HDMI, as we've pointed out elsewhere, is a format which was designed primarily to serve the interests of the content-provider industries, not to serve the interests of the consumer. The result is a mess, and in particular, the signal is quite hard to route and switch, cable assemblies are unnecessarily complicated, and distance runs are chancy. Why is this, and what did the designers of the standard do wrong? And what can we do about it? Check out this informative article from our friends at Bluejeans Cable.
This reminds me of the same stupid mentality used by Detroit to design cars by committee, it ends up being a disaster, remember the Pontiac Aztec? It's the HDMI of cars.
Kurt is a great guy and very knowledgable. He is also willing to go out of his way to help his customers in any way he can.
Great article and I would love to see him right more for Audioholics. Cable technology can be very interesting and Kurt has taught me a lot.
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Another issue on HDMI is that it imposes a very constrained and inefficient architecture on entertainment systems. HDMI was created to allow transmission of uncompressed video and audio from a source device (e.g. HD-DVD) to a display device. As described in Kurt's excellent article, this transmission is one-way with no error correction. The only two-way communication is transmission of control signals between devices. It is possible to distribute an HDMI source signal to multiple displays, but switches for this purpose are expensive and complex.
Because the transmission is uncompressed, this requires suitable codecs (e.g. MPEG-2/4) in each source device. It is also mandated that all modern TV's include an ATSC tuner that includes at least an MPEG-2 codec. Of course any codec in the display would be redundant with an HDMI input. I should also mention than an ATSC signal has only a 6MHz bandwidth, far smaller than that required by HDMI.
It sure would have been nice if more thought were given to allowing an entertainment system architecture that better met the needs of consumers prior to the mass adoption of HDMI. Whatever happened to HANA? The High-Defintion Audio-Video Network Alliance proposes a standard for networking CE devices over IEEE-1394 (firewire) that would be far more simple and less expensive than an HDMI implementation.
This reminds me of the same stupid mentality used by Detroit to design cars by committee
Agreed,stupid & costly .
As far as im concerned the whole business of HDMI is nothing more than snake oil & should be given the same negative attention as exotic cable vendors instead of being praised as the latest & greatest.
My own experience recently, in the course of research into HDMI DVD players, I noticed something while looking over user reviews of products that they had purchased.
What struck me was the trend that when people complained of poor player performance, it usually had to do with picture and sound trouble, picture would stall or drop out and the like, not quality issues such as mechanical part failure or apparent build quality.
My own suspicion, supported by what I know of HDMI and all the HDCP/DRM crap built into it and also from what this article says about the poor engineering considerations of the format's performance in favor of all the content protection, is that the problems encountered are not manufacturing defects per se, but rather HDMI incompatibility issues from the lousy standard and loads of software glitches from the copy protection schemes.
Electronics manufacturers have unfortunately bought into this standard that benefits no one but the content providers. The manufacturers are eating the costs of the returned products that are mistaken for having a defect when the only defect is the poor quality of the HDMI standard and the inherent HDCP problems. Which then, of course is passed back to the consumer yet again in higher prices, not only to compensate for additional costs of warranty replacement, but also to pay HDMI Licensing, LLC to licensing their faulty standard who's only purpose is to treat every consumer as a potential criminal, guilty with no way to prove innocence.
My own experience recently, in the course of research into HDMI DVD players, I noticed something while looking over user reviews of products that they had purchased.
What struck me was the trend that when people complained of poor player performance, it usually had to do with picture and sound trouble, picture would stall or drop out and the like, not quality issues such as mechanical part failure or apparent build quality.
My own suspicion, supported by what I know of HDMI and all the HDCP/DRM crap built into it and also from what this article says about the poor engineering considerations of the format's performance in favor of all the content protection, is that the problems encountered are not manufacturing defects per se, but rather HDMI incompatibility issues from the lousy standard and loads of software glitches from the copy protection schemes.
Electronics manufacturers have unfortunately bought into this standard that benefits no one but the content providers. The manufacturers are eating the costs of the returned products that are mistaken for having a defect when the only defect is the poor quality of the HDMI standard and the inherent HDCP problems. Which then, of course is passed back to the consumer yet again in higher prices, not only to compensate for additional costs of warranty replacement, but also to pay HDMI Licensing, LLC to licensing their faulty standard who's only purpose is to treat every consumer as a potential criminal, guilty with no way to prove innocence.
Btw, the article mentions new HDMI cables coming out by BlueJeans last month or this month. Would that be the current BJC Series 2 cables mentioned on this page?
You are off by a factor of 100 in your estimate on the amount of Megapixels per second that would be run on a HDMI cable. Due to compression, you're never actually going to be getting a true 1080P picture on your home TV. Not any time soon anyway - it would take a 1.2 Terabyte Storage device to store a single 2 hour movie in true 1080P.
We can do some simple math and figure out how many Megapixels are actually being sent:
The largest HD Storage device is currently a Dual-Layered BlueRay Disc at 50 GB.
Now combining these two and canceling like terms: ( 17066 MegaPixels / BlueRay Disc ) * ( BlueRay Disc / 7200 seconds ) = 2.3 MegaPixels / second.
This means that the rough maximum of MegaPixels per second that a 50 Gig BlueRay Disc can send over HDMI is around 2.3 MegaPixels / Second - Not 150 MegaPixels / Second like the article says. And even this estimate of 2.3 MegaPixels / Second is a bit high, since it ignores the Audio track on the disc, which would take up another huge chunk of space.
Additionally, this means that the maximum data transfer / second from a BlueRay Disc will be around 7 MB / Second - or 42 Megabits / Second. Well below the 100 Megabit / Second standard for Cat-5 which you mention.
Since no where near as much Information is being transfered over HDMI as you suggest in your article, Inductance and the Twisted-Pair configuration becomes much less of an issue. Even less so than with Cat-5. I fail to see where the problem with HDMI comes from then.
TL;DR: Data Compression makes a HUGE difference on how much information is being sent on HDMI. The math in this article is for how much information would be sent over the HDMI cable on an uncompressed 1080P picture, something which is never used, and the article's result is extremely skewed because of that. You can safely ignore everything said in this article.
What's the Matter with HDMI?
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