DM6437 OSD Color Distortion

Hi,

Thanks for your post.

I have few suggestion on OSD as below;

1. OSD should be configured in field/frame mode and this configures how the OSD would be reading the data from a buffer.

2. The field/frame mode configuration for the OSD windows shouldn't be different on the VID0 and they need to match with VID0 configuration. In other words, the configuration does not depend on the video getting fed to the OSD

The VPBE uses a OSD peripheral to handle its input formatting, the VID0 and VID1 windows in this OSD will be expecting YUV422 by default therefore if you feed RGB565 data into them you will get the wrong colors on the output as you have found. These two video windows in the OSD can only handle YUV422 or RGB888 input data, therefore if you have RGB565 in your frame buffer than you will not be able to use VID0 or VID1. The solution for this would be to use the OSD0 or OSD1 windows which are more suited to RGB inputs in that they can support bitmap or RGB565 formats. These windows and what they support are discussed further in section 4.3 of SPRU952 available below.

http://focus.ti.com/lit/ug/spru952a/spru952a.pdf

If you are using the DM6437 video driver from the Peripheral Support Package (PSP) provided with the EVM than you should be able to support this display mode by using the FVID_RGB565_INTERLEAVED option in your PSP_VPBEOsdConfigParams, an example of this usage can be found within dvsdk_1_01_00_15\psp_1_00_02_00\pspdrivers\system\dm6437\bios\dm6437_evm\src\video\sample\rawcapture.

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Sir,

Thanks for your reply.

I am using VID0 window for YUV422 video and OSD0 for 8-bit bitmap data. OSD0 and VID0 both are configured in Frame mode.

But still I am having an issue of color blur on whatever is provided in OSD0 window. And the amount of blurring varies with VID0 colors. For example if OSD0 is provided with yellow color. On black VID0 values the OSD0 appears perfectly well but as the color of VID0 changes (as of cyan or white or some other bright color) the blurring increased. There is a visual feeling of some wave is passing over OSD0 data which makes it visually degraded. What should I do to fix the issue. Kindly suggest.

Regards
SAIRA KANWAL

I want to display characters using OSD0 window. There appears some artifacts on the characters (flickering and smearing).  The issue is not particular with the display device. I had tested on various display devices but the problem still exists.

What would be the solution ?

Hi Saira,

Thanks for your update.

Are you using DM6437 video driver from the Peripheral Support Package (PSP) provided with the EVM? I mean, is it your own code or TI provided DVSDK example code?

If TI provided code, are you using examples from dvsdk_1_01_00_15\psp_1_00_02_00\pspdrivers\system\dm6437\bios\dm6437_evm\src\video\sample\rawcapture?

Have you tried the above example and check whether the flickering and smearing characters displayed on OSD0 window?

I think, you have to check for the supported display devices from the DM6437 datasheet compliant to display specifications. Please do confirm this.

Thanks & regards,

Sivaraj K

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