diff mbox series

drm: bridge: dw-hdmi: Fix RGB to YUV color space conversion

Message ID 20211106130044.63483-1-knaerzche@gmail.com (mailing list archive)
State New, archived
Headers show
Series drm: bridge: dw-hdmi: Fix RGB to YUV color space conversion | expand

Commit Message

Alex Bee Nov. 6, 2021, 1 p.m. UTC 
As per CEA-861 quantization range is always limited in case of YUV
output - indepentently which CEA mode it is or if it is an DMT mode.

This is already correctly setup in HDMI AVI inforame, but we always do
a RGB to YUV conversion which doesn't consider that RGB input can be
full range as well.
That leads to incorrect colors for all CEA modes except mode 1 for HDMI
and always for DVI.

To fix this, provide additional csc coefficents for converting from RGB
full range to EITU601/EITU709 limited range and rename the existing
arrays to clarify their meaning.

Signed-off-by: Alex Bee <knaerzche@gmail.com>
---
 drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 24 +++++++++++++++++++----
 1 file changed, 20 insertions(+), 4 deletions(-)


base-commit: 89636a06fa2ee7826a19c39c19a9bc99ab9340a9

Comments

Jernej Škrabec Nov. 10, 2021, 8:20 p.m. UTC | #1 
Hi Alex,

Dne sobota, 06. november 2021 ob 14:00:44 CET je Alex Bee napisal(a):
> As per CEA-861 quantization range is always limited in case of YUV
> output - indepentently which CEA mode it is or if it is an DMT mode.
> 
> This is already correctly setup in HDMI AVI inforame, but we always do
> a RGB to YUV conversion which doesn't consider that RGB input can be
> full range as well.
> That leads to incorrect colors for all CEA modes except mode 1 for HDMI
> and always for DVI.
> 
> To fix this, provide additional csc coefficents for converting from RGB
> full range to EITU601/EITU709 limited range and rename the existing
> arrays to clarify their meaning.
> 
> Signed-off-by: Alex Bee <knaerzche@gmail.com>
> ---
>  drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 24 +++++++++++++++++++----
>  1 file changed, 20 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/
bridge/synopsys/dw-hdmi.c
> index 62ae63565d3a..1cba08b70091 100644
> --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> @@ -80,13 +80,25 @@ static const u16 csc_coeff_rgb_out_eitu709[3][4] = {
>  	{ 0x2000, 0x0000, 0x3b61, 0x7e25 }
>  };
>  
> -static const u16 csc_coeff_rgb_in_eitu601[3][4] = {
> +static const u16 csc_coeff_rgb_full_in_eitu601[3][4] = {

I would rather move "full" and "limited" to the end, since RGB always has full 
range and we want YUV to have full or limited range.

Just one observation - no other matrix sets bit 15 in any coefficient, but yours 
do. I can't see anywhere documented if bit 15 is ignored or not. Can you try 
with it set to 0? If it still works, I would set it to 0 for consistency.

