This protocol is pretty important since it finally lets us solve the
longstanding issue of fractional scaling in wayland (no more mpv doing
rendering over the target resolution and then being scaled down). This
protocol also can completely replace the buffer_scale usage that we are
currently using for integer scaling so hopefully this can be removed
sometime in the future. Note that vo_dmabuf_wayland is omitted from the
fractional scale handling because we want the compositor to handle all
the scaling for that VO.
Fixes#9443.
The new single-pixel-buffer protocol is designed to optimize the case
for using a solid color as an underlay wl_surface. It works the same as
the wl_shm 1x1 pixel trick currently used, but it allows the compositor
to make optimizations with more certainty than the wl_shm trick.
The content-type protocol allows mpv to send compositor a hint about the
type of content being displayed on its surface so it could potentially
make some sort of optimization. Fundamentally, this is pretty simple but
since this requires a very new wayland-protocols version (1.27), we have
to mess with the build to add a new define and add a bunch of if's in
here. The protocol itself exposes 4 different types of content: none,
photo, video, and game.
To do that, let's add a new option (wayland-content-type) that lets
users control what hint to send to the compossitor. Since the previous
commit adds a VOCTRL that notifies us about the content being displayed,
we can also add an auto value to this option. As you'd expect, the
compositor hint would be set to photo if mpv's core detects an image,
video for other things, and it is set to none for the special case of
forcing a window when there is not a video track. For completion's sake,
game is also allowed as a value for this option, but in practice there
shouldn't be a reason to use that.
666cb91cf1 added support for v4 of the
dmabuf protocol. This was meant to be optional and the fallback support
for the old v2 (dates back to 2017[0] well before the 1.15
wayland-protocol version we depend on) was maintained. However, v4 added
several new functions and structs that of course aren't defined in old
protocol versions so naturally this breaks the build on those systems.
Since this is just a niche feature and not really critical to overall
wayland support in mpv, just give in and add another check in the build
system and #if out the newer stuff in wayland_common. v4 of linux-dmabuf
depends on wayland protocols 1-24[1], so go ahead and make that our new
check. Fixes#10807.
[0]: a840b3634a
[1]: 8a5cd28a0e
This driver makes use of dmabuffer and viewporter interfaces
to enable efficient display of vaapi surfaces, avoiding
any unnecessary colour space conversion, and avoiding scaling
or colour conversion using GPU shader resources.