type of format list
  
  passed to it, which allows me to re-use this helper in an upcoming
  
  commit.
  Slightly shortens the code, at the sole cost of doing several malloc
  
  (ff_add_format) instead of a single malloc.
  

  • [DH] libavfilter/vf_format.c