Sunday, December 19, 2010
How To Connect Your PC to an HDTV With HDMI
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The choice of how you connect your PC to your TV is critical
to optimizing your experience. Assuming your PC?s graphics
card supports it, HDMI, or High Definition Multimedia
Interface, is one of the best ways to connect a PC to your
HDMI is a single cable that carries all-digital,
uncompressed video at resolutions up to 1080p, as well as
uncompressed or compressed digital audio signals. While HDMI
is common in consumer electronics devices like the Xbox 360,
DVD and Blu-ray players, since 2007, we have seen more and
more PCs roll out with HDMI support - especially in the
laptop and notebook area. All major graphics card
manufacturers also offer cards with HDMI.
If your PC or laptop and TV are relatively recent, making an
HDMI connection is a simple. After making the connection,
you may have to adjust the resolution settings to ensure the
PC's output on the TV is making the best use of the
If you connect your laptops or netbooks to an HDTV through
HDMI, full HD video and audio will be sent to the TV set.
However, if you decide to insert an AV receiver into the
mix, say to handle surround sound, things may get more
complicated. While HDMI can provide an digital, high
definition audio and video experience, it can also be tricky
to implement with older devices, components, displays and AV
The most common challenge we see when integrating older PCs
or HD displays via HDMI has been the so-called "handshake
This is because an important part of the HDMI specification
involves a content protection scheme called HDCP
(high-bandwidth digital copy protection) in which the source
device checks the receiving device for an authentication
key. If all is well, they 'shake hands' and get on with the
business of your content. If you've ever watched a DVD on an
Xbox 360, you may have briefly seen a message on screen that
reads "Secure HDCP link established." after you've hit play.
That means you've had a successful handshake.
While connecting an Xbox or Blu-ray player to your HDTV via
HDMI is fairly straightforward, doing so with a PC involves
many more variables. Your graphics card may have an older
driver, for instance, or the firmware for your display may
be out of date. Many older devices such as graphics cards,
displays and receivers did not implement HDCP correctly (or
at all, in some cases). If your setup involves an AV
receiver or projector, you have introduced additional
components into the path that also have to successfully
implement HDCP in order to create a secure path between the
source (your PC) and the display (your HDTV).
With the release of Windows 7 and more products supporting
HDMI 1.3, it seems as though firmware and driver updates
have helped resolve many of the handshake issues. However,
Mike Garcen, one of MIcrosoft's Windows Entertainment and
Connected Home MVPs and the man behind the HTPC enthusiast
site Missing Remote, described some of the top symptoms of
an HDMI handshake issue are for an HTPC running Windows 7.
Here's what he reported as the most commonly reported
symptoms of a handshake issue he still sees today:
* A black screen when the primary video display is no
longer available. For example, you've switched to another
input, and then back to the HDMI input, or turned the TV off
and left the HTPC on, or the HTPC is resuming from
* Loss of audio is an issue we've seen on some older ATI
cards, but in my testing of Windows 7 SP1 beta, this seems
to be resolved.
* For HTPCs running Intel HD Graphics, we see reports
that the screen resolution is lower when the primary video
display is no longer available. This includes input
switching, TV on\off and resuming from sleep.
If you think you're experiencing a handshake issue using
HDMI, there are a few things Mike recommends trying:
* Power down everything and then restart. This restarts
the HDCP verification process. That means powering down your
PC, the display and any components you may have integrated
* Try a different HDMI cable (ideally of a different
length) than the one giving you an issue. Timing is a
critical component of the HDCP process, and sometimes
changing the cable can help resolve an issue. Note, also,
that if your display supports up to 1080p high definition,
ensure that you are using a High Speed HDMI cable, designed
for 1080p resolution and beyond. If you are using a Standard
HDMI cable, the best you can do is 720p.
* Start checking drivers and firmware: It's time to
start looking at the drivers and firmware for the cards and
components in your set-up. Are they up to date? Do they all
support the correct version of HDMI? Do some research and
check forums like those on Missing Remote, the Green Button
or the AV Science forums.
At the heart of most HDCP issues, you'll find you can remedy
the issue with a driver or firmware upgrade, or else
identify and replace the non-HDCP compliant device in your
chain. You may also want to check out a product like the
HDMI detective from Gefen, a small box whose job it is to
keep your HTPC and display in synch even when you go about
switching inputs. Otherwise, you'll have look at other
connection options instead of HDMI
The good news, Mike reports, is that as HDMI has matured and
more manufacturers have gotten HDCP down, the number of
handshake issues seems to be on the decline. Mike writes:
"Many of the early HDCP timing issues were due to the AVR
and TV firmware and early drivers. Most of those issues have
been resolved with (HDMI v.) 1.3."
The specification for version 1.4 of HDMI was released in
mid-2009, and brings with it some promising features,
including 3D over HDMI and an added Ethernet data channel.
While cautiously optimistic, Mike characterizes HDMI 1.4 as
"extremely new to the HTPC world."
While uncompressed, digital audio has been supported from
the beginning with HDMI, getting an HTPC to work with HDMI
in delivering full HD audio can be challenging. Check out
Missing Remote's guide on bit
streaming HDMI HD audio from an HTPC setup. For background
on why full HD audio has been tricky for HTPCs, see Anandtech?s write-up here.