PresentNotifyMSC turns out to be not only redundant, but also harmful with
mesa-backed egl/glx/vulkan VOs because for all of them, mesa uses
PresentPixmap behind the scenes when DRI3 is available, which already
spawns a PresentCompleteNotify event when the buffer swap actually
finishes. This is important because without using the timing information
from these PresentCompleteKindPixmap events, there's no way for mpv to know
exactly when a frame becomes visible on the display.
By using PresentNotifyMSC in conjunction with DRI3-enabled mesa, two
problems are created:
1. mpv assumes that a vblank won't elapse (i.e., it assumes the current MSC
won't change) between the time when mesa enqueues the buffer swap and
the time when mpv calls PresentNotifyMSC to ask xorg for a notification
at the next MSC, relative to the current MSC at the time that xorg reads
it for the PresentNotifyMSC call. This means that mpv could get a
notification one or more vblanks later than it expects, since the
intention here is for mpv to get a notification at the MSC that the
buffer swap completes.
2. mpv assumes that a buffer swap always takes one vblank to complete,
which isn't always true. A buffer swap (i.e., a page flip) could take
longer than that depending on hardware conditions (if the GPU is running
slowly or needs to exit a low-power state), scheduling delays (under
heavy system or GPU load), or unfortunate timing (if the raster scan
line happens to be at one of the last few rows of pixels and a vblank
elapses just before the buffer swap is enqueued).
This causes mpv to have a faulty assumption of when frames become visible.
Since mpv already receives the PresentCompleteNotify events generated by
mesa's buffer swaps under the hood, the PresentNotifyMSC usage is unneeded
and just throws a wrench in mpv's vsync timing when xpresent is enabled.
Simply removing the PresentNotifyMSC usage from the egl, glx, and vulkan
VOs fixes the xpresent vsync timing.
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.
This is in preparation for fractional scaling support. Basically, redo
all the coordinates in wayland so that wl->geometry is equal exactly to
what is being put out to the screen (no extra wl->scaling multiplication
required). The wl->vdparams variable is also eliminated for simplicity.
This changes mpv's behavior on wayland with hidpi scaling but that will
be addressed in more detail with the next commit.
This was already returning true/false but the type was int. Also
simplify a few places in the wayland contexts where we can just return
the value of this function instead of doing redundant checks.
vk->surface is a handle and not a pointer, so assign VK_NULL_HANDLE.
This fixes the following build error on 32bit Windows when using clang for example,
which errors out when assigning a 32bit pointer to a 64bit integer:
../mpv-0.35.0/video/out/vulkan/utils.c:37:21:
error: incompatible pointer to integer conversion assigning to 'VkSurfaceKHR' (aka 'unsigned long long') from 'void *' [-Wint-conversion]
vk->surface = NULL;
^ ~~~~
The new status quo is simple: all messages coming from libplacebo are
marked "vo/gpu{-next}/libplacebo", regardless of the backend API (vulkan
vs opengl/d3d11).
Messages coming from mpv's internal vulkan code will continue to come
from "vo/gpu{-next}/vulkan", and messages coming from the vo module
itself will be marked "vo/gpu{-next}".
This is significantly better than the old status quo of vulkan messages
coming from "vo/gpu{-next}/vulkan/libplacebo" whereas opengl/d3d11
messages simply came from "vo/gpu{-next}", even when those messages
originated from libplacebo.
(It's worth noting that the the destructor for the log is redundant
because it's attached to the ctx which is freed on uninit anyway)
The wayland presentation time code currently always assumes that only
CLOCK_MONOTONIC can be used. There is a naive attempt to ignore clocks
other than CLOCK_MONOTONIC, but the logic is actually totally wrong and
the timestamps would be used anyway. Fix this by checking a use_present
bool (similar to use_present in xorg) which is set to true if we receive
a valid clock in the clockid event. Additionally, allow
CLOCK_MONOTONIC_RAW as a valid clockid. In practice, it should be the
same as CLOCK_MONOTONIC for us (ntp/adjustime difference wouldn't
matter). Since this is a linux-specific clock, add a define for it if it
is not found.
This has had no effect since libplacebo v4.192.0, and was deprecated
upstream a year ago. No deprecation period in mpv is justified by this
being a debug / work-around option.
