Simultaneous and synchronous multiple camera playback

[jgazin]

Hello all,
I have a client who wants me to modify ZoneMinder to make it playback multiple cameras simultaneously. Currently you can only playback one at a time, though u could probably open multiple single camera windows and play them all back at the same time.
Have any of you managed to playback multiple cameras simultaneously and sunchronized to the same timestamp? The synchronization is important because he wants to be able to view the same camera event from multiple angles.
If you have tried and been unable to make it work, I'd like to know that too, as I'd hate to run up a big bill for this client trying to do something that can't be done.
Also, if you have any PHP scripts regarding this, I'd love to see them.

Thanks,

JGazin

[zoneminder]

You are right in that currently this is not possible.

It can potentially be done in one of two ways. Either several streams running at once but started just at the right time as each has something to show (which may not be at the same time). Or by merging the feeds into one stream.

The first method is easier but depends on the streams replaying at exactly the correct rate to stay in sync, which is unlikely to happen. The second method requires a bit more programming but will probably be nicer.

In your case it depends also on whether you are trying to replay motion detection events, which may start a few seconds apart, or from continuous streams. In the second case it is probably easier, though in the first case using linked monitors may enable you to time events to start simultaneously.

[jameswilson]

i was trying to do this via zm4ms and use the timstamps but its such a complicated query for sql i gave up as i dont know sql enough to make the query. As each image is time stamped it is realtivly easy to find another monitor with the exact same timestamp, but the problem is most images do not have the exact same time stamp. And whatever we do must work for modect as well as mo/record. I was hoping i could query on the closest matching image but again gave up on this. I think 4 should be max simultainous playback mind