[SOLVED] Can't get over 20 fps from camera?

Malvineous

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Hi all,

I have just set up a Dahua DH-IPC-HDW3666EMP-S-AUS (6MP eyeball), which is listed in the specs as supporting 1-25/30 fps in its max resolution of 3072x2048. However I can't seem to get it to go above 20 fps. Is there a trick to this?

In the camera's web config, under Camera > Encode, I can set the frame rate of the main or sub streams. If I set it to 15 fps then the video it produces is 15 fps. Set it to 20 fps and I get a 20 fps video. But if I set it to 25 fps, I still only get a 20 fps video.

I set it up as PAL during config (as opposed to NTSC) so I presume that's why it's showing 25 fps as the max rather than 30 fps, however it's strange that it will let me select 25 fps but then only deliver 20 fps.

Is this normal?

The 20 fps frame rate is what my video player reports from both the file metadata as well as the rate at which the live stream is delivered. I have other cameras that can do 25 fps without problem, so it doesn't appear to be an issue with the system I'm using for playback.

Does anyone else have a Dahua 6MP camera, and are they able to report the actual FPS they are getting from it when it's set to 25 or 30 fps?

Thanks!
 

TonyR

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Welcome to IPCT ! :wave:

The specs here state:

"Main stream: 3072× 2048 @ (1–25/30) fps
Sub stream 1: 704 × 576 @ (1–25 fps)/
704 × 480 @ (1–30 fps)
Sub stream 2: 1920 × 1080 @ (1–25/30 fps)
*The values above are the max. frame rates of each stream; for multiple streams, the values will be subjected to the total encoding capacity"

Regarding the statement after the *, have you tried adjusting both the 2 sub streams' fps downward to see if the main stream can reach 30 fps ?
 
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Malvineous

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Interesting idea! I didn't notice that on the specs page. It doesn't seem to be the case - with the main stream left as 3072x2048 and both substreams off, I still can only get up to and including 20 fps on the main stream, but no higher.

I also tried changing the codec from H.265 to H.264 (no difference) and the encoding strategy from "AI Codec" to "General". None of these allowed frame rates over 20 fps.

Weirdly I also tried lowering the resolution and even with a single main stream at 1920x1080 (and no sub streams) it wouldn't go over 20 fps. So there seems to be some kind of max frame rate limiter active?
 

Flintstone61

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Also isn't there some camera's where you chose PAL or NTSC and that defaults/toggles the camera between 25/30 fps?
Ive seen this on my older HIk Oems
(never mind LOL) my ADD ass needs to read the Original post more carefully, or more coffee,,,or both...
 
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wittaj

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For surveillance cams, anything more than 15FPS is a waste anyway LOL.

Shutter speed is more important than FPS.
 

TonyR

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Interesting idea! I didn't notice that on the specs page. It doesn't seem to be the case - with the main stream left as 3072x2048 and both substreams off, I still can only get up to and including 20 fps on the main stream, but no higher.
Have you tried switching back to NTSC?
Just throwing a Hail Mary here, as these are IP cams, not analog, so it shouldn't matter but.....NTSC is for 60Hz AC (half is 30) and PAL is for 50Hz (half is 25).
Won't hurt to try....but as @wittaj says, 15fps suits most CCTV appplications since we're not trying to video the wingbeats of hummingbirds. :cool:
 
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Malvineous

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All the cameras I already have max out at 15 fps and it has always annoyed me how jerky the motion is. I'm viewing the images live to see what's going on around me and it's so much nicer to have smooth fluid motion. If you don't need more frames for your use that's great but I certainly do, and I find it a bit dishonest Dahua advertised them as doing 25/30 fps if they can only do 20 - why not advertise them as 20 fps max then, why lie? I specifically chose a camera that could do at least 25 fps for a reason, as some of their models are listed as only doing lower frame rates so I chose not to buy those ones. I don't really understand the argument that well I don't need that feature therefore it's ok that they lied in the specs as nobody else could possibly have different needs to me.

Any idea how to switch it back to NTSC? The thought had crossed my mind just to see what difference it would make but I can't find an option in the web settings to do so. Hopefully you can do it without a factory reset given the hassle involved in setting it back up again.
 

MyDaHua

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mat200

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in my experience

Main stream: 3072× 2048 @ (1–25/30) fps

25 fps = PAL
30 fps = NTSC

also, you need to turn of some of the motion detection / line crossing / advanced features on some cameras as those use compute power which is limited.
 

