Bitrate confusion (input & output) NVR Spec error?

[ahb248]

Hi All,

Looking to get clarification on this so I can be better informed.

I'm looking at upgrading my security system from analog to digital IP system finally.

I looked at this link from Hunt and I'm a bit confused on the specs and the bitrate.

There is some conflicting bitrate information in general out there in bit rate charts to different websites on what bitrate goes with what video compresison etc. Leaving that aside and looking at the link below.

HNR51P6-16

16 Channel & 16 PoE Network Video Recorder <div id="product-description"> <ul> <li>Up to 16 Ch IP cameras input</li> <li>160 Mbps Input Max and 256 Mbps Output Max</li> <li>Support H.265</li> <li>Up to 12 MP resolution recording</li> <li>Independent VGA output up to 1080p, HDMI output...

huntcctv.com

1. "160 Mbps Input Max and 256 Mbps Output Max " I get the 160Mbps input Max for recording, but I've never seen an output bitrate? Is the output bitrate for live viewing?

2. If the output Max bitrate is for synchronous live viewing, than why does the spec state "Synchronous Playback 4 Ch. @ 4K, 16 Ch. @ 1080P" this would not make sense assuming 4K at H264 @ 30fps is ~20Mbps or H265 @ 30fps is 10Mbps? Is this an error in the datasheet, surely with 256 Mbps Output Max aggregate it should support more than 4 Channels at 4K?

3. There is an attached bitrate chart, than you look at the duaha link and its way off DahuaWiki. Here is another website for reference: Recommended Bit Rate For Your Security System – GW Security why is the dahua wiki so far off?


Looking for clarification specifically to the spec on the Hunt link b/c they actually list more specs than most, but I'm unclear on the output bitrate.

Cheers

 

[Mark_M]

1. "160 Mbps Input Max and 256 Mbps Output Max " I get the 160Mbps input Max for recording, but I've never seen an output bitrate? Is the output bitrate for live viewing?

160Mbps sounds standard for input bitrate.... I too have not heard of an output bit rate. Maybe that's zero channel preview or passthrough?

2. If the output Max bitrate is for synchronous live viewing, than why does the spec state "Synchronous Playback 4 Ch. @ 4K, 16 Ch. @ 1080P".

These are decoding resolutions on the HDMI output.
Decoding is the NVR taking the camera feed, decoding it and outputting from the HDMI port.
So 4ch @ 4K means the NVR can display 4 cameras, each camera at 4k and output to the HDMI (likely total output of 4k on the HDMI).
16ch @ 1080P means the NVR is viewing the cameras substreams, but 16 channels at 1080P is likely a total of 4K output on the HDMI.

 

[ahb248]

Hi Mark,

Thanks for the feedback.

I believe the synchro playback is just that. I don't believe it has to do with HDMI output. The HDMI output is just 4K. Hence the question on the output Bitrate and playback via mobile app or desktop app.

I could be wrong but there is a spec just for HDMI out so hence my need for clarification. I emailed Hunt if they respond I'll provide their feedback.