Skip to main content

Tech Forum

About Speed HQ mode

About Speed HQ mode

by Harumi Miura - Number of replies: 3

Hello, I'm using the AE plugin to test a system that sends still images to a media server(disguise VX4+).

The resolution of the still images used is very large, but there is no problem with the server's input video.

However, SHQ is in mode 0, and perhaps because of this, symptoms of banding are observed.

When I looked it up, images with a size of 2k or more are in mode 0, and if they are smaller, they are in mode 2.

Is this understanding correct for SHQ?

It seems that the mode changes automatically, but if there is a way to fix it, please let me know.

Thank you.


In reply to Harumi Miura

Re: About Speed HQ mode

by Kane Peterson -
The difference between SpeedHQ Mode 0 and Mode 2 is the color space.

SHQ0 is 4:2:0, commonly used with resolution higher than 1080p.
SHQ2 is 4:2:2, used with resolutions of 1080p and lower.

There isn't any adjustment between these for the output of the Adobe plug-in.
In reply to Kane Peterson

Re: About Speed HQ mode

by Kane Peterson -
I did a bit of testing using the generate gradient filter in AE. In the After Effects preview window, it looks pretty smooth, but that default color processing is RGB 4:4:4 color, while the NDI output (in 1080p or 4K) does have banding. I'm pretty sure most of this is caused by the RGB to YUV conversion process.

If I adjust After Effects working color space to "Rec.709 Gamma 2.4", then the AE preview is a bit closer to the NDI output.
In reply to Kane Peterson

Re: About Speed HQ mode

by Harumi Miura -
Hello, Kane. Sorry for the late reply. Thank you for providing me with such a wealth of information. I think it would be ideal if the CG designer could send data to the server through NDI and display it on the LED, making fine adjustments during shooting smoother. It depends on the color, but there will inevitably be banding in sky blue. Even in HD size and SHQ mode 2, there was a slight banding-like effect. The working color space was originally set to None. I think I tried Rec709/Gamma 2.4, but I don't think the banding changed much. I'll check again while reviewing the color settings. I hope there could be a way to prevent banding from occurring.