Malvineous

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Well I woke up this morning and - with no changes - noticed the camera was outputting 25 fps. So it looks like when it gets dark it drops back to 20fps to improve low light performance, and as the light level improves it returns to 25 fps. That's a relief, I can live with 20 fps at night to improve the low light performance as long as I get 25 fps during the daytime!

I noticed when there is movement at night it almost seems like the camera is doing binning, as the pixels seem to update in groups of 4x4 or even 8x8. The Raspberry Pi camera can do this, by grouping adjacent pixels together you get lower resolution but improved light sensitivity. I almost wonder whether it's doing a combination of full-resolution frames and binned frames, as that could explain this low light behaviour where things that are relatively static are sharp, but any motion is much blockier/pixellated especially when looking at the video at 100% zoom.

@Mike you are right, the standard option was under System > General. I changed it to NTSC and it automatically switched from 25 fps to 30 fps. This might be even better as I would prefer 30 fps but I thought I'd have to stick to 25 fps so that the low-light performance doesn't suffer too badly, but if it drops the framerate back automatically then leaving it on NTSC at 30 fps would be even better for my purposes. I'll let it run as NTSC/30fps and see what fps it drops back to at night.

IIRC these options have something to do with certain types of lighting (e.g. fluorescent), which can flicker at 50 or 60 Hz depending on the local mains frequency. Most cameras have options to set the frequency which I believe is supposed to stop strange flickering effects in the captured video when the timing of the shutter and flickering light don't line up perfectly, but I guess in the case of a security camera it depends on the lighting in the frame and if there's no flicker at 50 or 60 Hz then it doesn't matter which one you use. I do wonder though whether there's any real difference between PAL @ 25 fps, or NTSC @ 25 fps.

At any rate it looks like this issue is solved, but I will report back tonight with the actual fps the camera ends up dropping back to when set to NTSC.

Thanks all for your help, much appreciated!
 
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wittaj

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This is not a Reolink camera LOL and none of us experience the FPS dropping at night with Dahua cams...

I would suggest 3 factory resets as it sounds like maybe the firmware went wonky on you.
 

Malvineous

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How do you know the fps doesn't drop when the light level goes low? What method are you using to check the fps? Also you said above you don't use more than 15 fps so how would you notice a framerate reduction if it only happens when you've set the camera above 20 fps? You wouldn't see it happen if you've set all yours to 15 fps.
 

wittaj

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Before I knew better I would run the cams at max FPS LOL.

Many here still do run 30 FPS, especially for LPR purposes. And with LPR, you are running a fast shutter at night 1/2,000 so the entire image is black - you cannot get any darker than these images. All you see are the headlights and plates when a car passes LOL

1673147433493.png

I watch it in Blue Iris and the FPS stays the same as evident by looking at the status at night, the logs, and the storage requirements. They would drop significantly if the FPS dropped. Plus my cheapo cam that does drop FPS at night then throws up a yellow triangle caution and is logged in the log file.

It is why I dropped the FPS to anywhere from 8 to 15 FPS on my cams. I still get the great captures and at half the storage requirements, so double the number of weeks of stored video...
 
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I run my LPR cams at 25FPS in an attempt to get as many shots of the plates at night as possible. Sometimes the cars do fly through here. But as wittaj states, FPS has nothing to do with exposure. Exposure is controlled by the shutter speed and the Iris value.

These cams run at 25FPS all the time. They never change. Right now it is 9:17pm here in Houston and it has been dark for a few hours. They are still running at 25FPS. The firmware does not change the frame rate to compensate for the lighting. That would not do anything. Now you might have the cams set to a variable shutter speed and Iris setting. That will compensate for lighting.
 

Malvineous

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No argument from me about dropping the FPS for certain use cases like yours, but in my case I have the feed on a monitor I am looking at for most of the day so I like the smoother motion of a high framerate, and during the day with bright light it's perfectly fine. The server I'm using to record the footage has 24 TB available on it so having the footage take up more disk space doesn't worry me.

Interesting you mention the fast shutter at night. Every IP camera I've used until now slows down the shutter at low frame rates, which makes movement blurry especially at night, which is another reason why I don't like the low framerate. I didn't know you could speed up the shutter, but I'm guessing that's only for LPR cameras as the Dahua I'm using (DH-IPC-HDW3666EMP-S-AUS-BLK) doesn't appear to have an option for this, only framerate. I presume when it drops back to 20 fps it's also slowing down the shutter, otherwise there would be no reason to drop the framerate.

screenshot.png
 

wittaj

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Nope you can adjust the shutter for EVERY dahua IP camera... It is under exposure. We are not using an actual LPR camera, just a Dahua 5241-Z12E with a great optical zoom and we dialed it in to get plates.

And that is why we say shutter speed is more important than FPS.

