[Intel-gfx] [v5 2/2] drm/i915/icl: Enable Plane Input CSC for YUV to RGB Conversion

Shankar, Uma uma.shankar at intel.com
Thu Nov 1 06:33:43 UTC 2018



>-----Original Message-----
>From: Roper, Matthew D
>Sent: Wednesday, October 31, 2018 10:11 PM
>To: Shankar, Uma <uma.shankar at intel.com>
>Cc: intel-gfx at lists.freedesktop.org; Syrjala, Ville <ville.syrjala at intel.com>;
>Lankhorst, Maarten <maarten.lankhorst at intel.com>
>Subject: Re: [Intel-gfx] [v5 2/2] drm/i915/icl: Enable Plane Input CSC for YUV to
>RGB Conversion
>
>On Wed, Oct 31, 2018 at 05:34:19AM -0700, Shankar, Uma wrote:
>>
>>
>> >-----Original Message-----
>> >From: Roper, Matthew D
>> >Sent: Tuesday, October 30, 2018 4:59 AM
>> >To: Shankar, Uma <uma.shankar at intel.com>
>> >Cc: intel-gfx at lists.freedesktop.org; Syrjala, Ville
>> ><ville.syrjala at intel.com>; Lankhorst, Maarten
>> ><maarten.lankhorst at intel.com>
>> >Subject: Re: [Intel-gfx] [v5 2/2] drm/i915/icl: Enable Plane Input
>> >CSC for YUV to RGB Conversion
>> >
>> >On Fri, Oct 26, 2018 at 03:31:57PM +0530, Uma Shankar wrote:
>> >> Plane input CSC needs to be enabled to convert frambuffers from YUV
>> >> to RGB. This is needed for bottom 3 planes on ICL, rest of the
>> >> planes have hardcoded conversion and taken care by the legacy code.
>> >>
>> >> This patch defines the co-efficient values for YUV to RGB
>> >> conversion in BT709 and BT601 formats. It programs the coefficients
>> >> and enables the plane input csc unit in hardware.
>> >>
>> >> Note: This is currently untested and floated to get an early
>> >> feedback on the design and implementation for this feature. In
>> >> parallel, I will test this on actual ICL hardware and confirm with planar
>formats.
>> >>
>> >> v2: Addressed Maarten's and Ville's review comments and added the
>> >> coefficients in a 2D array instead of independent Macros.
>> >>
>> >> v3: Added individual coefficient matrix (9 values) instead of 6
>> >> register values as per Maarten's comment. Also addresed a shift
>> >> issue with B channel coefficient.
>> >>
>> >> v4: Added support for Limited Range Color Handling
>> >>
>> >> v5: Fixed Matt and Maarten's review comments.
>> >>
>> >> Signed-off-by: Uma Shankar <uma.shankar at intel.com>
>> >> ---
>> >>  drivers/gpu/drm/i915/intel_color.c   | 79
>> >++++++++++++++++++++++++++++++++++++
>> >>  drivers/gpu/drm/i915/intel_display.c | 23 ++++++++---
>> >>  drivers/gpu/drm/i915/intel_drv.h     |  2 +
>> >>  3 files changed, 98 insertions(+), 6 deletions(-)
>> >>
>> >> diff --git a/drivers/gpu/drm/i915/intel_color.c
>> >> b/drivers/gpu/drm/i915/intel_color.c
>> >> index 5127da2..681cd13 100644
>> >> --- a/drivers/gpu/drm/i915/intel_color.c
>> >> +++ b/drivers/gpu/drm/i915/intel_color.c
>> >> @@ -57,6 +57,15 @@
>> >>  #define CSC_RGB_TO_YUV_RV_GV 0xbce89ad8  #define
>> >CSC_RGB_TO_YUV_BV
>> >> 0x1e080000
>> >>
>> >> +#define  ROFF(x)          (((x) & 0xffff) << 16)
>> >> +#define  GOFF(x)          (((x) & 0xffff) << 0)
>> >> +#define  BOFF(x)          (((x) & 0xffff) << 16)
>> >> +
>> >> +/* Preoffset values for YUV to RGB Conversion */
>> >> +#define PREOFF_YUV_TO_RGB_HI		0x1800
>> >> +#define PREOFF_YUV_TO_RGB_ME		0x1F00
>> >> +#define PREOFF_YUV_TO_RGB_LO		0x1800
>> >> +
>> >>  /*
>> >>   * Extract the CSC coefficient from a CTM coefficient (in U32.32 fixed point
>> >>   * format). This macro takes the coefficient we want transformed
>> >> and the @@ -643,6 +652,76 @@ int intel_color_check(struct drm_crtc *crtc,
>> >>  	return -EINVAL;
>> >>  }
>> >>
>> >> +void icl_program_input_csc_coeff(const struct intel_crtc_state *crtc_state,
>> >> +				 const struct intel_plane_state *plane_state) {
>> >> +	struct drm_i915_private *dev_priv =
>> >> +		to_i915(plane_state->base.plane->dev);
>> >> +	struct intel_crtc *crtc = to_intel_crtc(crtc_state->base.crtc);
>> >> +	enum pipe pipe = crtc->pipe;
>> >> +	struct intel_plane *intel_plane =
>> >> +		to_intel_plane(plane_state->base.plane);
>> >> +	enum plane_id plane = intel_plane->id;
>> >> +
>> >> +	static const u16 input_csc_matrix[][9] = {
>> >
>> >Can you add comments to these indicating the human-readable values
>> >they translate to?
