Difference between HDW2231R-ZS and HDW5231R-ZE?

[Dxue]

Yes. Decoding H.264/265 takes compute power. Some hardware / firmware combos does it better than others, some do H.264 well but not H.265

just tested it out, the power difference between the sub stream and the main stream is really significant on a i5 4590 cpu and no dedicated gpu. from around 55% usage on full speed (1080p, 4k bitrate, 25fps, h265) to about 13% on half speed cpu (d1 (i think it is dvd resolution with 4:3 ratio), 1.5k bitrate, 25 fps, h265). this is based on 3 streams using smartpss software (not sure if the software is up to date or not, can't find the version info)

 

[looney2ns]

Thanks, I did see the setting option in UI3 which is great because on my particular devices it almost always errors through U!3 if using anything more than the min resolution (or jpeg option) so that's great.
I don't think apps like TinycamPro, which I just purchased recently, have similar options.

I have ridiculously low DSL upload bandwidth, (< 0.5Mpbs) so using the smallest stream will be important for it to even function I imagine.

TinycamPro does have options for different stream choices, read the help link in Tinycam.

 

[aristobrat]

if i use a nvr to record the mainstream that is one stream. If i use other devices like a mobile or another device to watch the mainstream, does that count towards a multiple stream or still the 1st main stream?

If Dahua's NVRs work like their PC-NVR, ... what I saw this afternoon was that multiple devices connected to the NVR to watch the main stream from the same camera do NOT count as multiple streams to the camera.

I had three devices (SmartPSS on my Mac, iDMSS on my phone and iDMSS on my tablet) all connected to PC-NVR and watching the same main stream from the same camera, and I only saw one stream going between PC-NVR and the camera.

 

[civic17]

Hi @nbstl68

Now let's say you have a device that wants to display all 8 8MP streams on a 1080P monitor... that's now basically 8x 1/2x "4K'" H.265 that devices needs to decode AND RESIZE for the 1080P display.

If you attempt to decode all 8 streams on some devices, when they run out of CPU power to decode - you will see a "decode" error on that channel.

This got me thinking about how the decoding works on the Dahua NVR5216-16P-4KS2E NVR that I want to buy. The specs say max decoding 4ch@8MP/16ch@1080P so does that mean if I were to display four 4K camera and four 1080P camera on a 1080P monitor it should be able to handle it since its only displaying 1080p and the rating can support 16 of them? Recording to NVR in 4K and decoding in 1080P onto the monitor screen are two different processes right?

 

[mat200]

This got me thinking about how the decoding works on the Dahua NVR5216-16P-4KS2E NVR that I want to buy. The specs say max decoding 4ch@8MP/16ch@1080P so does that mean if I were to display four 4K camera and four 1080P camera on a 1080P monitor it should be able to handle it since its only displaying 1080p and the rating can support 16 of them? Recording to NVR in 4K and decoding in 1080P onto the monitor screen are two different processes right?

Hi @civic17

NVRs are designed to save first - that is the priority, and as long as you are using < maxbandith and have a decent HDD it should do that.

Then, it will use the processing power for other functions, such as display.

Remember, Cameras typically have 2-3 streams - so it is possible to stream 9x "4K"/8MP cameras on a screen IF you are using their lower resolution streams.

When you attempt to use the full resolution "4K" / 8MP streams to decode eventually you will get a "decode error" if requesting the NVR to decode them all.

In cases where you need to make a wall of "4K" monitors each displaying "4K" video you will need another device(s) / box(es) to receive the encoded streams from the cameras / NVRs and display them.

Ok - now the math part:

max decoding 4ch@8MP/16ch@1080P

16 channel @1080P ~= 4 channels @8MP provided same frame rate / bandwidth used by the cameras / and encoding - this again is for display purposes, as the cameras are sending the encoded signal. Remember H.265 should take more processing power ( depends also on chip / dsp design and alogrithm / programming of firmware )

If that is the realistic max - that means once you use all that bandwidth to decode there is no more processing power available. ( naturally, in some cases there maybe some leftover - but do not plan on it )

Thus in theory, "four 4K camera and four 1080P camera" - you would have exceeded the spec with 4x "4K"/8MP camera streams being decoded provided you are sending the NVR the 8MP stream to decode. IF you are attempting to decode a lower resolution stream from the 8MP camera you should be OK.

Example - a "4K" UHD monitor and 9 channels displayed at once - if all are subchannels then the NVR maybe able to display them all.