Still Image Looks Different Than Video

[wxman]

I've noticed that when I save a still image from my 2032-I cam, the brightness/contrast of the picture looks a little different than the video stream. The video seems to have much more contrast and saturation. So much so that bright areas will sometimes blow out on the video, while I can save a still image capture at the same time and the bright area is not blown out.

Check this graphic out. I used the "capture" method on the firmware for the "image" and did hit the prt screen button on the keyboard while the video was playing to take a sample from the video. Comparing the edges side by side, you can see an obvious difference.

Is this normal? and if so, is there any way to make the video and image captures match?

 

[bp2008]

If I would have to guess I would say the right side "Video" image lost a little bit of color information during h264 encoding. Try maxing out the bit rate and maybe reduce the frame rate of the video, and see if that makes a difference.

 

[Peter]

This image is only 47kB so cannot really see any detail - maybe post original images!

 

[wxman]

Thanks guys. Sorry I'm just getting back to this. Been busy lately! Apparently Bp2008 is on the right track in that this has something to do with h.264 encoding. I tried out the substream in motion JPEG format and the still capture JPEG images match the motion JPEG. Yet when I go to the mainstream, the H.264 images are much brighter than the Jpeg still images. It's most obvious when looking at the sky. I'm attaching 2 full size examples looking at the sky.....

In the first example, notice how the original JPEG image (first image) shows different shades of grey in the clouds where the video capture (2nd image) has all the lighter grey shades completely blown out"

In this next example (again, JPEG Image first, video capture second), notice how much brighter the blue is in the sky on the video...Plus notice the puffy cloud how you can see the detail on the JPEG but most of the detail is blown out on the video.

I've tried maxing out the bit rate, but this hasn't really helped....Even if it did, it wouldn't be of much benefit because I'll mostly be using this to monitor remotely over the internet and will have limited upload bandwidth (thus I wouldn't be able to stream at maxed out bit rate).

This makes for a difficult situation because I'm trying to simultaneously upload streaming video and FTP snapshots. When I make the video not blown out, the still images look too dark. When the still images look just right, the video is too bright with blown out whites. If motion JPEG was offered at full "mainstream" resolution, that would solve the problem, but unfortunately only H.264 is offered....

Was curious if anyone else had ever noticed this issue, as I'm sure I'm not the only one that uses video and FTP at the same time.

I thought about using VLC for the video streaming as it has options to adjust the brightness and contrast. For some reason, I can't get that to work right either. The video on VLC is extremely choppy/skipping and every few seconds, the bottom half of the video turns a bright, fluorescent color (often pink or lime green)...I have to use "webcomponents" to get a stable video. Not sure what all of that is about.

 

[bp2008]

Maybe you can get VLC to be more smooth if you increase its buffer time (network-caching).

I really don't know what to tell you. Have you gone through the image adjustment options in the camera?

 

[wxman]

Maybe you can get VLC to be more smooth if you increase its buffer time (network-caching).

I really don't know what to tell you. Have you gone through the image adjustment options in the camera?

Yeah, I've gone through all of the image adjustments. Not having any luck finding anything that really looks good on both video and FTP images. Make one look good and the other doesn't.

As far as VLC goes, for some reason I'm not getting any kind of picture at the moment. This is all I see while playing the network stream on VLC right now:

Changing the latency does nothing...Usually I can at least get half of a the picture to work and a couple frames here and there of the whole frame working..Can't even get that much at the moment. No clue what's going on with that! I'll try the latency again later when I actually can get a picture to work with.

 

[bp2008]

Is any of this on WiFi ? VLC does have a tendency to do that corruption more than other decoders, but never to this extent.

The network-caching may be the key to getting a picture you can work with.

 

[wxman]

I am accessing the computer through WiFi, although I've got a solid 5 bar connection at 72 MBPS to the router.

Thank you helping with this! Even if we don't find a solution, I greatly appreciate you taking the time to offer advice. I'm fairly new to all of this IP/Networking stuff and still have a lot to learn.

 

[bp2008]

Well if you're sure it isn't the WiFi's fault (I'd still try a wired connection just to be sure) then I can only think of 2 other possibilities. I doubt the computer is too weak to decode the video stream... but it is a possibility nonetheless and only you can check the CPU usage to see if it is maxing out a core.

The other possibility is that the video encoding isn't quite right. Very unlikely though since all my hikvision cameras work fine in VLC. One thing you might try is to reduce the i-frame interval so that it matches the frame rate. i.e. 10 fps, 10 i-frame interval. This has been known to help with some cameras, though I haven't had to recommend that for a hikvision camera in a very long time... I would not set the i-frame interval that low unless it actually helps though. Because it will make compression less efficient having lower i-frame intervals.