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.
Just download the latest version and run the installer.
Spdifer is used automatically by DirectShow players (see a list of compatible Media players). Just open a media file with AC3 or DTS audio track.
To configure the filter run configuration utility from Start menu (All programs->Spdifer->Spdifer config).
NOTE! You should disable other AC3/DTS decoders to prevent the decoding of the filter's output. To use Spdifer in conjunction with AC3Filter, disable formats enabled in Spdifer at the AC3Filter:System page and disable 'SPDIF' format too.
Supports passthrough for AC3, DTS and MPEG Audio formats. All passthrough features of the 'big brother' AC3Filter filter are supported:
- SPDIF as PCM trick
- DTS output mode change
- Sample rate check
- Sound card reinitialization
For detailed information about how Spdifer works, read AC3Filter & SPDIF.
 Media Player Classic (Home Cinema)
If you want to use Spdifer in Media Player Classic, you have to disable MPC's internal AC3 and DTS decoders. Do to this, go to menu View-> Options -> Internal filters and uncheck decoders for formats you want to passthrough.