From VDR Wiki
The prinziple of the VDR software is avoiding to deal with MPEG data on software side as much as possible. Therefore for viewing of the MPEG2 stream provided by the DVB card a MPEG2 hardware decoder is needed. Up to now there are three different hardware possibilities:
- full-featured DVB card (a DVB card which has not only the tuner onboard, but also the hardware decoder with tv out)
- Dxr3 or Hollywood-Plus MPEG decoder card (MPEG decoder card, originally used for DVD viewing on slow computers)
- Hauppauge WinTV PVR350 (analogue TV card with onboard hardware MPEG2 decoder)
Beside of this there is now the possibility of software decoding - but you need a fast computer. The decoding is done by the the so called softdevice.