I had lunch today with one of my colleagues that has done standards work for video and audio since the DVD-Forum started back in the 90's.
There were a couple of interesting tidbits that I thought folks here would be interested in:
The BDA does have a 4K committee and has and still is working on getting BD to support 4K. Some of the challenges are with MPEG and SMPTE in regards to defining what minimum requirements there needs to be for BD 4K discs and for UHDTV's to support.
One of those things is SMPTE's REC2020, the new, expanded color gamut that would supersede REC709 (used for HD content today). Along with that is the desire to increase bit depth of 8-bits per color to 12-bits per color and YCbCr with 4:2:0 chroma subsampling to 4:4:4. Why is that REALLY important? REC2020 (which I asked if it meant that I have perfect vision) would introduce a much larger color space that would be closer to what we see for colors today. The increase to 12-bits per color and 4:4:4 subsampling would essentially remove all banding that you see even with HD content today. A great example of this is underwater photography where the video is looking up to the sun. The gradations of blue have bands in it. This isn't solved with a higher bit rate.
It's a given that the support for BD 4K would require a new player, just like 3D blu-ray did, but it would be backwards compatible. It is rumored that the new 4K BD players would have a HDD in them to allow for streaming downloads (aka Ultraviolet) that would allow the user to not purchase the optical disc. This would allow a user to have N movies on the HDD and just delete the ones that are not of utmost importance, similar to what you do with a DVR today. Of course, if you wanted the movie to watch again, you could just download it from your digital locker. I look at it as an insurance policy that BD player manufacturers can keep a market if people stop using optical disc and move to digital downloads. Kind of like those players back in the day that had both VHS and DVD...
The other question is how do you fit all of this on a BD disc? Won't it require a new disc? Well, if it did, then it wouldn't be backward compatible with existing BD players, something the BDA has to do, or there won't be a market to move forward with. This pretty much means that BD discs would have to stay at two layers and have the max capacity at 50GB.
There are a couple ways that all of this can come together. First, H.265, officially known as HEVC (High Efficiency Video Codec) which replaces H.264 officially known as AVC (Advanced Video Code). Geez, who on earth came up with those names?! According to my source, HEVC can do 4K at 20 Mbit/s without any problems.
OK, so you can supposedly fit a 4K title on a BD50 disc. If it is being encoded in HEVC, how on earth does that disc work in existing BD players? It turns out that Dolby, yes the one that does audio, has a video technology that allows for encoding 1080P content to work in existing BD players and then a carrier track that is in HEVC that would be used in the new 4K BD players that would allow for 4K playback.
Wow, this is sounding promising. When can I get my hands on it! Well, even if the BDA could get all of those starts to line up, there is the problem with UHD TV manufacturers.
Turns out that UHD TV's today can only display REC709 and don't necessarily support 4:4:4.... I asked my friend about the Sony UHD TV that we showed from CEDIA and the media player with Sony 4K content on it. Turns out that Sony is encoding those 4K titles with AVC, 8-bits per color and 4:2:0 chroma upsampling and that the display doesn't support the REC2020 color gamut even if the titles were encoded differently.
Sigh... Basically there still needs to be a lot of consensus between a bunch of different players to make this happen to the point that there would be something besides 4K content to really make the format something people could see.
Notice I said could see. Turns out the BDA 4K committee is also looking at advanced audio technology to pull off things that would be more akin to Dolby's Atmos technology. So, in addition to seeing, people could hear some differences (if they spend the money for more speakers and amps).
I walked into lunch thinking that I would become even less excited about UHD. Now I am quite excited IF everyone can agree to standards that actually make a difference.
What are your thoughts? More interested or are plenty happy with HD content?