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HDMI and What it Will Do for You
CrzyP writes "AnandTech has whipped up a short but informative article on the new HDMI digital audio/video connection standard that is said to be the successor of DVI. Take a look at what this new standard is all about and what we can expect from it in the future!"
From the article:
The first question that should pop into your head right now is why we would need HDMI on the PC when it physically does the job of DVI particularly considering how few people actually use DVI instead of analog connections! The answer is, again, copy protection.
Four years ago Cox wrote something in LKML that has stuck in my head since:
So you cant tap the data anywhere.
Think
encrypted music fed to an encrypted audio controller to speakers which
decrypt and add watermarks
encrypted video decrypted and macrovision + watermarked only in buffers
the CPU cant access
audio input that has legally mandated watermark checks and wont record
watermarked data.
That is the dream these people have. They'd also like the OS to scan for
"illicit" material and phone the law if you do, and to have a mandatory
remote shutdown of your box
(and if you read the MS media player license anyone who agrees to it signed
up to that)
Alan
Lurking at the bottom of the gravity well, getting old
HDMI enforces that only trusted (by RIAA) devices allowed to communicate - so no way perfect digital copies.
Morons.
You forgot one little detail:
"The first question that should pop into your head right now is why we would need HDMI on the PC when it physically does the job of DVI - particularly considering how few people actually use DVI instead of analog connections! The answer is, again, copy protection."
And even with a HDMI cable I don't see any improvement over DVI even though my dvd player is upsampling to 1080i. Also having sound over it is pretty useless in a home theater enviroment, I still have to run a tosh cable from my dvd player into my reciever. I guess it could be useful if the AV reciever had HDMI inputs, but that would still require 2 cables.
Have you ever been to a turkish prison?
HDMI cables run for a much longer distance than DVI. DVI cables longer than 6 meters are REALLY expensive.
HDMI does a few things right. Adding audio is very useful for a lot of people (one cable is always easier than than 2 or 3). They also tweaked the signaling to run longer ranges, and added support for YUV (if you thing YUV support is not a big deal then do searches for the whole PC RGB/Studio RGB crush and push issues people have with DVI DVD players).
There are tradeoffs of course. In order to reduce the connector size they eliminated the analog link and the second digital link. I think the improved signaling allows them to run their digital interface a little faster than DVI, so the second link may not be a huge issue. The lack of an analog link means that you cannot make a cheap cable only VGA adapter like you can for DVI-I, which seems like a pretty big issue if somebody were actually going to try to push computer adoption of this, especially for laptops.
If it wasn't for HDCP it would be a pretty nice improvement over DVI for many users.
Louis
While the HDMI interface has the bandwidth to carry 1080P signals (1080P is considered the best HD video standard), the chipsets used in TVs nowadays are not capable of handling the bitrate 1080P would use. This has been discussed on the AVS Forum, in one thread in particular, in the context of the new 1080P Samsung TVs unveiled at CES 2005.
The Doormat
If you're not outraged, then you're not paying attention.
that it is based on DVI.
DVI is limited to 60 frames per second, which means you get your butt handed to you on a plate by most online PC gamers using older analog monitors.
I can't believe the inventors of DVI were so short-sighted to believe 60fps max was acceptable for all uses. Whats worse is that the 'new' HDMI interface has the same problem.
So on the output of this chip there is a normal RGB (plus sync) signal. This is fed to the switching matrix (where it is combined with all other inputs the TV supports) and then this analog RGB signal is again digitized and fed to the scaler that scales it up or down to drive the LCD panel.
HDCP is designed to protect the digital stream, not the analog signal. If the chip decrypted the digital stream and fed it to the scaler, it would be vulnerable. It looks like that by converting it to analog in the same chip, they're preventing the decrypted digital signal from being copied. Sure you can re-encode it, but you can do that with an analog output just as well.
*Almost* off-topic - but not quite.
