wl_shm¤
Shared memory support
A singleton global object that provides support for shared memory.
Clients can create wl_shm_pool objects using the create_pool request.
On binding the wl_shm object one or more format events are emitted to inform clients about the valid pixel formats that can be used for buffers.
Methods:
-
create_pool–Create a shm pool
-
release–Release the shm object
-
on_format–Pixel format description.
wl_shm error values
These errors can be emitted in response to wl_shm requests.
-
invalid_format–Buffer format is not known -
invalid_stride–Invalid size or stride during pool or buffer creation -
invalid_fd–Mmapping the file descriptor failed
Pixel formats
This describes the memory layout of an individual pixel.
All renderers should support argb8888 and xrgb8888 but any other formats are optional and may not be supported by the particular renderer in use.
The drm format codes match the macros defined in drm_fourcc.h, except argb8888 and xrgb8888. The formats actually supported by the compositor will be reported by the format event.
For all wl_shm formats and unless specified in another protocol extension, pre-multiplied alpha is used for pixel values.
-
argb8888–32-bit argb format, [31:0] a:r:g:b 8:8:8:8 little endian -
xrgb8888–32-bit rgb format, [31:0] x:r:g:b 8:8:8:8 little endian -
c8–8-bit color index format, [7:0] c -
rgb332–8-bit rgb format, [7:0] r:g:b 3:3:2 -
bgr233–8-bit bgr format, [7:0] b:g:r 2:3:3 -
xrgb4444–16-bit xrgb format, [15:0] x:r:g:b 4:4:4:4 little endian -
xbgr4444–16-bit xbgr format, [15:0] x:b:g:r 4:4:4:4 little endian -
rgbx4444–16-bit rgbx format, [15:0] r:g:b:x 4:4:4:4 little endian -
bgrx4444–16-bit bgrx format, [15:0] b:g:r:x 4:4:4:4 little endian -
argb4444–16-bit argb format, [15:0] a:r:g:b 4:4:4:4 little endian -
abgr4444–16-bit abgr format, [15:0] a:b:g:r 4:4:4:4 little endian -
rgba4444–16-bit rbga format, [15:0] r:g:b:a 4:4:4:4 little endian -
bgra4444–16-bit bgra format, [15:0] b:g:r:a 4:4:4:4 little endian -
xrgb1555–16-bit xrgb format, [15:0] x:r:g:b 1:5:5:5 little endian -
xbgr1555–16-bit xbgr 1555 format, [15:0] x:b:g:r 1:5:5:5 little endian -
rgbx5551–16-bit rgbx 5551 format, [15:0] r:g:b:x 5:5:5:1 little endian -
bgrx5551–16-bit bgrx 5551 format, [15:0] b:g:r:x 5:5:5:1 little endian -
argb1555–16-bit argb 1555 format, [15:0] a:r:g:b 1:5:5:5 little endian -
abgr1555–16-bit abgr 1555 format, [15:0] a:b:g:r 1:5:5:5 little endian -
rgba5551–16-bit rgba 5551 format, [15:0] r:g:b:a 5:5:5:1 little endian -
bgra5551–16-bit bgra 5551 format, [15:0] b:g:r:a 5:5:5:1 little endian -
rgb565–16-bit rgb 565 format, [15:0] r:g:b 5:6:5 little endian -
bgr565–16-bit bgr 565 format, [15:0] b:g:r 5:6:5 little endian -
rgb888–24-bit rgb format, [23:0] r:g:b little endian -
bgr888–24-bit bgr format, [23:0] b:g:r little endian -
xbgr8888–32-bit xbgr format, [31:0] x:b:g:r 8:8:8:8 little endian -
rgbx8888–32-bit rgbx format, [31:0] r:g:b:x 8:8:8:8 little endian -