If you are running default/auto settings or running it with settings that are not optimized and instead set up to favor a bright image (it does that by dropping the shutter speed and increasing the gain), then you are not getting the best performance out of the camera as any motion will be blurry. Default settings may slow the shutter down to 1/12 or even 1/3 with cranked up gain. You need a shutter speed of 1/60 or faster to start to minimize or eliminate motion blur.

Here is my "standard" post that many use as a start for dialing in day and night that helps get the clean captures. These are done within the camera GUI thru a web browser.

Every field of view is different, but I have found you need contrast to usually be 6-8 higher than the brightness number at night.

We want the ability to freeze frame capture a clean image from the video at night, and that is only done with a shutter of 1/60 or faster. At night, default/auto may be on 1/12s shutter or worse to make the image bright.

In my opinion, shutter (exposure) and gain are the two most important parameters and then base the others off of it. Shutter is more important than FPS. It is the shutter speed that prevents motion blur, not FPS. 15 FPS is more than enough for surveillance cameras as we are not producing Hollywood movies. Match iframes to FPS. 15FPS is all that is usually needed.

Many people do not realize there is manual shutter that lets you adjust shutter and gain and a shutter priority that only lets you adjust shutter speed but not gain. The higher the gain, the bigger the noise and see-through ghosting start to appear because the noise is amplified. Most people select shutter priority and run a faster shutter than they should because it is likely being done at 100 gain, so it is actually defeating their purpose of a faster shutter.

Go into shutter settings and change to manual shutter and start with custom shutter as ms and change to 0-8.3ms and gain 0-50 (night) and 0-4ms exposure and 0-30 gain (day)for starters. Auto could have a shutter speed of 100ms or more with a gain at 100 and shutter priority could result in gain up at 100 which will contribute to significant ghosting and that blinding white you will get from the infrared or white light.

Now what you will notice immediately at night is that your image gets A LOT darker. That faster the shutter, the more light that is needed. But it is a balance. The nice bright night static image results in Casper blur and ghost during motion LOL. What do we want, a nice static image or a clean image when there is motion introduced to the scene?

In the daytime, if it is still too bright, then drop the 4ms down to 3ms then 2ms, etc. You have to play with it for your field of view.

Then at night, if it is too dark, then start adding ms to the time. Go to 10ms, 12ms, etc. until you find what you feel is acceptable as an image. Then have someone walk around and see if you can get a clean shot. Try not to go above 16.67ms (but certainly not above 30ms) as that tends to be the point where blur starts to occur. Conversely, if it is still bright, then drop down in time to get a faster shutter.

You can also adjust brightness and contrast to improve the image.

You can also add some gain to brighten the image - but the higher the gain, the more ghosting you get. Some cameras can go to 70 or so before it is an issue and some can't go over 50.

But adjusting those two settings will have the biggest impact. The next one is noise reduction. Want to keep that as low as possible. Depending on the amount of light you have, you might be able to get down to 40 or so at night (again camera dependent) and 20-30 during the day, but take it as low as you can before it gets too noisy. Again this one is a balance as well. Too smooth and no noise can result in soft images and contribute to blur.

Do not use backlight features until you have exhausted every other parameter setting. And if you do have to use backlight, take it down as low as possible.

After every setting adjustment, have someone walk around outside and see if you can freeze-frame to get a clean image. If not, keep changing until you do. Clean motion pictures are what we are after, not a clean static image.
 

Malvineous

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Totally agree with your logic, no argument against shutter speed being key, my focus on framerate is because I've never used an IP camera before that lets you adjust the shutter speed directly. They all seem to do it by framerate, so you need a high framerate in order to get a high shutter speed.

Also agree that in low light you want a clean still frame, and for that you need a fast shutter speed even if it makes the image darker.

However my camera doesn't appear to allow you to adjust the exposure - under Camera > Image the option for exposure is disabled and cannot be selected. I tried changing the profile but none of the options enable the exposure section. If I click Apply, when I leave the page and come back the Profile is back to "Day" so I guess this is not where you select the active profile, but rather the drop down list is used to access the settings for different profiles which are made active elsewhere. Changing to self-adaptive/customised/day-night switch does not enable the exposure settings regardless of profile selected.

It looks like this model of Dahua cannot have the exposure settings adjusted, unless there's some other trick to enabling that section?

EDIT: Turns out if you turn off "AI SSA" (whatever that is) then the options become enabled again - time for some experimenting...
screenshot.png
 

wittaj

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Are you using Internet Explorer? If not, other browsers can block settings.




According the spec, it is just like any other Dahua and you can manual set shutter

 
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