Dashcam Video Segments Lose SampleTime Resolution After 30 Seconds

[rwhalb]

ExifTool Version: 12.47
OS: Linux
DashCam: NextBase622GW
Video File Type: mp4
File Size: 336MB
CLI: /usr/bin/exiftool -q -j -g:3 -ee -c '%+.6f deg' -GPS* -Sample* /DATA/images/nextbase/220925_141308_036_FH.MP4

Issue: If a Nextbase622GW Dashcam Video is longer than 30 seconds in length the SampleTime resolution switches from a tenth of a second to a full second. This behavior is observed in all videos that I have recorded so far using a NextBass622GW Dashcam.

Google Link: https://drive.google.com/file/d/16h0QZ_2n9nxKKOWcdTgw7INPZpuqzg6e/view?usp=sharing

Piping the output to the jq utility reveals this:

    "Doc552": {
      "SampleTime": "29.80 s",
      "SampleDuration": "0.10 s"
    },
    "Doc553": {
      "GPSAltitude": "82.6 m",
      "GPSDOP": 0.96,
      "GPSLatitude": "+42.687550 deg",
      "GPSLongitude": "-73.860110 deg",
      "GPSSatellites": 11,
      "GPSTimeStamp": "18:13:39.7",
      "GPSDateTime": "2022:09:25 18:13:39.700Z",
      "GPSSpeed": 10.7175,
      "GPSTrack": 52.35
    },
    "Doc554": {
      "SampleTime": "29.90 s",
      "SampleDuration": "0.10 s"
    },
    "Doc555": {
      "GPSAltitude": "82.6 m",
      "GPSDOP": 0.96,
      "GPSLatitude": "+42.687552 deg",
      "GPSLongitude": "-73.860107 deg",
      "GPSSatellites": 11,
      "GPSTimeStamp": "18:13:39.8",
      "GPSDateTime": "2022:09:25 18:13:39.800Z",
      "GPSSpeed": 11.3694,
      "GPSTrack": 48.27
    },
    "Doc556": {
      "SampleTime": "0:00:30",
      "SampleDuration": "0.10 s"
    },
    "Doc557": {
      "GPSAltitude": "82.6 m",
      "GPSDOP": 0.96,
      "GPSLatitude": "+42.687554 deg",
      "GPSLongitude": "-73.860105 deg",
      "GPSSatellites": 11,
      "GPSTimeStamp": "18:13:39.9",
      "GPSDateTime": "2022:09:25 18:13:39.900Z",
      "GPSSpeed": 10.849,
      "GPSTrack": 49.05
    },
    "Doc558": {
      "SampleTime": "0:00:30",
      "SampleDuration": "0.10 s"
    },
    "Doc559": {
      "GPSAltitude": "82.6 m",
      "GPSDOP": 0.96,
      "GPSLatitude": "+42.687556 deg",
      "GPSLongitude": "-73.860102 deg",
      "GPSSatellites": 11,
      "GPSTimeStamp": "18:13:40",
      "GPSDateTime": "2022:09:25 18:13:40.000Z",
      "GPSSpeed": 11.3657,
      "GPSTrack": 48.7
    },

Notes:
1) Video "Doc" segments: "DOC552 - 555" => 29.80, 29.90
   Video "Doc" segments: "DOC556 - 559" => 0:00:30, 0:00:30
   Resolution switches from tenth of a second to a full second at the 30 second mark.
2) The "SampleTime" and "SampleDuration" attribute "Doc" segments are isolated either before or
   after the "Doc" segments with coordinate information. Hopefully this is fixed in ver: 12.48

[Phil Harvey]

By design, SampleTime is formatted like Duration tags.  Use the -n option to bypass this formatting.

Note that this will also bypass your -c option and give the full available coordinate resolution, and you will lose the units in the strings.

- Phil

[rwhalb]

Thanks for the clarification. From the man page:

-c FMT      (-coordFormat)       Set format for GPS coordinates

I did not think this would effect other GPS attributes. Thanks for your support and excellent work.

---Ron Henderson

[Phil Harvey]

Hi Ron,

-c does not affect other GPS attributes, but -n does.

- Phil