<html><span style="font-size:13px; line-height:1.6em">On Monday, December 16, 2013 12:22 CET, Stuart Morgan <stuart@tase.co.uk> wrote:</span><br /> <blockquote>On Monday 16 Dec 2013 12:07:05 Marius Schrecker wrote:<br />> Hi,<br />><br />> After recenrt updates (I'm not sure what) I'm noticing slightly more<br />> jerkyness and jitter on some videos and (possibly unrelated) wandering<br />> audio sync on others.<br />><br />> System is a dual core opteron with nvidia 620 video adapter doing vdpau<br />> rendering and jitterometer tells me that when playing affected full<br />> 1080@25p content frame rate varies at +- 1-2 Hz of 25 and both CPU cores<br />> are running at around 15% capacity. One of my recent changes was upgrading<br />> the Nvidia driver from 304 to 310 and google tells me that teghre was a<br />> substantial performance increase bertween these two drivers. Something that<br />> might be causing my CPU
usage and bus speed to drop so much that I'm<br />> getting throughput errors.<br />><br />> What's the best way to test the hypothesis?<br /><br />Change the minimum cpu speed.<br /><br />sudo echo {valid_speed} ><br />/sys/devices/system/cpu/cpu0/cpufreq/scaling_min_freq<br /><br />Where {valid_speed} is something above the minimum from<br />cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies<br /><br />You may need to try different values to find the best one, assuming it works at<br />all.<br /><br />These are the scripts I use to automatically boost my cpu speed during<br />playback of video with vdpau, with them I get stutter/jitter issues.<br /><br />-----------------<br /><br />frequencyup.sh<br /><br />#!/bin/bash<br /><br />echo 1800000 | sudo tee /sys/devices/system/cpu/cpu0/cpufreq/scaling_min_freq<br />> /dev/null<br /><br />-------------------<br /><br />frequencydown.sh<br /><br />#!/bin/bash<br /><br />echo 1000000 |
sudo tee /sys/devices/system/cpu/cpu0/cpufreq/scaling_min_freq<br />> /dev/null<br /><br />--------------------<br /><br />This is in my /etc/sudoers file<br />{username} ALL=(ALL) PASSWD: ALL, NOPASSWD: /usr/bin/tee<br />/sys/devices/system/cpu/cpu0/cpufreq/scaling_min_freq<br /><br />--------------------<br /><br />Finally I trigger the scripts with the "Playback started" and "Playback<br />stopped" system events. I also trigger the slower clockspeed when paused, and<br />unpaused but that bit's optional.<br />--<br />Stuart Morgan<br />MythTV<br />_______________________________________________<br />mythtv-users mailing list<br />mythtv-users@mythtv.org<br />http://www.mythtv.org/mailman/listinfo/mythtv-users</blockquote><br />Brilliant Stuart! That's just what I wanted.<br /><br />I may ask for help triggeringb from system events but will adjust the speeds manually first and see if that solves my problems.<br /><br />Cheers!<br /><br
/>Marius<br /><br /><br /> </html>