[FFmpeg-user] How to get 4-bit PNG frames?

[Carl Eugen Hoyos]

> Am 01.01.2021 um 11:57 schrieb Rocky Ji <rockyji3438 at gmail.com>:
> 
> ffmpeg -i /dev/video2 -r 4 -vf format=pal8 -pix_fmt pal8 -f image2
> s-%04d.png
> 
> to get 4 8-bit PNG screenshots every second from game capture device (if I
> am understanding it correctly).

No, this is not how pal8 conversion works, see:
https://ffmpeg.org/ffmpeg-filters.html#palettegen-1

You have to first record in qtrle or libx264rgb before you can use the palette filters in a second run.

> For my purposes, I need to reduce size
> further. So I want to get 4-bit PNGs

This is not supported by FFmpeg.

Happy new year, Carl Eugen