<div class="gmail_quote">On Sun, Dec 20, 2009 at 3:01 AM, Kevin.Liu <span dir="ltr"><<a href="mailto:kevin.liu@innosofts.com">kevin.liu@innosofts.com</a>></span> wrote:<br>
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<p class="MsoNormal"><span lang="EN-US"></span></p><span lang="EN-US"> The strange thing is that if I transport only audio stream like “mp3 file” the packet lost was very small ,but if I transport both audio and video stream like “mp4,mpg files” the packet loss was really big. </span>
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<p style="TEXT-INDENT: 5.25pt" class="MsoNormal"><span lang="EN-US"> And I found that a 6M mpg file only transport 37 seconds (sdp message “</span><span style="FONT-FAMILY: NSimSun; COLOR: red; FONT-SIZE: 10pt" lang="EN-US">a=range:npt=0-37.160</span><span lang="EN-US">”) but a 5M mp3 file transport 301 seconds in the same network environment.</span></p>
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<div> This is not strange, it's perfectly normal. Doing the math, your video file is 1.3 mbit/sec (48 mbit / 37 seconds), while your mp3 file is 132 kbit/sec (40 mbit / 301 seconds), or roughly one-tenth the bandwidth of your video file. Your problem is obvious: your network does not have enough bandwidth to transmit the video in real-time, and you're experiencing packet loss (from the sound of it, you have about 1 mbit/sec of bandwidth). You're experiencing packet loss because your network is insufficient to transmit the video stream, which is _much_ larger than the audio stream.</div>
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<div>Like Ross said, get more bandwidth or smaller media.<br></div></div><br>