What Are The Pros And Cons Of Client-Side Vs Camera-Side Dewarping Of Fisheye Cameras?

Takes the processing load of the client/server side. Dewarping at edge makes it much more feasible to display multiple, many fisheyes dewarped at same time. 

Camera-side dewarping is like a PTZ camera. You only record you're what looking at. 

Client-side deparping you are recording the whole image so you can dewarp the image live and recorded.  Plus multiple people can be dewarping different parts of the image at the same time. IMHO this is much better than camera-side.

Client Side

For client side dewarping, there are two key advantages:

• Using virtual PTZ controls on the client, users can virtually pan/tilt the view to see activity in all areas, on both live and recorded video. This allows a single stream to cover many angles, instead of using multiple camera side dewarp streams to view the same area.
• This also allows multiple users to view different areas at one time, like Michael said. This isn't typically possible with camera side dewarping, unless multiple dewarp regions are used, which adds to bandwidth and complexity. 
• This single stream is often lower bandwidth than multiple dewarped streams, with many cameras now offering smart codecs on warped overview streams.

The key disadvantage is integration complexity. Client side dewarping often requires the VMS to integrate a proprietary dewarping SDK for each manufacturer. For smaller camera manufacturers, this may be a challenge as VMSes are less likely to integrate less frequently used models.

Camera Side

For camera side dewarping, pros:

• Simplicity is the main advantage to camera side dewarping. For some people, they want to view the whole scene, but not train users on how to control the dewarping. So they can use a panorama/dual panorama or dewarped views and the camera appears as any other would, without needing to use virtual PTZ controls.
• Additionally, viewing fixed camera side dewarp streams makes sure operators are looking at what you plan them to be viewing, instead of potentially missing things because they are panning around in an overview stream. 
• Finally, camera side dewarping reduces and may eliminate the VMS integration required for client side dewarping (though integrating multiple streams and/or PTZ controls may still be necessary).

The cons of camera side dewarping are:

• Only what's viewed is recorded, so if a dewarped stream is looking in the opposite direction of activity, nothing wil be captured, whereas users could use virtual PTZ controls on recorded video with client side dewarping.
• Bandwidth is generally higher, because you are recording multiple dewarped streams instead of a single overview stream. These streams may also not allow smart codecs to be used (as is the case in the Hikvision 63C2 we just posted).

You may also want to see if the camera is using Immervision lens with their SDK.  Immervision uses different settings for different panamorphic lenses and the client has to detect which lens is in use to dewarp properly.  This is true of Hanwha Wisenet 5 panamorphs.