I’m trying to make a short .gif from a youtube video, but neither Gifsoup nor gickr seem to be working. Gifsoup just tells me that there was an error and gickr gives me this message:

Warning: dl(): Unable to load dynamic library ‘/usr/gickr/php/lib/php/extensions/no-debug-non-zts-20060613/ffmpeg.so’ – libavformat.so.51: cannot open shared object file: No such file or directory in /serv/www/gickr.com/actions/from_youtube.php on line 69 Can’t load extension /usr/gickr/php/lib/php/extensions/no-debug-non-zts-20060613/ffmpeg.so

Does anybody know what might be wrong?
Edit: I would prefer to not resort to taking individual screenshots of the frames. That is why I am using these video- .Gif converters