Wednesday, November 18, 2015

Connectivity in a Digital World



One of the most interesting seminars was called "The evolution of AV Connectivity: Past, Present & Future".  Joe Cornwall from Legrand gave it, and he really did a great job in explaining what was, what is, and what will be.  With the talk being all about 4K, UHD, and even 8K coming to a screen near you it was interesting how he dug through the technical to explain how and why some things have to happen first before the technology comes, but I am told with certainty that this future is coming.

Since the advent of TV, engineers have always sought better resolution of images we are producing.  Now with the advent of 4K our image is more detailed then ever, and of course with the talk of 4K there is 8K.  But a lot is hype because in order to get there there has to be certain changes in our connectivity.

DVI (digital visual interface) died in 2015.  It is no longer manufactured.  HDMI ports have become the norm now.  I remember DVI ports in my old non-linear editing devices and desktop computers way back when.

DVI was one of the most common digital video cables you would see on desktops, and LCD monitors not too long ago.  It was the most similar to VGA connectors, with up to 24 pins and supported analog as well as digital video.  DVI can stream up to 1920 x 1200 HD video, or with a dual-link DVI connectors you can support up to 2560 x 1600 pixels.  The biggest problem with DVI is that it doesn't support HDCP encryption by default, so if your hardware only includes DVI ports, you may not be able to playback full HD Blue-rays and other HD content.

HDMI is the default cable on newer HDTV's, Blue-ray players, Apple TV, and many new computers video cards, and a multitude of other video devices.  HDNI cables and ports are very easy to use, and are almost as easy to connect as USB devices.  No more bent pins; just push and play.  HDMI cables can stream digital video and audio simultaneously over the same cable.  HDMI supports up to 1920 x 1200 video and  8channel audio.  They also support HDCP encryption for the newest HD content.

With UHD we'll need 10 bit color, and both HDMI 1.4 and HDMI 2.0 are not fast enough.  HDMI 2.0 maximum data rate is 18 Gb/s, which I'm told is barely fast enough.  It clearly can't support 10-bit color.

Display Port 1.2 and 1.3 are better, with 1.3 being the best, but what I heard a lot about is Super MHL which seems to be the best.   MHL stands for Mobil High definition link.

To explain this I went to Wikipedia for the definition of these ports:

DisplayPort version 1.2 was approved on December 22, 2009.  The most significant improvement of the new version is the doubling of the effective bandwidth to 17.28 Gbit/s in high bit rate 2 (HBR2) mode, which allows increased resolutions, higher refresh rates, and greater color depth.  Other improvements include multiple independent streams (daisy-chain connection with multiple monitors) called Multi-stream transport, facilities for stereoscopic 3D, increased AUX channel bandwidth (from 1Mbit/s to 720 Mbit/s), more color spaces including xvYCC, scRGB and Adobe RGB 1998, and global time code (GTC) for sub 1 us audio/video synchronisation,  Also Apple's Inc.'s Mini display port connector, which is much smaller and designed for laptop computers and other small devices, is compatible with the new standard*

DisplayPort version 1.3 was approved on September 15, 2014.  This standard increases overall transmission bandwidth to 32.4 Gbit/s with the new HBR3 mode featuring 8.1 Gbit/s per lane (up from 5.4 Gbit/s with HBR3 in version 1.2), totalling 25.92 Gbit/s with overhead removed.  This bandwidth allows 5K displays (5120 x 2880 px) in RGB mode, and 8 K UHDTV at 7680 x 4320 ( 16:9, 33.18 megapixels) using 4:2:0 sub-sampling at 60 Hz.  The bandwidth also allows for two UHD (3840 x 2160 px)computer monitors at 60 Hz in 24-bit RGB node using coordinated video timing, a 4 K stereo 3D display, or a combination of 4K display and USB 3.0 as allowed at DockPort.  The new satndard features HDMI 2.0 compatibility mode with 2.2 content protection.  It also supports VESA display stream compression, which uses a visually lossless low-latency algorithm based on predictive DPCM and YCoCg-R*

Super MHL has a max data rate of 36 Gb/s, and is compatible with USB Type-C.  So in order to get 4K and even 8K this all must happen, and I'm told that it will happen, and that this is coming sooner then later.

Mobil High-Definition Link (MHL) is an industry standard for a mobile audio/video interface that allows consumers to connect mobil phones, tablets, and other portable consumer electronics (CE) devices to high-definition televisions (HDTV's) and audio receivers.  MHL-enabled products include adapters, automotive accessories, AV receivers, Blue-ray Disc players, cables, DTVs, media sticks, monitors, projectors, smart phones, tablets, TV accessories, and more.  MHL is a consortium made up of leading companies in the mobile and CE industries, including Nokia, Samsung, SIlicon Image, Sony, and Toshiba.*

In the meantime producers, and content providers produce at the highest resolution that their budgets can accommodate for.  Drilling down this far into 4K or 8K can be a bit mind numbing, but the seminars kind of brought a clarity to the technology.  The big thing now is being 4K compliant.  The consumer market seems to be driving this with the advent of home theaters, yet when it comes to the commercial market companies need to iron out problems that exist such as speed, security, and connectivity throughout it's IT and A/V infrastructure.  It is only a matter of time that this will happen, and that the future is right around the corner.

Digital technology improves at a much faster rate then analog, and because of this you can't take advantage of the improvements in digital without creating a whole new standard and by doing so back wards compatibility goes out the window.  But isn't that how it always is, and was.  Anyone remember 8-track?  Anybody?


* taken from Wikipedia



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