wlr screencopy

Screen content capturing on client buffers

This protocol allows clients to ask the compositor to copy part of the screen content to a client buffer.

Warning! The protocol described in this file is experimental and backward incompatible changes may be made. Backward compatible changes may be added together with the corresponding interface version bump. Backward incompatible changes are done by bumping the version number in the protocol and interface names and resetting the interface version. Once the protocol is to be declared stable, the 'z' prefix and the version number in the protocol and interface names are removed and the interface version number is reset.

Manager to inform clients and begin capturing

This object is a manager which offers requests to start capturing from a source.

capture_output(frame: new_id<zwlr_screencopy_frame_v1>, overlay_cursor: int, output: object<wl_output>)
Argument
Type
Description
framenew_id<zwlr_screencopy_frame_v1>
overlay_cursorint
composite cursor onto the frame
outputobject<wl_output>
Capture an output

Capture the next frame of an entire output.

capture_output_region(frame: new_id<zwlr_screencopy_frame_v1>, overlay_cursor: int, output: object<wl_output>, x: int, y: int, width: int, height: int)
Argument
Type
Description
framenew_id<zwlr_screencopy_frame_v1>
overlay_cursorint
composite cursor onto the frame
outputobject<wl_output>
xint
yint
widthint
heightint
Capture an output's region

Capture the next frame of an output's region.

The region is given in output logical coordinates, see xdg_output.logical_size. The region will be clipped to the output's extents.

destroy()
Destroy the manager

All objects created by the manager will still remain valid, until their appropriate destroy request has been called.


A frame ready for copy

This object represents a single frame.

When created, a series of buffer events will be sent, each representing a supported buffer type. The "buffer_done" event is sent afterwards to indicate that all supported buffer types have been enumerated. The client will then be able to send a "copy" request. If the capture is successful, the compositor will send a "flags" followed by a "ready" event.

For objects version 2 or lower, wl_shm buffers are always supported, ie. the "buffer" event is guaranteed to be sent.

If the capture failed, the "failed" event is sent. This can happen anytime before the "ready" event.

Once either a "ready" or a "failed" event is received, the client should destroy the frame.

copy(buffer: object<wl_buffer>)
Argument
Type
Description
bufferobject<wl_buffer>
Copy the frame

Copy the frame to the supplied buffer. The buffer must have a the correct size, see zwlr_screencopy_frame_v1.buffer and zwlr_screencopy_frame_v1.linux_dmabuf. The buffer needs to have a supported format.

If the frame is successfully copied, a "flags" and a "ready" events are sent. Otherwise, a "failed" event is sent.

destroy()
Delete this object, used or not

Destroys the frame. This request can be sent at any time by the client.

copy_with_damage(buffer: object<wl_buffer>)
Argument
Type
Description
bufferobject<wl_buffer>
Copy the frame when it's damaged

Same as copy, except it waits until there is damage to copy.

buffer(format: uint<wl_shm.format>, width: uint, height: uint, stride: uint)
Argument
Type
Description
formatuint<wl_shm.format>
buffer format
widthuint
buffer width
heightuint
buffer height
strideuint
buffer stride
Wl_shm buffer information

Provides information about wl_shm buffer parameters that need to be used for this frame. This event is sent once after the frame is created if wl_shm buffers are supported.

Argument
Type
Description
flagsuint<zwlr_screencopy_frame_v1.flags>
frame flags
Frame flags

Provides flags about the frame. This event is sent once before the "ready" event.

ready(tv_sec_hi: uint, tv_sec_lo: uint, tv_nsec: uint)
Argument
Type
Description
tv_sec_hiuint
high 32 bits of the seconds part of the timestamp
tv_sec_louint
low 32 bits of the seconds part of the timestamp
tv_nsecuint
nanoseconds part of the timestamp
Indicates frame is available for reading

Called as soon as the frame is copied, indicating it is available for reading. This event includes the time at which presentation happened at.

The timestamp is expressed as tv_sec_hi, tv_sec_lo, tv_nsec triples, each component being an unsigned 32-bit value. Whole seconds are in tv_sec which is a 64-bit value combined from tv_sec_hi and tv_sec_lo, and the additional fractional part in tv_nsec as nanoseconds. Hence, for valid timestamps tv_nsec must be in [0, 999999999]. The seconds part may have an arbitrary offset at start.

After receiving this event, the client should destroy the object.

failed()
Frame copy failed

This event indicates that the attempted frame copy has failed.

After receiving this event, the client should destroy the object.

damage(x: uint, y: uint, width: uint, height: uint)
Argument
Type
Description
xuint
damaged x coordinates
yuint
damaged y coordinates
widthuint
current width
heightuint
current height
Carries the coordinates of the damaged region

This event is sent right before the ready event when copy_with_damage is requested. It may be generated multiple times for each copy_with_damage request.

The arguments describe a box around an area that has changed since the last copy request that was derived from the current screencopy manager instance.

The union of all regions received between the call to copy_with_damage and a ready event is the total damage since the prior ready event.

linux_dmabuf(format: uint, width: uint, height: uint)
Argument
Type
Description
formatuint
fourcc pixel format
widthuint
buffer width
heightuint
buffer height
Linux-dmabuf buffer information

Provides information about linux-dmabuf buffer parameters that need to be used for this frame. This event is sent once after the frame is created if linux-dmabuf buffers are supported.

buffer_done()
All buffer types reported

This event is sent once after all buffer events have been sent.

The client should proceed to create a buffer of one of the supported types, and send a "copy" request.

Argument
Value
Description
already_used0
the object has already been used to copy a wl_buffer
invalid_buffer1
buffer attributes are invalid
flags { y_invert } 
Argument
Value
Description
y_invert1
contents are y-inverted

Copyright © 2018 Simon Ser Copyright © 2019 Andri Yngvason

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