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

Question

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).

Answer 1

I couldn't get ffmpeg to create a video that preserved the alpha channel and was Powerpoint friendly (not the fault of ffmpeg). 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).