How to use i.MX6DQ HDMI RGB limited range.

[satoshishimoda]

Hi community,

Our customer have a question about i.MX6DQ HDMI.

They want to know how to use HDMI RGB limited range (level 16 to 235) to MHL output.

(MHL requires RGB limited range)

I checked MCIMX6DQRM (Rev.3), and understood HDMI module supports limited range.

But did not understand how to set the registers to use RGB limited range.

Should we use the equation written in chapter 33.4.5 in IMX6DQRM Rev.3?

Or is it possible by YQ1_YQ0_YCC field in HDMI_FC_AVICONF3 register(Chapter 33.5.70)?

Best Regards,

Satoshi Shimoda

[Bio_TICFSL · Accepted solution]

Hi Satoshi,

This information is from the HDMI spec and the CEA-861-D( video standard).

HDMI_FC_AVICONF3[YQ1_YQ0_YCC]

YQ1_YQ0_YCC = 00     Limited range (16 to 255)

YQ1_YQ0_YCC = 01     Full range (0 to 255)

YQ1_YQ0_YCC = 10     Reserved

YQ1_YQ0_YCC = 11     Reserved

HDMI_FC_AVICONF0[FC_AVICONF0_RGB_YCC]

[Y1:Yo] = 00     RGB (default)   

[Y1:Yo] = 01     YCbCr 4:2:2

[Y1:Yo] = 10     YCbCr 4:4:4

[Y1:Yo] = 11     Future

Hope this helps

[satoshishimoda]

Hi Bio_TICFSL,

Thank you for your reply.

But unfortunately, the hdmi output was not change to limited range with the above setting, HDMI_FC_AVICONF3[YQ1_YQ0_YCC]=00b (limited range) and HDMI_FC_AVICONF0[FC_AVICONF0_RGB_YCC]=00b (RGB).

Actually, our customer tested all HDMI_FC_AVICONF3[YQ1_YQ0_YCC] value, not only 00b but also 01b to 11b, however HDMI output was not change to limited range never.

Is that all to use limited range?

Should we set HDMI_CSC_CFG or other register also?

Best Regards,

Satoshi Shimoda

[Bio_TICFSL]

Hi Satoshi,

An Internal ticket was summited and we have to wait for an answer from our experts in order to get a better explanation on this matter. It probably take a while.

Thanks for your patience

Regards

[satoshishimoda]

Hi Bio_TICFSL,

Would you let me know any update about this question?

Have you gotten the answer from your experts?

Best Regards,

Satoshi Shimoda

[Bio_TICFSL]

Hi Satoshi,

All CEA-861-E video formats up to 1080p at 60Hz and 720p/1080i at 120Hz Supported colorimetry: 24bit RGB 4:4:4

AVI infoFrame packet extension to support YCC Quantization range (Limited Range, Full Range)

For color space interpolation you should check register HDMI_CSC_CFG, for quantization according to CEA you should check HDMI_FC_AVICONF3 register and AVICONF0 check FC_AVICONF0_ RGB_YCC.

hope this helps

[satoshishimoda]

Hi Bio_TICFSL,

Thank you for your reply.

>  for quantization according to CEA you should check HDMI_FC_AVICONF3 register and AVICONF0 check FC_AVICONF0_ RGB_YCC.

I believe our customer want to use YCC Quantization range (limited).

So I understood our customer should check HDMI_FC_AVICONF3 and AVICONF0 as you mentioned.

However, reference manual does not mention about the detail of these fields.

So would you let me know the detail HDMI_FC_AVICONF3 and HDMI_FC_AVICONF0[FC_AVICONF0_RGB_YCC]?

(e.g. HDMI_FC_AVICONF3[YQ1_YQ0_YCC] : 00b = full range, 01b = limited range, 1xb = reserved )

Best Regards,

Satoshi Shimoda

[Bio_TICFSL]

Hi Satoshi,

In case of YCC quatization, i.mx6 supports

xvYCC601 - Y'CbCr, full range (as xvYCC 709, but using BT.601 for Y'CbCr encoding)

xvYCC709 - Y'CbCr, full range (wide -gamut ).

There is no more datails regarding YCC, you migth have to enter a case in nxp support.

Regards

[satoshishimoda]

Hi Bio_TICFSL,

Please reply how set the registers to use limited range ASAP.

The MHL certification test and mass production schedule have been delayed by no response to this question, so our customer is pushing hard us.

Best Regards,

Satoshi Shimoda

[satoshishimoda]

Hi Bio_TICFSL,

Our customer's product have to pass MHL certification.

And the certification schedule has been past.

So please give us the register setting for using limited range ASAP in order to minimize the schedule delay.

Best Regards,

Satoshi Shimoda

[satoshishimoda]

Hi Bio_TICFSL,

Thank you for your reply.

But I'm afraid that we want to know regarding the registers setting of HDMI_FC_AVICONF3[YQ1_YQ0_YCC] and HDMI_FC_AVICONF0[FC_AVICONF0_RGB_YCC] to use limited range, not regarding the detail of YCC.

Please give me the information about it.

Best Regards,

Satoshi Shimoda