Here you can find and be free to use and adapt to your needs: animated jpg with simple transition example:
Example you can find here: click here
Code you can see: here
Stripes are prepared in vector editing program cropping several pictures to same side and aligning them: download
Decided not to use png but jpg as here we don't need transition and are much smaller for download.
Solution is based on Klaus's animated PNG code, slightly adapted ;)
Regards
Umalo