<div dir="ltr"><div class="gmail_default" style="font-family:trebuchet ms,sans-serif">Hi Andy, thank you so much for your answer. I will ask Axis about how to set up the local clock. However, I don't know how to get that timestamps using ffmpeg. Maybe I am quite noob in streaming protocols. Could you please give me more details about it? For instance: does each AVPacket contains that timestamp? or AVFormatContext? I am quite confused.</div>
</div><div class="gmail_extra"><br clear="all"><div><font color="#666666"><div><font color="#666666">--</font></div>Dídac Pérez</font><div><br></div></div>
<br><br><div class="gmail_quote">2013/11/26 Andy Shaules <span dir="ltr"><<a href="mailto:bowljoman@gmail.com" target="_blank">bowljoman@gmail.com</a>></span><br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div bgcolor="#FFFFFF" text="#000000"><div><div class="h5">
<div>On 11/26/2013 12:34 AM, Dídac Pérez
wrote:<br>
</div>
</div></div><blockquote type="cite"><div><div class="h5">
<div dir="ltr">
<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>
</div>
</div>
</div>
<br>
<fieldset></fieldset>
<br>
</div></div><pre>_______________________________________________
Libav-user mailing list
<a href="mailto:Libav-user@ffmpeg.org" target="_blank">Libav-user@ffmpeg.org</a>
<a href="http://ffmpeg.org/mailman/listinfo/libav-user" target="_blank">http://ffmpeg.org/mailman/listinfo/libav-user</a>
</pre>
</blockquote>
<span>RTCP Sender Reports can be used and ip
cams usually include them in-band.
<a href="http://tools.ietf.org/html/rfc3550#section-6.4.1" target="_blank">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.<span class="HOEnZb"><font color="#888888"><br>
<br>
Andy<br>
<br>
</font></span></span>
</div>
<br>_______________________________________________<br>
Libav-user mailing list<br>
<a href="mailto:Libav-user@ffmpeg.org">Libav-user@ffmpeg.org</a><br>
<a href="http://ffmpeg.org/mailman/listinfo/libav-user" target="_blank">http://ffmpeg.org/mailman/listinfo/libav-user</a><br>
<br></blockquote></div><br></div>