This commit kind of mixes several related things together. The main
thing is to avoid calling any XPresent functions or internal functions
related to presentation when the feature is not auto-whitelisted or
enabled by the user. Internally rework this so it all works off of a
use_present bool (have_present is eliminated because having a non-zero
present_code covers exactly the same thing) and make sure it updates on
runtime. Finally, put some actual logging in here whenever XPresent is
enabled/disabled. Fixes#10326.
This builds off of present_sync which was introduced in a previous
commit to support xorg's present extension in all of the X11 backends
(sans vdpau) in mpv. It turns out there is an Xpresent library that
integrates the xorg present extention with Xlib (which barely anyone
seems to use), so this can be added without too much trouble. The
workflow is to first setup the event by telling Xorg we would like to
receive PresentCompleteNotify (there are others in the extension but
this is the only one we really care about). After that, just call
XPresentNotifyMSC after every buffer swap with a target_msc of 0. Xorg
then returns the last presentation through its usual event loop and we
go ahead and use that information to update mpv's values for vsync
timing purposes. One theoretical weakness of this approach is that the
present event is put on the same queue as the rest of the XEvents. It
would be nicer for it be placed somewhere else so we could just wait
on that queue without having to deal with other possible events in
there. In theory, xcb could do that with special events, but it doesn't
really matter in practice.
Unsurprisingly, this doesn't work on NVIDIA. Well NVIDIA does actually
receive presentation events, but for whatever the calculations used make
timings worse which defeats the purpose. This works perfectly fine on
Mesa however. Utilizing the previous commit that detects Xrandr
providers, we can enable this mechanism for users that have both Mesa
and not NVIDIA (to avoid messing up anyone that has a switchable
graphics system or such). Patches welcome if anyone figures out how to
fix this on NVIDIA.
Unlike the EGL/GLX sync extensions, the present extension works with any
graphics API (good for vulkan since its timing extension has been in
development hell). NVIDIA also happens to have zero support for the
EGL/GLX sync extensions, so we can just remove it with no loss. Only
Xorg ever used it and other backends already have their own present
methods. vo_vdpau VO is a special case that has its own fancying timing
code in its flip_page. This presumably works well, and I have no way of
testing it so just leave it as it is.
Wayland had some specific code that it used for implementing the
presentation time protocol. It turns out that xorg's present extension
is extremely similar, so it would be silly to duplicate this whole mess
again. Factor this out to separate, independent code and introduce the
mp_present struct which is used for handling the ust/msc values and some
other associated values. Also, add in some helper functions so all the
dirty details live specifically in present_sync. The only
wayland-specific part is actually obtaining ust/msc values. Since only
wayland or xorg are expected to use this, add a conditional to the build
that only adds this file when either one of those are present.
You may observe that sbc is completely omitted. This field existed in
wayland, but was completely unused (presentation time doesn't return
this). Xorg's present extension also doesn't use this so just get rid of
it all together. The actual calculation is slightly altered so it is
correct for our purposes. We want to get the presentation event of the
last frame that was just occured (this function executes right after the
buffer swap). The adjustment is to just remove the vsync_duration
subtraction. Also, The overly-complicated queue approach is removed.
This has no actual use in practice (on wayland or xorg). Presentation
statistics are only ever used after the immediate preceding swap to
update vsync timings or thrown away.
Because wayland is a special snowflake, mpv wound up incorporating a lot
of logic into its render loop where visibilty checks are performed
before rendering anything (in the name of efficiency of course). Only
wayland actually uses this, but there's no reason why other backends
(x11 in this commit) can't be smarter. It's far easier on xorg since we
can just query _NET_WM_STATE_HIDDEN directly and not have to do silly
callback dances.
The function, vo_x11_check_net_wm_state_change, already tracks net wm
changes, including _NET_WM_STATE_HIDDEN. There is an already existing
window_hidden variable but that is actually just for checking if the
window was mapped and has nothing to do with this particular atom. mpv
also currently assumes that a _NET_WM_STATE_HIDDEN is exactly the same
as being minimized but according to the spec, that's not neccesarily
true (in practice, it's likely that these are the same though). Anyways,
just keep track of this state in a new variable (hidden) and use that
for determing if mpv should render or not.
There is one catch though: this cannot work if a display sync mode is
used. This is why the previous commit is needed. The display sync modes
in mpv require a blocking vsync implementation since its render loop is
directly driven by vsync. In xorg, if nothing is actually rendered, then
there's nothing for eglSwapBuffers (or FIFO for vulkan) to block on so
it returns immediately. This, of course, results in completely broken
video. We just need to check to make sure that we aren't in a display
sync mode before trying to be smart about rendering. Display sync is
power inefficient anyways, so no one is really being hurt here. As an
aside, this happens to work in wayland because there's basically a
custom (and ugly) vsync blocking function + timeout but that's off
topic.
