Does NVR re-encode the stream?

[jackdakota 0]

Does an NVR simply save the stream or does it re-encode the footage again using whatever codec it can handle. I see many screenshots of the Dahua NVR and it lets you specify the bitrate, frame rate, resolution, etc. for each channel. I'm assuming that it is re-encoding the stream to according to those settings. I really want to avoid the NVR from encoding again a stream that's already highly compressed by the camera.

 

My cameras are Vivotek IP8332 and they have been tested to work with ONVIF software. I use it with Vivotek's own server software(ST7501). The camera has 4 streams and the server can "record" from any stream. It saves the stream directly onto the hard drive in .3gp format. I want to use a standalone NVR to record from my cameras as I don't want to leave my power draining server up 24/7 just to record.

[MaxIcon 0]

It depends on the software. Re-encoding causes a big hit on CPU, so many/most systems dump the video straight to disk, though they may put it in a proprietary wrapper.

 

Some NVRs can control the camera directly, especially if they're from the same manufacturer, while others just take what the camera is sending, and any changes need to be done on the camera.

 

ONVIF is not very cross-compatible yet, so you'll want to be sure whatever you're looking at will support the cameras you have now.