If this mode is enabled, the player tries to strictly synchronize video
to display refresh. It will adjust playback speed to match the display,
so if you play 23.976 fps video on a 24 Hz screen, playback speed is
increased by approximately 1/1000. Audio wll be resampled to keep up
with playback.
This is different from the default sync mode, which will sync video to
audio, with the consequence that video might skip or repeat a frame once
in a while to make video keep up with audio.
This is still unpolished. There are some major problems as well; in
particular, mkv VFR files won't work well. The reason is that Matroska
is terrible and rounds timestamps to milliseconds. This makes it rather
hard to guess the framerate of a section of video that is playing. We
could probably fix this by just accepting jittery timestamps (instead
of explicitly disabling the sync code in this case), but I'm not ready
to accept such a solution yet.
Another issue is that we are extremely reliant on OS video and audio
APIs working in an expected manner, which of course is not too often
the case. Consequently, the new sync mode is a bit fragile.
Instead of calling it "future frames" and adding or subtracting 1 from
it, always call it "requested frames". This simplifies it a bit.
MPContext.next_frames had 2 added to it; this was mainly to ensure a
minimum size of 2. Drop it and assume VO_MAX_REQ_FRAMES is at least 2;
together with the other changes, this can be the exact size of the
array.
draw_image_timed is renamed to draw_frame. struct frame_timing is
renamed to vo_frame. flip_page_timed is merged into draw_frame (the
additional parameters are part of struct vo_frame). draw_frame also
deprecates VOCTRL_REDRAW_FRAME, and replaces it with a method that
works for both VOs which can cache the current frame, and VOs which
need to redraw it anyway.
This is preparation to making the interpolation and (work in progress)
display sync code saner.
Lots of other refactoring, and also some simplifications.
For now, this is trivial (and actually redundant). The future display
sync code will make better use of it. The main point is that the new
internal API pretty much makes this transparent to the vo_opengl
interpolation code.
Now the VO can request a number of future frames with the last parameter
of vo_set_queue_params(). This will be helpful to fix the interpolation
code.
Note that the first frame (after playback start or seeking) will usually
not have any future frames (to make seeking fast). Near the end of the
file, the number of future frames will become lower as well.
Instead of having separate backends, make use of GLES a flag. This
reduces the number of backends and the resulting annoyances.
Also, nobody cares about using GLES, so there's no backward
compatibility either.
Interrupt video timing. This means the Cocoa event loop does not have
to up to 2 video frame durations until redrawing the frame finally has
finished.
We abuse the VO event flags for this. Eventually this should use
wait_vo() or so in the video timing wait function, but for now the
interaction this would require with the code of other VOs/backends
would cause too much of a mess.
I think this used to be quite important, because the ancient VfW support
in MPlayer used to output flipped frames. This code has been dead in mpv
for quite some time (because VfW decoders were removed, and the --flip
option was dropped too), so get rid of it.
Rarely used and essentially useless. The only VO for which this was
implemented correctly and for which this did anything was vo_xv, but you
shouldn't use vo_xv anyway (plus it support BT.601 only, plus a vendor
specific extension for BT.709, whose presence this function essentially
reported - use xvinfo instead).
This caused complaints because the fps was basically rounded on
microsecond boundaries in the vsync interval (it seemed convenient to
store only the vsync interval). So store the fps as float too, and let
the "display-fps" property return it directly.
I'm not comfortable with VOCTRL_GET_DISPLAY_FPS being called every
frame.
This requires the VO to set VO_EVENT_WIN_STATE if the FPS could have
changed. At least the X11 backend does this.
This will be pretty useful to let mpv automatically change VO parameters based
on ambient lighting conditions.
The conversion code and polinomial equation from Apple LMU values to Lux is
taken from Firefox: their license, MPL is GPL compatible and allows
relicensing to GPL (MPL is more liberal).