A bit of a personal pet peeve. vulkan, opengl, and wlshm all had
different methods for doing wayland's "check for visibility before
drawing" thing. The specific backend doesn't matter in this case and the
logic should all be shared. Additionally, the external swapchain that
the opengl code on wayland uses is done away with and it instead copies
vulkan by using a param. This keeps things looking more uniform across
backends and also makes it easier to extend to other platforms (see the
next couple of commits).
As found out by @philipl, failing to pass this from the VkInstance to
the VkDevice is bad style. We might want to override the get_proc_addr
pointer in the future.
While the basic Vulkan Display context can theoretically drive the
display without the involvement of any non-Vulkan code, that prevents
us from using VAAPI acceleration. When initialising VAAPI without a
window system, we need to provide it with an opened DRM render fd
corresponding to the device to use.
In the context of using VK_KHR_display, that means we need to identify
which DRM device matches the selected Vulkan device, and then open its
render fd and set the necessary state that VAAPI expects to find.
With that done, the normal VAAPI<->Vulkan interop can kick in and we
get working acceleration
In practice, this is for wayland. vo_gpu_next doesn't check the
check_visible parameter since it didn't descend into the
vulkan/context.c file when starting a frame. To make this happen, just
call the start_frame function pointer but pass NULL as the ra_fbo. In
there, we can do the visibility checks and after that bail out of the
start_frame function if ra_fbo is NULL.
This vulkan-specific parameter was poorly named and probably causes
confusion. Just rename it to check_visible instead to make clear what is
going on here. Only wayland uses it for now but in theory anyone else
can. As an aside, wayland egl accomplishes this by using an external
swapchain instead (an opengl-only concept in the mpv code). This may or
may not need to be changed in the future when gpu-next gets opengl
support.
The wl_surface lives for the entire lifetime of the vo. It's only
neccesary to set the scale initially and when the output scaling changes
(the surface moves to a different output with a different scale or the
output itself changes it scale). All of the calls that were being made
in the egl/vulkan resize functions are not needed. vo_wlshm wasn't
correctly rescaling itself before this commit since it had no logic to
handle scale changes. This should all be shared, common code in the
surface/output listeners.
A subtle regression from c26d833. On sway if mpv was set to be a
floating window in the config, set_buffer_scale would actually get
applied twice according to the wayland log. That meant a 1920x1080
window would appear as a 960x540 window if the scale of the wl_output
was set to 2. This only affected egl on sway (didn't occur on weston and
was too lazy to try anything else; probably they were fine). Since
wl->render is initially false, that meant that the very first run
through the render loop returns false. This probably caused something
weird to happen with the set_buffer_scale calls (the egl window gets
created and everything but mpv doesn't write to it just yet) which makes
the set_buffer_scale call happen an extra time. Since it was always
intended for mpv to initally render, this is worth fixing. Just chnage
wl->render to wl->hidden (again) and flip the bools around. That way,
the initial false value results in render == true and mpv tries to draw
on the first pass. This fixes the weird scaling behavior because
reasons.
Mostly a cosmetic change that (hopefully) makes things look better. Some
functions and structs that were previously being exported in the wayland
header were made static to the wayland_common.c file (these shouldn't be
accessed by anyone else).
If a plane is not connected to any displays, we won't set an entry in
the mapping of planes to displays. So ensure these unset entries are
null and skip them.
Fixes#8913
This is the Vulkan equivalent of the drm context for OpenGL, with
the big difference that it's implemented purely in terms of Vulkan
calls and doesn't actually require drm or kms.
The basic idea is to identify a display, mode, and plane on a device,
and then create a display backed surface for the swapchain. In theory,
past that point, everything is the same, and this is in fact the case
on Intel hardware. I can get a video playing on a vt.
On nvidia, naturally, things don't work that way. Instead, nvidia only
implemented the extension for scenarios where a VR application is
stealing a display from a running window system, and not for
standalone scenarios. With additional code, I've got this scenario to
work but that's a separate incremental change.
Other people have tested on AMD, and report roughly the same behaviour
as on Intel.
Note, that in this change, the VT will not be correctly restored after
qutting. The only way to restore the VT is to introduce some drm
specific code which I will illustrate in a separate change.
