Alpha blending support on i.MX6ULL

[namanthaker]

Hello,
I am using a i.MX6ULL processor to display two Framebuffer streams on a LCDIF simultaneously. The use-case is to display a camera stream and a GUI with various controls through two FB on a single LCDIF.

I have below queries regarding the use-case implementation:
1. Can I use MXCFB_SET_GBL_ALPHA ioctl on i.MX6ULL to set/enable the Global alpha settings?
2. I understand that i.MX6ULL supports alpha blending through PXP through the IMX6ULLCEC datasheet, but I could not find any example code or command to use the PXP for alpha blending. Could anyone help to provide some example code to use the alpha blending feature on i.MX6ULL ?
3. Are there any other methods available on i.MX6ULL aside from PXP or MXC_FB ioctl to achieve the use-case requirement ?

[Bio_TICFSL]

Hello,

some alpha blending examples can be found in

https://community.nxp.com/t5/i-MX-Processors/imx6ul-pxp/m-p/872222

https://community.nxp.com/t5/i-MX-Processors/Alpha-Blending-overlay-framebuffer-fb1/m-p/644414

Regards

[namanthaker]

Hello @Bio_TICFSL ,

Thank you for suggesting the imx-test application. I was able to use the pxp_v4l2_test application from imx-test package for setting global alpha.
I am writing a RGB pattern onto fb0, which will be the GUI. Then I am using the pxp_v4l2_test application to play a YUV video with global alpha value of 100. Here is the command I am using for pxp_v4l2_test application:
pxp_v4l2_test -sx 800 -sy 480 -res 352:240 -a 100 /tmp/fb-352x240.yuv BLANK

With this I can see the RGB and the YUV video simultaneously as seen in the attached image. But both are translucent, so we see blended image of both. I am trying to make both buffers opaque so that I can properly display the YUV video over the RGB image. I have tried the ALPHA_OVERRIDE bit in AS_CTRL register, but they did not affect the outcome.

Could you suggest some way to achieve opaque video over the image?

[namanthaker]

@Bio_TICFSL,

Could you please help to update on above query?