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<p class="MsoNormal">Not sure how live555 task schedule works but usleep(0) will take some time and once the process give up the CPU and there is no guarantee when it will get back CPU.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Bo<span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p></o:p></span></p>
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<p class="MsoNormal"><b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> live-devel-bounces@ns.live555.com [mailto:live-devel-bounces@ns.live555.com]
<b>On Behalf Of </b>Ross Finlayson<br>
<b>Sent:</b> Tuesday, April 23, 2013 10:09 AM<br>
<b>To:</b> LIVE555 Streaming Media - development & use<br>
<b>Subject:</b> Re: [Live-devel] low latency transmit<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New"">Can MultiFramedRTPSink::sendPacketIfNecessary() be enhanced safely with the following code ?</span><span style="font-size:11.0pt;font-family:"Calibri","sans-serif""><o:p></o:p></span></p>
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<p class="MsoNormal">No, because it's not correct. The whole point of the existing code is to delay the sending of the next packet, as appropriate, based on the value of "durationInMicroseconds" that was passed (to "afterGettingFrame()") by the upstream source
object. (Note the calculation of "fNextSendTIme" on lines 321-323.)<o:p></o:p></p>
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<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New"">I would like to transmit all packets within one video frame as soon as possible instead of scheduling packet one by one ? uSecondsToGo gets 1 usec</span><span style="font-size:11.0pt;font-family:"Calibri","sans-serif""><o:p></o:p></span></p>
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<p class="MsoNormal">Then the upstream source object must have set a non-zero value of "fDurationInMicroseconds" - which is probably not what you wanted. (Note that if you're streaming from a live input source (as opposed to a file, for example) , then it's
OK for it *not* to set "fDurationInMicroseconds", which means that it'll retain its default value of 0.<o:p></o:p></p>
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<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New"">but cause the schedule to run and actually add a lot of latency between packets.</span><span style="font-size:11.0pt;font-family:"Calibri","sans-serif""><o:p></o:p></span></p>
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<p class="MsoNormal">No. If you happen to take longer than expected to get back to this code again, then it'll catch up. That's why we call "gettimeofday()", and compare the result to "fNextSendTime". If the current time happens to be later than "fNextSendTime",
then "uSecondsToGo" will be 0, and scheduler will send the next packet ASAP.<o:p></o:p></p>
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<p class="MsoNormal"><span class="apple-style-span"><span style="font-size:13.5pt;font-family:"Helvetica","sans-serif";color:black">Ross Finlayson</span></span><span style="font-size:13.5pt;font-family:"Helvetica","sans-serif";color:black"><br>
<span class="apple-style-span">Live Networks, Inc.</span><br>
<span class="apple-style-span"><a href="http://www.live555.com/">http://www.live555.com/</a></span></span>
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