The VkDisplayKHR context type requires making calls against the
physical device before the libplacebo context is initialised.
That means we can't simply use the physical device object that
libplacebo would create - instead we have to create a separate one,
but make sure it's referring to the same physical device.
To that end, we need the device name that the user may have requested
so we can pass it on.
Take two. f4e89dd went wrong by moving vo_wayland_wait_frame before
start_frame was called. Whether or not this matters depends on the
compositor, but some weird things can happen. Basically, it's a
scheduling issue. vo_wayland_wait_frame queues all events and sends them
to the server to process (with no blocking if presentation time is
available). If mpv changes state while rendering (and this function is
called before every frame is drawn), then that event also gets
dispatched and sent to the compositor. This, in some cases, can cause
some funny behavior because the next frame gets attached to the surface
while the old buffer is getting released. It's safer to call this
function after the swap already happens and well before mpv calls its
next draw. There's no weird scheduling of events, and the compositor log
is more normal.
The second part of this is to fix some stuttering issues. This is mostly
just conjecture, but probably what was happening was this thing called
"composition". The easiest way to see this is to play a video on the
default audio sync mode (probably easiest to see on a typical 23.976
video). Have that in a window and float it over firefox (floating
windows are bloat on a tiling wm anyway). Then in firefox, do some short
bursts of smooth scrolling (likely uses egl). Some stutter in video
rendering could be observed, particularly in panning shots.
Compositors are supposed to prevent tearing so what likely was happening
was that the compositor was simply holding the buffer a wee bit longer
to make sure it happened in sync with the smooth scrolling. Because the
mpv code waits precisely on presentation time, the loop would timeout on
occasion instead of receiving the frame callback. This would then lead
to a skipped frame when rendering and thus causing stuttering.
The fix is simple: just only count consecutive timeouts as not receiving
frame callback. If a compositor holds the mpv buffer slightly longer to
avoid tearing, then we will definitely receive frame callback on the
next round of the render loop. This logic also appears to be sound for
plasma (funfact: Plasma always returns frame callback even when the
window is hidden. Not sure what's up with that, but luckily it doesn't
matter to us.), so get rid of the goofy 1/vblank_time thing and just
keep it a simple > 1 check.
This is actually a very nice simplification that should have been
thought of years ago (sue me). In a nutshell, the story with the
wayland code is that the frame callback and swap buffer behavior doesn't
fit very well with mpv's rendering loop. It's been refactored/changed
quite a few times over the years and works well enough but things could
be better. The current iteration works with an external swapchain to
check if we have frame callback before deciding whether or not to
render. This logic was implemented in both egl and vulkan.
This does have its warts however. There's some hidden state detection
logic which works but is kind of ugly. Since wayland doesn't allow
clients to know if they are actually visible (questionable but
whatever), you can just reasonably assume that if a bunch of callbacks
are missed in a row, you're probably not visible. That's fine, but it is
indeed less than ideal since the threshold is basically entirely
arbitrary and mpv does do a few wasteful renders before it decides that
the window is actually hidden.
The biggest urk in the vo_wayland_wait_frame is the use of
wl_display_roundtrip. Wayland developers would probably be offended by
the way mpv abuses that function, but essentially it was a way to have
semi-blocking behavior needed for display-resample to work. Since the
swap interval must be 0 on wayland (otherwise it will block the entire
player's rendering loop), we need some other way to wait on vsync. The
idea here was to dispatch and poll a bunch of wayland events, wait (with
a timeout) until we get frame callback, and then wait for the compositor
to process it. That pretty much perfectly waits on vsync and lets us
keep all the good timings and all that jazz that we want for mpv. The
problem is that wl_display_roundtrip is conceptually a bad function. It
can internally call wl_display_dispatch which in certain instances,
empty event queue, will block forever. Now strictly speaking, this
probably will never, ever happen (once I was able to to trigger it by
hardcoding an error into a compositor), but ideally
vo_wayland_wait_frame should never infinitely block and stall the
player. Unfortunately, removing that function always lead to problems
with timings and unsteady vsync intervals so it survived many refactors.
Until now, of course. In wayland, the ideal is to never do wasteful
rendering (i.e. don't render if the window isn't visible). Instead of
wrestling around with hidden states and possible missed vblanks, let's
rearrange the wayland rendering logic so we only ever draw a frame when
the frame callback is returned to use (within a reasonable timeout to
avoid blocking forever).
