When hardware can’t handle it, MX Player switches to (using the CPU). This is resource-heavy, causing your phone to heat up and the video to lag. This is where the Neon Codec comes in.

Most modern phones have hardware decoders (chips specifically designed for this). However, not all file formats are supported by hardware. This is particularly true for older file types (like the popular Xvid/DivX AVI format) or non-standard audio tracks (like AC3 or DTS).

Have you ever tried playing an MKV or AVI file only to hear silence? That is usually DTS, AC3 (Dolby Digital), or MLP audio. The stock version of MX Player cannot decode these due to licensing restrictions. The unlocks these audio formats.

The app will restart, and you can verify the installation in Help > About Key Benefits Fixes "EAC3 Not Supported" Errors:

💡 If you frequently switch phones, keep the AIO (All-in-One) codec pack in your cloud storage. It works across almost all Android devices regardless of the specific ARM architecture.

Scroll to the bottom. Under Custom Codec , tap Install Custom Codec .

Force close MX Player (swipe it away from recent apps) and reopen it. Go back to Settings → Decoder . You should now see Custom Codec: v1.49.0 (ARMv8 NEON) listed.