bgrx8888–32-bit bgrx format, [31:0] b:g:r:x 8:8:8:8 little endian -
abgr8888–32-bit abgr format, [31:0] a:b:g:r 8:8:8:8 little endian -
rgba8888–32-bit rgba format, [31:0] r:g:b:a 8:8:8:8 little endian -
bgra8888–32-bit bgra format, [31:0] b:g:r:a 8:8:8:8 little endian -
xrgb2101010–32-bit xrgb format, [31:0] x:r:g:b 2:10:10:10 little endian -
xbgr2101010–32-bit xbgr format, [31:0] x:b:g:r 2:10:10:10 little endian -
rgbx1010102–32-bit rgbx format, [31:0] r:g:b:x 10:10:10:2 little endian -
bgrx1010102–32-bit bgrx format, [31:0] b:g:r:x 10:10:10:2 little endian -
argb2101010–32-bit argb format, [31:0] a:r:g:b 2:10:10:10 little endian -
abgr2101010–32-bit abgr format, [31:0] a:b:g:r 2:10:10:10 little endian -
rgba1010102–32-bit rgba format, [31:0] r:g:b:a 10:10:10:2 little endian -
bgra1010102–32-bit bgra format, [31:0] b:g:r:a 10:10:10:2 little endian -
yuyv–Packed ycbcr format, [31:0] cr0:y1:cb0:y0 8:8:8:8 little endian -
yvyu–Packed ycbcr format, [31:0] cb0:y1:cr0:y0 8:8:8:8 little endian -
uyvy–Packed ycbcr format, [31:0] y1:cr0:y0:cb0 8:8:8:8 little endian -
vyuy–Packed ycbcr format, [31:0] y1:cb0:y0:cr0 8:8:8:8 little endian -
ayuv–Packed aycbcr format, [31:0] a:y:cb:cr 8:8:8:8 little endian -
nv12–2 plane ycbcr cr:cb format, 2x2 subsampled cr:cb plane -
nv21–2 plane ycbcr cb:cr format, 2x2 subsampled cb:cr plane -
nv16–2 plane ycbcr cr:cb format, 2x1 subsampled cr:cb plane -
nv61–2 plane ycbcr cb:cr format, 2x1 subsampled cb:cr plane -
yuv410–3 plane ycbcr format, 4x4 subsampled cb (1) and cr (2) planes -
yvu410–3 plane ycbcr format, 4x4 subsampled cr (1) and cb (2) planes -
yuv411–3 plane ycbcr format, 4x1 subsampled cb (1) and cr (2) planes -
yvu411–3 plane ycbcr format, 4x1 subsampled cr (1) and cb (2) planes -
yuv420–3 plane ycbcr format, 2x2 subsampled cb (1) and cr (2) planes -
yvu420–3 plane ycbcr format, 2x2 subsampled cr (1) and cb (2) planes -
yuv422–3 plane ycbcr format, 2x1 subsampled cb (1) and cr (2) planes -
yvu422–3 plane ycbcr format, 2x1 subsampled cr (1) and cb (2) planes -
yuv444–3 plane ycbcr format, non-subsampled cb (1) and cr (2) planes -
yvu444–3 plane ycbcr format, non-subsampled cr (1) and cb (2) planes -
r8–[7:0] r -
r16–[15:0] r little endian -
rg88–[15:0] r:g 8:8 little endian -
gr88–[15:0] g:r 8:8 little endian -
rg1616–[31:0] r:g 16:16 little endian -
gr1616–[31:0] g:r 16:16 little endian -
xrgb16161616f–[63:0] x:r:g:b 16:16:16:16 little endian -
xbgr16161616f–[63:0] x:b:g:r 16:16:16:16 little endian -
argb16161616f–[63:0] a:r:g:b 16:16:16:16 little endian -
abgr16161616f–[63:0] a:b:g:r 16:16:16:16 little endian -
xyuv8888–[31:0] x:y:cb:cr 8:8:8:8 little endian -
vuy888–[23:0] cr:cb:y 8:8:8 little endian -
vuy101010–Y followed by u then v, 10:10:10. non-linear modifier only -
y210–[63:0] cr0:0:y1:0:cb0:0:y0:0 10:6:10:6:10:6:10:6 little endian per 2 y pixels -
y212–[63:0] cr0:0:y1:0:cb0:0:y0:0 12:4:12:4:12:4:12:4 little endian per 2 y pixels -
