Xvid or MJPEG (Motion JPEG) are the most widely compatible for old handhelds.

Often cited as the gold standard for legacy format conversion, XMedia Recode provides deep control over frame rates, aspect ratios, and resolution settings. It is particularly effective at ensuring audio bitrates (often also 128 or 160 kbps) are perfectly synced.

Master the AVI 128x160 Converter: Essential Guide for Legacy Device Video

Choosing the right software depends on your operating system and technical comfort level.