The HDMI Repeater Issues

One day I got the silly idea to build a theater in my basement, I documented the process here. In doing so however, I was exposed to the reality that although our PC technology is quite well suited for home theater use, much of it is remarkably broken in that sense.

At launch, G45 was the epitome of the broken HTPC space. Hardware decode acceleration didn't work right, there were HDCP issues on various displays and something called HDMI repeater support was broken.

The HDCP spec was created to be flexible for use in both PC and consumer electronics devices, as such there's support for three types of devices: source, sink and repeater. The source in a HDCP chain is the, well, source - it's what is originally outputting the content. The source could be your PC or a Blu-ray player among other things. The sink is the final device in the chain, its only purpose is to decrypt the HDCP signal and display the final output; an example of a sink is your monitor or a TV. The third type of device is a repeater and what it does is accepts an incoming HDCP signal, decrypts it, optionally adds additional data or processing to the signal then re-encrypts it and passes it along.

The best example of a repeater is a HDMI receiver. Many high end HDMI receivers will take any input and upscale it to 1080p before sending it out to your display. That feature alone requires that the receiver be a repeater as it needs to decrypt the incoming signal, upscale the video, then encrypt the new signal and send it out to your display. Any audio processing done to the signal also requires the same decrypt, process, encrypt path.

As far as I can tell, implementing support for repeaters in both the HDMI and HDCP specs is fairly trivial. There's a single bit that indicates support and the whole chain should just work, however at G45's launch the chipset didn't support HDMI/HDCP repeaters. And today, despite many driver and software revisions - support is still broken.

The initial incompatibilities were actually due to the software player vendors, mainly Corel and Cyberlink. Without repeater support, my G45 testbed would not propagate HDCP and thus I'd get this error from PowerDVD:

The repeater in this case was an Integra DTC-9.8 pre-processor. I used the latest version of Arcsoft's Total Media Theater to see if perhaps this was a Cyberlink issue and although Arcsoft didn't throw an error, I couldn't get the player to actually play any encrypted content when my Integra was in the HDMI chain.

Gary tried the Denon AVR-3808 and got the same error: HDCP failed until a firmware update from Denon although the unit worked fine with competing solutions. His situation was slightly different with the Pioneer VSX-94TXH as it worked properly (finally) after the latest updates from ArcSoft and Corel. However, Cyberlink's PowerDVD 8 Ultra still does not have G45 repeater support at this time.

Intel is apparently still getting down to the root of the HDMI repeater issue with G45, but one thing is for sure: it doesn't exist on our 780G or GeForce 8200 based test beds. Even the add-in Radeon HD 4800 or 4600 series cards don't have this problem. If you don't have an AV receiver then the flaky repeater support won't matter, but home theater aficionados beware.

Blu-ray Playback: Integrated Graphics Matters Again The Boards: ASUS P5Q-EM
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  • Butterbean - Wednesday, September 24, 2008 - link

    I'm not sure why this board is measured/reviewed for its gaming ability (or lack of). A lot of HTPC peeps get these because they are quiet and can play DVD's without the noise /heat. Not many people really expect to play Oblivion on it.
  • 8steve8 - Wednesday, September 24, 2008 - link

    the dg45id has the unique ability to ouptut simultaniously to two displays with a digital interface.

    imo its the prefect board for non-gamers with dual-monitors..

    seriouosly.. analog sucks.

    should be listed in the pros/cons.
  • CSMR - Wednesday, September 24, 2008 - link

    Yes, a very important feature for a work system with integrated graphics. Presumably common to all G45 boards with DVI and hdmi?
  • yehuda - Saturday, September 27, 2008 - link

    No, the Gigabyte board can't do that even though it has both ports.

    http://download.gigabyte.ru/manual/motherboard_man...">http://download.gigabyte.ru/manual/motherboard_man... (p. 8, footnote 1)
  • npp - Wednesday, September 24, 2008 - link

    SPCR measured the power consumtion of the same mini-ITX G45 board and found it to consume 35W at idle with an E7200 CPU installed (which should consume a tiny bit more than a 5200, given it works at higher FSB speeds and has more cache).

    Your figures showed something like 57W; one would say, hey, no big deal, we're talking about only 22W here. But if you take this as relative difference - it turns out to be 60%! SPCR used only one DIMM, but I doubt this can explain the discrepancy. The PSU was a 400W model, so I guess it has similar efficiency curve as the Corsair model you used.

    Given the strange results of you power consumption measurements recently, I have reasons to doubt that something simply isn't right out there.
  • CSMR - Wednesday, September 24, 2008 - link

    SPCR people will make more efficient choices. Efficient PSU, notebook hard drive, non-overclocked RAM. 57W is a good result for a mainstream review. Little things can add up to 22W, especially PSU efficiency.
  • MadDogMorgan - Wednesday, September 24, 2008 - link

    ANAND! These vibrant media popups are KILLING ME!!!!

    I am about ready to GO INSANE reading your site. You CAN'T POSSIBLY be making any MONEY off those things, they are too INCREDIBLY ANNOYING for anyone to ever THINK about watching one or clicking one.

    Oh, and I LIKE PS/2 ports. What's wrong with PS/2 ? It works great, takes less cpu than USB (in my VERY informal mouse testing) and the headers take up very little space on the mobo. You also have the option to use the USB connections instead, if you want.
  • Anand Lal Shimpi - Wednesday, September 24, 2008 - link

    Visit this URL: http://anandtech.com/siteinfo.aspx?off=yes">http://anandtech.com/siteinfo.aspx?off=yes

    It'll disable all IntelliTXT on AnandTech for you :)

    -A
  • zagood - Wednesday, September 24, 2008 - link

    Wow, thank you! Now how do we do that on DT?
  • MadDogMorgan - Wednesday, September 24, 2008 - link

    Thank you VERY MUCH for providing this option.

    Also, please keep up the good work and I appreciate you spending some time in the HTPC area. It seems to me there is a decided lack of good technical coverage in this arena. The kind of in-depth coverage that only your and a couple of other notable sites provide.
    I would like to see some TV Tuner card reviews from your site comparing the technical details of the latest offerings from Hauppauge, ATI and any other popular ones. Toss in a review of a few PVR apps like GB-PVR, SageTV, MythTV and BeyondTV and (HTPC) life would be complete. Don't forge to address the difficulty of getting the channel listings when using a freebe like GB-PVR, or the ins and outs of getting scheduled recordings to actually WORK when the app uses the Windows Task Scheduler.

    Thanks Again.

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