[PATCH] drm: Add optional COLOR_ENCODING and COLOR_RANGE properties to drm_plane
Hans Verkuil
hverkuil at xs4all.nl
Tue Feb 6 18:08:34 UTC 2018
On 02/06/2018 06:58 PM, Ville Syrjälä wrote:
> On Mon, Jun 12, 2017 at 12:10:04AM +0300, Jyri Sarha wrote:
>> Add a standard optional properties to support different non RGB color
>> encodings in DRM planes. COLOR_ENCODING select the supported non RGB
>> color encoding, for instance ITU-R BT.709 YCbCr. COLOR_RANGE selects
>> the value ranges within the selected color encoding. The properties
>> are stored to drm_plane object to allow different set of supported
>> encoding for different planes on the device.
>>
>> Signed-off-by: Jyri Sarha <jsarha at ti.com>
>> ---
>> drivers/gpu/drm/drm_atomic.c | 8 ++++
>> drivers/gpu/drm/drm_color_mgmt.c | 91 ++++++++++++++++++++++++++++++++++++++++
>> include/drm/drm_color_mgmt.h | 19 +++++++++
>> include/drm/drm_plane.h | 8 ++++
>> 4 files changed, 126 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
>> index 77dcef0..8067681 100644
>> --- a/drivers/gpu/drm/drm_atomic.c
>> +++ b/drivers/gpu/drm/drm_atomic.c
>> @@ -786,6 +786,10 @@ int drm_atomic_plane_set_property(struct drm_plane *plane,
>> state->rotation = val;
>> } else if (property == plane->zpos_property) {
>> state->zpos = val;
>> + } else if (property == plane->color_encoding_property) {
>> + state->color_encoding = val;
>> + } else if (property == plane->color_range_property) {
>> + state->color_range = val;
>> } else if (plane->funcs->atomic_set_property) {
>> return plane->funcs->atomic_set_property(plane, state,
>> property, val);
>> @@ -846,6 +850,10 @@ int drm_atomic_plane_set_property(struct drm_plane *plane,
>> *val = state->rotation;
>> } else if (property == plane->zpos_property) {
>> *val = state->zpos;
>> + } else if (property == plane->color_encoding_property) {
>> + *val = state->color_encoding;
>> + } else if (property == plane->color_range_property) {
>> + *val = state->color_range;
>> } else if (plane->funcs->atomic_get_property) {
>> return plane->funcs->atomic_get_property(plane, state, property, val);
>> } else {
>> diff --git a/drivers/gpu/drm/drm_color_mgmt.c b/drivers/gpu/drm/drm_color_mgmt.c
>> index 3eda500..9077bf6 100644
>> --- a/drivers/gpu/drm/drm_color_mgmt.c
>> +++ b/drivers/gpu/drm/drm_color_mgmt.c
>> @@ -88,6 +88,19 @@
>> * drm_mode_crtc_set_gamma_size(). Drivers which support both should use
>> * drm_atomic_helper_legacy_gamma_set() to alias the legacy gamma ramp with the
>> * "GAMMA_LUT" property above.
>> + *
>> + * Support for different non RGB color encodings is controlled through
>> + * &drm_plane specific COLOR_ENCODING and COLOR_RANGE properties:
>> + *
>> + * "COLOR_ENCODING"
>> + * Optional plane enum property to support different non RGB
>> + * color encodings. The driver can provide a subset of standard
>> + * enum values supported by the DRM plane.
>> + *
>> + * "COLOR_RANGE"
>> + * Optional plane enum property to support different non RGB
>> + * color parameter ranges. The driver can provide a subset of
>> + * standard enum values supported by the DRM plane.
>> */
>>
>> /**
>> @@ -336,3 +349,81 @@ int drm_mode_gamma_get_ioctl(struct drm_device *dev,
>> drm_modeset_unlock(&crtc->mutex);
>> return ret;
>> }
>> +
>> +static const char * const color_encoding_name[] = {
>> + [DRM_COLOR_YCBCR_BT601] = "ITU-R BT.601 YCbCr",
>> + [DRM_COLOR_YCBCR_BT709] = "ITU-R BT.709 YCbCr",
>> + [DRM_COLOR_YCBCR_BT2020] = "ITU-R BT.2020 YCbCr",
>
> I was just looking at this again (in the hopes of landing it finally),
> and then I realized we probably need to split this BT.2020 into
> constant and non-constant luminance variants.