Usually, a VO must react to VOCTRL_REDRAW_FRAME in order to redraw the
current screen correctly if video is paused (this is done to update
OSD). But if it's not supported, we can just draw the current image
again in the generic vo.c code.
Unfortunately, this turned out pretty useless, because the VOs which
would benefit from this need to redraw even if there is no image, in
order to draw a black screen in --idle --force-window mode. The way
redrawing is handled in the X11 common code and in vo_x11 and vo_xv is
in the way, and I'm not sure what exactly vo_wayland requires. Other VOs
have a non-trivial implementation of VOCTRL_REDRAW_FRAME, which
(probably) makes redrawing slightly more efficient, e.g. by skipping
texture upload. So for now, no VO uses this new functionality, but since
it's trivial, commit it anyway.
The vo_driver->untimed case is for forcibly disabling redraw for vo_lavc
and vo_image always.
At the time screenshot support was added, images weren't refcounted yet,
so screenshots required specialized implementations in the VOs. But now
we can handle these things much simpler. Also see commit 5bb24980.
If there are VOs in the future which can't do this (e.g. they need to
write to the image passed to vo_driver->draw_image), this still could be
disabled on a per-VO basis etc., so we lose no potential performance
advantages.
Use different VOCTRLs for "window" and normal screenshot modes. The
normal one will probably be removed, and replaced by generic code in
vo.c, and this commit is preparation for this. (Doing it the other way
around would be slightly simpler, but I haven't decided yet about the
second one, and touching every VO is needed anyway in order to remove
the unneeded crap. E.g. has_osd has been unused for a long time.)
vo.c queried the VO at initialization whether it wants to be updated on
every display frame, or every video frame. If the smoothmotion option
was changed at runtime, the rendering mode in vo.c wasn't updated.
Just let vo_opengl set the mode directly. Abuse the existing
vo_set_flip_queue_offset() function for this.
Also add a comment suggesting the use of --display-fps to the manpage,
which doesn't have anything to do with the rest of this commit, but is
important to make smoothmotion run well.
SmoothMotion is a way to time and blend frames made popular by MadVR. It's
intended behaviour is to remove stuttering caused by mismatches between the
display refresh rate and the video fps, while preserving the video's original
artistic qualities (no soap opera effect). It's supposed to make 24fps video
playback on 60hz monitors as close as possible to a 24hz monitor.
Instead of drawing a frame once once it's pts has passed the vsync time, we
redraw at the display refresh rate, and if we detect the vsync is between two
frames we interpolated them (depending on their position relative to the vsync).
We actually interpolate as few frames as possible to avoid a blur effect as
much as possible. For example, if we were to play back a 1fps video on a 60hz
monitor, we would blend at most on 1 vsync for each frame (while the other 59
vsyncs would be rendered as is).
Frame interpolation is always done before scaling and in linear light when
possible (an ICC profile is used, or :srgb is used).
And remove all uses of the VFCAP_CSP_SUPPORTED* constants. This is
supposed to reduce conversions if many filters are used (with many
incompatible pixel formats), and also for preferring the VO's natively
supported pixel formats (as opposed to conversion).
This is worthless by now. Not only do the main VOs not use software
conversion, but also the way vf_lavfi and libavfilter work mostly break
the way the old MPlayer mechanism worked. Other important filters like
vf_vapoursynth do not support "proper" format negotation either.
Part of this was already removed with the vf_scale cleanup from today.
While I'm touching every single VO, also fix the query_format argument
(it's not a FourCC anymore).
Previously we just forced loading a profile from file, but that has poor
integration for querying the OS / display server for an ICC profile, and
generating profiles on the fly (which we might use in the future for creating
preset 3dluts).
Also changed the previous icc-profile-auto code to use this mechanism, and
moved gl_lcms to be an opaque type with state instead of just providing pure
functions.
There are currently 568 pixel formats (actually fewer, but the namespace
is this big), and for each format elaborate synchronization was done to
call it synchronously on the VO. This is completely unnecessary, and we
can do with just a single call.
