AC3Filter is a free and high-quality audio decoder and audio filter. AC3Filter is a DirectShow audio decoder and processor for audio encoded in DTS and AC3 formats. It gives software players the ability to play soundtracks in these formats. It can also be used to process any other audio track, and you will be able to adjust all the sound parameters: gains, delays, equalizer and dynamic range. Any stereo source can be upmixed with AC3Filter to six channels. AC3 and DTS tracks can also be passed unchanged to an external receiver over SPDIF. The program is open source under the GNU GPL; its last version dates from 2013 and it is no longer developed.
One main benefit of using AC3Filter is its ability to decode and process audio in DTS and AC3 formats, enhancing sound quality and customization.