What could be better than relaxing at home watching a film, browsing the Internet for sites of interest, listening to your favourite music, watching your favourite TV show either live or recorded from digital High Definition TV or spending a couple of hours whacking your enemy, the Horde, in World of Warcraft. Once upon a time you needed at least half a dozen different expensive items of hardware in your home to do this, but not any more.
It's a truism now to say that readers of newspapers and magazines are down while online based news, reviews and entertainment are up. Even more true its proving far more resilient in these tough and turbulent times than traditional media. Computer entertainment is so engaging and involving. You can immerse yourself in a virtual world of an alternate reality it's no surprise it's proving very attractive and growing an ever larger community.
What is an HTPC?
The Home Theatre PC is just that, a PC which is capable of also serving as a home theatre system. You can use it to:
• Watch films on Blu-Ray, DVD or HD-DVD, or directly off the disk storage in your PC
• Watch live digital or analogue, terrestrial, cable or satellite TV (known as DVB-T, DVB-C and DVB-S, or for HD content DVB-T2, DVB-C2 and DVB-S2)
• Listen to high quality music from CD, DVD-Audio, SACD or High Definition audio on Blu-Ray
• To manage your own personal video (H.264 or MPEG4) and photograph collections
• To manage your own music collection in MP3, record off your CD collection or directly from the Internet through Spotify or a similar channel
• Browse the Internet or your emails
• Do your office word-processing or financial admin
• Play PC games and simulators with wireless motion controllers and game pads
Because of its incredible versatility the PC can do everything you'd expect of a PC and all the functions of a high end powerful Home Theatre setup. Modern advances in monitors, keyboards and mice also mean they are very useable from the comfort of your living room. No need to tuck it all away in your home office.
Why is an HTPC better than a BluRay player, or specialised device?
Recent reviews in specialist magazines of high end Home Theatre PC's have demonstrated that the PC's compute power and upgrade flexibility give it the capability to quickly adopt emerging standards and surpass the performance of a dedicated device. Typically a dedicated device will use relatively long in the tooth trusted and reliable old technology. Utilising processors from five or so years ago when a modern video card for example has over a Teraflop of compute power to bring to dedicate to the process of decoding Blu-Ray content and displaying it in the best possible quality, frame after frame.
De-mystifying the common techno-babble
Rarely have there been so many standards and acronyms and consequentially misinformation tied up with what is essentially a very simple task. From the viewers or listeners perspective all they want to do is watch a film or listen to music, or both. We don't care how it's stored, what cable it comes out of, how it's encoded or copyright protected etc. All the acronyms and technical specs you see are really about these things and understanding what they relate to makes it very easy to work out what matters and what doesn't. So let's divide these up into categories and see what there is, and what we really need. After this background it will be easier to understand what you need your Home Theatre PC to do and why.
Copyright protection: There are a variety of standards but for the HD broadcasts or pre-recorded content HDCP is the one you want to make sure your Home Theatre system is compliant with. That means everything in the system; the player, monitor, Digital Signal Processors (DSP) and receivers. Anything that isn't HDCP compliant won't understand the bitstream and so won't be able to play the audio or video content. It's designed this way to make it hard to make unauthorised copies of copy protected content. For delayed live TV recordings the standard allows temporary storage by the PVR (Personal video Recorder) unit for up to 90minutes.
Physical connection⁄interface: All media is now recorded digitally and the best way to get digital content to a digital display or audio device is digitally. So where possible you want to avoid converting your signal to and from digital and analogue, every conversion results in some degradation in quality. Hence why almost all displays now use either HDMI or DVI as both are digital interfaces and comfortably support 1080 lines of display as required for High Definition (1080p). HDMI has the advantage that it also supports 7.1 audio channels as well, so one neat lead from your HTPC to your TV can transmit both the audio and video content.
Most manufacturers also provide DVI to HDMI converters with their graphics cards. The cards also have what are sometimes called HD or S-Video output sockets. These are useful for legacy analogue devices as they can support composite and component video, the latter being the best quality of the two. Component video however was designed for 480 line (480i) displays so if you use this instead of the digital interface you will be getting degraded quality video.
