Highest-quality GIF encoder based on pngquant.
gifski converts video frames to GIF animations using pngquant's fancy features for efficient cross-frame palettes and temporal dithering. It produces animated GIFs that use thousands of colors per frame.
It's a CLI tool, but it can also be compiled as library for seamelss use in other apps (note that for closed-source apps you need a commercial pngquant license).
See releases page for executables.
If you have Rust, you can also get it with cargo install gifski. Run cargo build --release to build from suorce.
I haven't finished implementing proper video import yet, so for now you need ffmpeg to convert video to PNG frames first:
sh
ffmpeg -i video.mp4 frame%04d.png
and then make the GIF from the frames:
sh
gifski -o file.gif frame*.png
See gifski -h for more options.