On Sun, Dec 17, 2017 at 02:17:21AM +0200, Laurent Pinchart wrote:
> Color keying is the action of replacing pixels matching a given color
> (or range of colors) with transparent pixels in an overlay when
> performing blitting. Depending on the hardware capabilities, the
> matching pixel can either become fully transparent, or gain a
> programmable alpha value.
>
> Color keying is found in a large number of devices whose capabilities
> often differ, but they still have enough common features in range to
> standardize color key properties. This commit adds four properties
> related to color keying named colorkey.min, colorkey.max, colorkey.alpha
> and colorkey.mode. Additional properties can be defined by drivers to
> expose device-specific features.
>
> Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@xxxxxxxxxxxxxxxx>
> ---
> drivers/gpu/drm/drm_atomic.c | 16 +++++++
> drivers/gpu/drm/drm_blend.c | 108 +++++++++++++++++++++++++++++++++++++++++++
> include/drm/drm_blend.h | 4 ++
> include/drm/drm_plane.h | 28 ++++++++++-
> 4 files changed, 155 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
> index 37445d50816a..4f57ec25e04d 100644
> --- a/drivers/gpu/drm/drm_atomic.c
> +++ b/drivers/gpu/drm/drm_atomic.c
> @@ -756,6 +756,14 @@ static 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->colorkey.mode_property) {
> + state->colorkey.mode = val;
> + } else if (property == plane->colorkey.min_property) {
> + state->colorkey.min = val;
> + } else if (property == plane->colorkey.max_property) {
> + state->colorkey.max = val;
> + } else if (property == plane->colorkey.value_property) {
> + state->colorkey.value = val;
> } else if (plane->funcs->atomic_set_property) {
> return plane->funcs->atomic_set_property(plane, state,
> property, val);
> @@ -815,6 +823,14 @@ drm_atomic_plane_get_property(struct drm_plane *plane,
> *val = state->rotation;
> } else if (property == plane->zpos_property) {
> *val = state->zpos;
> + } else if (property == plane->colorkey.mode_property) {
> + *val = state->colorkey.mode;
> + } else if (property == plane->colorkey.min_property) {
> + *val = state->colorkey.min;
> + } else if (property == plane->colorkey.max_property) {
> + *val = state->colorkey.max;
> + } else if (property == plane->colorkey.value_property) {
> + *val = state->colorkey.value;
> } 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_blend.c b/drivers/gpu/drm/drm_blend.c
> index 2e5e089dd912..79da7d8a22e2 100644
> --- a/drivers/gpu/drm/drm_blend.c
> +++ b/drivers/gpu/drm/drm_blend.c
> @@ -98,6 +98,10 @@
> * planes. Without this property the primary plane is always below the cursor
> * plane, and ordering between all other planes is undefined.
> *
> + * - Color keying is set up with drm_plane_create_colorkey_properties(). It adds
> + * support for replacing a range of colors with a transparent color in the
> + * plane.
> + *
> * Note that all the property extensions described here apply either to the
> * plane or the CRTC (e.g. for the background color, which currently is not
> * exposed and assumed to be black).
> @@ -405,3 +409,107 @@ int drm_atomic_normalize_zpos(struct drm_device *dev,
> return 0;
> }
> EXPORT_SYMBOL(drm_atomic_normalize_zpos);
> +
> +/**
> + * drm_plane_create_colorkey_properties - create colorkey properties
> + * @plane: drm plane
> + * @modes: array of supported color keying modes
> + * @num_modes: number of modes in the modes array
> + * @replace: if true create the colorkey.replacement property
> + *
> + * This function creates the generic color keying properties and attach them to
> + * the plane to enable color keying control for blending operations.
> + *
> + * Color keying is controlled through four properties:
> + *
> + * colorkey.mode:
> + * The mode is an enumerated property that controls how color keying
> + * operates. Modes are driver-specific, except for a "disabled" mode that
> + * disables color keying and is guaranteed to exist if color keying is
> + * supported.