Media formats: There are only four formats we need to worry about CD, DVD, HD-DVD and BluRay. The story with media formats is fairly simple it's all about storage capacity from CD's measly 700MB all the way up to Blu-Ray's 50GB. Blu-Ray has enough storage to be able to support HD Video and multi-channel sound. Blu-Ray players can usually support the reading of all formats and the writing to most so you only need the one player in your device.
Audio and Video encoding standards: The first digital standard most of us were exposed to was CD (CDDA - Compact Disc Audio Standard), which surprisingly still today is a very good lossless standard by which audio quality is measured. It's called lossless as unlike digital sound encoding standards such as Dolby Digital or MP3 it does not compress or alter the content of the sound in anyway, it is recorded and then replayed exactly.
Compression was originally required because storing multi-channel soundtracks required more storage space than was available on older media like the CD or legacy PC's. CDDA took an analogue music track recorded on multi-track tape in a studio and converted it to digital by sampling it at 44.1KHz and storing it as a 16-bit binary number, and called it a digital Audio CD.
Then things got complicated with multi-channel home theatre sound and video that required much more space and much higher data rates. The only way to fit sound and video into the small capacity media and low data rate interfaces was to compress it and lose data thought not important. Research into what could be safely compressed and discarded while maintain reasonable quality resulted in the MP3 and MPEG digital compression standards.
Bear in mind that your average MP3 audio recording is typically 128kbit⁄s whereas the trusty old 1980's veteran CD supports 1,411.2kbit⁄s. That means the venerable CD has over ten times higher a bit density and hence a lot better quality. Many younger people who have only ever had the opportunity to listen to MP3 are missing out on the difference.
Now computers are much more powerful, the media has much more capacity and interfaces support much higher data rates and compression is falling out of fashion. Audiophiles and video enthusiasts categorically state that important stuff is lost with compression; they can see and hear the loss of quality.
Herald the arrival of High Definition lossless audio with DTS-HD Master Audio and TrueHD (only HDMI1.3 supports the bit streaming of the lossless high definition formats as-is for decoding in an external DSP). DVD-Audio or SACD are also lossless standards which are essentially the same as CD but at a higher sampling rate and greater bit depth at 192KHzt⁄24-bit.
How do I choose which HTPC is right for me?
Home Theatre PC's have all the same variables as a regular PC you need to make sure that at a minimum there is:
• enough memory (4GB at least)
• a 64-bit operating system (so Windows Vista or 7)
• a modern dual core processor
• a DVB tuner card for TV programmes
• a quiet case with good cooling that supports standard sized components so it's easy to upgrade
• an HDCP compliant graphics card with Blu-Ray decoding video acceleration (PureVideo or AVIVO) and an HDMI output
• a good quality, low-noise soundcard with HDMI1.3 support if you need DTS-HD Master Audio or TrueHD
• enough storage for your music, photo and video library and live TV recordings, at least 1TB (1000GB)
• and finally a good quality Blu-Ray player that also supports HD-DVD, DVD and CD, as you require.
How do I setup my HTPC with an existing system?
The versatility of an HTPC almost makes it possible to integrate it into an existing Hi-fi or Home Theatre system in many useful ways. Here are a number of options you could consider:
• Stand-alone low cost multi-purpose Home Theatre system - use it as a
Blu-Ray player, digital TV receiver and Personal Video Recorder (PVR) feeding HDMI
combined video and audio to your TV for it to decode.
• Home Theatre system and Digital Signal Processor⁄Receiver - use a built in multi-channel sound card in the HTPC as your sound processor feeding out over analogue or digital interconnects to a Hi-fi system or amplifier and speakers.
• As a High definition receiver and player in an existing high end system - with a DVB TV tuner card and good quality soundcard you can feed HDMI1.3 High Definition digital output to your dedicated external Digital Signal Processor/Receiver. The receiver then feeds analogue to your systems amplifier(s) and speakers.
The systems to fulfill your objectives here can cost anything from US$1000 at the low end up to US$5000 at the high end. As with all Home Theatre and Hi-fi kit they come in varying degrees of aesthetics and functionality that add to the cost. The best cases can cost US$1000 on their own with built-in touch screens, motorised front covers and displays, card readers and solid cast brushed aluminum chassis. The limit is only your budget...
Alan is Chief Technologist at [cryopc.co.uk Cryo PC is no more].
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