>-----Original Message----- >From: Ville Syrjälä [mailto:ville.syrjala@xxxxxxxxxxxxxxx] >Sent: Thursday, May 9, 2019 8:28 PM >To: Shankar, Uma <uma.shankar@xxxxxxxxx> >Cc: Sharma, Shashank <shashank.sharma@xxxxxxxxx>; intel- >gfx@xxxxxxxxxxxxxxxxxxxxx >Subject: Re: [PATCH] drm/i915/icl: Handle YCbCr to RGB conversion for >BT2020 case > >On Thu, May 09, 2019 at 02:54:19PM +0000, Shankar, Uma wrote: >> >> >> >-----Original Message----- >> >From: Ville Syrjälä [mailto:ville.syrjala@xxxxxxxxxxxxxxx] >> >Sent: Tuesday, May 7, 2019 9:08 PM >> >To: Shankar, Uma <uma.shankar@xxxxxxxxx> >> >Cc: Sharma, Shashank <shashank.sharma@xxxxxxxxx>; intel- >> >gfx@xxxxxxxxxxxxxxxxxxxxx >> >Subject: Re: [PATCH] drm/i915/icl: Handle YCbCr to RGB >> >conversion for >> >BT2020 case >> > >> >On Tue, May 07, 2019 at 02:35:15PM +0000, Shankar, Uma wrote: >> >> >> >> >> >> >-----Original Message----- >> >> >From: Intel-gfx [mailto:intel-gfx-bounces@xxxxxxxxxxxxxxxxxxxxx] >> >> >On Behalf Of Ville Syrjälä >> >> >Sent: Tuesday, May 7, 2019 7:37 PM >> >> >To: Sharma, Shashank <shashank.sharma@xxxxxxxxx> >> >> >Cc: intel-gfx@xxxxxxxxxxxxxxxxxxxxx >> >> >Subject: Re: [PATCH] drm/i915/icl: Handle YCbCr to RGB >> >> >conversion for >> >> >BT2020 case >> >> > >> >> >On Tue, May 07, 2019 at 06:32:57PM +0530, Shashank Sharma wrote: >> >> >> From: Uma Shankar <uma.shankar@xxxxxxxxx> >> >> >> >> >> >> Currently input csc for YCbCR to RGB conversion handles only >> >> >> BT601 and Bt709. Extending it to support BT2020 as well. >> >> >> >> >> >> Signed-off-by: Uma Shankar <uma.shankar@xxxxxxxxx> >> >> >> Signed-off-by: Shashank Sharma <shashank.sharma@xxxxxxxxx> >> >> >> --- >> >> >> drivers/gpu/drm/i915/intel_sprite.c | 24 >> >> >> ++++++++++++++++++++++++ >> >> >> 1 file changed, 24 insertions(+) >> >> >> >> >> >> diff --git a/drivers/gpu/drm/i915/intel_sprite.c >> >> >> b/drivers/gpu/drm/i915/intel_sprite.c >> >> >> index 44aaeac1b2ed..2536e757bec2 100644 >> >> >> --- a/drivers/gpu/drm/i915/intel_sprite.c >> >> >> +++ b/drivers/gpu/drm/i915/intel_sprite.c >> >> >> @@ -433,6 +433,18 @@ icl_program_input_csc(struct intel_plane *plane, >> >> >> 0x9EF8, 0x7800, 0xABF8, >> >> >> 0x0, 0x7800, 0x7ED8, >> >> >> }, >> >> >> + /* >> >> >> + * BT.2020 full range YCbCr -> full range RGB >> >> >> + * The matrix required is : >> >> >> + * [1.000, 0.000, 1.474, >> >> >> + * 1.000, -0.1645, -0.5713, >> >> >> + * 1.000, 1.8814, 0.0000] >> >> >> + */ >> >> >> + [DRM_COLOR_YCBCR_BT2020] = { >> >> >> + 0x7BC8, 0x7800, 0x0, >> >> >> + 0x8928, 0x7800, 0xAA88, >> >> >> + 0x0, 0x7800, 0x7F10, >> >> >> + }, >> >> >> }; >> >> >> >> >> >> /* Matrix for Limited Range to Full Range Conversion */ @@ >> >> >> -461,6 >> >> >> +473,18 @@ icl_program_input_csc(struct intel_plane *plane, >> >> >> 0x8888, 0x7918, 0xADA8, >> >> >> 0x0, 0x7918, 0x6870, >> >> >> }, >> >> >> + /* >> >> >> + * BT.2020 Limited range YCbCr -> full range RGB >> >> >> + * The matrix required is : >> >> >> + * [1.164, 0.000, 1.717, >> >> >> + * 1.138, -0.1873, -0.6504, >> >> >> + * 1.1380, 2.1417, 0.0000] >> >> > >> >> >Where are those 1.138 coming from? >> >> >> >> Hi Ville, >> >> This is the original YCBCR to RGB BT2020 matrix: >> >> { >> >> 1.00000000000, 0.00000000000, 1.47460000000, >> >> 1.00000000000, -0.16455312684, -0.57135312684, >> >> 1.00000000000, 1.88140000000, 0.00000000000 }; >> >> >> >> We have to convert Limited Range YCbCr to Full Range RGB. Hence we >> >> need to >> >apply a scale factor: >> >> yscalefactor = 219.0 * normalizingfactor; cbcrscalefactor = 224.0 >> >> * normalizingfactor; >> >> >> >> /* Scale factors are inverted for LR to FR conversion */ >> >> yscalefactor = 1.0 / yscalefactor; cbcrscalefactor = 1.0 / >> >> cbcrscalefactor; >> >> >> >> This yields the above results. >> > >> >Those are the coefficients for Y, so they should still be the same >> >for all three output channels. >> > >> >igt_color_encoding gives me: >> >|1.1644, 0.0000, 1.6787,| >> >|1.1644,-0.1873,-0.6504,| >> >|1.1644, 2.1418, 0.0000,| >> >> Ok, I used the igt_color_encoding method and able to get values what you got. >> Will update the matrix. Thanks Ville. >> >> >Looks like we're also misprogramming the Y pre-offset for the full range YCbCr >case. >> For full range, I am getting same values as programmed above. Looks ok, can you >double check. > >The matrix itself looks OK (some minor rounding differences perhaps, but nothing >major). But the Y preoffset should be zero for full range YCbCr. Hi Ville, This is what I got for Full Range from igt_color_encoding. m4.d[m(row=0, col=0)] = 1.000000 m4.d[m(row=1, col=0)] = 1.000000 m4.d[m(row=2, col=0)] = 1.000000 m4.d[m(row=3, col=0)] = 0.000000 m4.d[m(row=0, col=1)] = 0.000000 m4.d[m(row=1, col=1)] = -0.164553 m4.d[m(row=2, col=1)] = 1.881400 m4.d[m(row=3, col=1)] = 0.000000 m4.d[m(row=0, col=2)] = 1.474600 m4.d[m(row=1, col=2)] = -0.571353 m4.d[m(row=2, col=2)] = 0.000000 m4.d[m(row=3, col=2)] = 0.000000 m4.d[m(row=0, col=3)] = -188.748810 m4.d[m(row=1, col=3)] = 94.195992 m4.d[m(row=2, col=3)] = -240.819199 m4.d[m(row=3, col=3)] = 1.000000 which matches our table. This is the argument list for : struct igt_mat4 m4 = igt_ycbcr_to_rgb_matrix(DRM_FORMAT_YUV420, DRM_FORMAT_XRGB8888, IGT_COLOR_YCBCR_BT2020, IGT_COLOR_YCBCR_FULL_RANGE); Am I am missing something ? Regards, Uma Shankar >Ville Syrjälä >Intel _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
