The feature was already implemented in Macroscop - synchronization with SD card archive for Axis and Panasonic IP-cameras. Starting with v1.12, RVI and Hikvision had been added to support SD card sync.
Usage of an archive of SD card allows to minimize the risks of losing records. If the connection between the camera and the server is lost due to Internet connection, power supply shortage or any other reason - Macroscop receives data from SD card and restores the missing pieces of an archive stored on the server. While watching restored recording the user will not notice any lags.
Synchronizing an archive with SD card improves the reliability of video surveillance systems and also allows to use archive from SD cards on cameras only on a demand or on a schedule.