CQ Values backwards and wrong for VideoToolbox in v1.4.0 on Apple Silicon

[coolaj86]

Problem description:

Rather than 21 being "high quality" and 79 being "low quality", the CQ values go in the wrong direction and don't seem to follow the same scale when using VideoToolbox on Apple Silicon.

HandBrake version (e.g., 1.3.0):

v1.4.0-beta.1

Operating system and version (e.g., Ubuntu 19.10, macOS 10.15 Catalina, Windows 10 1909):

macOS Big Sur (Apple Silicon M1)

Error message text and/or screenshot:

For a 45m show the size is small and quality is horrendous at 20 (< 250mb), but 80 is HUGE (> 5gb) and crystal clear at 80.

I have no idea what a "good" setting is (the default I think was 47 or so, and it was pretty bad for both h.264 and h.265).

HandBrake Activity Log:

HandBrake.EncodeLogs.tar.gz

[galad87]

No, they are not backwards. Each encoder has got its own CQ scale and direction.
~60 could be a good starting value.

[coolaj86]

@galad87 Thanks. Are those rules documented anywhere? Perhaps some source code or SDK docs for whatever Handbrake is using under the hood?

Also, this is the tooltip that mislead me, for reference:

That shows up with both VideoToolbox encoders.

[galad87]

The tooltip is not wrong. Moving the slider to the right increase quality on both x264/x265 and videotoolbox.
There isn't any documentation. The videotoolbox headers simply say: "quality is a double going from 0 to 1". HandBrake rescales it to 0 - 100.

[drmandarin]

The HandBrake documentation does have a section on video CQ. However the article is still draft and at the moment details for encoders other than x264 are pending.

If you feel it is important for this detail to be reflected in the HB documentation then may I suggest that you raise a feature request on the HandBrake-docs repository? Of course whether it gets accepted is another matter but it might highlight a current need.