AC3Filter

AC3Filter is a high quality free audio decoder and processor filter. It allows media players to playback movies with AC3 and DTS audio tracks. Also it can process any audio track, much of processing options allows to adjust the sound in almost any way. It is possible to upmix any audio source to 6 channels. Filter can do multi-channel and digital (SPDIF) output. It can encode any audio source to AC3 on-the-fly and send it over SPDIF to the receiver.

Spdifer is a DirectShow filter that allows media players to passthrough multi-channel sound to the digital (SPDIF) output without any change, so an external receiver can decode it.

AC3Filter Audition plugin allows CoolEdit / Adobe Audition to read AC3 and DTS files and write AC3 files.

AC3Filter tools is a set of command-line tools for manipulating audio files

Winamp 2.x/5.x input plugin to play .ac3 and .dts files. Based on the same decoder library used in AC3Filter.

AC3File is a DirectShow source filter.