AM625: AM625 Alpha blending

Tran Thang

Part Number: AM625

Dear TI.

We try to set alpha blending on am625 on early display running on m4 (we porting from splash screen on U boot). If we set GLOBAL ALPHA register at initialize stage it will ok (we see image dimmer). But when we set this register continuously at runtime, the image not change transparency but color changed. Sequence to set GLOBAL ALPHA register as follow:

wait GO bit to 0
set GLOBAL ALPHA register
Set GO bit to 1.

Thank for your support.

over 2 years ago

0 Krunal Bhargav34 over 2 years ago

TI__Mastermind 43625 points

Hello,

I am observing the issue on my side as well and I will discuss with our internal team for further debug.

Regards,
Krunal

0 Krunal Bhargav34 over 2 years ago in reply to Krunal Bhargav34

TI__Mastermind 43625 points

Hello,

Based on my internal discussion, the Global Alpha register is for the overlay manager and it is used to blend two images (one image in background and one image in forground). In your case, you have a single image and it's being displayed on a single video pipeline. Is the understanding correct?

Regards,
Krunal

0 Tran Thang over 2 years ago in reply to Krunal Bhargav34

Prodigy 120 points

Dear TI.

Thanks for your answer.

We use two interface LVDS and DPI so two pipeline has used. Can we setting blending with black background?. Or use one pipeline for two interface? (so we can use another interface for alpha blending)

Thank for your support

0 Krunal Bhargav34 over 2 years ago in reply to Tran Thang

TI__Mastermind 43625 points

Hello,

Could you please explain your setup? We have the following DSS image:

Are you passing two different images to the Video Pipeline and Video Lite Pipeline? Next, are you using the overlay manager to combine both images and passing that to OLDI or DPI?

Regards,
Krunal

0 Tran Thang over 2 years ago in reply to Krunal Bhargav34

Prodigy 120 points

Daer TI,

We use the same image (we use same dma buffer for both) for both DPI and LVDS. This is my setting

Vidl->overlay 0 layer 1->vp0 (LVDS)

Vid->overlay 1 layer 1->vp1 (DPI)

We also try use vidl for both overlay 0 and 1 but image become shattering.

For your question, please give me guideline for di that.

Thank for your support.

0 Krunal Bhargav34 over 2 years ago in reply to Tran Thang

TI__Mastermind 43625 points

Do you have any example that I can try on my side?

Regards,
Krunal

0 Tran Thang over 2 years ago in reply to Krunal Bhargav34

Prodigy 120 points

Dear Ti,

Because off policy I can't share source with you. After setup gamma table it work with me.

Thanks for your support

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AM625: AM625 Alpha blending