Interpretation of Xserver Xorg.0.log output when frame rate control is active
The following log output typically is seen after starting video replay.
|<- -20ms 0 +20ms ->| R 958351
-------|--------------------------------*--------------------------------------- -265 -16590 [ -3-168] 999986
-------|--------------------------------+-*------------------------------------- 1009 -16687 [-28-156] 1000916
--------|-------------------------------*--------------------------------------- -243 -16284 [-37-165] 999081
---------|------------------------------+*-------------------------------------- 564 -15511 [-37-149] 999834
----------|-----------------------------+*-------------------------------------- 736 -15076 [-37-143] 1000008
------------|---------------------------+*-------------------------------------- 718 -14349 [-37-136] 999990
-------------|--------------------------+*-------------------------------------- 732 -13619 [-37-128] 1000003
---------------|------------------------+*-------------------------------------- 744 -12891 [-37-121] 1000016
----------------|-----------------------+*-------------------------------------- 671 -12163 [-37-114] 999943
------------------|---------------------+--*------------------------------------ 1678 -11397 [-37 -97] 1000949
-------------------|--------------------*--------------------------------------- -175 -10703 [-37-108] 999097
---------------------|------------------+*-------------------------------------- 719 -9973 [-37 -92] 999992
----------------------|-----------------+*-------------------------------------- 737 -9246 [-37 -85] 1000009
-----------------------|----------------+*-------------------------------------- 727 -8517 [-37 -77] 999995
-------------------------|--------------+*-------------------------------------- 742 -7787 [-37 -70] 1000014
--------------------------|-------------+*-------------------------------------- 744 -7058 [-37 -63] 1000015
----------------------------|-----------+*-------------------------------------- 696 -6330 [-37 -56] 999968
-----------------------------|----------+*-------------------------------------- 769 -5599 [-37 -48] 1000041
-------------------------------|--------+*-------------------------------------- 709 -4860 [-37 -41] 999958
--------------------------------|-------+*-------------------------------------- 725 -4122 [-37 -33] 999998
----------------------------------|-----+*-------------------------------------- 719 -3129 [-37 -24] 999992
-----------------------------------|----+*-------------------------------------- 747 -2665 [-37 -19] 1000016
-------------------------------------|--+*-------------------------------------- 742 -1938 [-37 -11] 1000016
--------------------------------------|-+*-------------------------------------- 722 -1207 [-37 -4] 999996
----------------------------------------|*-------------------------------------- 943 -471 [-37 +4] 1000215
----------------------------------------*--------------------------------------- 433 341 [-33 +7] 999806
----------------------------------------*|-------------------------------------- 403 729 [-26 +11] 999962
----------------------------------------*-|------------------------------------- 168 1048 [-15 +12] 999997
----------------------------------------*-|------------------------------------- -164 1044 [ -3 +8] 999994
----------------------------------------*|-------------------------------------- -392 727 [ 5 +3] 1000050
----------------------------------------*--------------------------------------- -339 392 [ 8 +0] 1000224
---------------------------------------*|--------------------------------------- -816 -352 [ 8 -11] 999753
---------------------------------------|*--------------------------------------- -334 -825 [ -3 -11] 999997
---------------------------------------|*--------------------------------------- 0 -989 [-14 -9] 1000010
---------------------------------------|*--------------------------------------- 257 -845 [-23 -5] 999983
----------------------------------------*--------------------------------------- 446 -467 [-28 +0] 999994
----------------------------------------|*-------------------------------------- 731 110 [-28 +8] 1000261
----------------------------------------*|-------------------------------------- 19 509 [-20 +5] 999741
----------------------------------------*|-------------------------------------- 118 564 [-15 +6] 1000007
----------------------------------------*|-------------------------------------- -55 592 [ -9 +5] 999998
^ ^ ^ ^ ^
/ | | | |
25 frame average of drift speed VGA-video timing against xine-lib calls | | | |
to XvPutimage(). it's represented by asterisks '*' in debug output | | | |
| | | |
/ | | |
sync point displacement indicated by bars '|' in debug output. it's a | | |
25 frame average of where frame updates hit the 40ms update interval | | |
| | |
/ | |
frame rate adjustement active for the last 25 frames | |
| |
/ |
yet unclipped relative frame rate adjustement |
calculated for upcoming 25 frames |
|
/
time elapsed since last 25 frames sent by xine-lib
legend:
| syncpoint: frame update position within 40ms interval averaged over 25 frames * driftspeed: skew between video stream frame (input rate) and VGA video timing (output rate) averaged over 25 framesalgorithm:
by altering the drift speed accordingly we let the sync point drift towards the center region of 40ms update interval