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<div class="moz-cite-prefix">On 11/26/2013 12:34 AM, Dídac Pérez
wrote:<br>
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<blockquote
cite="mid:CAM0v-hJ98tv-=MgXK9HccJ5KZoBzOj9g+D39firL5sVbDLX_5w@mail.gmail.com"
type="cite">
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<div class="gmail_default" style="font-family:trebuchet
ms,sans-serif">Hi all,</div>
<div class="gmail_default" style="font-family:trebuchet
ms,sans-serif"><br>
</div>
<div class="gmail_default" style="font-family:trebuchet
ms,sans-serif">
I am using ffmpeg C++ libraries for connecting to network IP
cameras and retrieve the video stream through RTSP. I need to
synchronize the video frames to another video stream whose
frames have timestamps that come from a GPS signal. The
problem is that I am not able to find the absolute timestamp
of the frames I get from the cameras. pts/dts values are
zero-based relative to the first frame, but I don't know how
to know the absolute timestamps (for instance, relative to 1
Jan 1900). In addition, I don't know if it is actually
possible.</div>
<div class="gmail_default" style="font-family:trebuchet
ms,sans-serif"><br>
</div>
<div class="gmail_default" style="font-family:trebuchet
ms,sans-serif">Please, I am stuck in this point and I need
urgent help with this, and I will really appreciate any help
from you. Thank you so much.</div>
<div class="gmail_default" style="font-family:trebuchet
ms,sans-serif">Kindest regards,</div>
<div class="gmail_default" style="font-family:trebuchet
ms,sans-serif"><br>
</div>
<div><font color="#666666">Dídac Pérez</font>
<div>
<br>
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</pre>
</blockquote>
<span class="comment-copy">RTCP Sender Reports can be used and ip
cams usually include them in-band.
<a class="moz-txt-link-freetext" href="http://tools.ietf.org/html/rfc3550#section-6.4.1">http://tools.ietf.org/html/rfc3550#section-6.4.1</a><br>
<br>
THe camera manufacturer should have more info on setting up a
local network clock for the cameras to sync their clocks to.<br>
<br>
Using Axis? they have so much documentation that you can
accomplish everything you can imagine.<br>
<br>
Andy<br>
<br>
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