This slight rearrangement of the wait allows for several simplifications
to be made. Namely, wl_display_roundtrip stops being needed. Instead, we
can rely entirely on totally nonblocking calls (dispatch_pending, flush,
and so on). We still need to poll the fd here to actually get the frame
callback event from the compositor, but there's no longer any reason to
do extra waiting. As soon as we get the callback, we immediately draw.
This works quite well and has stable vsync (display-resample and audio).
Additionally, all of the logic about hidden states is no longer needed.
If vo_wayland_wait_frame times out, it's okay to assume immediately that
the window is not visible and skip rendering.
Unfortunately, there's one limitation on this new approach. It will only
work correctly if the compositor implements presentation time. That
means a reduced version of the old way still has to be carried around in
vo_wayland_wait_frame. So if the compositor has no presentation time,
then we are forced to use wl_display_roundtrip and juggle some funny
assumptions about whether or not the window is hidden or not. Plasma is
the only real notable compositor without presentation time at this stage
so perhaps this "legacy" mechanism could be removed in the future.
Today, validation is only possible for string type options. But there's
no particular reason why it needs to be restricted in this way, and
there are potential uses, to allow other options to be validated
without forcing the option to have to reimplement parsing from
scratch.
The first part, simply making the validation function an explicit
field instead of overloading priv is simple enough. But if we only do
that, then the validation function still needs to deal with the raw
pre-parsed string. Instead, we want to allow the value to be parsed
before it is validated. That in turn leads to us having validator
functions that should be type aware. Unfortunately, that means we need
to keep the explicit macro like OPT_STRING_VALIDATE() as a way to
enforce the correct typing of the function. Otherwise, we'd have to
have the validator take a void * and hope the implementation can cast
it correctly.
For help, we don't have this problem, as help doesn't look at the
value.
Then, we turn validators that are really help generators into explicit
help functions and where a validator is help + validation, we split
them into two parts.
I have, however, left functions that need to query information for both
help and validation as single functions to avoid code duplication.
In this change, I have not added an other OPT_FOO_VALIDATE() macros as
they are not needed, but I will add some in a separate change to
illustrate the pattern.
Originally when presentation time was implemented, the frame callback
and presentation feedback functions were called in each rendering api's
separate backend (egl and vulkan). This meant that their respective
structs were basically copy and pasted across both files. Plus later
vo_wlshm started using frame callbacks too. Things got refactored a few
times and it turns out there's actually no need to have these things
separate anymore. The frame callback can just be initialized in
vo_wayland_init and then everything else will follow from there. Just
move all of this code to wayland_common and get rid of the duplication.
Sidenote: This means that vo_wlshm can actually receive presentation
feedback now. It's really simple to do so might as well. See the next
commit.
30dcfbc is a workaround for incorrect border sizes that could occur on
sway/wlroots in certain edge cases. This seemed harmless enough, but it
turns out that on mutter the extra wl_surface_commit somehow causes the
window always go to the top left of the screen after you leave
fullscreen. No idea why this occurs, but the original commit is a
workaround a sway bug and causing regressions for other users isn't
right despite the author being biased towards sway/wlroots.
This reverts commit 30dcfbc9cb.
Made possible with 00b9c81. 34b8adc let the wayland surface set an
opaque region depending on if alpha was set by the user or not. However,
there was no attempted detection for runtime changes and it is possible
(at least in wayland vulkan) to toggle the alpha on and off. So this
meant, we could be incorrectly signalling an opaque region if the user
happened to change the alpha. Additionally, add a helper function for
this and use it everywhere we want to set the opaque region.
efb0c5c changed the rendering logic of mpv on wayland and made it skip
rendering when it did not receive frame callback in time. The idea was
to skip rendering when the surface was hidden and be less wasteful. This
unfortunately had issues in certain instances where a frame callback
could be missed (but the window was still in view) due to imprecise
rendering (like the default audio video-sync mode). This would lead to
the video appearing to stutter since mpv would skip rendering in those
cases.
To account for this case, simply re-add an old heuristic for detecting
if a window is hidden or not since the goal is to simply not render when
a window is hidden. If the wait on the frame callback times out enough
times in a row, then we consider the window hidden and thus begin to
skip rendering then. The actual threshold to consider a surface as
hidden is completely arbitrary (greater than your monitor's refresh
rate), but it's safe enough since realistically you're not going to miss
60+ frame callbacks in a row unless the surface actually is hidden.
