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• ffmpeg.js running extremely slow in iOS cordova (but fine in iOS safari ?)

  14 mai 2019, par PEWify

  I’m trying to create a phonegap app that converts videos into maybe 30 or so jpeg frames..
  This page converts a bigbuckbunny video into 30 frames > https://www.pewify.com/test/ (taken from https://bgrins.github.io/videoconverter.js/demo/)

  It runs fine on an iPhone x running iOS 12 in mobile safari, it takes about 12-15 seconds to complete, but the same code packaged into a iOS cordova app running on the same phone will take almost 160 seconds to complete (both end results the same, but almost 10x as long), it works fine for android browsers or an android cordova app though

  I’m using cordova android 7.0 and cordova ios 4.5.4 (phonegap cli-8.0.0) for the app

  I’ve tried removing all unneeded plugins with just the bare minimum code but to no effect, it still runs just as slow

  From what i understand phonegap is just using a webview similar to safari to render the app but in this case it works but much slower, on top of that the phone starts to get heated up (presumably doing some intensive CPU ?)

  Did read something about using WKWebview being faster in cordova instead but that messes up the app with lots of CORS and ’operation insecure" errors so have decided not to implement that for now (unless that is the solution ?)

  Hopefully someone can point me in the right direction as i’m not exactly sure what is the issue here as it works somewhat flawlessly in android (both chrome and phonegap) but only in iOS safari and not the phonegap app

• How to open a HEIF (.heic) image ?

  14 décembre 2022, par Jean-Milost Reymond

  For a c++ project, I need to open and show a HEIF (.heic) image. What I know (if I'm right) is that the HEIF images are based on the ffmpeg standard, and requires a H265 codec to be read.

  



  I found several open-source H265 codecs :

  



  

  • OpenHEVC (https://github.com/OpenHEVC/openHEVC)

  


  • x265 (https://bitbucket.org/multicoreware/x265/downloads/)

  


  • libde265 (https://github.com/strukturag/libde265)

  


  



  I can open and show H265 encoded video files with each of them, but I'm unable to simply open, show or convert a .heic image. All of them return an error, or just do nothing.

  



  To be honest I'm a little puzzled, because the HEIF standard seem to be a well kept secret. I'm unable to find a relevant info that could allow me to walk to a solution. Those I found are just tricks and workarounds, like e.g. forcing the device (I'm speaking here about the Apple iPhone using the new iOS11) to generate a jpg image instead of a heic, or using a third party application like dr.fone. Of course these solutions are irrelevant for me.

  



  So, somebody can tell me which codec I should use with a .heif image, and how I can use it to open it ? Or are there open source libraries or examples that allow to manipulate this type of image file ? Somebody can point me to the good direction ?

  


• Prevent libavformat (FFmpeg) from adding "ENCODER" tag to output / stripping tags

  1er mars 2014, par Wyatt8740

  I made a bash script that transfers audio or video metadata from one file to another, regardless of media container format, via FFMpeg. My problem is that FFMpeg consistently adds a 'ENCODER' tag.

  Example :

  Before running through FFMpeg :

   File : track01.cdda.flac

    Metadata:
  
      ALBUM           : Wish You Were Here
  
      ARTIST          : Pink Floyd
  
      COPYRIGHT       : 1975 Harvest Records
  
      DATE            : 1975
  
      GENRE           : Experimental Rock
  
      TITLE           : Shine On You Crazy Diamond
  
      track           : 1

  After running through FFMpeg :

   File : track01-iphone-alac.m4a

    Metadata:
  
      ALBUM=Wish You Were Here
  
      ARTIST=Pink Floyd
  
      COPYRIGHT=1975 Harvest Records
  
      DATE=1975
  
      GENRE=Experimental Rock
  
      TITLE=Shine On You Crazy Diamond
  
      track=1
  
      ENCODER=Lavf55.12.100

  So really, I want to either force FFMpeg to not add the 'ENCODER' tag, or I want to strip that tag off afterwards. Is there a way to do this ? I really don't want to spend hours trying to compile FFMpeg again on my Pentium 4 HT - the only working computer I have at the moment. I'd prefer not to have to use another program unless it's related enough to FFMpeg or MPlayer/Mencoder that I won't have to install anything new if I have those installed.