MPEG-2

MPEG-2

As the compression format for both DVD and digital television (both ATSC and DVB), as well as for some consumer camcorders and other PC peripherals, MPEG-2 is a major feature of the digital media landscape and will continue to be so for some time.

For DVD playback, DirectShow provides the DVD Navigator filter, which demultiplexes the MPEG-2 program streams and passes them down to the decoder for decrypting and decoding. For demultiplexing of MPEG-2 transport streams and program streams from any source except DVDs, DirectShow provides the MPEG-2 Demultiplexer. This filter works with regular DirectShow filter graphs (such as file playback or capture from non-BDA-compliant devices) as well as Microsoft Broadcast Driver Architecture (BDA) digital TV graphs.

For digital television, Microsoft provides a set of filters and related components collectively referred to as Microsoft TV Technologies. (This set of DirectShow components should not be confused with Microsoft TV, which develops Windows CE based software for set-top boxes.) The Microsoft TV Technologies components are designed to be used with digital TV tuner cards whose drivers are compliant with BDA. As of this writing, such devices are not widely available, but the DirectShow support exists for ATSC, DVB-T (terrestrial), DVB-S (satellite) and DVB-C (cable) transport streams.

For MPEG-2 playback from any source including DVD, you ll need to obtain an MPEG-2 decoder from an independent software vendor, unless you have Windows XP Media Center Edition. Although some hardware decoders work with DirectShow, these devices are rapidly becoming obsolete. Software decoders for MPEG-2 are highly recommended. Several good software decoders are available; if you have a choice, get one that supports Microsoft DirectX Video Acceleration. MPEG-2 encoding and multiplexing is also possible through DirectShow, but as with MPEG-2 decoders, you ll need the necessary filters (and possibly hardware) from third-party vendors.