2009-06-29 12:33:36     Linphone CPU load

Document created by Aaronwu Employee on Aug 15, 2013
Version 1Show Document
  • View in full screen mode

2009-06-29 12:33:36     Linphone CPU load

Rob Maris (GERMANY)

Message: 76476   


I have some findings in CPU utilization of Linphone (V3.1.2):


In Idle, top shows 0% CPU load by linphonec

Connect ulaw without echo cancellation: 0%

Connect ulaw with echo cancellation: 11-18%

Connect speex with echo cancellation: approx. 25%



CPU is BF537@525 MHz according to U-boot message.


I'd consider the cpu-usage a bit high related to blackfin processing capabilities.


Anyone having other (better) measuring results or comments?






2009-06-30 08:04:18     Re: Linphone CPU load

Samuel Ayet (SPAIN)

Message: 76523   


Hi Rob,


Take this post to a comment to the accuracy of your measurement method of the CPU usage.


I´m also using linphone (but 2.0.1 included in R20081.5) with STAMP BF537 @ CCLK = 525MHz - SCLK = 131.25MHz, and I´m not sure why you get a 0% of load with the PCMU codec, because I think I get some load with this configuration.


I explain. I´m using Linphone to send / recieve audio and MPlayer with ffmpeg (one in each side of the comunication) to transmit video. First I start the video transmision in background and then I start Linphone to make a call with PCMU @ 8kHz while video is running. The fact is that when I start this comunications the frames per second of the video goes from 12fps to 8fps so Linphone is consuming resources, not 0% as you measure.


I´m using right now the AD1836 wich samples the audio at 48kHz and then the kernel needs to diezmate it to 8kHz for to be the input for the PCMU codec (2 Stereo Channels @ 8kHz). If I use the AD73311 I that supports sampling at 8kHz maybe I will have less CPU consuming by audio app like Linphone using PCMU.


This is the only way I have measuered (maybe will be better say noticed) the usage of resources.




>> CPU is BF537@525 MHz according to U-boot message.


This is only while you are running the U-Boot. When you start the kernell you can reprogramm clocks. See /proc/cpuinfo to see if you are reprogramming clocks or if you don´t do it.


For example when I boot U-boot says:


Clock: VCO: 500MHz, Core: 500MHz, System: 100MHz


But then I have reprogramed the clocks and if I see the /proc/cpuinfo once I have booted the kernel:


root> cat /proc/cpuinfo




cpu MHz        :  525.000/131.25




Don´t confuse it.




Best regards,