Best regards,
Jernej

> +	{ 0x2044, 0x106f, 0x0644, 0x0040 },
> +	{ 0xe677, 0x1c1c, 0xfd46, 0x0200 },
> +	{ 0xed60, 0xf685, 0x1c1c, 0x0200 }
> +};
> +
> +static const u16 csc_coeff_rgb_limited_in_eitu601[3][4] = {
>  	{ 0x2591, 0x1322, 0x074b, 0x0000 },
>  	{ 0x6535, 0x2000, 0x7acc, 0x0200 },
>  	{ 0x6acd, 0x7534, 0x2000, 0x0200 }
>  };
>  
> -static const u16 csc_coeff_rgb_in_eitu709[3][4] = {
> +static const u16 csc_coeff_rgb_full_in_eitu709[3][4] = {
> +	{ 0x2750, 0x0baf, 0x03f8, 0x0040 },
> +	{ 0xe677, 0x1c1c, 0xfd6d, 0x0200 },
> +	{ 0xea55, 0xf98f, 0x1c1c, 0x0200 }
> +};
> +
> +static const u16 csc_coeff_rgb_limted_in_eitu709[3][4] = {
>  	{ 0x2dc5, 0x0d9b, 0x049e, 0x0000 },
>  	{ 0x62f0, 0x2000, 0x7d11, 0x0200 },
>  	{ 0x6756, 0x78ab, 0x2000, 0x0200 }
> @@ -1023,9 +1035,13 @@ static void dw_hdmi_update_csc_coeffs(struct dw_hdmi 
*hdmi)
>  			csc_coeff = &csc_coeff_rgb_out_eitu709;
>  	} else if (is_input_rgb && !is_output_rgb) {
>  		if (hdmi->hdmi_data.enc_out_encoding == 
V4L2_YCBCR_ENC_601)
> -			csc_coeff = &csc_coeff_rgb_in_eitu601;
> +			csc_coeff = hdmi->hdmi_data.rgb_limited_range
> +				? &csc_coeff_rgb_limited_in_eitu601
> +				: &csc_coeff_rgb_full_in_eitu601;
>  		else
> -			csc_coeff = &csc_coeff_rgb_in_eitu709;
> +			csc_coeff = hdmi->hdmi_data.rgb_limited_range
> +				? &csc_coeff_rgb_limted_in_eitu709
> +				: &csc_coeff_rgb_full_in_eitu709;
>  		csc_scale = 0;
>  	} else if (is_input_rgb && is_output_rgb &&
>  		   hdmi->hdmi_data.rgb_limited_range) {
> 
> base-commit: 89636a06fa2ee7826a19c39c19a9bc99ab9340a9
> -- 
> 2.30.2
> 
>
Jernej Škrabec Nov. 10, 2021, 9:26 p.m. UTC | #2 
Dne sreda, 10. november 2021 ob 21:20:46 CET je Jernej Škrabec napisal(a):
> Hi Alex,
> 
> Dne sobota, 06. november 2021 ob 14:00:44 CET je Alex Bee napisal(a):
> > As per CEA-861 quantization range is always limited in case of YUV
> > output - indepentently which CEA mode it is or if it is an DMT mode.
> > 
> > This is already correctly setup in HDMI AVI inforame, but we always do
> > a RGB to YUV conversion which doesn't consider that RGB input can be
> > full range as well.
> > That leads to incorrect colors for all CEA modes except mode 1 for HDMI
> > and always for DVI.
> > 
> > To fix this, provide additional csc coefficents for converting from RGB
> > full range to EITU601/EITU709 limited range and rename the existing
> > arrays to clarify their meaning.
> > 
> > Signed-off-by: Alex Bee <knaerzche@gmail.com>
> > ---
> > 
> >  drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 24 +++++++++++++++++++----
> >  1 file changed, 20 insertions(+), 4 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/
> 
> bridge/synopsys/dw-hdmi.c
> 
> > index 62ae63565d3a..1cba08b70091 100644
> > --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> > +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> > @@ -80,13 +80,25 @@ static const u16 csc_coeff_rgb_out_eitu709[3][4] = {
> > 
> >  	{ 0x2000, 0x0000, 0x3b61, 0x7e25 }
> >  
> >  };
> > 
> > -static const u16 csc_coeff_rgb_in_eitu601[3][4] = {
> > +static const u16 csc_coeff_rgb_full_in_eitu601[3][4] = {
> 
> I would rather move "full" and "limited" to the end, since RGB always has
> full range and we want YUV to have full or limited range.
> 
> Just one observation - no other matrix sets bit 15 in any coefficient, but
> yours do. I can't see anywhere documented if bit 15 is ignored or not. Can
> you try with it set to 0? If it still works, I would set it to 0 for
> consistency.
> 
> Best regards,
> Jernej
> 
> > +	{ 0x2044, 0x106f, 0x0644, 0x0040 },
> > +	{ 0xe677, 0x1c1c, 0xfd46, 0x0200 },

By my calculations, above line should be:
{ 0xe876, 0x1c1c, 0xfb6e, 0x0200}

Can you check again?

