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Hi there, starting a new project and want to try using Hybrid due to its wide selection of encoders. However, I don't seem to be able to manually edit the arguments at the bottom of the window. Is it not possible, or am I missing something?

E.G. I wish to force 2-pass mode on constant quantizer, which (according to documentation and attestation) is available for some encoders, but not available in Hybrid's options. But just in general (testing experimental settings/flags, etc), I'd like to have full access to the arguments if possible.
Last I checked 2pass crf was abandoned (Hybrid did support it while the x264 devs did too) and 2pass cq doesn't make any sense, since cq always uses a constant quantizer.
You can add command line additions under 'x264->Misc->Imports/Additions->Command line->Addition', in x264 the last mention of an option overwrite existing ones.

Quote:which (according to documentation and attestation)
I would like some reference to any documentation regarding this from the x264 team, since like I wrote before 2pass cq doesn't make sense and 2pass crf was abandoned.

Cu Selur
Sorry, I wasn't clear -- I'm using VP9 and AV1, specifically.

Example of VP9 (using vpxenc, as I believe Hybrid does) and CQ 2-pass: https://www.webmproject.org/docs/encoder-parameters/

relevant section: 
Code:
CQ mode is available for one-pass encodes, but is generally intended for two-pass. For one-pass, CQ applies the user cq-value, but can't adapt to a higher value if the clip is difficult.

In the two-pass variant of CQ mode there is a further refinement. If the first pass analysis suggests that a clip is too difficult to be encoded at the user-selected --cq-level, then rather than code part of the clip at this level and the rest at a much lower quality, it tries to pick a sustainable "auto-cq" level. Under no circumstances will this "auto-cq" value drop below the user-selected value.

likewise, for VP1 (libaom): https://www.reddit.com/r/AV1/comments/k7...9_be_more/ 
Code:
--passes=2
– The interesting thing about libvpx-vp9 and libaom-av1 is that 2-pass mode is actually quite fast, unlike 2-pass x264 and x265. It also enables a bunch of nice options for higher quality so use it! Only use 1-pass mode if you need to stream in real time.


That being said, I do see the option to add commandline arguments for x265/x265, but the misc tabs for VP9/AV1 don't seem to have it.
VP8/VP9/av1 don't have a custom additions option since nobody ever asked for it. Smile

Sadly I couldn't find any documentation of the developers about it whether aomenc supports this.
If you have the time you could test whether aomenc does support this.

Sadly the google team takes ages to:
a. care about bug reports (regarding vp8/vp9/av1) (after waiting for one bug report for 2years to get a reply, I gave up reporting problems to them)
b. update or provide any accurate documentation.

-> I can look into implementing 'constrained quality (2pass)'- and 'custom addition'-support over the weekend (probably on Sunday).

Cu Selur
That'd be wonderful.

If you want, you can just do the custom arguments capability, and I can report back to you what I can get to work on each encoder that isn't currently listed in the GUI.

I'm in a encode-once, hundreds of people use it multiple times per day use case, and I have a water-cooled and overclocked threadripper, so I don't mind brute forcing every option I can find reference to and seeing what sticks and what doesn't.
Assuming you are on Windows, I created a dev version which has custom addition support for VPX and aomenc and send you a link via pm. Not sure how the vpx&aomenc command line parsers work and whether they allow to overwrite options when the option is set multiple time in a command line (like x264 and x265 do).

Cu Selur
Wrote a dev version which supports 'constrained quality (2pass)', will send you a link one I packaged and uploaded the version via pm (in ~15min).

Cu Selur