Recode UHD Bluray ?

[jd17]

I agree with excellentswordfight.

--preset slow, --no-sao and a CRF below ~20 is all you need for a transparent UHD-BD encode.

In my experience, --keyint 120 or --keyint 96 (and --min-keyint 1) are good trade-offs between seeking compatibility and bitrate savings.

[Nico8583]

Thank you both, I'll try that

[Boulder]

What about these values:

--colorprim bt2020 --transfer smpte2084 --colormatrix bt2020nc --master-display "G(13250,34500)B(7500,3000)R(34000,16000)WP(15635,16450)L(10000000,0.0050)"

Do you need to pick them from the source characteristics, i.e. are they distinct for every source?

[Asmodian]

The first bit is for anything BT.2020.

However, the --master-display command describe the primaries used, the white point, and the luminance (peek white nits and black level nits) for the mastering display. You would probably only need to change the L(1000000,0.0050) for different sources. I think most of my UHD blurays' metadata uses L(4000,0.0050) or L(1000,0.0050). The example command seems to be setting peek white of the mastering display to 10 million instead of 10 thousand? Isn't 10 thousand the max?

[FranceBB]

If he can take them from his source, it would be better, 'cause my line was just an example of common settings.

[user1085]

Originally Posted by FranceBB

If he can take them from his source, it would be better, 'cause my line was just an example of common settings.

So look for these values with Mediainfo and replace?

[FranceBB]

Yes, check media info, it should provide the original information.

[Boulder]

What if all the values are not available? For example, The Last Jedi video file has this information:

Color range                              : Limited
Color primaries                          : BT.2020
Transfer characteristics                 : PQ
Matrix coefficients                      : BT.2020 non-constant
Mastering display color primaries        : Display P3
Mastering display luminance              : min: 0.0020 cd/m2, max: 1000 cd/m2

In fact, the couple of videos I could check had only these values there.

[Asmodian]

That is all the information. You simply need to look up what "P3" means in terms of:
--master-display "G(13250,34500)B(7500,3000)R(34000,16000)WP(15635,16450)L(1000,0.0020)"
(I believe these values are for P3, with the standard D65 white point)

While the luminance values inform:
--master-display "G(13250,34500)B(7500,3000)R(34000,16000)WP(15635,16450)L(1000,0.0020)"

[user1085]

Originally Posted by Asmodian

That is all the information. You simply need to look up what "P3" means in terms of:
--master-display "G(13250,34500)B(7500,3000)R(34000,16000)WP(15635,16450)L(1000,0.0020)"
(I believe these values are for P3, with the standard D65 white point)

While the luminance values inform:
--master-display "G(13250,34500)B(7500,3000)R(34000,16000)WP(15635,16450)L(1000,0.0020)"

Similar question to poster above, what about the last two values (Maximum Content Light Level & Maximum Frame-Average Light Level). This is from Dark Knight Rises

Transfer characteristics : PQ 
Matrix coefficients : BT.2020 non-constant 
Original source medium : Blu-ray 
Mastering display color primaries : Display P3 
Mastering display luminance : min: 0.0050 cd/m2, max: 4000 cd/m2 
Maximum Content Light Level : 500 cd/m2 
Maximum Frame-Average Light Level : 200 cd/m2

[Boulder]

Thanks I think I also saw "P2" in some video but I need to make sure since I just made some quick checks.

Regarding the L value, is it OK to use the values directly or do they need to be normalized? The x265 docs say that for L(max=1000, min=0.0001) the parameter would be L(10000000,1). It probably must be calculated as per the docs: "The SEI includes X,Y display primaries for RGB channels and white point (WP) in units of 0.00002 and max,min luminance (L) values in units of 0.0001 candela per meter square" so you need to divide the L value shown by MediaInfo by 0.0001?

EDIT: also, what about the "transfer" value? It's PQ but what's the correct parameter in x265?

[Asmodian]

You are correct, I see why it looked like 10 million instead of 10 thousand. No decimal points.

Not sure about PQ, I would leave it smpte2084 for HDR but there may be situations where this is incorrect.

[tyler durdan]

Hi all

I just wanted to resurrect this.
I have a number of UHD rips that I really want to reduce the size
while keeping the video as transparent as possible.

I went through this thread and others but I seem to get lost.
The last encoding I have done was 1080p with Staxrip where I just had CRF @ 18, preset to very slow and tune to film.

That was it, where as now UHD seems alot more complicated
Can someone point me to the right GUI i should be using please and what settings

Thanks

[MeteorRain]

Tyler:

The only difference is the visual parameters as suggested above. All you need is copy-paste from #23 and change some numbers according to mediainfo results.