> > +	{ 0xed60, 0xf685, 0x1c1c, 0x0200 }
> > +};
> > +
> > +static const u16 csc_coeff_rgb_limited_in_eitu601[3][4] = {
> > 
> >  	{ 0x2591, 0x1322, 0x074b, 0x0000 },
> >  	{ 0x6535, 0x2000, 0x7acc, 0x0200 },
> >  	{ 0x6acd, 0x7534, 0x2000, 0x0200 }
> >  
> >  };
> > 
> > -static const u16 csc_coeff_rgb_in_eitu709[3][4] = {
> > +static const u16 csc_coeff_rgb_full_in_eitu709[3][4] = {
> > +	{ 0x2750, 0x0baf, 0x03f8, 0x0040 },
> > +	{ 0xe677, 0x1c1c, 0xfd6d, 0x0200 },
> > +	{ 0xea55, 0xf98f, 0x1c1c, 0x0200 }
> > +};
> > +
> > +static const u16 csc_coeff_rgb_limted_in_eitu709[3][4] = {
> > 
> >  	{ 0x2dc5, 0x0d9b, 0x049e, 0x0000 },
> >  	{ 0x62f0, 0x2000, 0x7d11, 0x0200 },
> >  	{ 0x6756, 0x78ab, 0x2000, 0x0200 }
> > 
> > @@ -1023,9 +1035,13 @@ static void dw_hdmi_update_csc_coeffs(struct
> > dw_hdmi
> 
> *hdmi)
> 
> >  			csc_coeff = &csc_coeff_rgb_out_eitu709;
> >  	
> >  	} else if (is_input_rgb && !is_output_rgb) {
> >  	
> >  		if (hdmi->hdmi_data.enc_out_encoding ==
> 
> V4L2_YCBCR_ENC_601)
> 
> > -			csc_coeff = &csc_coeff_rgb_in_eitu601;
> > +			csc_coeff = hdmi->hdmi_data.rgb_limited_range
> > +				? 
&csc_coeff_rgb_limited_in_eitu601
> > +				: &csc_coeff_rgb_full_in_eitu601;
> > 
> >  		else
> > 
> > -			csc_coeff = &csc_coeff_rgb_in_eitu709;
> > +			csc_coeff = hdmi->hdmi_data.rgb_limited_range
> > +				? &csc_coeff_rgb_limted_in_eitu709
> > +				: &csc_coeff_rgb_full_in_eitu709;
> > 
> >  		csc_scale = 0;
> >  	
> >  	} else if (is_input_rgb && is_output_rgb &&
> >  	
> >  		   hdmi->hdmi_data.rgb_limited_range) {
> > 
> > base-commit: 89636a06fa2ee7826a19c39c19a9bc99ab9340a9
diff mbox series

Patch

diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
index 62ae63565d3a..1cba08b70091 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
@@ -80,13 +80,25 @@  static const u16 csc_coeff_rgb_out_eitu709[3][4] = {
 	{ 0x2000, 0x0000, 0x3b61, 0x7e25 }
 };
 
-static const u16 csc_coeff_rgb_in_eitu601[3][4] = {
+static const u16 csc_coeff_rgb_full_in_eitu601[3][4] = {
+	{ 0x2044, 0x106f, 0x0644, 0x0040 },
+	{ 0xe677, 0x1c1c, 0xfd46, 0x0200 },
+	{ 0xed60, 0xf685, 0x1c1c, 0x0200 }
+};
+
+static const u16 csc_coeff_rgb_limited_in_eitu601[3][4] = {
 	{ 0x2591, 0x1322, 0x074b, 0x0000 },
 	{ 0x6535, 0x2000, 0x7acc, 0x0200 },
 	{ 0x6acd, 0x7534, 0x2000, 0x0200 }
 };
 
-static const u16 csc_coeff_rgb_in_eitu709[3][4] = {
+static const u16 csc_coeff_rgb_full_in_eitu709[3][4] = {
+	{ 0x2750, 0x0baf, 0x03f8, 0x0040 },
+	{ 0xe677, 0x1c1c, 0xfd6d, 0x0200 },
+	{ 0xea55, 0xf98f, 0x1c1c, 0x0200 }
+};
+
+static const u16 csc_coeff_rgb_limted_in_eitu709[3][4] = {
 	{ 0x2dc5, 0x0d9b, 0x049e, 0x0000 },
 	{ 0x62f0, 0x2000, 0x7d11, 0x0200 },
 	{ 0x6756, 0x78ab, 0x2000, 0x0200 }
@@ -1023,9 +1035,13 @@  static void dw_hdmi_update_csc_coeffs(struct dw_hdmi *hdmi)
 			csc_coeff = &csc_coeff_rgb_out_eitu709;
 	} else if (is_input_rgb && !is_output_rgb) {
 		if (hdmi->hdmi_data.enc_out_encoding == V4L2_YCBCR_ENC_601)
-			csc_coeff = &csc_coeff_rgb_in_eitu601;
+			csc_coeff = hdmi->hdmi_data.rgb_limited_range
+				? &csc_coeff_rgb_limited_in_eitu601
+				: &csc_coeff_rgb_full_in_eitu601;
 		else
-			csc_coeff = &csc_coeff_rgb_in_eitu709;
+			csc_coeff = hdmi->hdmi_data.rgb_limited_range
+				? &csc_coeff_rgb_limted_in_eitu709
+				: &csc_coeff_rgb_full_in_eitu709;
 		csc_scale = 0;
 	} else if (is_input_rgb && is_output_rgb &&
 		   hdmi->hdmi_data.rgb_limited_range) {