>>
>> Sure Matt, will add that.
>>
>> >> +		/* BT.601 full range YCbCr -> full range RGB */
>> >> +		[DRM_COLOR_YCBCR_BT601] = {
>> >> +			0x7AF8, 0x7800, 0x0,
>> >> +			0x8B28, 0x7800, 0x9AC0,
>> >> +			0x0, 0x7800, 0x7DD8,
>> >> +		},
>> >> +		/* BT.709 full range YCbCr -> full range RGB */
>> >> +		[DRM_COLOR_YCBCR_BT709] = {
>> >> +			0x7C98, 0x7800, 0x0,
>> >> +			0x9EF8, 0x7800, 0xABF8,
>> >> +			0x0, 0x7800,  0x7ED8,
>> >> +		},
>> >> +	};
>> >> +
>> >> +	/* Matrix for Limited Range to Full Range Conversion */
>> >> +	static const u16 input_csc_matrix_lr[][9] = {
>> >> +		/* BT.601 Limted range YCbCr -> full range RGB */
>> >> +		[DRM_COLOR_YCBCR_BT601] = {
>> >> +			0x7CC8, 0x7950, 0x0,
>> >> +			0x8CB8, 0x7918, 0x9C40,
>> >> +			0x0, 0x7918, 0x7FC8,
>> >
>> >Are these obtained by scaling the first row (Y-based) by 256/219 and
>> >the other two rows (Cb and Cr) by 256/224?  If so, it looks like
>> >you've always rounded down, whereas in some cases rounding up gives
>> >you a closer value (and matches how the bspec seems to have chosen the full
>range encodings for their example).
>>
>> Yes, this is how it's done. But the only reason of delta is that you
>> have taken 8 bit max value as 256, but I am taking it as 255. I feel
>> it should be (1 << bpc ie 8) - 1. If you put that, the values which you got will
>match to what I have here. Please let me know if that's ok.
>
>Ah, okay, that makes sense.  I do get the same values as you for the
>BT.601 table that way, but I still get a slight rounding difference in one cell of the
>BT.709 matrix down below.
>
>>
>> And thanks for detailed review and useful pointers.
>>
>> Regards,
>> Uma Shankar
>>
>> >        [ 0x7CD0, 0x7958,    0x0 ]
>> >        [ 0x8CC0, 0x7928, 0x9C48 ]
>> >        [    0x0, 0x7928, 0x7FD8 ]
>> >
>> >Our encodings of the 1.0 value on the second two rows seems to
>> >deviate slightly more for some reason; not sure why that is.
>> >
>> >For completeness, here's how I came up with 0x7928:
>> >
>> >        1 * 256/224 = 1.142857143
>> >        Sign bit = 0
>> >        Exponent bits = 0b111
>> >        Mantissa bits = round(1.142857143 << 8)
>> >                      = round(292.571428571)
>> >                      = 293
>> >                      = 0b100100101
>> >        Reserved bits = 0b000
>> >
>> >        Result = 0111 1001 0010 1000
>> >               = 0x7928
>> >
>> >If you did floor() instead of round() for the mantissa, you'd get
>> >292, which would translate to 0x7920 instead.
