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techguy wrote:

I've done blind tests with UHD Blu-ray using subjects that had only experienced Blu-ray up until that point and every single person:

Sure you have.

techguy wrote:

But I don't need to justify my purchase to some random person on the internet, it's my money and I'm very satisfied with my purchases.

And yet here you are.

sophisticles wrote:

Waco wrote:

sophisticles wrote:

Sorry, but you are incorrect; with regards to quality the most important things are the camera lens, aperture settings,  camera, lens filter used, lighting, and acquisition format. These come into play long before anything you see in that video you linked to.
After that you have the debayering (if needed), grading, software filtering and mezzanine format used.
The delivery encoder and bit rate used are much less important than many would have you think; I have seen 6mb/s 1080p encoding with Apple's H264 encoder (which is generally considered one of the worst encoders out there) and the video was crisp, clear and vivid.
Youtube video is generally considered of poor quality and it has to do with the settings used not the bit rate.
I just took the previously referenced open source Meridian video and encoded it to 2160p60 (technically 59.94fps) at 25mb/s with nvenc_hevc via ffmpeg and the encode was pristine and the reason has a lot to do with the quality of the source.

Disagree.  Everything matters, and assuming a good source, the codec, settings, and bitrate matter more than almost anything else.


For fast action, there's no replacement for a good encoder and bitrate.

The encoder and settings used are nearly meaningless if your source is crap, GIGO (Garbage In, Garbage Out). With regards to bit rate, you are semi-correct, pros use segmented encoding, where they'll break up a movie into scenes and encode each scene according to the bit rate needed to eliminate artifacts, then they concatenate the resulting segments into one file.

It would help if you read my post before responding condescendingly.

A couple of really simple sanity checks:

1.

4K resolution is 4x the pixel count of 1080p
UHD has 4x the capacity of a standard BD disc or 2x the capacity of a BD-DL disc.
So, UHD either has the same bitrate per pixel or half the bitrate per pixel.

2.
Don't get too distracted by colorspace differences, WCG and whether it's 8-bpc or 10pc colour. Sure, 10-bpc encodes mean that you need a higher bitrate for the same pixel information (yet another thorn in the UHD bitrate argument) but think of it as the contrast ratio of your TV/monitor's panel:

• If the standard BD disc has pixels in frames that are low-resolution, 8-bpc, standard gamut pixels, your TV will display these 0,0,0 pixels as black as it can. Likewise, white is white and 255,255,255 will be all three colour subpixels burning as bright as they can.
• The UHD 4K disc of the same movie has pixels that are high-resolution, 10-bpc, wide-gamut. 0,0,0 is still going to be the same black as before. and white will be the same three subpixels burning as brightly as they can too. Just because the data value is now 1024,1024,1024 doesn't change the television technology at the subpixel end whatsoever.

The only thing that can have an effect on black detail is HDR, but that's not exclusive to 4K or UHD. So I haven't included it here. Arguably the HDR should be put into the master in the first place to prevent ambiguity at the consumer end - but ambiguity sells expensive new hardware and opens up a whole new segment for marketing buzzwords and jargon!

The crap about UHD playback requiring very recent PC hardware and then some, kind of reminds me about the DAT cassettes back during the early(?) to mid 90's. It didn't catch on for audio due to DRM(among other factors). Now I'm wondering how many other promising multimedia technology were killed at birth due to DRM.

Chrispy_ wrote:

So, UHD either has the same bitrate per pixel or half the bitrate per pixel.

4K Blu-ray Discs support both high dynamic range by increasing the color depth to 10-bit per color and a greater color gamut by using the Rec. 2020 color space using HEVC. The 4K-Blu-ray specification allows for three disc sizes, each with their own data rate: 50 GB with 82 Mbit/s, 66 GB with 108 Mbit/s, and 100 GB with 128 Mbit/s.

For users recording digital television programming, the recordable Blu-ray Disc standard's initial data rate of 36 Mbit/s is more than adequate to record high-definition broadcasts from any source (IPTV, cable/satellite, or terrestrial). BD Video movies have a maximum data transfer rate of 54 Mbit/s, a maximum AV bitrate of 48 Mbit/s (for both audio and video data), and a maximum video bit rate of 40 Mbit/s. This compares to HD DVD movies, which have a maximum data transfer rate of 36 Mbit/s, a maximum AV bitrate of 30.24 Mbit/s, and a maximum video bitrate of 29.4 Mbit/s.