y216–[63:0] cr0:y1:cb0:y0 16:16:16:16 little endian per 2 y pixels -
y410–[31:0] a:cr:y:cb 2:10:10:10 little endian -
y412–[63:0] a:0:cr:0:y:0:cb:0 12:4:12:4:12:4:12:4 little endian -
y416–[63:0] a:cr:y:cb 16:16:16:16 little endian -
xvyu2101010–[31:0] x:cr:y:cb 2:10:10:10 little endian -
xvyu12_16161616–[63:0] x:0:cr:0:y:0:cb:0 12:4:12:4:12:4:12:4 little endian -
xvyu16161616–[63:0] x:cr:y:cb 16:16:16:16 little endian -
y0l0–[63:0] a3:a2:y3:0:cr0:0:y2:0:a1:a0:y1:0:cb0:0:y0:0 1:1:8:2:8:2:8:2:1:1:8:2:8:2:8:2 little endian -
x0l0–[63:0] x3:x2:y3:0:cr0:0:y2:0:x1:x0:y1:0:cb0:0:y0:0 1:1:8:2:8:2:8:2:1:1:8:2:8:2:8:2 little endian -
y0l2–[63:0] a3:a2:y3:cr0:y2:a1:a0:y1:cb0:y0 1:1:10:10:10:1:1:10:10:10 little endian -
x0l2–[63:0] x3:x2:y3:cr0:y2:x1:x0:y1:cb0:y0 1:1:10:10:10:1:1:10:10:10 little endian -
yuv420_8bit– -
yuv420_10bit– -
xrgb8888_a8– -
xbgr8888_a8– -
rgbx8888_a8– -
bgrx8888_a8– -
rgb888_a8– -
bgr888_a8– -
rgb565_a8– -
bgr565_a8– -
nv24–Non-subsampled cr:cb plane -
nv42–Non-subsampled cb:cr plane -
p210–2x1 subsampled cr:cb plane, 10 bit per channel -
p010–2x2 subsampled cr:cb plane 10 bits per channel -
p012–2x2 subsampled cr:cb plane 12 bits per channel -
p016–2x2 subsampled cr:cb plane 16 bits per channel -
axbxgxrx106106106106–[63:0] a:x:b:x:g:x:r:x 10:6:10:6:10:6:10:6 little endian -
nv15–2x2 subsampled cr:cb plane -
q410– -
q401– -
xrgb16161616–[63:0] x:r:g:b 16:16:16:16 little endian -
xbgr16161616–[63:0] x:b:g:r 16:16:16:16 little endian -
argb16161616–[63:0] a:r:g:b 16:16:16:16 little endian -
abgr16161616–[63:0] a:b:g:r 16:16:16:16 little endian -
c1–[7:0] c0:c1:c2:c3:c4:c5:c6:c7 1:1:1:1:1:1:1:1 eight pixels/byte -
c2–[7:0] c0:c1:c2:c3 2:2:2:2 four pixels/byte -
c4–[7:0] c0:c1 4:4 two pixels/byte -
d1–[7:0] d0:d1:d2:d3:d4:d5:d6:d7 1:1:1:1:1:1:1:1 eight pixels/byte -
d2–[7:0] d0:d1:d2:d3 2:2:2:2 four pixels/byte -
d4–[7:0] d0:d1 4:4 two pixels/byte -
d8–[7:0] d -
r1–[7:0] r0:r1:r2:r3:r4:r5:r6:r7 1:1:1:1:1:1:1:1 eight pixels/byte -
r2–[7:0] r0:r1:r2:r3 2:2:2:2 four pixels/byte -
r4–[7:0] r0:r1 4:4 two pixels/byte -
r10–[15:0] x:r 6:10 little endian -
r12–[15:0] x:r 4:12 little endian -
avuy8888–[31:0] a:cr:cb:y 8:8:8:8 little endian -
xvuy8888–[31:0] x:cr:cb:y 8:8:8:8 little endian -
p030–2x2 subsampled cr:cb plane 10 bits per channel packed
create_pool(fd: fd, size: int) -> wl_shm_pool
Create a shm pool
Create a new wl_shm_pool object.
The pool can be used to create shared memory based buffer objects. The server will mmap size bytes of the passed file descriptor, to use as backing memory for the pool.
Parameters:
Returns:
-
wl_shm_pool(wl_shm_pool) –The created object
release() -> None
Release the shm object
Using this request a client can tell the server that it is not going to use the shm object anymore.
Objects created via this interface remain unaffected.
on_format(format: format) -> None
Pixel format description.
Override to handle wayland.wl_shm.events.format.