QDX is an old lossy audio compression format, designed for portable multimedia players with small amount of memory.

Overview

QDX files are encoded at 128 kbit/s but bitrate can be "peeled" so that lower bitrate stream can be extratced and saved on portable player (up to 2.5 hours of music on a 32 MB) without need of transcoding, which is called Fit-To-Media.

What is more, this format is resistant to dropouts while streaming, which is called Fit-To-Stream.

QDX format also offers DRM info, which prevents from unauthorized use of those files.

Hardware support

iriver iDP-100 can play QDX files