ZoneMinder Forums

W. wrote:

SyRenity wrote: I will increase the buffers to 120, with 119 pre-event (according to Phil recommendation in another thread) and 120 post-event, and let you know how it goes.

and you will get exactly the same effect. leave buffers at 70 and decrease prealarm framecount to say 50, that might help you

Can you please explain? Shouldn't increasing pre and post actually give more space for ZMA, if it's not fast enough and drops frames?

SyRenity wrote:

W. wrote:

SyRenity wrote: I will increase the buffers to 120, with 119 pre-event (according to Phil recommendation in another thread) and 120 post-event, and let you know how it goes.

and you will get exactly the same effect. leave buffers at 70 and decrease prealarm framecount to say 50, that might help you

Can you please explain? Shouldn't increasing pre and post actually give more space for ZMA, if it's not fast enough and drops frames?

increasing buffer count gives more space for zma, pre and post are number of frames that have to be saved for any given event and they are kept in buffer just for this one purpose, to save them when event triggers. default settings are 40 frames buffer, 10 frames prealarm and 10 frames postalarm, what you do is use up all buffer space for preaalarm frames and leave no space for actual frames that are captured when event triggers.

increasing buffer count gives more space for zma, pre and post are number of frames that have to be saved for any given event and they are kept in buffer just for this one purpose, to save them when event triggers. default settings are 40 frames buffer, 10 frames prealarm and 10 frames postalarm, what you do is use up all buffer space for preaalarm frames and leave no space for actual frames that are captured when event triggers.

So, what you mean is that ZMA doesn't process the pre frames at all?

I'm asking this because I'm seeing a considerable improvement in the recordings, there are much less pops right now. It still not 100%, so I would like to know how it actually works.

SyRenity wrote:

increasing buffer count gives more space for zma, pre and post are number of frames that have to be saved for any given event and they are kept in buffer just for this one purpose, to save them when event triggers. default settings are 40 frames buffer, 10 frames prealarm and 10 frames postalarm, what you do is use up all buffer space for preaalarm frames and leave no space for actual frames that are captured when event triggers.

So, what you mean is that ZMA doesn't process the pre frames at all?

I'm asking this because I'm seeing a considerable improvement in the recordings, there are much less pops right now. It still not 100%, so I would like to know how it actually works.

well, you can either ask author how it works, or make your way through source and find it out on your own. my opinion is that second option is the best if you really want to know how it works.

Hi.

I meant, that with the settings of 120 images and 119 pre-event, it works ok (not 100% though). So before changing the settings, I would like to know if it actually will improve the matter.

the buffers mean

buffers = 120
120 images are stored in ram

pre alarm = 60
when an event is detected the previous 60 images from ram are added to the start of the event

post buffer = 60
the system carries on adding 60 images to the end of the last event.

Thanks James, but I understand this.

What I don't understand, is why it's not recommended to set the pre-event buffer almost as large as the images buffer (i.e. 120 image buffer, 119 pre-event buffer). Does it means the system not analyzes the pre-event frames?

Phil, could you shed some light on this please?