<div dir="ltr">They're in close proximity - for a live sport event. So all on the same network.<div><br></div><div>Thanks, I'll take a look into some of your suggestions!</div></div><div class="gmail_extra"><br><br>
<div class="gmail_quote">On Mon, Apr 28, 2014 at 2:00 PM, Jeff Shanab <span dir="ltr"><<a href="mailto:jshanab@jfs-tech.com" target="_blank">jshanab@jfs-tech.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div dir="ltr"><div><div><div><div>That is a reasonable resolution so you should not have multi-slice keyframes. Stick to main or baseline, High would probably be 2 pass with B frames. <br></div>H264 is of course comprised of Key frames and difference frames. But the decoder should pump out one frame per iteration at one frame delay. <br>
<br></div>Synchronizing multiple sources is an interesting issue. You will have to buck the tradition of ignoring the absolute time and using the timestamps only as a relative indicator. Instead sync the clocks on the Pi's and then rely on this time???. Probably pick one Pi as a time server and the other two use that to keep the clocks synced. Then control the two encoders relative to this clock so you even start the Keyframe generation in sync.<br>
<br></div>Perhaps the master Pi could run live555 and create a single Transport stream with multiple video streams from the other Pi's. The transport stream is defined as a container for streams sharing the same clock base. <br>
<br></div>Is this to sync multiple cameras in close proximity? or distant?<br></div><div class="HOEnZb"><div class="h5"><div class="gmail_extra"><br><br><div class="gmail_quote">On Mon, Apr 28, 2014 at 7:23 AM, Mark Theunissen <span dir="ltr"><<a href="mailto:mark.theunissen@gmail.com" target="_blank">mark.theunissen@gmail.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><span style="font-family:arial,sans-serif;font-size:13px">> What is the resolution / profile? </span><br>
<div><span style="font-family:arial,sans-serif;font-size:13px"><br></span></div><div><font face="arial, sans-serif">I'm at 854x480. I've tried baseline, high and main. Same result.</font></div>
<div><font face="arial, sans-serif"><br></font></div><div><font face="arial, sans-serif">I'm using UDP.</font></div><div><font face="arial, sans-serif"><br></font></div><div><font face="arial, sans-serif">Encoded in hardware on the Pi's Broadcom chip.</font></div>
<div><font face="arial, sans-serif"><br></font></div><div><span style="font-family:arial,sans-serif;font-size:13px">> Whoa? did I hear you correctly? stdin? I cannot even speculate how you can</span><br style="font-family:arial,sans-serif;font-size:13px">
<span style="font-family:arial,sans-serif;font-size:13px">> quantify stdin timing. (try sockets, shared memory)</span><font face="arial, sans-serif"><br></font></div><div><span style="font-family:arial,sans-serif;font-size:13px"><br>
</span></div><div><span style="font-family:arial,sans-serif;font-size:13px">So should I try using perhaps v4l2 driver (/dev/video0) instead of piping from one program to live555's stdin?</span></div><div><span style="font-family:arial,sans-serif;font-size:13px"><br>
</span></div><div><span style="font-family:arial,sans-serif;font-size:13px">> Make sure you create your timestamps at end of image capture/beginning of</span></div><div><span style="font-family:arial,sans-serif;font-size:13px">> encoding time. Since you are the source, the timestamps can be based all</span><br style="font-family:arial,sans-serif;font-size:13px">
<span style="font-family:arial,sans-serif;font-size:13px">> off the same clock.</span><span style="font-family:arial,sans-serif;font-size:13px"><br></span></div><div><span style="font-family:arial,sans-serif;font-size:13px"><br>
</span></div><div><span style="font-family:arial,sans-serif;font-size:13px">I am the source, but it's 3 different computers (raspberry pis) - not sure how to sync in that case?</span></div><div><span style="font-family:arial,sans-serif;font-size:13px"><br>
</span></div><div>Thanks for your replies and help.</div><span><font color="#888888"><div><br></div><div>- Mark</div></font></span></div>
</blockquote></div><br></div>
</div></div></blockquote></div><br></div>