With no response in two weeks, do you think I should conclude that there are just no good DVR options currently on the market?
There might be something out, especially on the higher end boxes but most of the DVRs today on the market are Chinese OEMs (or direct) and tend not to have many advanced features.
Maybe Hikvision has something? I presume you want to stick to lower cost DVRs?
I'll promote this and see what anyone has to say.
I will take a look at Hikvision, but we would use anything that works well regardless of price. This is requested mostly by high-end homes that already have expensive system in place, so they just want something that works reliably with the cloud. thanks.
Although Axis is IP maybe take a look at Axis Encoders, I am pretty sure they will work for your application. We recently did a similar test with HIK and Dahua without luck.
Eagle Eye Networks
This may be a good situation to consider Eagle Eye Networks. (full disclosure - I work for Eagle Eye.) It seems that you are describing our product, I've tried to address each of your points below.
Eagle Eye records all video locally (either constantly or on motion) and then synchronizes that video with the cloud based on available bandwidth.
The Eagle Eye Bridge (the box that's installed on site) makes an outbound connection from inside the firewall to the Eagle Eye Cloud. This means that there is no need for a static IP address, no reverse DNS, no port forwarding and usually no changes to the firewall or router on site.
Eagle Eye works with most ONVIF compatible cameras and also works with Analog cameras - so swapping out a DVR/NVR is doable.
The problem is your requirement is too vague. Saying "HTTPS uploading" doesn't carry any meaning without a protocol specification to go along with it. HTTPS is just a transport mechanism--there also needs to be a server on the other side that implements a protocol both the client and server can agree with, and there no real standards/conventions.
You might want to look for a DVR that carries a mechanism for "scripting" or user-customizable programming around motion events. Then implement the DVR-side yourself. I'm at a loss to point to any real examples of this off-hand, sorry.
@Integrator - Thanks for the Axis encoder recommendation - do you have any experience of their reliability? The user manual looks good in support of HTTP uploading on event triggers (http://www.axis.com/files/manuals/um_m7001_43683_en_1107.pdf)
@Hans - does your bridge require use of your cloud service? I work at a competing cloud service (camiocam.com) so need a DVR/NVR that is open in its support for settings changes.
@Steve - we adapt CamioCam to any protocol for uploading, so as long as the DVR can push via HTTP[S] (or even FTP, email), we're fine (regardless of PUT/POST/multi-part/jpeg/png etc...)
Brickcom can do it with Http but they only have a 1ch encoder so not really for your case