>
> ..._BT2020_CL and ..._BT2020_NCL maybe?
This is what V4L2 uses:
https://hverkuil.home.xs4all.nl/spec/uapi/v4l/colorspaces-defs.html
V4L2_YCBCR_ENC_BT2020 and V4L2_YCBCR_ENC_BT2020_CONST_LUM.
I've never seen V4L2_YCBCR_ENC_BT2020_CONST_LUM in the wild. Non-constant
Bt.2020 is what is normally used, so I'd keep the define just as-is:
DRM_COLOR_YCBCR_BT2020. And add a DRM_COLOR_YCBCR_BT2020_CONST_LUM if
you think you need it. I've never seen anyone use this.
And in case you wonder why: this is the BT.2020 OpenGL Y'CbCr to R'G'B'
conversion:
float r = y + 1.4719 * v;
float g = y - 0.1646 * u - 0.5703 * v;
float b = y + 1.8814 * u;
And this for BT.2020 constant luminance:
float b = u <= 0.0 ? y + 1.9404 * u : y + 1.5816 * u;
float r = v <= 0.0 ? y + 1.7184 * v : y + 0.9936 * v;
float lin_r = (r < 0.081) ? r / 4.5 : pow((r + 0.099) / 1.099, 1.0 / 0.45);
float lin_b = (b < 0.081) ? b / 4.5 : pow((b + 0.099) / 1.099, 1.0 / 0.45);
float lin_y = (y < 0.081) ? y / 4.5 : pow((y + 0.099) / 1.099, 1.0 / 0.45);
float lin_g = lin_y / 0.6780 - lin_r * 0.2627 / 0.6780 - lin_b * 0.0593 / 0.6780;
float g = (lin_g < 0.018) ? lin_g * 4.5 : 1.099 * pow(lin_g, 0.45) - 0.099;
Brr :-)
Regards,
Hans
>
>> +};
>> +
>> +static const char * const color_range_name[] = {
>> + [DRM_COLOR_YCBCR_FULL_RANGE] = "YCbCr full range",
>> + [DRM_COLOR_YCBCR_LIMITED_RANGE] = "YCbCr limited range",
>> +};
>> +
>> +/**
>> + * drm_plane_create_color_properties - color encoding related plane properties
>> + * @supported_encodings: bitfield indicating supported color encodings
>> + * @supported_ranges: bitfileld indicating supported color ranges
>> + * @default_encoding: default color encoding
>> + * @default_range: default color range
>> + *
>> + * Create and attach plane specific COLOR_ENCODING and COLOR_RANGE
>> + * properties to to the drm_plane object. The supported encodings and
>> + * ranges should be provided in supported_encodings and
>> + * supported_ranges bitmasks. Each bit set in the bitmask indicates
>> + * the its number as enum value being supported.
