Re: [PATCH v3 4/6] drm: bridge: dw-hdmi: Switch to V4L bus format and encodings

[Jose Abreu]

Hi Neil,


On 08-03-2017 12:12, Neil Armstrong wrote:
>
> Hi Jose,
>
> It seems here that we only have the RGB444<->YUV444 8bit tables, from the Amlogic
> source I have the following for 10bit, 12bit and 16bit for itu601 :
>
> static const u16 csc_coeff_rgb_out_eitu601_10b[3][4] = {
> 	{ 0x2000, 0x6926, 0x74fd, 0x043b },
> 	{ 0x2000, 0x2cdd, 0x0000, 0x7a65 },
> 	{ 0x2000, 0x0000, 0x38b4, 0x78ea }
> };
>
> static const u16 csc_coeff_rgb_out_eitu601_12b_16b[3][4] = {
> 	{ 0x2000, 0x6926, 0x74fd, 0x10ee },
> 	{ 0x2000, 0x2cdd, 0x0000, 0x6992 },
> 	{ 0x2000, 0x0000, 0x38b4, 0x63a6 }
> };

These two do not match anything I have here.

>
> static const u16 csc_coeff_rgb_in_eitu601_10b[3][4] = {
> 	{ 0x2591, 0x1322, 0x074b, 0x0000 },
> 	{ 0x6535, 0x2000, 0x7acc, 0x0800 },
> 	{ 0x6acd, 0x7534, 0x2000, 0x0800 }
> };

This is more or less correct, I have small offsets. Note that I
even have offsets with the values that are in dw-hdmi driver,
which can be caused because I'm seeing the latest document that
contain these values. I guess they were updated.

>
> static const u16 csc_coeff_rgb_in_eitu601_12b_16b[3][4] = {
> 	{ 0x2591, 0x1322, 0x074b, 0x0000 },
> 	{ 0x6535, 0x2000, 0x7acc, 0x2000 },
> 	{ 0x6acd, 0x7534, 0x2000, 0x2000 }
> };

The same for this.

>
> But I miss the itu709 values.
>
> Could you confirm these values and maybe provide the itu709 values ?

I will have to check if I can provide you the values. I will get
back to you.

Best regards,
Jose Miguel Abreu

>
> Thanks !
> Neil
>