Review-SD4A425DB-HNY 1/2.8" CMOS 4MP 25x Starlight Auto-tracking MiniPTZ

When does this happen? Any videos you can post? I am not seeing this on mine, as far as I know.

Pretty much continually. Both day and night. Night I have saturation set to 0 and still see the same. WB doesn't seem to affect it. Can set to a manual exposure or auto and the same. Bitrate doesn't affect it. FPS/IFrame does but again just changes the frequency of the heartbeat. AI codec is the only thing that I found that eliminates minimizes it (looking again closely I can still see it some but much better).

Can't see it well in the small preview below. Open in YouTube and watch, for example, in the grass at the base of the tree. It's about a 1 second pulse interval.

 
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Yea, I don't think I am seeing that. Do you want to see any of my settings? I doubt it, but maybe I have something set differently?
 
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Think that I've gone through everything at this point but I'm open to any suggestions.

Here's bp2008's article re pulsing:
Troubleshooting Streaming Problems

I think it's mostly just a function of a combination of the encoder and the scene. Areas of grass like I have there is where I've seen the same the most with other cams. Where the car is and to the left it's there but you don't see it nearly as much. Kenzi's setting looks like kind of a nightmare scenario for it. lol

It's not all that bad but once you see it you can't not notice it. As long as the AI codec doesn't cause me any other troubles I'm fine with using that. That takes it down to a level that I have to look hard to see it.
 
Thank you

Just curious 25Frame Rate to 150 iFrame rate, does it not cause issues with ivs detection ? or in general any issues?
Maybe I'm running into some problems with IVS, there are often times where I think it's too slow to register movements, but I don't know if it's related to the 25 frames and the 150 ?
 
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Pretty much continually. Both day and night. Night I have saturation set to 0 and still see the same. WB doesn't seem to affect it. Can set to a manual exposure or auto and the same. Bitrate doesn't affect it. FPS/IFrame does but again just changes the frequency of the heartbeat. AI codec is the only thing that I found that eliminates minimizes it (looking again closely I can still see it some but much better).

Can't see it well in the small preview below. Open in YouTube and watch, for example, in the grass at the base of the tree. It's about a 1 second pulse interval.




That looks to me like compression.

A camera compresses items in a frame that do not change between frames in order to save space. It does this by setting a key frame which is the reference frame and then it compresses the content and guesses the missing bits of data it has chucked away from the data that's there and the key frame in for every frame after that. It does that between every key frame. I think what you're seeing there are differences between the guesses each time. That's why it changes regularly = probably every 15 frames which is the key frame interval. I'd hazard a guess if you were to change the iframe interval to 30, the period between the pulses would probably double. - At least that's my understanding of how compression works.

As to why you don't see this normally. On a less detailed area, the changes are less noticeable. You see it in the grass because you have a lot of very fine detail close together and so any changes in the guessed missing data is very highly visible as your eye easily references the data and detail next to the changed pixels.

Although, I can live with this, this is another reason to give people a compression (not just a bit rate option) in camera to allow those with more storage space and who require better quality to opt for less compression.

From my BI stream data, it appears whatever my 4kT records the data in, it compresses it by a factor of 8:1. As the streamed data received by BI is exactly (almost by a few kb's) 1/8th of the bit rate set in the camera. Having such a large compression ratio kind of destroys the point of setting a high bit rate. Personally, Andy, if you can request it of Dahua, I'd like to see Ultra High Quality (Large File Size Warning) Setting added to the firmware that still allows the standard bit rates unchanged eg 1-16380 in the case of the 4KT but sets a compression ratio behind the scenes of say at least 4:1 so the stream to BI or an NVR eg at 16830 would be 4,200kbs not 2,000kbs. I would prefer an option that gives a 2:1 ratio so the stream was around 8,000kbs - please request this.

It is going to double the storage requirements (quadruple on 2:1), but in turn, it will raise the quality by some way by doing away with as many artefacts and guesses. I can see why it wouldn't be feasible as less compression = less work for the camera so it's easier not harder in CPU terms.

It seems to me a bit pointless to have high bit rate options eg 16803kbs and then destroy the quality by streaming it at 2,000kbs to your storage. Even more so where for lower bit rate settings, the stream is much lower still.

It's not an option for everyone as some corporate clients with large camera numbers will still prefer size of ultimate quality. However, for many smaller users, with storage becoming cheap now, I think there ill be more emphasis towards quality over file size as with small numbers of cameras it becomes economic to save streams. I believe changes to lower compression are the future as storage becomes almost throw away. Moore's law is hitting storage in a big way. When I bought my 4TB HD a year ago, it cost £180 from memory. Today that same money buys 8TB. I dare say in 12 months or less, that will be 12-16TB. Storage isn't going to be a limiting factor going forwards in my view.
 
I think the 8:1 is just a math difference. BI reports in kBytes vs the cam settings in kbits.

Compression does come into play and I suppose more so where you have areas that are somewhat consistent like a large area of grass like that where it's attempting to decide whether anything has changed and what can be compressed. But that's different than the pulse effect. Does make it so that you see it more. You can change the iFrame to affect the frequency of the pulse but it's still there. Not sure about the practical effects otherwise of going high/low enough to make it less apparent.
 
Although less compression would make the pulsing less obvious, my concern is less with the pulsing and more with the ability to have a background you can zoom into without suffering quality issues as the camera appears to concentrate less compression on the foreground areas, I'm guessing by design. Some might argue, if you need to zoom into the background, you need more cameras, but then that takes more storage space in itself and incurs other penalties such as purchase price, additional poe switches, cable, mounts, electricity etc. It's horses for courses and as said, lower compression rates aren't ever going to be for everyone, at least not until storage is very very cheap to the point even large corporations don't have to worry. However, for home users and small businesses, I don't see the harm in offering the option given the low cost of storage and those annoying situations where the item you need to capture has a habit of being in the background and the picture quality becomes pants when you zoom in to try to identify the subject digitally as the data just isn't there to support the zoom despite a seeming large pixel count.
 
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I have couple of questions about the specs:

Pan: 0° to 360° endless
Does this mean it can go round and round forever? Does it use some kind of rotating/sliding contact mechanism?

auto flip 180°
What is this?
 
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I have couple of questions about the specs:

Pan: 0° to 360° endless
Does this mean it can go round and round forever? Does it use some kind of rotating/sliding contact mechanism?

auto flip 180°
What is this?

I haven't tested it endless, but it will spin 360 and keep going LOL.

Auto flip means someone is approaching the camera and it is tracking them and then they walk under the camera and continue walking behind the camera - the image will flip so that they are not walking upside down as the lens sweeps from front to back while tracking them.
 
the image will flip so that they are not walking upside down as the lens sweeps from front to back while tracking them.
Bummer, I would SO love to have them walking upside down in a video!