Displaying 1280 * 720 NV12 image in DSS -VID1 pipeline via HDMI showing last row with green line

jeyaseelan kirubaharan

Dear Sir,

I am using DRA74xx and running my direct display driver code in cortex M4 IPU1. Everything looks so fine except that when showing one NV12 picture (1280*720) through VID1- DSS pipeline. This picture shows last row as green line in the display.

When i filled (1280*721*1.5) data bytes, the last line changed as corrupted pixel with scattered green. With that i concluded that ,this picture has to be shown with Vertical Up-scaling by 1. From 1280*720 into 1280*721.

Is my conclusion is right? If so what are the VID1 DSS registers i have to modify. I tried changing DISPC_VID1_FIR(0x5800 10E0) register. But still the issue present

The data flow path is DSS. VID1-> HDMI ->LVDS->Display.

Please let me know what is the actual issue and how this could be resolved.

With regards,

Jeyaseelan

over 7 years ago

0 Yordan Kamenov over 7 years ago

TI__Mastermind 42515 points

Hi Jeyaseelan,

which SDK you use?

Regards,
Yordan

0 Brijesh Jadav over 7 years ago

TI__Guru**** 476505 points

Hi,

I did not get your dataflow. is it HDMI -> LVDS -> Display??
Who converts HDMI to LVDS??

Regards,
Brijesh

0 jeyaseelan kirubaharan over 7 years ago in reply to Brijesh Jadav

Expert 1330 points

Hi Brijesh/Yadav,

This is a custom driver with directly accessing DSS registers from M4-IPU1 ,not through any SDK.

We use serializer - DS90UB914A for HDMI to LVDS

Please let me know if vertical up-scaling using poly-phase filter in display controller in DISPC of VID1, can be used for converting 1280*720 to 1280*721 of NV12 image. If so ,what are the registers to be configured and in what order.

Also confirm if this upscaling removes the green line in the last row.

With regards,

Jeyaseelan

0 Brijesh Jadav over 7 years ago in reply to jeyaseelan kirubaharan

TI__Guru**** 476505 points

914 for HDMI to LVDS conversion ?? Strange?

Well there is a scalar in the video pipeline, which potentially can be converting 720 to 721 lines.. Please check if it is enabled.
Other than that, please check if size of the LCD is set up correctly. Even if the VID size is set to 720, if LCD size is set to 721, it will output 721 lines..

but i think when you fill up entire 721 lines of buffer, you see difference in the output, which means your input video pipeline itself is configured incorrectly.. Please check video pipeline configuration.

Rgds,
Brijesh

0 jeyaseelan kirubaharan over 7 years ago in reply to jeyaseelan kirubaharan

Expert 1330 points

Hi ,

It is actually DS90UB913A serializer and DS90UB913A - deserializer through FPD-III link(similar to LVDS).

Now miraculously the issue is resolved,if we fill the memory area (1280*720*3) initially with 0x80 before copying the NV12 frame. If somebody knows what is happening behind,please share.

memset(VID1_MEM_ADDR, 0x80, (DRA7XX_BA_PIC_WIDTH * DRA7XX_BA_PIC_HEIGHT * 3));

With regards,
Jeyaseelan

0 Brijesh Jadav over 7 years ago in reply to jeyaseelan kirubaharan

TI__Guru**** 476505 points

Why size 1280x720x3? Why not 1280x720x1.5? Aren't you using YUV420 frame format?

Rgds,
Brijesh

0 jeyaseelan kirubaharan over 7 years ago in reply to Brijesh Jadav

Expert 1330 points

The same pipeline is being used for displaying from 2 sources , 1 from RGB source and another from NV12 .The above initialization was done once at the beginning before switching between these sources.
Yes the NV12 source should be 1280*720*1.5 . I will check the behavior and update if initialization is done with 1280*720*1.5 as well.

With regards,
Jeyaseelan

0 Brijesh Jadav over 7 years ago in reply to jeyaseelan kirubaharan

TI__Guru**** 476505 points

Hi,

So you are trying to display both RGB and NV12. But when you change the source, do you also change the VID pipeline's configuration? When the input format changes, lot of configuration changes, for example, input format, pitch, scalar etc ..

Rgds,
Brijesh

0 jeyaseelan kirubaharan over 7 years ago in reply to Brijesh Jadav

Expert 1330 points

Yes we are doing that only . Based on user selection of source ,display configuration are changed dynamically. CSC, Scaling Conversion,Display Controller configs etc and it is displayed out through TV output.

With regards,
Jeyaseelan

0 Brijesh Jadav over 7 years ago in reply to jeyaseelan kirubaharan

TI__Guru**** 476505 points

May be it is scaled down using pipeline scalar from 722 to 720. can you check if scalar is enabled in the path?

Rgds,
Brijesh

0 Yordan Kamenov over 7 years ago in reply to Brijesh Jadav

TI__Mastermind 42515 points

Hi Jeyaseelan,

We haven't heard back from you, I'm assuming you were able to resolve your issue.
If not, just post a reply below (or create a new thread if the thread has locked due to time-out).

Regards,
Yordan

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Displaying 1280 * 720 NV12 image in DSS -VID1 pipeline via HDMI showing last row with green line