Another busy few weeks but thought this was useful enough to post details...
VVF file exports are pretty common place. They come from a variety of different cheap DVR's some branded and some not!
We have had a few in here recently for a number of different reasons and have found that the native file export to USB can be very temperamental. Even if it does work, you are limited to 2gb USB flash devices and actually setting the export parameters is pretty hit and miss due to the poor GUI.
Pull the drive and use FTK Imager to image the drive - select Raw(DD) Image. Select 1Gb chunks. Leave it running whilst you go home!
Come back in the morning and view all your new image chunks. You then need to make a copy..eats storage but needed to preserve the original image.
Using your copy, rename a chunk with the new file extn .vvf
Now comes the difficult bit. We need to change its endian. In other words we need to byte flip the data. I used a gaming byte flipper and used the number 2 (the amount of bytes to flip)
This new VVF file will now play in the VVF player for that type of unit. There are a few different types and remember that if you use one for a 8channel and your system is a 4channel, the date and time info will corrupt.
Saves loads of time.
Best of luck and hope this helps