yes. There are two main things to UHD Blu-ray. the codec used and then capacity of the disc. 

things like the codec  can be patched in via firmware but doing so isn't enough for sony to claim their consoles can play UHD movies. That's thanks to the capacity.

As it stands a typical BR movie can be as big as 18-35GB. That's all well and good for the two layer (50GB) discs the drives in the PS4/PS4pro has. the average UHD movie goes up to 45-80GB. so if sony patched in support for them there will be a good number of discs that won't just work (basically any disc that uses more than 2 layers). 

So this isn't something that Sony can just add in via a software update. There is also the matter of the drive speed. UHD BR require a higher nitrate than what the 6x drive in the PS4's can do. You need at least 8x..... (not too sure of this last part tho)

If it all it takes to run UHD Blu-ray is an update - then wouldn't it be true the original X1, PS4 and even the damn PS3 could run UHD Blu-ray?

Wow you sure do know a lot about this UHD blu ray business. I'm not questioning your knowledge on it.  I was just wondering if Sony would have put a cheaper option for a UHD drive and decided to patch in the availibility to work. If this isn't possible because they would have simply charged for the Pro, then I won't contest anything. My knowledge on this minimal to nothing. So don't mind me. :-p

Thats ok. 

Sony simply opted to not do it. For sony and MS, With the amount of hardware the order from OEMs the differemce between a bluray drive and a UHD drive cant possibly be more than $15. 

Sony simy gauaged how everyone has been using the existing PS4s, and probably noticed that of that 40M+ install base a significantly small number of them were actually watching Blu-ray movie discs on their consoles (yes they can tell as long as your console is connected). So they felt it was a feature that wasn't worth the extra $10-$15 in manufacturing costs. 

Something like that is more important to MS cause being that they have been losing the race on their consoles merits as a gaming console they have to come up with as many ways as possible to add value to their console and differentiate themselves from Sony. 

And there is no "cheaper" option for UHD. You either put in the hardware or not. And if they were going that route, there won't be any need to patch anything in later cause we already have a $300 console with a UHD working drive in the XB1. It was purely a design choice. 

And don't let the internet fool you. The minority on the internet is always the loudest. Ever wondered how we have suddenly heard more about UHD Blu-ray in the last 4 weeks than we have since the Blu-ray format was even created?

Well depends how they encode the video i guess if they use H265 there is no valid reason as to why a movie should be over 50gb lol. Anything larger is just being lazy at encoding.

So in theory a firmware upgrade could potentially play dual layer discs.

Unless there is some sort of mechanical restriction when reading dual layer UHD discs.

Makes sense for 3-4 layer discs for this not to work.

The PS4.... hell even the PS3 is alresdy able to play dual layer discs. The issue is the triple or quad layer discs that make up the BDXL standard. 

And HEVC encoding while better doesn't make a dramatic difference in size when ur already talking UHD video content. 

As I said before, a UHD movie on a disc (this means no funny compression stuff as u see in pirate copies of movies) can be anywhere from 35GB -80GB+. the whole point of having standards is that any and every player on the planet that says it's a UHD player will be able to play UHD movies. 

Sony can't just patch in support for HEVC codec and HDMI 2.0 video compliance and then just sit and hope that no one makes a movie that ships on a disc larger than 50GB, when in truth probably every single IHD movie will ship on a BDXL disc of some sort which means at least 75GB even if they don't use up all that capacity. 

I don't believe this rumor. It is just so far fetched.

The rumor it can play 8K movies yet to be made? Now that one has some merit.

No. HEVC roughly cuts the size in half but you have 4 times the amount of pixels. Nothing being lazy here.

Its not just a codec thing. Its an API thing.

Sony would update their API and their media app to allow it to work.

Its the same thing for HDR its the same type of data management that happens.

I have heard reports that the PS4 blu ray is capable of reading quad layered blu rays i believe this was known prior to launch even and people were wondering why Sony didn't use it for games. 

It is being lazy. This stuff does not need to be 40-80 Mbit/s bitrate but closer to 10-20 Mbit/s will do. But to get it looking as good as 40Mbit/s you need more processing to encode it which takes longer.

A quality 2hour30min video at 1080p can be compressed to 5gb or so @ 5Mbit/s in h264.   So lets times it by 4 to represent 4K that is 20GB, double it for 10Mbit/s to 40GB. Then remebr this will be encoded in HEVC which is about half so lets assume 20GB. So 20Mbit/s would be 40GB, that leaves 10GB for audio.