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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal>Hi Ross,<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>I have recently updated the LIVE555 libraries I am using, ultimately to version 2014.08.23, though I originally updated to 2014.07.25 and the same problem happens. The problem is that the library is using a large amount of CPU when streaming both UDP and TCP from the same OnDemandServerMediaSubsession. I can reproduce this problem both on my embedded system (with my own setup code) and on an Ubuntu Linux machine running an almost un-modified version of testOnDemandRTSPServer (the only change is setting reuseFirstSource to ‘True’).<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>To test this yourself:<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoListParagraph style='text-indent:-.25in;mso-list:l1 level1 lfo1'><![if !supportLists]><span style='mso-list:Ignore'>1.<span style='font:7.0pt "Times New Roman"'> </span></span><![endif]>Modify testOnDemandRTSPServer by setting reuseFirstSource to True.<o:p></o:p></p><p class=MsoListParagraph style='text-indent:-.25in;mso-list:l1 level1 lfo1'><![if !supportLists]><span style='mso-list:Ignore'>2.<span style='font:7.0pt "Times New Roman"'> </span></span><![endif]>Start an instance of ‘top’ to watch the CPU usage.<o:p></o:p></p><p class=MsoListParagraph style='text-indent:-.25in;mso-list:l1 level1 lfo1'><![if !supportLists]><span style='mso-list:Ignore'>3.<span style='font:7.0pt "Times New Roman"'> </span></span><![endif]>Start one copy of openRTSP, streaming using TCP via –t. CPU usage should be very low. For me it is < 1%.<o:p></o:p></p><p class=MsoListParagraph style='text-indent:-.25in;mso-list:l1 level1 lfo1'><![if !supportLists]><span style='mso-list:Ignore'>4.<span style='font:7.0pt "Times New Roman"'> </span></span><![endif]>Start another copy of openRTSP, streaming using UDP. CPU usage should now be very high. For me it is > 90%.<o:p></o:p></p><p class=MsoListParagraph><o:p> </o:p></p><p class=MsoNormal>For my testing I was reading pre-recorded H.264 data via ‘h264ESVideoTest’.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>I think the core problem is that RTPInterface (via StreamState->fRTCPInstance-> fRTCPInterface) is not properly handling receiving RTCP over both the TCP socket and UDP socket at the same time:<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoListParagraph style='text-indent:-.25in;mso-list:l0 level1 lfo2'><![if !supportLists]><span style='mso-list:Ignore'>1.<span style='font:7.0pt "Times New Roman"'> </span></span><![endif]>Some RTCP data comes in over the UDP socket.<o:p></o:p></p><p class=MsoListParagraph style='text-indent:-.25in;mso-list:l0 level1 lfo2'><![if !supportLists]><span style='mso-list:Ignore'>2.<span style='font:7.0pt "Times New Roman"'> </span></span><![endif]>The code eventually gets into RTPInterface::handleRead, which tries to read the data from the TCP socket, since fNextTCPReadStreamSocketNum is valid. This read fails with EAGAIN almost all the time, and no data is processed.<o:p></o:p></p><p class=MsoListParagraph style='text-indent:-.25in;mso-list:l0 level1 lfo2'><![if !supportLists]><span style='mso-list:Ignore'>3.<span style='font:7.0pt "Times New Roman"'> </span></span><![endif]>On the next iteration through the event loop, the UDP socket is still readable, since no data was read from it, and once again the code gets into RTPInterface::handleRead, which tries to read the data from the TCP socket. This results in the UDP RTCP socket being kept in a continuously readable state, which then causes the event loop to spin.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>I dug through the changes for the previous months and discovered that a change to RTPInterface::handleRead in the 2014.03.25 version causes this problem to occur. The attached patch undoes the change and fixes this problem. Applying this patch might cause other problems though, since I think you removed it for the following reason given in the change log for 2014.03.25:<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>“- Fixed an issue in the "RTPInterface" code that could cause "SetSpecificRRHandler()" to not<o:p></o:p></p><p class=MsoNormal>work properly when RTP/RTCP is being carried over TCP.”<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Thanks for your time, and please let me know if you would like me to test anything else or send additional data.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Thanks,<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Chris Richardson<o:p></o:p></p><p class=MsoNormal>WTI<o:p></o:p></p></div></body></html>