Question about the H.265 encoder

[Spawn]

Hello,
I have a question of understanding:
If I select H.265 10-bit (x265) under Video Encoder in Handbrake 1.7.2, my computer processes a source file with 16 frames per second.
If I select H.265 (x265), the computer processes the same file at only 5 frames per second.
All other settings in my preferences remain unchanged.
Actually, I would have expected the processing to be slower with the H.265 - 10 bit version, as I understand that a larger colour space is displayed here than with the pure H.265 version.
The H.265 10-bit file is also slightly larger than the H.265, which I would attribute to the additional information stored in the file.

Where is my error in thinking, or what is the reason that the H.265 10-bit version is processed faster?

Thanks and best regards
Matthias

[rollin_eng]

Could you please post your HB logs, instructions can be found here:

https://handbrake.fr/docs/en/latest/hel ... y-log.html

[Spawn]

Hi,
hope, this works:
Log for the H.265: https://pastebin.com/vkXd2kz5
Log for the H-265-10: https://pastebin.com/qg60xs3S

regards
Matthias

[mduell]

You've specified additional options on your 10-bit encode that improve the speed of the encode at the cost of compression:

Code: Select all

[18:32:52]    + encoder: H.265 (libx265)
[18:32:52]      + preset:  veryslow
[18:32:52]      + profile: auto
[18:32:52]      + level:   auto
[18:32:52]      + quality: 18.00 (RF)

Code: Select all

[18:30:32]    + encoder: H.265 10-bit (libx265)
[18:30:32]      + preset:  veryslow
[18:30:32]      + options: strong-intra-smoothing=0:rect=0:aq-mode=1:rd=4:psy-rd=0.75:psy-rdoq=4.0:rdoq-level=1:rskip=2
[18:30:32]      + profile: auto
[18:30:32]      + level:   auto
[18:30:32]      + quality: 18.00 (RF)

[Spawn]

Hi,
Thanks for the info.
I hadn't set these additional options by myself, Handbrake sets these additional options automatically when you change the Video Encoder selection.
My goal was / is about getting the best possible image.
Now I'm not that deep into the subject, but what would happen if I removed these additional options?
Does this selection make sense? So, does the 10 bit version produce a better image? Should I remove the additional options?
The speed doesn't really matter. The difference in size is not too big, so it also doesn't really matter.
The most important point for me is the best possible picture.

regards
Matthias

[mduell]

Eh, I'd keep at least rect=0; rect=1 (the default) is excessively slow for what it gains.

[Spawn]

Many thanks for the information.
rect=1 (the default) is used when the options are empty, do I understand this correctly?
I am an absolute beginner with the options.
Is there a good overview or guide?

[Spawn]

I did a test run with H.265 10-bit and removed all options.

+ encoder: H.265 10-bit (libx265)
+ preset: veryslow
+ profile: auto
+ level: auto
+ quality: 18.00 (RF)

The speed was of course lower than with H.265.
What surprised me here was the fact that the file was also smaller than with H.265.

My conclusion is that H.265 10-bit, without options, takes about twice as much time as H.265, but the output file is smaller, even though the 10-bit version contains more information.

...or am I wrong here?

[mduell]

rect=1 (the default) is used when the options are empty, do I understand this correctly?

Yes.

Is there a good overview or guide?

https://x265.readthedocs.io/en/stable/cli.html

My conclusion is that H.265 10-bit, without options, takes about twice as much time as H.265, but the output file is smaller, even though the 10-bit version contains more information.

The quality scale isn't the same across different settings, including bit depth.

[Spawn]

Thank you very much for your support, it really helped me.

cu
Matthias