Commit d38bc531 is incorrect: the 50ms queue-ahead value and the flip
queue offset have different functions. The latter is about calling
flip_page in advance, so the change attempted to show video frames 50ms
in advance on all VOs.
The change was for vo_opengl_cb, but that can be handled differently.
This adds API to libmpv that lets host applications use the mpv opengl
renderer. This is a more flexible (and possibly more portable) option to
foreign window embedding (via --wid).
This assumes that methods like context sharing and multithreaded OpenGL
rendering are infeasible, and that a way is needed to integrate it with
an application that uses a single thread to render everything.
Add an example that does this with QtQuick/qml. The example is
relatively lazy, but still shows how relatively simple the integration
is. The FBO indirection could probably be avoided, but would require
more work (and would probably lead to worse QtQuick integration, because
it would have to ignore transformations like rotation).
Because this makes mpv directly use the host application's OpenGL
context, there is no platform specific code involved in mpv, except
for hw decoding interop.
main.qml is derived from some Qt example.
The following things are still missing:
- a way to do better video timing
- expose GL renderer options, allow changing them at runtime
- support for color equalizer controls
- support for screenshots
XRRGetOutputInfo contains a "name" element which corresponds to to the
display names given to the user by the "xrandr" command line
utility. Copy it into the xrandr_display struct for each display.
On VOCTRL_GET_DISPLAY_NAMES, send a copy of the names
of the displays spanned by the mpv window on.
Add a generic mechanism to the VO to relay "extra" events from VO to
player. Use it to notify the core of window resizes, which in turn will
be used to mark all affected properties ("window-scale" in this case) as
changed.
(I refrained from hacking this as internal command into input_ctx, or to
poll the state change, etc. - but in the end, maybe it would be best to
actually pass the client API context directly to the places where events
can happen.)
When the VO was moved it its own thread, responsibility for redrawing
was given to the VO thread itself. So if there was a condition that
indicated that redrawing was required, like expose events or certain
VOCTRLs, the VO thread was redrawing itself.
This worked fine, but there are some corner cases where this works
rather badly. E.g. if I fullscreen the player and hit panscan controls
with mpv's default autorepeat rate, playback stops. This happens because
the VO redraws itself after every panscan change command. Running each
(repeated) command takes so long due to redrawing and (involuntary)
waiting on vsync, that it never leaves the input processing loop while
the key is held down. I suspect that in my case, redrawing in fullscreen
mode just gets slow enough that it takes 2 vsyncs instead of 1 on
average, and the processing time gets larger than the autorepeat delay.
Fix this by taking redraw control from the VO, and instead let the
playloop issue a "real" redraw command to the VO if needed. This
basically reverts redraw handling to what it was before moving the VO to
a thread.
CC: @mpv-player/stable
vo_vdpau uses its own framedrop code, mostly for historic reasons. It
has some tricky heuristics, of which I'm not sure how they work, or if
they have any effect at all, but in any case, I want to keep this code
for now. One day it might get fully ported to the vo.c framedrop code,
or just removed.
But improve its interaction with the user-visible framedrop controls.
Make --framedrop actually enable and disable the vo_vdpau framedrop
code, and increment the number of dropped frames correctly.
The code path for other VOs should be equivalent. The vo_vdpau behavior
should, except for the improvements mentioned above, be mostly
equivalent as well. One minor change is that frames "shown" during
preemption are always count as dropped.
Remove the statement from the manpage that vo_vdpau is the default; this
hasn't been the case for a while.
This could be used by VO implementations to report a recent vsync time
to the generic VO code, which in turn will use it and the display FPS
to estimate at which point in time the next vsync will happen.
This works only on X11, and only if the refresh rate changes due to the
window being moved to another screen (detected by us). It doesn't
include system screen reconfiguration yet.
This calls VOCTRL_GET_DISPLAY_FPS on every frame, which makes me uneasy.
