AC3Filter - it is a DirectShow filter for AC3 decoding to play .AVI with AC3 audio tracks and MPEG2 (DVD). Distributed absolutely for free (FREEWARE, OpenSource).Features: • Full AC3 standard compliance. • S/P DIF passthrough support. • Decode MPEG2 PES streams. • Multichannel output support. • LFE support. • Dynamic Range Compression (DRC) support. • Overflow control and automatic gain control. • Gain levels control. • Bitstream information (channel format, bitrate, sample rate, coupling freq and maximun freq). • Input/output levels. • Matrix mixer with direct control of mixing matrix. • Stereo to multichannel mixing. • DolbySurround/ProLogic/ProLogicII downmixing. • Delays for each channel. • Equalizer. What's New in version 1.51a: • CPU usage takes in account number of processors • Center, Voice and LFE levels are synchronized across Mixer and Gains pages • 'Decoder info' box did not work sometimes • Slovak, Spanish and Italian translations updated