between mjpeg or jpeg?

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ynn
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between mjpeg or jpeg?

Post by ynn » Wed Aug 01, 2007 5:34 pm

I just came across the preset menu while adding new monitor, just noticed that MJPEG give me better images for my Panasonic ip camera, but the load seems to be higher than usual, is that normal things when using MJPEG require more Load comparing to JPG?
for ZM which one if more preferable between MJPEG or JPEG?

thanks.

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cordel
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Post by cordel » Fri Aug 03, 2007 10:55 pm

Mjpeg will give you a higher frame rate as it pushes the images to your zm server vs the static image that zm has to request for each image. If you set your fps to the same rate you had before, you should see that mjpeg has better performance as zm does not have to request each image.
The higher the frame rate, the higher the load regardless. But mjpeg is more efficient.

ynn
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Post by ynn » Sat Aug 04, 2007 2:59 am

does this theory works for all ip cameras?because I have tried my pixord and gadspot cameras, both produce less Load with JPEG just around 2.00 but if I uses MJPEG the Load rise to 3.00 and up. Is this normal?

and what is actually better with "Alarm Maximum FPS" in Monitor Edit/Create window just leave it blank or put 5 if the Maximum FPS is also 5?

thanks Cordel.

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MJN
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Post by MJN » Tue Aug 07, 2007 8:48 am

On a related note does the specified frame rate effect network traffic when using MJPEG as it does for static JPEGs?

To put it another way, if we had the frame rate set at 3fps then regardless of the maximum frame rate of the camera we'd be putting 3fps across the wire if using static JPEGs.

However, if usign MJPEGs does ZM request a stream of 3fps from the camera, or does it get the full rate camera frame rate and simply drop the frames it doesn't require?

The reason behind my question is that I'm not seeing any discernable difference in CPU load between using MJPEG's and static JPEGs, however I think I'm seeing an increase in network traffic. It's hard to tell for sure as it depends on the sampling rate of the measurements.

Ynn, when you say MJPEG is giving you 'better images' can you elaborate on what you mean? (and what camera?)

Mathew

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cordel
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Post by cordel » Tue Aug 07, 2007 1:27 pm

MJN wrote: However, if usign MJPEGs does ZM request a stream of 3fps from the camera, or does it get the full rate camera frame rate and simply drop the frames it doesn't require?
This depends on how you:
A) Configured the camera OR
B) How you configured the camera PATH

I would suspect that if you don't define a restriction in either of those two places, your going to see what ever the camera can produce for max fps. ZM will just ignore what it don't need according to its configuration.

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MJN
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Post by MJN » Tue Aug 07, 2007 1:31 pm

Sure, I specifically mean the camera has no fps set (or at least no user setting available - it's obviously limited internally) and ZM capture rate is set to 3fps (the PATH setting is not defining the framerate in this instance). Would this still mean 3fps on the network regardless of whether MJPEG or static JPEG capture is chosen?

It's not all that important, but I do like to know how these things work!

Mathew

Edit: Having just re-read your response I guess you've answered my question - ZM is likely just dropping (or ignoring) surplus frames.

ynn
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Post by ynn » Wed Aug 08, 2007 5:07 am

MJN, What I mean by using MJPEG ang getting better images are, that the images are clearer,sharper and not as many doted images than using JPEG especially under low light condition, I am using Panasonic BLC10.

but not for Pixord and Gadspot cameras, they seem to run better with JPEG as of Load concern and no effect on Images for MJPEG or JPEG method.

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MJN
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Post by MJN » Wed Aug 08, 2007 9:26 am

I see - that's interesting. I've not been able to discern any differences in quality on my BLC1 (static version of yours I guess, although they could be fundamentally different under the hood). I might try some further experimentation because in either case the CPU load is quite acceptable for me and so may as well get the most out of it.

I wonder why there could be difference in image quality? It's tempting to look at how MJPEG functions but this could be barking up the wrong tree - it could well be more down to how the camera processes the images before serving it up that is making the difference.

Mathew

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Post by jameswilson » Sat Aug 11, 2007 3:37 pm

i would suggest there is a compression (jpeg) setting that is diffrent between your jpeg and mjpeg urls or config
James Wilson

Disclaimer: The above is pure theory and may work on a good day with the wind behind it. etc etc.
http://www.securitywarehouse.co.uk

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