moving videocams GPS data extraction?

[peterleighjones]

I have a Sony HDR-XR550 "Professional" video camera fitted with GPS and a Hard disk. I can use the GPS data extraction tools I have very well for its stills I have taken.  However, if I am moving, it appears to me, after _many_ attempts at recovery of GPS _tracking_ data, that there is none?  The video camera does appear to sometimes record one GPS data string including GPS Timestamp, GPS latitude and longitude.  I have not determined what enables the "sometimes" and as yet, whether that time and place is only when the camera may have been stationary!  (I can, and will do that, soon.)
Do any of you guys know the answer to this: does it record moving videocam GPS data, not just "possibly?",?  And if it does, how do I get just the GPS Timestamp, GPS latitude and longitude?
Thanks.

[Phil Harvey]

It likely records moving GPS in the video stream.  ExifTool should extract this if the format is M2TS/AVCHD.  If MP4, I haven't been able to decode this yet, but it should exist.

- Phil

[peterleighjones]

All data pertaining to the video files is contained in 6 of  the camera's HD directories
AVCHD
   BDMV
      ClIPINF
      PLAYLIST
      STREAM
   AVF_INFO
Of the first 5 (as nested) directories only STREAM contains the .mts video files and the rest are only big enough to, possibly???, only contain pointers to data in 3 other very big, currently dated files, in the AVF_INFO directory.  They are called AVIN0001.BNP (155,648KB), AVIN0001.INP (155,648KB) and AVIN001.INT (288,000KB).
My guess is that the metadata like the GPS data, if it is recorded anywhere, is simply straight binary and the particular data needed for any one of the video .mts files requested, is pointed to in one of the AVF_INFO files?  (Yes, if you've guessed by the REAL*8 above, I am a PGI Parallel FORTRAN user and I run a SuperMicro tower HPC!!!).
Does this help in any way?
I am contemplating searching the AVF_INFO files for binary REAL*8 data of 134.nnnnnn-2.nnnnnn as some lat and long data will be recorded in some known video files?

[Phil Harvey]

ExifTool should read the GPS from the MTS files if it exists.  An example from the exiftool application documentation:

       exiftool -ee -p '$gpslatitude, $gpslongitude, $gpstimestamp' a.m2ts
            Extract all GPS positions from an AVCHD video.

- Phil