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• How to preserve transparency when using png to make video with ffmpeg

  27 septembre 2016, par Ryan James

  I have a series of png’s that have an alpha channel as a background. Each file is named like file_name.0001.png and so on, in subsequent order. I’d like to join these png’s into a video with ffmpeg and maintain the transparency.

  I’ve tried a couple of things but I suspect I’m running into a codec issue. When I run ffmpeg, the video is created but the background is black.

  If it makes a difference, I’m wanting to use the video in Microsoft Powerpoint. Thanks !

  Edit
  The suggested duplicate is very close to what I was looking for, thank you ! The only reason it’s not a complete solution is none of the options presented in the other thread work well with Microsoft Powerpoint. None of the codecs used in the suggested solution play well with Powerpoint. This is not the fault of ffmpeg, but of Powerpoint.

  Though ffmpeg doesn’t seem to be able to do what I need, I found that imagemagick did the trick. I was able to create a gif from the images and the alpha channel was preserved. I used the following :

  convert -dispose 3 -coalesce images.*.png gif_file_name.gif

  The -dispose 3 is critical as it tells imagemagick to clear the image prior to overlay, otherwise, you can see each image overlaid on each other (since they have the transparent background).

• Can't get FFMPEG to convert Samsung Motion Photos from .jpg to .mp4 [closed]

  27 août 2024, par welbeebee

  I pulled a bunch of Samsung Galaxy S21 Ultra motion photos to my PC (Windows 11) for video editing, but they were in .jpg, and for some reason Microsoft Clipchamp couldn't convert them to video. But, I knew the motion photos were intact, bc Microsoft Photos was showing the MOTION option and playing the videos just fine.
So, I'm in FFMPEG just throwing everything at the wall, but can only get still MP4's out of it, with none of the video.

  


  Here's the breakdown of what I'm looking at for :
ffmpeg -i input.jpg

  


  Input #0, image2, from '20240623_233601.jpg':
  Duration: 00:00:00.04, start: 0.000000, bitrate: 874324 kb/s
  Stream #0:0: Video: mjpeg (Baseline), yuvj420p(pc, bt470bg/unknown/unknown), 2944x2208 [SAR 59:59 DAR 4:3], 25 fps, 25 tbr, 25 tbn


  


  So to get the whole folder converted, I'm trying :
for %i in (*.jpg) do ffmpeg -i "%i" -c:v libx264 -map 0:0 -preset veryslow -crf 18 "%~ni.mp4"

  


  But this just results in a bunch of those still MP4's I mentioned.

  


  I'm assuming the problem starts with that odd duration of 00:00:00.04, with a bitrate of 874324 kb/s, but I'm not sure. I don't understand this mjpeg video format very well at all.

  


  I been trying to work through this with copilot to no success, and so I'm turning to stackoverflow in case anyone can help me out.
Or am I going about this all the wrong way ? Let me know.

  


• Revision 98724 : Sur les entrées de type page=truc, on ajoute une classe sur l’entrée ...

  11 juin 2018, par rastapopoulos@… — Log

  Sur les entrées de type page=truc, on ajoute une classe sur l’entrée du nom de la page, automatiquement, pour avoir de quoi le cibler en CSS ou JS d’office, savoir avoir à demander à rajouter une classe manuellement.