It usually depends on the brand name and store. I used to work for Best Buy and we got everything 10% above store cost. Cabling and Car Audio were the two most marked-up products. Car speakers and decks were commonly marked up over 600%. I've seen cabling marked up as high as 2000% (yeah - three zeros)! Watch batteries that sell for $3.97 cost me around $0.26. I bought $1600 worth of car audio equipment (deck, four new speakers, all new cabling, amp, sub, box, etc.) for less than $400 - installed.
In other words...
Retail will rip you off! Retailers often make more money off of the USB cable you have to buy (because it's not included with your printer) than they make on the whole ocmputer/monitor/printer combo.
Never buy high-end A/V or computer cables retail. If you see a $100 DVI cable at Best Buy or Circuit City, you should be able to find it online for less than $40. It's still a rip-off, but it doesn't hurt to walk or sit down afterwards.
"The object of war is not to die for your country, but to make the other bastard die for his." - Patton
Do you think that "digital" signal is somehow magically different from an analog signal and is totally immune to all analog phenomena? Why don't you try passing 100MBps from my phone lines, then?
I'd never advise anyone to buy $200 cables (even if this might seem a small part of a $10000 setup). But be reasonable! A nice $30-50 cable is not a bad choice. As a matter of fact, quality of construction becomes increasingly important for digital circuits because the tolerance for analog noise/errors is getting smaller. I wouldn't be surprised if USB3 of firewire1600 had some rather special requirements. And your memory,CPU and motherboard has gold contacts, I suppose? (why?)
P.
DVI already has DRM in most TV's. It's called HDCP, and almost all HDTV STBs and TVs support it.
That's the same thing done in HDMI.
I don't think that the loss over that short of an analog link would be something to care about.
It's not cable loss, it's the D/A and A/D converters themselves that are less than perfect, and thus introduce noise.
Ooh, a sarcasm detector. Oh, that's a real useful invention.
It's not only possible, it's easy, using off-the-shelf components.
First, convert the DVI signal to HD-SDI, which is the standard that all the professional HDTV editing gear uses.
Miranda DVI-Ramp
Next, capture the HD-SDI signal to your hard drive.
Blackmagic DeckLink HD
You will need a serious disk array to handle the bandwidth, but you will end up with a digital copy of the signal put out over DVI. That Miranda box does sub-sample the RGB (4:4:4) signal to YCbCr (4:2:2), but it is only a matter of time before someone makes a box that keeps it at 4:4:4.
Certainly not with SCSI but maybe with SATA+PCIe?
..wait, someone's at the door
Let's do some calculations!
The raw data rate is 4Gbps/8=500MB/s.
A single PCIe channel is 250MB/s so we need at least two, not counting any overhead.
Very, very few and expensive cards support more than 4 HDDs/card so it's cheaper to get three cards.
Fastest hard drives can barely sustain 50MB/s writes (remember to check the rate for the entire platter, not just the fastest part!) so we need at least 10 HDDs, not counting any overhead.
A 10x73GB SCSI array could hold only 24,3 minutes of programs, maybe a single episode with the commercials cut off in real-time?
A 10x500GB SATA array could hold 2 hours and 46 minutes of data, enough for most movies.
There is absolutely no redundancy so pray every night that no single drive fails or your movie is gone.
Would you buy three PCIe RAID controllers and ten 500GB drives, a new PSU & server case just to record A SINGLE MOVIE?
As for sharing with your friends it's just ~10TB/movie..
The only solution is to use realtime MPEG2/4 compressor, there ARE some (very impressive looking, I might add!) HDTV rips floating around, for instance Terminator 3 is about 8300MB compressed as MPEG2 in 1280x720.
But what happens when your capture card refuses to save the data due to flags/watermarks/the evil bit? Clearly just saving the raw stream is not feasible so better get that capture card now at least if you live in the US. Thank goddess we don't have a Federal Censorship Committee (yet).
I'm sorry for ranting a bit, the very idea that my own hardware doesn't follow my simple orders like "record" but obeys someone elses wishes is downright disgusting. Well, at least I can modify the hardware I bought so they don't obey the overlord's...
Capitalization is the difference between "Helping your uncle jack off a horse" and "Helping your uncle Jack off a horse"