There are two ways:
Hardware MPEG decoder
The principle 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, an 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)
Software MPEG decoder
Now that many computers are fast enough (CPU 500 MHz and more), there is also the possibility of software decoding. In fact, many (most?) cards sold nowadays are so-called budget cards, i.e. don't have hardware decoders any more.