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 frames
    
  • algorithm:

    by altering the drift speed accordingly we let the sync point drift towards the center region of 40ms update interval Obtenir mon rio orange ou bien mon rio orange pour résilier monopérateur telecom facilement et sans frais