RTOS/TDA3XEVM: Enabling black and white mode for night video

Hi Athira,

The easiest way to have blank & white images is to fill up chroma buffer with the 0x80. In this usecase, whole chain is working in YUV420 frame format. So in the display link, you could have a chroma buffer filled with 0x80 and use this buffer instead of incoming chroma buffer.

Rgds,
Brijesh

Hi Brijesh,

Can you please update on this ?

• Can you please give more details about your suggestion ? Which is the buffer exactly we need to fill with 0x80 for getting black and white ? In "vision_sdk/links_fw/src/rtos/links_ipu/display/displayLink_drv.c" file (function : DisplayLink_drvProcessData()) we saw a buffer pFrame. 

pFrame->addr[1U][1U] = (UInt8 *) pFrame->addr[0U][1U] + pObj->dssPrms.inFmt.pitch[1U];

• Is it possible to change color to black and white mode from image pipe , ISP or from somewhere like Color conversion or color correction takes place ?

ATHIRA V NAIR said:

Hi Brijesh,

Can you please update on this ?

• Can you please give more details about your suggestion ? Which is the buffer exactly we need to fill with 0x80 for getting black and white ? In "vision_sdk/links_fw/src/rtos/links_ipu/display/displayLink_drv.c" file (function : DisplayLink_drvProcessData()) we saw a buffer pFrame. 

pFrame->addr[1U][1U] = (UInt8 *) pFrame->addr[0U][1U] + pObj->dssPrms.inFmt.pitch[1U];

• Is it possible to change color to black and white mode from image pipe , ISP or from somewhere like Color conversion or color correction takes place ?

Here we suspect like this pFrame->addr[][] arrays will hold the address of pixel data values of each lines. Thats why adding "pObj->dssPrms.inFmt.pitch[1U]" with (UInt8 *) pFrame->addr[0U][1U]. Because the pObj->dssPrms.inFmt.pitch[1U] value is 1920 always. How can we fill chroma buffer with 0x80 here ?

Can you please confirm about another options to make video black and white from ISP or color conversion matrices ? If so please give some details regarding this. 

Brijesh,

Thanks for the updates.
We are trying to make black and white video from display by changing color phase rotation matrix coefficients. We will check the option you suggested from ISP ie, RGB2YUV matrix. Can you just mention which file exactly I need to check for RGB2YUV matrix ?

Hi Athira,

What is the output color format that you are using from DSS? You could CPR module in DSS also depending on your output format.
RGB2YUV matrix is part of the DCC profile binary. I would suggest not changing it. Instead, after DCC is applied, change the RGB2YUV matrix using driver and link provided ioctl.

Regards,
Brijesh