MPEG4 on DVR. Quality issues

[Guest Rockford]

OK, we have a client who has a PC based DVR that uses MPEG4 as its compression codec.

They have a camera looking at a street on quite a wide viewing angle on which the picture quality is quite poor, though it looks perfect on a composite monitor.

we have another customer on the SAME model unit with a MUCH more expensive camera (has a bigger lens) ALSO on quite a wide view and the picture quality is much better, though that said, the two look the same in terms of quality on a composite monitor.

Could it be the lens size that's causing the difference or what?

Thanks for any and all advice from everyone!

[ian.cant]

Certainly the quality of the lens & camera come to that will have an effect but also the monitor could be the problem from what your saying.

When you put either camera onto a composite video monitor the picture is good, then it doesnt sound like the lens or camera to me.

I also wonder about the back focus of the camera & lens.

[Doktor Jon]

If I'm reading your post correctly Rockford, what you're saying is that the displayed image from both cameras is fine, but the replayed recordings are noticeably different.

If that is indeed correct, then the camera / lens issue would be a bit of a red herring.

If the camera / lens set up were a factor you would expect to see some variance just on the displayed image, although by playing back a recording (depending on DVR set up) you would expect to see any general shortcomings 'somewhat magnified'.

If you put a quality monitor on the input side of the DVR and then compare the quality against the picture coming out of the recorder, that may give you some clues. Try the same with both set-ups and see if the variance is slight or significant between the two.

[breff]

Mpeg4 is very heavily compressed and will never be as good quality as composite.

Are there any settings on the DVR for image quality, ie 15k per image, 18k per image etc, the more hard disk space used the better the quality.

[Rich]

whats the tvl of the cameras?

[Guest Maciek]

Many DVR-cards very poor works with AMD processor.

When you have INTEL processor.

- motherboard with INTELL CHIPSET NOT VIA or SIS

- graphics accelerator only ATI RADEON NOT GEFORCE OR INTEGRATED

What is DVR-card and PC ?????

[Guest Rockford]

Mpeg4 is very heavily compressed and will never be as good quality as composite.

Are there any settings on the DVR for image quality, ie 15k per image, 18k per image etc, the more hard disk space used the better the quality.

69024[/snapback]

Oh sure, I completely understand that. What's weird is that we have another client using the SAME DVR and at least one of the SAME cams and theirs is fine! ALL look fine on composite at both of our clients, but the one client's gives poor quality and the other client's is fine! Can't figure that out. This is why I thought the cams might have something to do with it.

thanks guys! !

[Guest Rockford]

Many DVR-cards very poor works with AMD processor.

69122[/snapback]

Its definately NOT to do with the DVR unit itself. There is another at another client site which is identical and is fine. Most of the cams are different though which is what made me think that the cams might be to blame.

[Guest Rockford]

If I'm reading your post correctly Rockford, what you're saying is that the displayed image from both cameras is fine, but the replayed recordings are noticeably different.

69008[/snapback]

Not quite, no. The live view image on the DVR at ONE site is dodgy though fine on composite. The same model DVR at another site is fine.

[CompostCORNER]

We have installed a few DVRs that allow the recorded images to be played/viewed in 'Windows Media Player'.

On some machines, the playback is fine whilst on others, it's poor with very limited colur and shading. A simple 'CODEC' download installed into WMP increased image quality.

I'm not entirely sure but these 'CODECs' may need to be installed onto the host playback PC even if the recorded CD has it's own viewing software to run in.

A shot in the dark post that may aid. Worth a try as the 'Windows Media Player' option on our 'Flat-Tec' models had the image quality increase considerably after installation of an MPEG4 Codec.