[mythtv-commits] Ticket #12819: Enabling time stretch on Raspberry Pi v3 platform causes jerky playback.

[MythTV]

#12819: Enabling time stretch on Raspberry Pi v3 platform causes jerky playback.
--------------------------------------+----------------------
     Reporter:  nemiroal@…            |      Owner:  pbennett
         Type:  Bug Report - General  |     Status:  new
     Priority:  minor                 |  Milestone:  unknown
    Component:  Ports - rPi           |    Version:  0.28.0
     Severity:  medium                |   Keywords:
Ticket locked:  0                     |
--------------------------------------+----------------------
 Enabling Time Stretch < 1.0x or > 1.0x causes jerky playback.    Using USB
 based external audio adapter improves playback greatly, but still jerky
 enough to be annoying.  Disabling audio all together has no problem
 playing fast and looks very smooth at 1.5x. Seems to be some kind of sync
 issue.

 CPU load over a 10 sec sample play the game 1080i content using onboard
 audio via HDMI output on 720p HDTV.

 Time Stretch OFF:
 09:24:24 PM  CPU    %usr   %nice    %sys %iowait    %irq   %soft  %steal
 %guest  %gnice   %idle
 09:24:34 PM  all    3.60    0.00    2.78    0.00    0.00    0.67    0.00
 0.00    0.00   92.95
 09:24:34 PM    0    3.27    0.00    0.98    0.00    0.00    2.83    0.00
 0.00    0.00   92.92
 09:24:34 PM    1    2.42    0.00    3.43    0.00    0.00    0.00    0.00
 0.00    0.00   94.15
 09:24:34 PM    2    4.33    0.00    2.32    0.00    0.00    0.00    0.00
 0.00    0.00   93.35
 09:24:34 PM    3    4.37    0.00    4.27    0.00    0.00    0.00    0.00
 0.00    0.00   91.35

 Time Stretch 1.1x:
 09:23:24 PM  CPU    %usr   %nice    %sys %iowait    %irq   %soft  %steal
 %guest  %gnice   %idle
 09:23:34 PM  all   19.67    0.00    1.48    0.03    0.00    0.46    0.00
 0.00    0.00   78.37
 09:23:34 PM    0   14.76    0.00    1.15    0.00    0.00    1.88    0.00
 0.00    0.00   82.20
 09:23:34 PM    1   37.26    0.00    1.81    0.00    0.00    0.00    0.00
 0.00    0.00   60.93
 09:23:34 PM    2   23.80    0.00    0.30    0.00    0.00    0.00    0.00
 0.00    0.00   75.90
 09:23:34 PM    3    2.45    0.00    2.65    0.10    0.00    0.00    0.00
 0.00    0.00   94.80

 Moving content from my BE to target's onboard SD card makes no difference
 and rules out my wired onboard Ethernet and/or network stack. Performance
 is the same.

--
Ticket URL: <https://code.mythtv.org/trac/ticket/12819>
MythTV <http://www.mythtv.org>
MythTV Media Center