The actual numbers.

Not a retort, not a reply, just the pedantic fairy visiting.

So I was being unfair to old-fashioned Blu-ray?

at 54Mbit/s for 1080p, a 25GB BD disc has a data rate of 26 bits per pixel per second.
at 128Mbit/s for 4K, a 100GB UHD disc has a data rate of 15.4 bits per pixel per second.

It's not even close. At best UHD is barely half the bitrate of standard Blu-Ray and standard Blu-ray's biggest problem was bitrate IMO. 

Chrispy_ wrote:

So I was being unfair to old-fashioned Blu-ray?

at 54Mbit/s for 1080p, a 25GB BD disc has a data rate of 26 bits per pixel per second.
at 128Mbit/s for 4K, a 100GB UHD disc has a data rate of 15.4 bits per pixel per second.

It's not even close. At best UHD is barely half the bitrate of standard Blu-Ray and standard Blu-ray's biggest problem was bitrate IMO. 

So upscaled 1080P should look better than a native 4K? What about the efficiency of the new codec? Wouldn't the final effective bitrate of the 4K video be ~256Mbit/s with H.265?

If you buy into the fallacy that H.265 is twice as good as H.264, sure - why not.

Seriously though, H.265 is different to H.264 and although I'm not disputing that it's better, it's not universally better and it's not two times better than H.264
Look at this graph:



What we are talking about for UHD-BD and Blu-ray comparisons is at bitrates so far off the right of the scale that they're practically going to be flat lines at that point. Yes, H.265 is twice as good as H.264 at low bitrates like 1-2Mbit/s. At 40Mbit/s the difference is just about nil because those lines flattened out and touched each other at around 16-20Mbit/s. Arguably, at very high bitrates H.265 actually smooths out noise that may be desirable (like the oft-cited examples of moving tree-leaves, diffracted light of rippling water, or distant details in a sea of similar colour). It will give a cleaner but less detailed picture that actually works against the purpose of UHD - which is to expose more of the subtle details.

In reality, I think the real issue with both H.264 and H.265 is that they could both benefit from better VBR control. Some scenes display artefacts at 1080p60 40 Mbit/s. Other scenes are less complex and would look almost perfect at 5 Mbit/s. I'd like to see more things encoded with multiple passes so that 85% of the content is encoded at under 10Mbit/s and then the savings are used to give the 10% of the movie that's most demanding an extra 400% bitrate.

To get back to the original topic: optical disc formats are becoming niche options for people who aren't willing to trust streaming video sites to have their favorite movies available. DVD has been in decline for years but clings on for inexpensive child appeasement, budget titles, and a rung of lo-fi enthusiasts willing to pay for 480p quality reproductions of shot on video kit from the '80s and '90s. If you don't believe me, check out Sub Rosa Video and the like; there's a niche that it still serves in small volume. Blu-ray is becoming a collector's medium that's good enough for most viewing environments. For most intents and purposes, the cost of a UHD player, screen or projector large enough to appreciate the visual difference, speaker and amp setup to make Dolby Atmos really sing, and a proper viewing environment aren't worth it except to a very small cutting edge. UHD will be lucky to go down in history with the kind of prestige LaserDisc enjoyed.

I say all of this as someone who owns hundreds of movies. Streaming video sites are great for viewing some things some of the time, but if I want to watch a particular movie, I don't want to hunt through the streaming video services we subscribe to in order to find it. And I don't invest in Amazon or iTunes digital video because I don't want to watch an intermittently grungy low bitrate stream because I'm using the computer across the house to download a game for later.

Chrispy_ wrote:

I'd like to see more things encoded with multiple passes so that 85% of the content is encoded at under 10Mbit/s and then the savings are used to give the 10% of the movie that's most demanding an extra 400% bitrate.

I don't know about anyone else, but that's how I do my encodings. Multiple passes with an average bitrate set at some reasonable amount, and the maximum essentially unbounded (within reason).

