4MP dismal sub stream resolution

[Schmark]

I am using a mix of 3MP (2332) and 4MP (2342) cameras on a 7106 NVR. The two problems with such a mix are evident when displaying -say- a 2 x 2 setup. In 2 x 2, each quadrant is optimized for the 4:3 aspect ratio of the 3MP cameras, so the 16:9 aspect ratio of the 4MP camera looks horizontally compressed. Further, the 2 x 2 setup uses the sub stream of each camera (I think) and this is where the 4MP sub stream resolution really sucks. That's because the best sub stream of the 4MP is only 640x360 (or 230,400 pixels), while the best sub stream of the 3MP is 704x576 (or 405,504 pixels, almost double).

While nothing can be done about the aspect ratios (imposed by the camera detector), is there anything that can be done to raise the sub stream resolution?

For example, a 4MP sub stream resolution that matches the 3MP could be 864x486 or 419,904 pixels (keeping an A/R of 16:9 and whole numbers for vertical and horizontal pixels).

Thoughts?

-S

 

[CTF]

Hello,
I just installed a couple of 4MP, and I also have some 3MP and have seen the same issue.
Substream is really not very good...
It would be good to have an option somewhere to fix this.
I am using XProtect if that makes any difference...

 

[fenderman]

Have you tried raising the bitrate?

 

[CTF]

Unfortunately, even on constant bitrate or highest variable quality, the MAX substream resolution is still 640x360.
I do not understand why they went from 704x576 to 640x360.
Quality of substream on a tablet is really low.

 

[Schmark]

The next question is: is the substream resolution adjustable via firmware? I, for one, think it is because the substream is most likely obtained by binning the pixels in both X and Y directions.

For example, the 4MP camera has a max resolution of 2688 x 1520 pixels. Consequently, the substream resolution of 640 x 360 pixels could be the result of a 4 x 4 binning (actually closer to 4.2 which does not make sense).

Sooo, if the FW performs a 2 x 2 binning, the substream will have a resolution of 1344 x 760 pixels which is probably too high. However, if the FW performs a 3 x 3 binning, the substream resolution will then be 896 x 507 (~454,000 pixels) pixels which is very much in family with the 3MP cameras substream resolution (~406,000 pixels)

For work, I build space cameras and all our pixel binning is performed in firmware.

Interestingly, I posed the substream resolution question to Hikvision USA, and the response was evasive at best (ie it got nowhere)

-S

 

[CTF]

It certainly would be great to be able to increase that substream resolution...