Struct DrmFormat

pub struct DrmFormat {
    pub fourcc: u32,
    pub modifiers: u64,
}

In the Linux DRM+KMS system (i.e. kernel-side GPU drivers), a “DRM format” is an image format (i.e. a specific byte-level encoding of texel data) that framebuffers (or more generally “surfaces” / “images”) could use, provided that all the GPUs involved support the specific format used.

See also https://docs.kernel.org/gpu/drm-kms.html#drm-format-handling.

Fields

fourcc: u32

FourCC code for a “DRM format”, i.e. one of the DRM_FORMAT_* values defined in drm/drm_fourcc.h, and the main aspect of a “DRM format” that userspace needs to care about (e.g. RGB vs YUV, bit width, etc.).

For example, non-HDR RGBA surfaces will almost always use the format DRM_FORMAT_ABGR8888 (with FourCC "AB24", i.e. 0x34324241), and:

• “A” can be replaced with “X” (disabling the alpha channel)
• “AB” can be reversed, to get “BA” (ABGR -> BGRA)
• “B” can be replaced with “R” (ABGR -> ARGB)
• “AR” can be reversed, to get “RA” (ARGB -> RGBA)
• “24” can be replaced with “30” or “48” (increasing bits per channel)

Some formats also require multiple “planes” (i.e. independent buffers), and while that’s commonly for YUV formats, planar RGBA also exists.

modifiers: u64

Each “DRM format” may be further “modified” with additional features, describing how memory is accessed by GPU texture units (e.g. “tiling”), and optionally requiring additional “planes” for compression purposes.

To userspace, the modifiers are almost always opaque and merely need to be passed from an image exporter to an image importer, to correctly interpret the GPU memory in the same way on both sides.

Trait Implementations

impl Clone for DrmFormat

fn clone(&self) -> DrmFormat

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl DeBin for DrmFormat

fn de_bin(o: &mut usize, d: &[u8]) -> Result<Self, DeBinErr>

fn deserialize_bin(d: &[u8]) -> Result<Self, DeBinErr>

impl DeJson for DrmFormat

fn de_json(s: &mut DeJsonState, i: &mut Chars<'_>) -> Result<Self, DeJsonErr>

fn deserialize_json(input: &str) -> Result<Self, DeJsonErr>

impl Debug for DrmFormat

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl PartialEq for DrmFormat

fn eq(&self, other: &DrmFormat) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl SerBin for DrmFormat

fn ser_bin(&self, s: &mut Vec<u8>)

fn serialize_bin(&self) -> Vec<u8>

impl SerJson for DrmFormat

fn ser_json(&self, d: usize, s: &mut SerJsonState)

fn serialize_json(&self) -> String

impl Copy for DrmFormat

impl StructuralPartialEq for DrmFormat