>> >
>> >> +		},
>> >> +		/* BT.709 Limited range YCbCr -> full range RGB */
>> >> +		[DRM_COLOR_YCBCR_BT709] = {
>> >> +			0x7EA8, 0x7950, 0x0,
>> >> +			0x8888, 0x7918, 0xADA8,
>> >> +			0x0, 0x7918,  0x6870,
>
>For BU I get 0xADA0 instead of 0xADA8.
>
>        -.187 * 255/224 = -0.212879464
>        Sign bit = 1
>        Exponent bits = 0b010
>        Mantissa bits = round(0.212879464 << (9+2))
>                      = round(435.977142272)
>                      = 436
>                      = 0b110110100
>        Reserved bits = 0b000
>        Result = 1010 1101 1010 0000
>               = 0xADA0
>
>All of the other values match now though.

Actually this is due to precision I took as reference value. The
Actual value is  -0.18732427293, if we take this much precision,
the value will match to what I got. So I feel this should be ok.

>
>Matt
>
>
>> >
>> >For these I get
>> >
>> >        [ 0x7EB8, 0x7958,      0 ]
>> >        [ 0x8890, 0x7928, 0xADB0 ]
>> >        [    0x0, 0x7928, 0x6878 ]
>> >
>> >So all the numbers are still pretty close to what you have.
>> >
>> >
>> >Matt
>> >
>> >> +		},
>> >> +	};
>> >> +	const u16 *csc;
>> >> +
>> >> +	if (plane_state->base.color_range ==
>> >DRM_COLOR_YCBCR_FULL_RANGE)
>> >> +		csc = input_csc_matrix[plane_state->base.color_encoding];
>> >> +	else
>> >> +		csc = input_csc_matrix_lr[plane_state->base.color_encoding];
>> >> +
>> >> +	I915_WRITE(PLANE_INPUT_CSC_COEFF(pipe, plane, 0), ROFF(csc[0]) |
>> >> +		   GOFF(csc[1]));
>> >> +	I915_WRITE(PLANE_INPUT_CSC_COEFF(pipe, plane, 1), BOFF(csc[2]));
>> >> +	I915_WRITE(PLANE_INPUT_CSC_COEFF(pipe, plane, 2), ROFF(csc[3]) |
>> >> +		   GOFF(csc[4]));
>> >> +	I915_WRITE(PLANE_INPUT_CSC_COEFF(pipe, plane, 3), BOFF(csc[5]));
>> >> +	I915_WRITE(PLANE_INPUT_CSC_COEFF(pipe, plane, 4), ROFF(csc[6]) |
>> >> +		   GOFF(csc[7]));
>> >> +	I915_WRITE(PLANE_INPUT_CSC_COEFF(pipe, plane, 5), BOFF(csc[8]));
>> >> +
>> >> +	I915_WRITE(PLANE_INPUT_CSC_PREOFF(pipe, plane, 0),
>> >> +		   PREOFF_YUV_TO_RGB_HI);
>> >> +	I915_WRITE(PLANE_INPUT_CSC_PREOFF(pipe, plane, 1),
>> >> +		   PREOFF_YUV_TO_RGB_ME);
>> >> +	I915_WRITE(PLANE_INPUT_CSC_PREOFF(pipe, plane, 2),
>> >> +		   PREOFF_YUV_TO_RGB_LO);
>> >> +
>> >> +	I915_WRITE(PLANE_INPUT_CSC_POSTOFF(pipe, plane, 0), 0x0);
>> >> +	I915_WRITE(PLANE_INPUT_CSC_POSTOFF(pipe, plane, 1), 0x0);
>> >> +	I915_WRITE(PLANE_INPUT_CSC_POSTOFF(pipe, plane, 2), 0x0); }
>> >> +
>> >>  void intel_color_init(struct drm_crtc *crtc)  {
>> >>  	struct drm_i915_private *dev_priv = to_i915(crtc->dev); diff
>> >> --git a/drivers/gpu/drm/i915/intel_display.c
>> >> b/drivers/gpu/drm/i915/intel_display.c
>> >> index fe045ab..d16a064 100644
>> >> --- a/drivers/gpu/drm/i915/intel_display.c
>> >> +++ b/drivers/gpu/drm/i915/intel_display.c
>> >> @@ -3666,6 +3666,7 @@ u32 glk_plane_color_ctl(const struct
>> >> intel_crtc_state
>> >*crtc_state,
>> >>  	struct drm_i915_private *dev_priv =
