30 fps cap

[sunflare]

hi

i'm using windowless rendering from the new 2062 branch (rev 1804) and can't seem to get past 30 fps. CefBrowserSettings.windowless_frame_rate doesn't seem to do anything above 30, if i set it lower than 30, the setting works. According to the comment in the header file, this should go up to 60.

i'm pretty sure that this is not a performance problem, because i get almost exactly 30 fps, even if i resize the browser window to 100x100 pixels.
It shouldn't be a message loop problem either, I call CefDoMessageLoopWork() after every frame of my graphics engine, which runs uncapped at about 3000fps at the moment.

while we're at it: why is there a cap on CefBrowserSettings.windowless_frame_rate at all? Why shouldn't I be able to render the cef frame at 120 fps if it makes sense for my application?

thanks in advance

[nvine]

I think the problem is that you are not calling CefDoMessageLoopWork() very often. Decrease the resolution of the timer used to call CefDoMessageLoopWork(), say to 1000/60 milliseconds.

[sunflare]

I think the problem is that you are not calling CefDoMessageLoopWork() very often. Decrease the resolution of the timer used to call CefDoMessageLoopWork(), say to 1000/60 milliseconds.

as stated in the previous post, CefDoMessageLoopWork() is called about 3000 times a second.

[magreenblatt]

while we're at it: why is there a cap on CefBrowserSettings.windowless_frame_rate at all?

Because there is a trade-off between fps and resource usage.

Why shouldn't I be able to render the cef frame at 120 fps if it makes sense for my application?

New frames are generated at the vsync rate, which is generally 60fps.

See https://code.google.com/p/chromiumembed ... il?id=1257 for details.

[sunflare]

New frames are generated at the vsync rate, which is generally 60fps.

generally yes, but not always
there are more and more 120/144hz displays coming out.

but thats just an aside, i can live with 60 fps. the real problem is that it caps at 30

[magreenblatt]

What frame rate do you get in cefclient when running with the `--off-screen-rendering-enabled` command-line flag? Last I checked https://webglsamples.googlecode.com/hg/field/field.html was reporting around 45fps on Windows and 60fps on Linux and OS X. Unfortunately that URL is currently down so you'll have to find something else to test with.

[sunflare]

the benchmark (the URL works for me btw.) reports 60 fps but it doesn't seem to actually display 60 fps, it looks like 30
when i open the same thing in chrome or in cefclient without --off-screen-rendering-enabled it looks a lot smoother, even though it reports the same fps

[magreenblatt]

Ok, so that's likely the behavior with the default framerate (30fps). Now try adding `--off-screen-frame-rate=60` and see if that makes a difference.

[sunflare]

yeah, with --off-screen-frame-rate=60 it works in cefclient

[sunflare]

ok, i'm not so sure anymore

i've written a little patch that measures the onPaint() calls that happen each second in cefclient

according to this, cefclient can't get above 30 fps either with '--off-screen-rendering-enabled --off-screen-frame-rate=60' o.O

here is the patch:

Code: Select all

--- osrenderer.cpp   2014-08-12 17:11:46.708042600 +0200
+++ /home/sunflare/osrenderer.cpp   2014-08-12 17:09:05.000000000 +0200
@@ -4,6 +4,9 @@
 
 #include "cefclient/osrenderer.h"
 
+#include <iostream>
+#include <ctime>
+
 #if defined(OS_WIN)
 #include <gl/gl.h>
 #include <gl/glu.h>
@@ -264,6 +267,18 @@
     // Disable alpha blending.
     glDisable(GL_BLEND);
   }
+
+  if (type == PET_VIEW) {
+    static unsigned framesSinceTime = 0;
+    static unsigned lastTime = time(0);
+    unsigned currentTime = time(0);
+    ++framesSinceTime;
+    if ((currentTime - lastTime) > 0) {
+      std::cout << "fps: " << framesSinceTime << "\n";
+      framesSinceTime = 0;
+      lastTime = currentTime;
+    }
+  }
 }
 
 void ClientOSRenderer::SetSpin(float spinX, float spinY) {