Notably missing from the Media Center Extender feature set is the ability to playback DVD movies via the Media Center PC.
Assuming you haven't built a small form factor HTPC and installed in it your living room, you may instead choose to use your main PC (with MCE 2005 interface) together with a Media Center Extender. Under that scenario, your extender would sit in your A/V rack as a component of the home theatre. As a result you'd probably finish up with a DVD player, an extender, a receiver, and a television that all work together to serve your home theatre needs. If you’re only looking to watch traditional DVDs (on disc) under that setup, your best bet would be to purchase a standalone DVD player.
If, however, you’re looking to be able to archive your movies to the hard drive of your MCPC and then have quick and easy access to your library through your extender, then you’ll need to take a different approach. This isn't a new thing, people have been creating DVD archives for quite some time now and standard formats have begun to emerge (some are well entrenched and some are emerging bright spots, and there’s plenty of mini-battles going on still amongst formats). Some of the common formats you’ll see out there include:
VCD - MPEG1 compressed version of a DVD that fits on one or more CDs.
SVCD - MPEG2 compressed version of a DVD that fits on one or more CDs or DVDs.
DIVX/XVID - MPEG4 compressed version of a DVD that fits on one or more CDs or DVDs.
WMV - Windows Media compressed version of a DVD, generally used for streaming and commercial services.
WMV is the least common of those formats but is being seen more often now in areas where digital rights management is important (such as legal online movie distribution). DIVX/XVID seem to be the most common emerging format (with lots of good tools as well),
but it is not supported by the Media Center Extender.
So now let’s delve into a bit more detail about how this impacts the Media Center Extender platform. Unlike a the Media Center PC, the extender
plays back video only using a decoder chip that it has built into the hardware. This means that the extender can only decode video & audio formats that are understood by the chip and cannot use the software decoders that are installed on your PC (Divx for example is a software-based decoder at this time). This is very similar to the way most DVD players work - the majority can only play back DVDs using MPEG2 and AC3 audio, while some have specialised decoder chips inside them that can also play back JPEG, MP3, and Windows Media.
The chip inside the extenders can play back the following formats only:
Windows Media 9 Audio and Video (standard profiles only)
MPEG-1 video and audio
MPEG-2 video and audio
Additionally, the chip can only play back video with an aspect ratio of 4:3. Aspect ratios seem like a pretty simple concept, but there’s a lot of odd magic that happens to make them work. See
this doom9 article on aspect ratios to get a good feel for the complexities. Basically, you can still play back 16:9 video in a letterboxed format without any problems but may have some difficulty playing 16:9 anamorphic video on the extender. Don’t worry, we can work around that.
So what are the gaps between the information stored on a DVD and what we can play back with the extender? The video on all DVDs is stored using MPEG2, which our extender can deal with just fine. However, the extender’s inability to deal with AC3 (Dolby Digital) audio causes it significant heartburn. Most DVDs use AC3 as the standard audio format, which immediately means that we can’t use it on the extender. We will need to transcode the AC3 audio into something that the extender recognises before it will play back properly. Additionally, the DVD menu system is something that is unique to DVD players and we won’t be able to use on the extender. Finally, most new DVDs use 16:9 anamorphic aspect ratios which we’ll need to fix as well.
The most flexible way of achieving any video conversion is by using a cascading mix of software components, but that may be overly complex for the majority of us. Wherever possible, it would be easier to one or two pieces of software. Note that any DVD conversion will take several hours of computing time, regardless of the software chosen.
So where does that leave us for when MCE Extenders finally arrive? Well in a nutshell, if we want to be able to access DVD movies using an extender, they'll need to be modified and archived.
So let's throw this open to everyone, what do you use to "backup" your DVDs bearing in mind that to be accessible by your extender, the output will need to be either Windows Media or MPEG (1 or 2) video and audio?
