[libcamera-devel] [PATCH v5 0/9] qcam: viewfinder_gl: add RAW8, RAW10P and RAW12P formats

[Laurent Pinchart]

Hi Andrey,

Very nice patch series, thank you !

On Tue, Jun 22, 2021 at 04:46:43PM +0300, Andrey Konovalov wrote:
> This patchset adds support for both 10-bit, and 12-bit raw Bayer packed
> and 8-bit raw Bayer formats. GL_RED texture is used to store the image data.
> Not only this allows to use the same shader code in 10-bit and 12-bit cases.
> But it also turned out that sampling from GL_RED texture is easier (less
> "patterns") than from GL_RGB - even though we loose the "auto-skipping the LS
> bytes of pixel values" feature in the 12-bit case.
> 
> Changes in v5 vs v4 [1]:
> * 8-bit raw Bayer format is back, but it is now split into several patches
>   (4/9 to 8/9) to make it easier to see the particular changes done to
>   the original shader code.
>   With the first 8 of the total 9 patches applied I am seeing some
>   artifacts (note the horizontal colour lines which change when the viewfinder
>   window height is changed) [2].
>   Patch 9/9 fixes that, but the root cause of the issue isn't currently known.
>   That's why 9/9 comes as RFC, and the series can be merged without it.

I've noticed in
https://github.com/motmot/libcamiface/blob/master/demo/liveview-glut.c
that GL_TEXTURE_MIN_FILTER is set to GL_LINEAR, while you set it to
GL_NEAREST. Could it be related to the artifacts you're seeing ?

I'll merge patches 1/9 to 8/9 already, and merge 9/9 or a different fix
once we finish this discussion.

> * s/tex_raw/tex_y in the shaders to match the uniform name used in the cpp
>   code.
> 
> [1] https://patchwork.libcamera.org/cover/12629/
> [2] https://people.linaro.org/~andrey.konovalov/cam-56/20210622.imx219-RAW8-artifacts.viewfinder_gl-add-RAW1xP-and-RAW8-support-v4.1-raw8.0.mp4
> 
> 

-- 
Regards,

Laurent Pinchart