<br><br><div class="gmail_quote">On Tue, Nov 17, 2009 at 8:11 PM, Zhao, Halley <span dir="ltr"><<a href="mailto:halley.zhao@intel.com">halley.zhao@intel.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
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<p class="MsoNormal"><font face="Arial" size="1"><span style="font-size: 9pt; font-family: Arial;" lang="EN-US">Hi all:</span></font></p>
<p class="MsoNormal"><font face="Arial" size="1"><span style="font-size: 9pt; font-family: Arial;" lang="EN-US">My camera needs ~20ms to get one frame of data, and a
video sink in the pipeline needs ~4ms to render it.</span></font></p>
<p class="MsoNormal"><font face="Arial" size="1"><span style="font-size: 9pt; font-family: Arial;" lang="EN-US">But when I set pipeline fps to 35, I only got 20 fps
(calculate by GST CLOCK). CPU is not busy at this time, only 60%.</span></font></p>
<p class="MsoNormal"><font face="Arial" size="1"><span style="font-size: 9pt; font-family: Arial;" lang="EN-US"> </span></font></p>
<p class="MsoNormal"><font face="Arial" size="1"><span style="font-size: 9pt; font-family: Arial;" lang="EN-US">I guess the reason is following:</span></font></p>
<p class="MsoNormal"><font face="Arial" size="1"><span style="font-size: 9pt; font-family: Arial;" lang="EN-US">When we got nth frame at time 0, gst framework
schedule to get next frame after 30ms (1000/35), and when the camera src
element got scheduled to create one frame, it needs 20ms to get the data.</span></font></p>
<p class="MsoNormal"><font face="Arial" size="1"><span style="font-size: 9pt; font-family: Arial;" lang="EN-US">Then the time between n frame and n+1 frame is 30+20=50ms,
so I just got 20 fps.</span></font></p>
<p class="MsoNormal"><font face="Arial" size="1"><span style="font-size: 9pt; font-family: Arial;" lang="EN-US">Is my assumption right?</span></font></p>
<p class="MsoNormal"><font face="Arial" size="1"><span style="font-size: 9pt; font-family: Arial;" lang="EN-US">If yes, is there any way to adjust it?</span></font></p></div></div></blockquote><div>You can speed it up by adding a queue right after your source element. It will create another thread to push data after it, the thread used to request a frame from the camera will quickly return to the source and it will request another one.<br>
</div><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"><div link="blue" vlink="purple" lang="ZH-CN"><div style="">
<p class="MsoNormal"><font face="Arial" size="1"><span style="font-size: 9pt; font-family: Arial;" lang="EN-US"> </span></font></p>
<p class="MsoNormal"><font face="Arial" size="1"><span style="font-size: 9pt; font-family: Arial;" lang="EN-US">I had though to create another thread inside camera
source, and prepare the frame data in a buffer before it is schedule.</span></font></p>
<p class="MsoNormal"><font face="Arial" size="1"><span style="font-size: 9pt; font-family: Arial;" lang="EN-US">However, I think it is hack, and make timestamp
differ. I think it’s better settled inside gst framework. </span></font></p>
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<p class="MsoNormal"><font face="Arial" size="1"><span style="font-size: 9pt; font-family: Arial;" lang="EN-US"> </span></font></p>
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<p class="MsoNormal" style="text-indent: 20.1pt;"><b><font face="Arial" size="2" color="blue"><span style="font-size: 10pt; font-family: Arial; color: blue; font-weight: bold;" lang="EN-US">ZHAO,
Halley (Aihua)</span></font></b><span lang="EN-US"></span></p>
<p class="MsoNormal" style="text-indent: 20pt;"><font face="Arial" size="2" color="blue"><span style="font-size: 10pt; font-family: Arial; color: blue;" lang="EN-US">Email: halley.zhao<a title="mailto:aihua.zhao@intel.com
mailto:hui.xue@intel.com">@intel.com</a></span></font><font color="blue"><span style="color: blue;" lang="EN-US"></span></font></p>
<p class="MsoNormal" style="text-indent: 16pt;"><font face="Arial" size="1" color="blue"><span style="font-size: 8pt; font-family: Arial; color: blue;" lang="DA">Tel: +86(21)61166476</span></font><span lang="DA"></span></p>
<p class="MsoNormal" style="text-indent: 16pt;"><font face="Arial" size="1" color="blue"><span style="font-size: 8pt; font-family: Arial; color: blue;" lang="DA">iNet: 8821-6476</span></font><span lang="DA"></span></p>
<p class="MsoNormal" style="text-indent: 20pt;"><font face="Arial" size="2" color="#3366ff"><span style="font-size: 10pt; font-family: Arial; color: rgb(51, 102, 255);" lang="DA">SSG/OTC/Moblin 3W038
Pole: F4</span></font><span lang="EN-US"></span></p>
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