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<p class=MsoPlainText><font size=1 face=宋体><span lang=EN-US style='font-size:
9.0pt'>HI, Malte!<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=1 face=宋体><span lang=EN-US style='font-size:
9.0pt'> Thanks,<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=1 face=宋体><span lang=EN-US style='font-size:
9.0pt'> The following blue notes are my questions.<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=1 face=宋体><span lang=EN-US><o:p> </o:p></span></font></p>
<p class=MsoPlainText><font size=1 face=宋体><span lang=EN-US><o:p> </o:p></span></font></p>
<p class=MsoPlainText><font size=1 face=宋体><span lang=EN-US style='font-size:
9.0pt'>-----</span>邮件原件<span lang=EN-US>-----<br>
</span>发件人<span lang=EN-US>: Malte Tancred [mailto:malte@frontbase.com] <br>
</span>发送时间<span lang=EN-US>: <st1:chsdate IsROCDate="False" IsLunarDate="False"
Day="24" Month="9" Year="2008" w:st="on">2008<span lang=EN-US><span lang=EN-US>年9</span></span><span
lang=EN-US><span lang=EN-US>月24</span></span><span lang=EN-US><span
lang=EN-US>日</span></span></st1:chsdate> 13:56<br>
</span>收件人<span lang=EN-US>: <st1:PersonName w:st="on">live-devel@ns.live555.com</st1:PersonName><br>
</span>主题<span lang=EN-US>: Re: [Live-devel] question about the live555 RTP
sending speed</span></font></p>
<p class=MsoPlainText><font size=1 face=宋体><span lang=EN-US><o:p> </o:p></span></font></p>
<p class=MsoPlainText><font size=1 face=宋体><span lang=EN-US style='font-size:
9.0pt'>On 23 sep 2008, at 15.11, Ross Finlayson wrote:<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=1 face=宋体><span lang=EN-US><o:p> </o:p></span></font></p>
<p class=MsoPlainText><font size=1 face=宋体><span lang=EN-US style='font-size:
9.0pt'>> The transmission speed is determined by the value of the <o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=1 face=宋体><span lang=EN-US style='font-size:
9.0pt'>> "fDurationInMicroseconds" variable. Your
"*Framer* object (in this <o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=1 face=宋体><span lang=EN-US style='font-size:
9.0pt'>> case, your "H264VideoStreamFramer" subclass) needs to
properly set <o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=1 face=宋体><span lang=EN-US style='font-size:
9.0pt'>> this for each H.264 NAL unit that it delivers.<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=1 face=宋体><span lang=EN-US><o:p> </o:p></span></font></p>
<p class=MsoPlainText><font size=1 face=宋体><span lang=EN-US><o:p> </o:p></span></font></p>
<p class=MsoPlainText><font size=1 face=宋体><span lang=EN-US><o:p> </o:p></span></font></p>
<p class=MsoPlainText><font size=1 face=宋体><span lang=EN-US style='font-size:
9.0pt'>I suppose this is correct. However, "properly set" doesn't
necessarily<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=1 face=宋体><span lang=EN-US style='font-size:
9.0pt'>mean what you first think it means. These are my findings:<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=1 face=宋体><span lang=EN-US><o:p> </o:p></span></font></p>
<p class=MsoPlainText><font size=1 face=宋体><span lang=EN-US style='font-size:
9.0pt'>- all NAL units that belong to the same frame, except the last NAL<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=1 face=宋体><span lang=EN-US style='font-size:
9.0pt'> unit in that frame, should have a duration of 0 (zero).<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=1 color=black face=宋体><span lang=EN-US><o:p> </o:p></span></font></p>
<p class=MsoPlainText><font size=1 color=blue face=宋体><span lang=EN-US
style='font-size:9.0pt;color:blue'>[Aiden: ] : what's the meaning of " duration
", I guess, your mean</span></font><font color=blue face="Courier New"><span
lang=EN-US style='font-family:"Courier New";color:blue'>’</span></font><font
color=blue><span lang=EN-US style='color:blue'>s that the consecutive nal units
in the same frame have the same timestamp, right?<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=1 color=black face=宋体><span lang=EN-US><o:p> </o:p></span></font></p>
<p class=MsoPlainText><font size=1 face=宋体><span lang=EN-US style='font-size:
9.0pt'>- the last NAL unit in each frame should have a duration matching<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=1 face=宋体><span lang=EN-US style='font-size:
9.0pt'> that of its frame.<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=1 color=blue face=宋体><span lang=EN-US
style='font-size:9.0pt;color:blue'>[Aiden: ] : now, my all NAL unit in an
access unit have the same timestamp. Is it accord with your meaning?<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=1 color=black face=宋体><span lang=EN-US><o:p> </o:p></span></font></p>
<p class=MsoPlainText><font size=1 face=宋体><span lang=EN-US style='font-size:
9.0pt'>- all NAL units in a frame should have the same presentation time.<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=1 color=blue face=宋体><span lang=EN-US
style='font-size:9.0pt;color:blue'>[Aiden: ] : what</span></font><font
color=blue face="Courier New"><span lang=EN-US style='font-family:"Courier New";
color:blue'>’</span></font><font color=blue><span lang=EN-US style='color:blue'>s
the presentation time? ---- Timestamp ?</span></font><span lang=EN-US><o:p></o:p></span></p>
<p class=MsoPlainText><font size=1 face=宋体><span lang=EN-US style='font-size:
9.0pt'>(Please note that what I call "frame" above is called an
"access unit"<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=1 face=宋体><span lang=EN-US style='font-size:
9.0pt'>in the liveMedia library)<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=1 face=宋体><span lang=EN-US><o:p> </o:p></span></font></p>
<p class=MsoPlainText><font size=1 face=宋体><span lang=EN-US><o:p> </o:p></span></font></p>
<p class=MsoPlainText><font size=1 face=宋体><span lang=EN-US style='font-size:
9.0pt'>What brought my attention to this was the following message to the list,<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=1 face=宋体><span lang=EN-US style='font-size:
9.0pt'>regarding zero duration "frames" delivered by the MPEG stream
framer:<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=1 face=宋体><span lang=EN-US><o:p> </o:p></span></font></p>
<p class=MsoPlainText><font size=1 face=宋体><span lang=EN-US style='font-size:
9.0pt'>
http://lists.live555.com/pipermail/live-devel/2004-April/000650.html<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=1 face=宋体><span lang=EN-US><o:p> </o:p></span></font></p>
<p class=MsoPlainText><font size=1 face=宋体><span lang=EN-US><o:p> </o:p></span></font></p>
<p class=MsoPlainText><font size=1 face=宋体><span lang=EN-US style='font-size:
9.0pt'>Regards,<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=1 face=宋体><span lang=EN-US style='font-size:
9.0pt'>Malte<o:p></o:p></span></font></p>
<p class=MsoPlainText><font size=1 face=宋体><span lang=EN-US><o:p> </o:p></span></font></p>
<p class=MsoPlainText><font size=1 face=宋体><span lang=EN-US><o:p> </o:p></span></font></p>
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