unknown vsync refresh rate

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wallyz21
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unknown vsync refresh rate

Unread post by wallyz21 » Mon Apr 15, 2019 8:10 pm

I compiled my retro 6809 Tandy Color Computer emulator (SDL2) and it works.

However it is having trouble detecting the sync rate and drops down to 28-29 fps instead of the usual 60 fps. This is causing audio issues as the audio uses the fps for timing.

I then down loaded an SDL2 vsync tester and ran that and the refresh rate went through the roof 100+ fps.

So I checked with xrandr and there appears to be no refresh rate set for the screen:

Code: Select all

odroid@odroid:~$ xrandr
xrandr: Failed to get size of gamma for output default
Screen 0: minimum 1920 x 1080, current 1920 x 1080, maximum 1920 x 1080
default connected 1920x1080+0+0 0mm x 0mm
   1920x1080      0.00* 
odroid@odroid:~$ 
As you can see the refresh rate is 0.00!!!

This might explain many of the issues with jittery video play back in applications (Chromium & Vivaldi)

One other SDL2 strangeness is starting any SDL2 program causes the following error:

dbus[3659]: arguments to dbus_message_new_method_call() were incorrect, assertion "path != NULL" failed in file ../../../dbus/dbus-message.c line 1362.
This is normally a bug in some application using the D-Bus library.

D-Bus not built with -rdynamic so unable to print a backtrace
Aborted (core dumped)

There is a work around for this by setting the IBUS ADDRESS to some invalid value before launching the program:

IBUS_ADDRESS=bääää ./some_sdl2_app

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odroid
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Re: unknown vsync refresh rate

Unread post by odroid » Tue Apr 16, 2019 7:49 pm

Since Mate/X11 desktop doesn't have any Mali GPU acceleration, xrandr command might be useless.
You have to use the framebuffer for game emulation with mali-fbdev driver package which has a properly implemented VSYNC.
https://wiki.odroid.com/odroid-n2/os_im ... u/20190329

crashoverride
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Re: unknown vsync refresh rate

Unread post by crashoverride » Tue Apr 16, 2019 9:19 pm

wallyz21 wrote:
Mon Apr 15, 2019 8:10 pm
One other SDL2 strangeness is starting any SDL2 program causes the following error:

dbus[3659]: arguments to dbus_message_new_method_call() were incorrect, assertion "path != NULL" failed in file ../../../dbus/dbus-message.c line 1362.
This is normally a bug in some application using the D-Bus library.
viewtopic.php?f=150&t=30652

Code: Select all

sudo killall ibus-daemon
These users thanked the author crashoverride for the post:
mad_ady (Wed Apr 17, 2019 1:27 pm)

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Re: unknown vsync refresh rate

Unread post by odroid » Wed Apr 17, 2019 8:42 am

Thanks, how I missed the important tip? :o

wallyz21
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Re: unknown vsync refresh rate

Unread post by wallyz21 » Thu Apr 18, 2019 1:31 pm

Thanks!

Confirmed that fixed the ibus issue.

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