Still have no idea how this has devolved into another "4k is useless" thread.

Anyway, the arguments being made here against UHD Blu-ray are incomplete, and therefore incorrect.  You keep rambling on about "pixel quality" and how supposedly UHD Blu-ray has insufficient bit-rate for the "necessary" pixel quality.  In all of this, you fail to account for one simple fact: pixel density.  You don't need 4x the pixel quality for 4x the pixels because...

wait for it...

THE PIXELS ARE 4X SMALLER AT THE SAME PANEL SIZE!
Get a larger panel you say?  Sure.  I did.  My new 70" 4k HDR tv is 62% larger (by screen area) than the 55" 1080p screen it replaced.  Guess what.  That's not 4x as big, so the pixels are :gasp: SMALLER!

techguy wrote:

Still have no idea how this has devolved into another "4k is useless" thread.

Anyway, the arguments being made here against UHD Blu-ray are incomplete, and therefore incorrect.  You keep rambling on about "pixel quality" and how supposedly UHD Blu-ray has insufficient bit-rate for the "necessary" pixel quality.  In all of this, you fail to account for one simple fact: pixel density.  You don't need 4x the pixel quality for 4x the pixels because...

wait for it...

THE PIXELS ARE 4X SMALLER AT THE SAME PANEL SIZE!
Get a larger panel you say?  Sure.  I did.  My new 70" 4k HDR tv is 62% larger (by screen area) than the 55" 1080p screen it replaced.  Guess what.  That's not 4x as big, so the pixels are :gasp: SMALLER!

Adding in pixel density doesn't change the fact that, today, 4K UHD Blu-Rays have less bandwidth per pixel, and are therefore measurably worse with everything else held constant (pixel size included).

1080P on an 85" screen looks pretty ****. 4K on an 85" screen looks pretty great.

Waco wrote:

techguy wrote:

Still have no idea how this has devolved into another "4k is useless" thread.

Anyway, the arguments being made here against UHD Blu-ray are incomplete, and therefore incorrect.  You keep rambling on about "pixel quality" and how supposedly UHD Blu-ray has insufficient bit-rate for the "necessary" pixel quality.  In all of this, you fail to account for one simple fact: pixel density.  You don't need 4x the pixel quality for 4x the pixels because...

wait for it...

THE PIXELS ARE 4X SMALLER AT THE SAME PANEL SIZE!
Get a larger panel you say?  Sure.  I did.  My new 70" 4k HDR tv is 62% larger (by screen area) than the 55" 1080p screen it replaced.  Guess what.  That's not 4x as big, so the pixels are :gasp: SMALLER!

Adding in pixel density doesn't change the fact that, today, 4K UHD Blu-Rays have less bandwidth per pixel, and are therefore measurably worse with everything else held constant (pixel size included).

1080P on an 85" screen looks pretty ****.  4K on an 85" screen looks pretty great.

You're arguing that reality does not matter.  If we want to have this discussion in 10 years when everyone is on 180" projector screens then I'd be happy to have it.  

There are 2 primary methods of increasing visual quality, short of inventing new display tech.

1) increase pixel quality
2) decrease pixel size

They're interchangeable.  

techguy wrote:

Still have no idea how this has devolved into another "4k is useless" thread.

...wait for it...

techguy wrote:

THE PIXELS ARE 4X SMALLER AT THE SAME PANEL SIZE!

Yes. I have no idea how that happened.

/s

Glorious wrote:

techguy wrote:

Still have no idea how this has devolved into another "4k is useless" thread.

...wait for it...

techguy wrote:

THE PIXELS ARE 4X SMALLER AT THE SAME PANEL SIZE!

Yes. I have no idea how that happened.

/s

So my most recent reply to the thread is the reason why something which had already occurred, had in fact occurred?  Wow, didn't know I could time travel and cause a thing to happen in the past by taking action in the future!

techguy wrote:

So my most recent reply to the thread is the reason why something which had already occurred, had in fact occurred? Wow, didn't know I could time travel and cause a thing to happen in the past by taking action in the future!

You're arguing that bitrate doesn't matter because you can't see these pixels anyway...