>> + */
>> +int drm_plane_create_color_properties(struct drm_plane *plane,
>> + u32 supported_encodings,
>> + u32 supported_ranges,
>> + enum drm_color_encoding default_encoding,
>> + enum drm_color_range default_range)
>> +{
>> + struct drm_device *dev = plane->dev;
>> + struct drm_property *prop;
>> + struct drm_prop_enum_list enum_list[max(DRM_COLOR_ENCODING_MAX,
>> + DRM_COLOR_RANGE_MAX)];
>> + int i, len;
>> +
>> + len = 0;
>> + for (i = 0; i < DRM_COLOR_ENCODING_MAX; i++) {
>> + if ((supported_encodings & BIT(i)) == 0)
>> + continue;
>> +
>> + enum_list[len].type = i;
>> + enum_list[len].name = color_encoding_name[i];
>> + len++;
>> + }
>> +
>> + prop = drm_property_create_enum(dev, 0, "COLOR_ENCODING",
>> + enum_list, len);
>> + if (!prop)
>> + return -ENOMEM;
>> + plane->color_encoding_property = prop;
>> + drm_object_attach_property(&plane->base, prop, default_encoding);
>> + if (plane->state)
>> + plane->state->color_encoding = default_encoding;
>> +
>> + len = 0;
>> + for (i = 0; i < DRM_COLOR_RANGE_MAX; i++) {
>> + if ((supported_ranges & BIT(i)) == 0)
>> + continue;
>> +
>> + enum_list[len].type = i;
>> + enum_list[len].name = color_range_name[i];
>> + len++;
>> + }
>> +
>> + prop = drm_property_create_enum(dev, 0, "COLOR_RANGE",
>> + enum_list, len);
>> + if (!prop)
>> + return -ENOMEM;
>> + plane->color_range_property = prop;
>> + drm_object_attach_property(&plane->base, prop, default_range);
>> + if (plane->state)
>> + plane->state->color_range = default_range;
>> +
>> + return 0;
>> +}
>> +EXPORT_SYMBOL(drm_plane_create_color_properties);
>> diff --git a/include/drm/drm_color_mgmt.h b/include/drm/drm_color_mgmt.h
>> index 03a59cb..b3b6d30 100644
>> --- a/include/drm/drm_color_mgmt.h
>> +++ b/include/drm/drm_color_mgmt.h
>> @@ -26,6 +26,7 @@
>> #include <linux/ctype.h>
>>
>> struct drm_crtc;
>> +struct drm_plane;
>>
>> uint32_t drm_color_lut_extract(uint32_t user_input, uint32_t bit_precision);
>>
>> @@ -37,4 +38,22 @@ void drm_crtc_enable_color_mgmt(struct drm_crtc *crtc,
>> int drm_mode_crtc_set_gamma_size(struct drm_crtc *crtc,
>> int gamma_size);
>>
>> +enum drm_color_encoding {
>> + DRM_COLOR_YCBCR_BT601,
>> + DRM_COLOR_YCBCR_BT709,
>> + DRM_COLOR_YCBCR_BT2020,
>> + DRM_COLOR_ENCODING_MAX,
>> +};
>> +
>> +enum drm_color_range {
>> + DRM_COLOR_YCBCR_LIMITED_RANGE,
>> + DRM_COLOR_YCBCR_FULL_RANGE,
>> + DRM_COLOR_RANGE_MAX,
>> +};
>> +
>> +int drm_plane_create_color_properties(struct drm_plane *plane,
>> + u32 supported_encodings,
>> + u32 supported_ranges,
>> + enum drm_color_encoding default_encoding,
>> + enum drm_color_range default_range);
>> #endif
>> diff --git a/include/drm/drm_plane.h b/include/drm/drm_plane.h
>> index 9ab3e70..f4de5f9 100644
>> --- a/include/drm/drm_plane.h
>> +++ b/include/drm/drm_plane.h
>> @@ -26,6 +26,7 @@
>> #include <linux/list.h>
>> #include <linux/ctype.h>
>> #include <drm/drm_mode_object.h>
>> +#include <drm/drm_color_mgmt.h>
>>
>> struct drm_crtc;
>> struct drm_printer;
>> @@ -112,6 +113,10 @@ struct drm_plane_state {
>> unsigned int zpos;
>> unsigned int normalized_zpos;
>>
>> + /* Color encoding for non RGB formats */
>> + enum drm_color_encoding color_encoding;
>> + enum drm_color_range color_range;
>> +
>> /* Clipped coordinates */
>> struct drm_rect src, dst;
>>
>> @@ -523,6 +528,9 @@ struct drm_plane {
>>
>> struct drm_property *zpos_property;
>> struct drm_property *rotation_property;
>> +
>> + struct drm_property *color_encoding_property;
>> + struct drm_property *color_range_property;
>> };
>>
>> #define obj_to_plane(x) container_of(x, struct drm_plane, base)
>> --
>> 1.9.1
>
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