I don't see why we need driver specific modes. It should be possible to
come up with some standard modes. I suppose a simple src vs. dst doesn't
suffice, but if we combine that with a bit more information it should be
good enough? Eg. i915 would expose something like src-min-max and
dst-value-mask.
> + *
> + * colorkey.min, colorkey.max:
> + * Those two properties specify the colors that are replaced by transparent
> + * pixels. Pixel whose values are in the [min, max] range are replaced, all
> + * other pixels are left untouched. The minimum and maximum values are
> + * expressed as a 64-bit integer in AXYZ16161616 format, where A is the
> + * alpha value and X, Y and Z correspond to the color components of the
> + * plane's pixel format. In most cases XYZ will be either RGB or YUV.
> + *
> + * When a single color key is supported instead of a range, userspace shall
> + * set the min and max properties to the same value, and drivers return an
> + * error from their plane atomic check when the min and max values differ.
> + *
> + * Note that depending on the selected mode, not all components might be
> + * used for comparison. For instance a device could support color keying in
> + * YUV format using luma (Y) matching only, ignoring the chroma components.
> + * This behaviour is driver-specific.
This doesn't quite seem to support the common value+mask approach.
Your luma matching thing could maybe be expressed via the mask by
just setting both the key value and mask to zero for any component
that shouldn't participate in the match. Although I suppose for i915
we'd need to have a src-min-max-mask type of mode for that, and we
couldn't actually support arbitrary masks in that case (just 0 and ~0).
So maybe there should be separate mode for that to indicate that
particular restriction.
> + *
> + * colorkey.value:
"value" makes me think of the key value. replacement-value or some
such would be a bit more descriptive.
> + * This property specifies the color value that replaces pixels matching
> + * the [min, max] range. The value is expressed in AXYZ16161616 format as
> + * the min and max properties.
> + *
> + * This property is optional and only present when the device supports
> + * configurable color replacement for matching pixels in the plane. If
> + * color keying capabilities of the device are limited to making the
> + * matching pixels fully transparent the colorkey.value property won't be
> + * created.
> + *
> + * Note that depending on the device, or the selected mode, not all
> + * components might be used for value replacement. For instance a device
> + * could support replacing the alpha value of the matching pixels but not
> + * its color components. This behaviour is driver-specific.
> + *
> + * The @modes parameter points to an array of all color keying modes supported
> + * by the plane. The first mode has to be named "disabled" and have value 0. All
> + * other modes are driver-specific, and at least one mode has to be provided in
> + * addition to the "disabled" mode.
> + *
> + * Returns:
> + * Zero on success, negative errno on failure.
> + */
> +int drm_plane_create_colorkey_properties(struct drm_plane *plane,
> + const struct drm_prop_enum_list *modes,
> + unsigned int num_modes, bool replace)
> +{
> +#define CREATE_COLORKEY_PROP(plane, name, type, args...) ({ \
> + prop = drm_property_create_##type(plane->dev, 0, "colorkey." #name, \
> + args); \
> + if (prop) { \
> + drm_object_attach_property(&plane->base, prop, 0); \
> + plane->colorkey.name##_property = prop; \
> + } \
> + prop; \
> +})
> +
> + struct drm_property *prop;
> +
> + /*
> + * A minimum of two modes are required, with the first mode must named
> + * "disabled".
