I asked this same question before two years ago and it got no replies and got locked ... Is there nobody from the Varia radar team notified of these posts? Are no developers working with the metadata from the Garmin Varia RCT715?
What are the 33 bytes in the MP4 metadata being recorded by the Garmin Varia RCT715 in all of its MP4 files? 
This is in addition to all the other standard metadata. What I am interested in is the exact timecode of each frame in the video ... preferrably GPS synced since ya know Garmin is a GPS company after all. I am hoping that the binary data is some sort of encoded timestamp of exactly when the video started recording ... rather than unreliable created/modified date/time. Any help would be appreciated.
Does no-one else need precise time out of the video? If you do, then can you please tell me how you are getting millisecond precision time out of the video frames? Thanks again in advance for any help.