Fixes#8169.
Apparently a part of the wayland spec. A compositor may use a surface
that has set part of itself as opaque for various optimizations. For
mpv, we simply set the entire surface as opaque as long as the user has
not set alpha=yes (note: alpha is technically broken in the wayland EGL
backend at the time of this commit but oh well). wlshm is always opaque.
Fixes#8125.
Back in the olden days, mpv's wayland backend was driven by the frame
callback. This had several issues and was removed in favor of the
current approach which allowed some advanced features (like
display-resample and presentation time) to actually work properly.
However as a consequence, it meant that mpv always rendered, even if the
surface was hidden. Wayland people consider this "wasteful" (and well
they aren't wrong). This commit aims to avoid wasteful rendering by
doing some additional checks in the swapchain. There's three main parts
to this.
1. Wayland EGL now uses an external swapchain (like the drm context).
Before we start a new frame, we check to see if we are waiting on a
callback from the compositor. If there is no wait, then go ahead and
proceed to render the frame, swap buffers, and then initiate
vo_wayland_wait_frame to poll (with a timeout) for the next potential
callback. If we are still waiting on callback from the compositor when
starting a new frame, then we simple skip rendering it entirely until
the surface comes back into view.
2. Wayland on vulkan has essentially the same approach although the
details are a little different. The ra_vk_ctx does not have support for
an external swapchain and although such a mechanism could theoretically
be added, it doesn't make much sense with libplacebo. Instead,
start_frame was added as a param and used to check for callback.
3. For wlshm, it's simply a matter of adding frame callback to it,
leveraging vo_wayland_wait_frame, and using the frame callback value to
whether or not to draw the image.
It was possible for sway to get incorrectly sized borders if you resized
the mpv window in a creative manner (e.g. open a video in a non-floating
mode, set window scale to 2, then float it and witness wrong border
sizes). This is possibly a sway bug (Plasma doesn't have these border
issues at least), but there's a reasonable workaround for this.
The reason for the incorrect border size is because it is possible for
mpv to ignore the width/height from the toplevel listener and set its
own size. This new size can differ from what sway/wlroots believes the
size is which is what causes the sever side decorations to be drawn on
incorrect dimensions.
A simple trick is to just explicitly commit the surface after a resize
is performed. This is only done if mpv is not fullscreened or maximized
since we always obey the compositor widths/heights in those cases.
Sending the commit signals the compositor of the new change in the
surface and thus sway/wlroots updates its internal coordinates
appropriately and borders are no longer broken.
When using presentation time, we have to be sure to update the ust when
no presentation events are received to make sure playback is still
smooth and in sync. Part of the recent presentation time refactor was to
use the presentation discarded event to signal that the window is
hidden. Evidently, this doesn't work the same everywhere for whatever
reason (drivers?? hardware??) and at least one user experienced issues
with playback getting out of sync since (presumably) the discarded event
didn't occur when hiding the window. Instead, let's just go back to the
old way of checking if the last_ust is equal to the ust value of the
last member in the wayland sync queue. Fixes#8010.
The motivation for this change was a segfault caused by e107342 which
has complicated reasons for occuring (i.e. I'm not 100% sure but I think
it is a really weird race). The major part of this commit is moving the
initialization of presentation listener to the frame_callback function.
Calling it in swap_buffers worked fine but in practice it meant a lot of
meaningless function calls if a window was hidden (the presentation
would just be immediately discarded). By calling it in frame_callback,
we ensure the listener is only created when it is possible to receive a
presentation event.
Of course calling the presentation listener in feedback_presented or
feedback_discarded was considered, but ultimately these events are too
slow. Receiving the ust/msc/sbc triplet here and then passing it to mpv
results in higher vsync judder since there is (likely) not enough time
before the next pageflip. By design, the frame callback is meant to give
us as much time as possible before the next repaint so calling it here
is probably optimal.
Additionally, we can make better use of the feedback_discarded event.
The wp_presentation_feedback should not be destroyed here. It will be
taken care of either when we get feedback again or when the player
quits. Instead what we can do is set a bool that tells wayland_sync_swap
to update itself based on mp_time delta. In practice, the result is not
any different than before, but it should be more understandable what is
going on now.
Of course, the segfault mentioned at the beginning is fixed with this as
well.