...right after you stated you had "no idea how this has devolved into another "4k is useless" thread." followed by "anyway,"

The irony, like so much else, is only lost on you, my friend.

techguy wrote:

There are 2 primary methods of increasing visual quality, short of inventing new display tech.

1) increase pixel quality
2) decrease pixel size

They're interchangeable.  

No, they're not.

Unless the information content being conveyed in the encoded video stream scales with the increased pixel density, pixel quality goes down, partially (or in extreme cases, completely) obliterating any gains from the smaller/denser pixels.

JBI wrote:

Unless the information content being conveyed in the encoded video stream scales with the increased pixel density, pixel quality goes down, partially (or in extreme cases, completely) obliterating any gains from the smaller/denser pixels.

No, no, no! My 2x2 bitmap of alternating white/black blocks looks great on this 1000ppi display of well-formed pixels.

How could you ever make it look any better, short of new display tech?

Glorious wrote:

JBI wrote:

Unless the information content being conveyed in the encoded video stream scales with the increased pixel density, pixel quality goes down, partially (or in extreme cases, completely) obliterating any gains from the smaller/denser pixels.

No, no, no! My 2x2 bitmap of alternating white/black blocks looks great on this 1000ppi display of well-formed pixels.

How could you ever make it look any better, short of new display tech?

Sigh. You just greyed-out the thread.

just brew it! wrote:

techguy wrote:

There are 2 primary methods of increasing visual quality, short of inventing new display tech.

1) increase pixel quality
2) decrease pixel size

They're interchangeable.  

No, they're not.

Unless the information content being conveyed in the encoded video stream scales with the increased pixel density, pixel quality goes down, partially (or in extreme cases, completely) obliterating any gains from the smaller/denser pixels.

Sure. But the point still stands that the bitrate doesn't need to necessarily scale proportionally to increase in resolution to achieve appreciable perceived gains in video quality with a vast majority of content, playback equipment, observers, etc.

At the end of the day a 100 mb/s stream has the capacity to hold more information than a 50 mb/s stream. It just doesn't have 4x the informational density as the 4k/UHD moniker suggests. But then it may not have to to translate into appreciably perceptible benefit in many situations due to complexity of content (i.e., frame transitions), increase in encoder efficiency, and yes, the actual distribution of panel size and viewing distance among the actual viewing population. Obviously when talking about final perception,we are getting into highly subjective territory.

cynan wrote:

just brew it! wrote:

techguy wrote:

There are 2 primary methods of increasing visual quality, short of inventing new display tech.

1) increase pixel quality
2) decrease pixel size

They're interchangeable.  

No, they're not.

Unless the information content being conveyed in the encoded video stream scales with the increased pixel density, pixel quality goes down, partially (or in extreme cases, completely) obliterating any gains from the smaller/denser pixels.

Sure. But the point still stands that the bitrate doesn't need to necessarily scale proportionally to increase in resolution to achieve appreciable perceived gains in video quality with a vast majority of content, playback equipment, observers, etc.

At the end of the day a 100 mb/s stream has the capacity to hold more information than a 50 mb/s stream. It just doesn't have 4x the informational density as the 4k/UHD moniker suggests. But then it may not have to to translate into appreciably perceptible benefit in many situations due to complexity of content (i.e., frame transitions), increase in encoder efficiency, and yes, the actual distribution of panel size and viewing distance among the actual viewing population. Obviously when talking about final perception,we are getting into highly subjective territory.

Lower bitrate per pixel can add up to FAR more noticeable compression artifacts that would not have shown up at all given a linear scaling in bitrate. The added detail in a 4K source encoding actually pushes the demands higher at a given bitrate from what I can see.

techguy wrote:

Waco wrote:

Adding in pixel density doesn't change the fact that, today, 4K UHD Blu-Rays have less bandwidth per pixel, and are therefore measurably worse with everything else held constant (pixel size included).

1080P on an 85" screen looks pretty ****.  4K on an 85" screen looks pretty great.

You're arguing that reality does not matter.  If we want to have this discussion in 10 years when everyone is on 180" projector screens then I'd be happy to have it.   

Funny, I went from a 70" 1080p to a 70" 4K. I guess that's 10 years out?