> + */
> + if (!modes || num_modes == 0 || strcmp(modes[0].name, "disabled"))
> + return -EINVAL;
> +
> + prop = CREATE_COLORKEY_PROP(plane, mode, enum, modes, num_modes);
> + if (!prop)
> + return -ENOMEM;
> +
> + prop = CREATE_COLORKEY_PROP(plane, min, range, 0, U64_MAX);
> + if (!prop)
> + return -ENOMEM;
> +
> + prop = CREATE_COLORKEY_PROP(plane, max, range, 0, U64_MAX);
> + if (!prop)
> + return -ENOMEM;
> +
> + if (replace) {
> + prop = CREATE_COLORKEY_PROP(plane, value, range, 0, U64_MAX);
> + if (!prop)
> + return -ENOMEM;
> + }
> +
> + return 0;
> +}
> +EXPORT_SYMBOL(drm_plane_create_colorkey_properties);
> diff --git a/include/drm/drm_blend.h b/include/drm/drm_blend.h
> index 17606026590b..1d4c965dd5e2 100644
> --- a/include/drm/drm_blend.h
> +++ b/include/drm/drm_blend.h
> @@ -49,4 +49,8 @@ int drm_plane_create_zpos_immutable_property(struct drm_plane *plane,
> unsigned int zpos);
> int drm_atomic_normalize_zpos(struct drm_device *dev,
> struct drm_atomic_state *state);
> +
> +int drm_plane_create_colorkey_properties(struct drm_plane *plane,
> + const struct drm_prop_enum_list *modes,
> + unsigned int num_modes, bool replace);
> #endif
> diff --git a/include/drm/drm_plane.h b/include/drm/drm_plane.h
> index 8185e3468a23..a5804a4ea5c3 100644
> --- a/include/drm/drm_plane.h
> +++ b/include/drm/drm_plane.h
> @@ -52,6 +52,13 @@ struct drm_modeset_acquire_ctx;
> * where N is the number of active planes for given crtc. Note that
> * the driver must call drm_atomic_normalize_zpos() to update this before
> * it can be trusted.
> + * @colorkey.mode: color key mode. 0 disabled color keying, other values are
> + * driver-specific.
> + * @colorkey.min: color key range minimum. The value is stored in AXYZ16161616
> + * format, where A is the alpha value and X, Y and Z correspond to the
> + * color components of the plane's pixel format (usually RGB or YUV).
> + * @colorkey.max: color key range maximum (in AXYZ16161616 format)
> + * @colorkey.value: color key replacement value (in in AXYZ16161616 format)
> * @src: clipped source coordinates of the plane (in 16.16)
> * @dst: clipped destination coordinates of the plane
> * @state: backpointer to global drm_atomic_state
> @@ -112,6 +119,14 @@ struct drm_plane_state {
> unsigned int zpos;
> unsigned int normalized_zpos;
>
> + /* Plane colorkey */
> + struct {
> + unsigned int mode;
> + u64 min;
> + u64 max;
> + u64 value;
> + } colorkey;
> +
> /* Clipped coordinates */
> struct drm_rect src, dst;
>
> @@ -481,9 +496,13 @@ enum drm_plane_type {
> * @funcs: helper functions
> * @properties: property tracking for this plane
> * @type: type of plane (overlay, primary, cursor)
> + * @helper_private: mid-layer private data
> * @zpos_property: zpos property for this plane
> * @rotation_property: rotation property for this plane
> - * @helper_private: mid-layer private data
> + * @colorkey.mode_property: color key mode property
> + * @colorkey.min_property: color key range minimum property
> + * @colorkey.max_property: color key range maximum property
> + * @colorkey.value_property: color key replacement value property
> */
> struct drm_plane {
> struct drm_device *dev;
> @@ -558,6 +577,13 @@ struct drm_plane {
>
> struct drm_property *zpos_property;
> struct drm_property *rotation_property;
> +
> + struct {
> + struct drm_property *mode_property;
> + struct drm_property *min_property;
> + struct drm_property *max_property;
> + struct drm_property *value_property;
> + } colorkey;
> };
>
> #define obj_to_plane(x) container_of(x, struct drm_plane, base)
> --
> Regards,
>
> Laurent Pinchart
>
> _______________________________________________
> dri-devel mailing list
> dri-devel@xxxxxxxxxxxxxxxxxxxxx
> https://lists.freedesktop.org/mailman/listinfo/dri-devel
--
Ville Syrjälä
Intel