This normally gets printed by libplacebo itself when initializing the
context, but due to the way our code is structured (for convenience) we
don't have the log hook enabled by the time this function call is
relevant. So instead just print it manually as an easier work-around
than restructuring the code.
libplacebo exposes this feature already, because this particular type of
bug is unusually common in practice. Simply make use of it, by exposing
it as an option.
Could probably also bump the libplacebo minimum version to get rid of
the #if, but that would break debian oldoldstable or something.
Fixes#7867.
Commit 07b0c18 introduced some build breakages. Some breakages
were fixed on c1fc535 and a1adafe. This one is still remaining.
This commit fixes the following build error:
[153/521] Compiling video/out/vulkan/context_wayland.c
../video/out/vulkan/context_wayland.c:26:10: fatal error: video/out/wayland/presentation-time.h: No such file or directory
26 | #include "video/out/wayland/presentation-time.h"
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
compilation terminated.
Relevant to: #7802
One not-so-nice hack in the wayland code is the assumption of when a
window is hidden (out of view from the compositor) and an arbitrary
delay for enabling/disabling the usage of presentation time. Since you
do not receive any presentation feedback when a window is hidden on
wayland (a feature or misfeature depending on who you ask), the ust is
updated based on the refresh_nsec statistic gathered from the previous
feedback event.
The flaw with this is that refresh_nsec basically just reports back the
display's refresh rate (1 / refresh_rate * 10^9). It doesn't tell you
how long the vsync interval really was. So as a video is left playing
out of view, the wl->last_queue_display_time becomes increasingly
inaccurate. This led to a vsync spike when bringing the mpv window back
into sight after it was hidden for a period of time. The hack for
working around this is to just wait a while before enabling presentation
time again. The discrepancy between the "bogus"
wl->last_queue_display_time and the actual value you get from the
feedback only happens initially after a switch. If you just discard
those values, you avoid the dramatic vsync spike.
It turns out that there's a smarter way to do this. Just use mp_time_us
deltas. The whole reason for these hacks is because
wl->last_queue_display_time wasn't close enough to how long it would
take for a frame to actually display if it wasn't hidden. Instead, mpv's
internal timer can be used, and the difference between wayland_sync_swap
calls is a close enough proxy for the vsync interval (certainly better
than using the monitor's refresh rate). This avoids the entire conundrum
of massive vsync spikes when bringing the player back into view, and it
means we can get rid of extra crap like wl->hidden.
Change all OPT_* macros such that they don't define the entire m_option
initializer, and instead expand only to a part of it, which sets certain
fields. This requires changing almost every option declaration, because
they all use these macros. A declaration now always starts with
{"name", ...
followed by designated initializers only (possibly wrapped in macros).
The OPT_* macros now initialize the .offset and .type fields only,
sometimes also .priv and others.
I think this change makes the option macros less tricky. The old code
had to stuff everything into macro arguments (and attempted to allow
setting arbitrary fields by letting the user pass designated
initializers in the vararg parts). Some of this was made messy due to
C99 and C11 not allowing 0-sized varargs with ',' removal. It's also
possible that this change is pointless, other than cosmetic preferences.
Not too happy about some things. For example, the OPT_CHOICE()
indentation I applied looks a bit ugly.
Much of this change was done with regex search&replace, but some places
required manual editing. In particular, code in "obscure" areas (which I
didn't include in compilation) might be broken now.
In wayland_common.c the author of some option declarations confused the
flags parameter with the default value (though the default value was
also properly set below). I fixed this with this change.
This originally existed as a hack for weston. In certain scenarios, a
frame taking too long to render would cause vo_wayland_wait_frame to
timeout which would result in a ton of dropped frames. The naive
solution was to just to add a slight delay to the time value. If a
frame took too long, it would likely to fall under the timeout value and
all was well. This was exposed to the user since the default delay
(1000) was completely arbitrary.
However with presentation time, this doesn't appear to be neccesary.
Fresh frames that take longer than the display's refresh rate (16.666 ms
in most cases) behave well in Weston. In the other two main compositors
without presentation time (GNOME and Plasma), they also do not
experience any ill effects. It's better not to overcomplicate things, so
this "feature" can be removed now.
There's 2 stupid things here that need to be fixed. First of all,
vulkan wasn't actually using presentation time because somehow the
get_vsync function in context.c disappeared. Secondly, if the mpv window
was hidden it was updating the ust time based on the refresh_usec but
really it should simply just not feed any information to the vsync info
structure. So this adds some logic to assume whether or not a window is
hidden.
