mp3PRO is an audio compression algorithm (or codec) that combines the MP3 audio format with spectral band replication compression methods. It claims to achieve transparency at lower bitrates than MP3, resulting in a file nearly half the size of standard MP3. RCA was the only company to offer portable players compatible with mp3PRO, but they have dropped support for the format.

Compatibility

Any mp3 player can play mp3PRO files but they will be played at half the intended sample rate. To play mp3PRO files with the full sample rate in Microsoft Windows, users are required to install extra software. This extra software can be a player such as Musicmatch Jukebox or Thomson Demo mp3PRO Player, or a plug-in for an existing audio player. Optical disc authoring software such as Nero Burning ROM includes mp3PRO support as well. For Macintosh computers, the now-discontinued Audion shareware supports both real-time mp3PRO encoding and decoding.

mp3PRO playback in Linux may be possible under Wine using Thomson Demo mp3PRO Player or Winamp with the mp3PRO plug-in. There is also an mp3PRO plug-in for Linux XMMS-Player. The absence of an mp3PRO player for Linux is largely due to RCA not releasing the mp3PRO source code, even after discontinuing its support of the format. Methods for playing mp3PRO files under Linux (including using the XMMS plugin from within Mplayer) are detailed here.