>> >>  		to_i915(plane_state->base.plane->dev);
>> >>  	const struct drm_framebuffer *fb = plane_state->base.fb;
>> >> +	struct intel_plane *plane =
>> >> +to_intel_plane(plane_state->base.plane);
>> >>  	u32 plane_color_ctl = 0;
>> >>
>> >>  	if (INTEL_GEN(dev_priv) < 11) {
>> >> @@ -3676,13 +3677,23 @@ u32 glk_plane_color_ctl(const struct
>> >intel_crtc_state *crtc_state,
>> >>  	plane_color_ctl |= glk_plane_color_ctl_alpha(plane_state);
>> >>
>> >>  	if (fb->format->is_yuv) {
>> >> -		if (plane_state->base.color_encoding ==
>> >DRM_COLOR_YCBCR_BT709)
>> >> -			plane_color_ctl |=
>> >PLANE_COLOR_CSC_MODE_YUV709_TO_RGB709;
>> >> -		else
>> >> -			plane_color_ctl |=
>> >PLANE_COLOR_CSC_MODE_YUV601_TO_RGB709;
>> >> +		if (!icl_is_hdr_plane(plane)) {
>> >> +			if (plane_state->base.color_encoding ==
>> >> +					DRM_COLOR_YCBCR_BT709)
>> >> +				plane_color_ctl |=
>> >> +
>> >	PLANE_COLOR_CSC_MODE_YUV709_TO_RGB709;
>> >> +			else
>> >> +				plane_color_ctl |=
>> >> +
>> >	PLANE_COLOR_CSC_MODE_YUV601_TO_RGB709;
>> >>
>> >> -		if (plane_state->base.color_range ==
>> >DRM_COLOR_YCBCR_FULL_RANGE)
>> >> -			plane_color_ctl |=
>> >PLANE_COLOR_YUV_RANGE_CORRECTION_DISABLE;
>> >> +			if (plane_state->base.color_range ==
>> >> +					DRM_COLOR_YCBCR_FULL_RANGE)
>> >> +				plane_color_ctl |=
>> >> +
>> >	PLANE_COLOR_YUV_RANGE_CORRECTION_DISABLE;
>> >> +		} else {
>> >> +			icl_program_input_csc_coeff(crtc_state, plane_state);
>> >> +			plane_color_ctl |= PLANE_COLOR_INPUT_CSC_ENABLE;
>> >> +		}
>> >>  	}
>> >>
>> >>  	return plane_color_ctl;
>> >> diff --git a/drivers/gpu/drm/i915/intel_drv.h
>> >> b/drivers/gpu/drm/i915/intel_drv.h
>> >> index db24308..bd9e946 100644
>> >> --- a/drivers/gpu/drm/i915/intel_drv.h
>> >> +++ b/drivers/gpu/drm/i915/intel_drv.h
>> >> @@ -2285,6 +2285,8 @@ int intel_plane_atomic_check_with_state(const
>> >> struct intel_crtc_state *old_crtc_  int intel_color_check(struct
>> >> drm_crtc *crtc, struct drm_crtc_state *state);  void
>> >> intel_color_set_csc(struct drm_crtc_state *crtc_state);  void
>> >> intel_color_load_luts(struct drm_crtc_state *crtc_state);
>> >> +void icl_program_input_csc_coeff(const struct intel_crtc_state *crtc_state,
>> >> +				 const struct intel_plane_state *plane_state);
>> >>
>> >>  /* intel_lspcon.c */
>> >>  bool lspcon_init(struct intel_digital_port *intel_dig_port);
>> >> --
>> >> 1.9.1
>> >>
>> >> _______________________________________________
>> >> Intel-gfx mailing list
>> >> Intel-gfx at lists.freedesktop.org
>> >> https://lists.freedesktop.org/mailman/listinfo/intel-gfx
>> >
>> >--
>> >Matt Roper
>> >Graphics Software Engineer
>> >IoTG Platform Enabling & Development
>> >Intel Corporation
>> >(916) 356-2795
>
>--
>Matt Roper
>Graphics Software Engineer
>IoTG Platform Enabling & Development
>Intel Corporation
>(916) 356-2795


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