Quicksync Advanced Options (Missing/Updates/Issues)

[mikk9]

Description of the feature or enhancement you'd like to see in HandBrake

Correct me if I'm wrong, Handbrake uses a strict gop (Intel default). If it's a strict gop the quality is actually surprisingly good.

Of course fps x 5 is recommended instead of fps x 1, but this is something I can change with gop-pic-size myself.

I would like to see support of open gop because it improves the bitrate efficiency quite a bit in some videos. In QSVEnc the videos are a few percent smaller at the same quality versus strict gop. Tested on an i7-1165G7 and confirmed with VQMT.

What Operating System are you running?

Windows 10 x64

What version of HandBrake are you running?

1.5.1

Where did you download HandBrake from?

No response

Activity Log, Crash Log or any other details

No response

[mikk9]

After more testing......Bframes 9-15 is not supported by the gop-ref-dist command which is unfortunate. 14 bframes is the optimum setting in CQP bitrate mode (highest bitrate efficiency). No matter if I set it to 9 or 15 it always jumps straight to 16. Only bigger steps seems supported like 4/8/16.

Similar with the the gop size as well. If I set it to exactly 120 (24fps x 5) Handbrake uses 128 according to the log.

[Mister-XY]

look at here
#3949

[mikk9]

Thanks for the link. I think it's a Handbrake limitation/issue rather than a Quicksync limitation because with QSVEnc I can use whatever gop and bframes I want. Reference frames doesn't make sense either as you said. I set 5 or 6 and Handbrake uses 8. With 16 bframes+bpyramid 6 reference frames are enough, this is what Intels implementation uses when I set it to 0 (set at runtime by the implementation) and same in QSVEnc. Therefore it's a Handbrake issue and I set it to 0.

But I think the bigger addition would be the support of open gop. Apart from that Handbrake looks fine from what I can see after 5 hours of testing.

There are some other things like mbbrc, extbrc, adaptive LTR are not supported in HEVC CBR/VBR which is supported in QSVEnc, although seems like the quality looks about right.

[sr55]

The option for open-gop is on the "todo" list. Not sure why it wasn't added in the first place but there is a "todo" in our code base for it.

[sr55]

Note to self, look into why la-depth option isn't working.

[sr55]

Notes:

• Investigate new "Tune" Option per [REQ] Intel QuickSync's --tune and other (new) advanced features #5119 . May not be of much use at the moment but leaving a note here regardless. Maybe we add it for consistency as a tune set per the other encoders.

The following options don't appear to be supported in qsv_common.c hb_qsv_param_parse(...)

• Fade Detect
• weightb
• weightp
• adapt-ref,
• adapt-ltr
• adapt-cqm
• bframes

[mikk9]

bframes and gop-ref-dist are basically the same. bframes+1= gop-ref-dist. bframes 7 and gop-ref-dist 8 is the same. You would want to add Lookahead for AV1, this is working for ffmpeg or QSVEnc. scenario-info could be interesting as well.

Tune options requires API 2.9 which I hope we get with the next driver update. It could be interesting if one of the tune options is better for the subjective quality.