H265 conversion quality in handbrake?

[ihandbrake]

Hye,

this is kinda follow-up to my previous post.
I'm using handbrake Version 0.10.3 x86_64 (2016012200) on Mac os X El Capitan 10.11.3 (15D21) in order to convert .mov files recorded on my iPod touch 6th generation running iOS 9.2 to H.265 file format, which can now be played without problem by the VLC app on the iPod touch.

Now, whereas the compression rate is impressive (4,5 Go => 150 Mb), quality obviously suffers.
I'd like to know whether there's any settings in handbrake allowing me to retain better image quality on H265 format, even if the file is less compressed.

Thanks.

These are my logs :

http://pastebin.com/fsMA3PxT

[rollin_eng]

The quality slider on the video tab can be used to adjust quality.

[ihandbrake]

ok, thanks, never thought of that...
Silly question : in order to augment the quality, do I have to move the cursor to the left or to the right?

[rollin_eng]

Lower number = better quality

[ihandbrake]

well, ahem, i tried to toggle the RF value both to the extreme right (value "0") and the extreme left (value "51") and both option yield like 50 Mb like files that are utterly low quality and unwatchable... Obviously this isn't the right parameter...

[rollin_eng]

Can you post your logs?

[mduell]

well, ahem, i tried to toggle the RF value both to the extreme right (value "0") and the extreme left (value "51") and both option yield like 50 Mb like files that are utterly low quality and unwatchable... Obviously this isn't the right parameter...

You don't want either of those extremes. Try something reasonable, like moving in increments of 3 or 5 from your starting point.

[s55]

x265 doesn't support lossless yet so I think 51 and 0 are actually the same at the moment.

However all the intermediate values work as expected. Remember it's a logarithmic scale so small changes = big difference.

[ihandbrake]

@ s55,

well, according to
http://x265.readthedocs.org/en/default/lossless.html
H265 does support lossless encoding. But this is the command-line instructions only.
Why isn't there a simple check button for lossless encoding in handbrake?

[s55]

Let me be more clear, The x265 encoder in HandBrake is not lossless ready yet. We either need to tweak our library calls or update the x265 library again. Either way, it doesn't work at the moment.

We also don't use x265 CLI ergo, no "simple check button for lossless"

[mduell]

Why isn't there a simple check button for lossless encoding in handbrake?

Almost no one actually wants, or understands, what lossless means.

[Woodstock]

You mean, just because they are trying to compress something that has already been passed through a lossy compression scheme before they ripped it?

[arcuser]

Looking at your source size (4.5gb) - was this a DVD or some kind of HD source?

In x265 what is a good RF setting to try and keep the a watchable quality of this source but still with some compression?

[mduell]

The default.

[ihandbrake]

@arcuser

it was a 40 min. long academic lecture recorded with my 6th gen iPod touch.
I'll try to play with the RF settings to see whether it helps.

I tried to play with the encoder options : choosing "placebo" instead of default medium, but that doesn't yield a much improved quality, although it did take 24h to get the job done !!

[mduell]

I tried to play with the encoder options : choosing "placebo" instead of default medium, but that doesn't yield a much improved quality, although it did take 24h to get the job done !!

That's why it's called placebo...

[ihandbrake]

@mduell,



so, what is it good for?
Isn't a slower encoding speed supposed to yield better results?

[rollin_eng]

@mduell,



so, what is it good for?
Isn't a slower encoding speed supposed to yield better results?

Absolutely nothing, just say it again.

The definition of placebo is:

A measure designed merely to humour or placate someone.

Basically it is there so people who use it can say they did.

[nhyone]

ihandbrake, from your log, the original video bitrate is 14,939 kbps, and is encoded to a mere 296.02 kbps with CRF 20. This is pretty impressive. So, what's wrong with it?

[ihandbrake]

@nhyone

well, basically, what bothers me, is the loss of detail in the facial features of the lecturer.
It's quite less sharp than the original.
There isn't a lot of movement or flashy action sections, obviously, but if there's a way to retain the quality of the lecturer's face, that would be welcome !
It might be due to the impossibility in handbrake to encode losslessly in H265, which is quite a pity !