SteadyEddie
Hi,
First, you need to make sure that this is indeed the entire size of the SD card. To do this, open Disk Management and see if there is any other Unallocated or RAW space next to the 1.6GB partition. If there is such space, then most likely all your videos are located there. To recover them from the unallocated or RAW space, use data recovery software and scan not just the 1.6GB partition, but the entire SD card.
If the size of your SD card is also displayed as 1.6GB in Disk Management, then I have bad news for you, it's most likely a hardware problem with your card. In this case, I advise you to recover the files with professional help.
Regarding the .bin file, considering that the partition of your SD card is only occupied by 200MB, there will be nothing valuable for you in this file. However, I would refrain from further interaction with the SD card to avoid worsening its condition, if its entire volume is indeed shown as 1.6GB in Disk Management.