It means extra thread communication with the win32 and Cocoa backends.
On the other hand, a frame doesn't happen _that_ often, and the
communication should still be pretty cheap and fast, so it's probably
ok.
Also needs some extra fuzz for vo_vdpau.c, because that does everything
differently.
This mostly uses the same idea as with vo_vdpau.c, but much simplified.
On X11, it tries to get the display framerate with XF86VM, and limits
the frequency of new video frames against it. Note that this is an old
extension, and is confirmed not to work correctly with multi-monitor
setups. But we're using it because it was already around (it is also
used by vo_vdpau).
This attempts to predict the next vsync event by using the time of the
last frame and the display FPS. Even if that goes completely wrong,
the results are still relatively good.
On other systems, or if the X11 code doesn't return a display FPS, a
framerate of 1000 is assumed. This is infinite for all practical
purposes, and means that only frames which are definitely too late are
dropped. This probably has worse results, but is still useful.
"--framedrop=yes" is basically replaced with "--framedrop=decoder". The
old framedropping mode is kept around, and should perhaps be improved.
Dropping on the decoder level is still useful if decoding itself is too
slow.
The previous commit broke these things, and fixing them is separate in
this commit in order to reduce the volume of changes.
Move the image queue from the VO to the playback core. The image queue
is a remnant of the old way how vdpau was implemented, and increasingly
became more and more an artifact. In the end, it did only one thing:
computing the duration of the current frame. This was done by taking the
PTS difference between the current and the future frame. We keep this,
but by moving it out of the VO, we don't have to special-case format
changes anymore. This simplifies the code a lot.
Since we need the queue to compute the duration only, a queue size
larger than 2 makes no sense, and we can hardcode that.
Also change how the last frame is handled. The last frame is a bit of a
problem, because video timing works by showing one frame after another,
which makes it a special case. Make the VO provide a function to notify
us when the frame is done, instead. The frame duration is used for that.
This is not perfect. For example, changing playback speed during the
last frame doesn't update the end time. Pausing will not stop the clock
that times the last frame. But I don't think this matters for such a
corner case.
The VO is run inside its own thread. It also does most of video timing.
The playloop hands the image data and a realtime timestamp to the VO,
and the VO does the rest.
In particular, this allows the playloop to do other things, instead of
blocking for video redraw. But if anything accesses the VO during video
timing, it will block.
This also fixes vo_sdl.c event handling; but that is only a side-effect,
since reimplementing the broken way would require more effort.
Also drop --softsleep. In theory, this option helps if the kernel's
sleeping mechanism is too inaccurate for video timing. In practice, I
haven't ever encountered a situation where it helps, and it just burns
CPU cycles. On the other hand it's probably actively harmful, because
it prevents the libavcodec decoder threads from doing real work.
Side note:
Originally, I intended that multiple frames can be queued to the VO. But
this is not done, due to problems with OSD and other certain features.
OSD in particular is simply designed in a way that it can be neither
timed nor copied, so you do have to render it into the video frame
before you can draw the next frame. (Subtitles have no such restriction.
sd_lavc was even updated to fix this.) It seems the right solution to
queuing multiple VO frames is rendering on VO-backed framebuffers, like
vo_vdpau.c does. This requires VO driver support, and is out of scope
of this commit.
As consequence, the VO has a queue size of 1. The existing video queue
is just needed to compute frame duration, and will be moved out in the
next commit.
With software decoding, images were uploaded to vdpau surfaces as they
were queued to the VO. This makes it slightly more complicated
(especially later on), and has no advantages - so stop doing it.
The only reason why this was done explicitly was due to attempts to keep
the code equivalent (instead of risking performance regressions). The
original code did this naturally for certain reasons, but now that we
can measure that it has no advantages and just requires extra code, we
can just drop it.
wm4
Marcin Kurczewski
Stefano Pigozzi
xylosper
Kevin Mitchell