ExifTool Forum

ExifTool => Newbies => Topic started by: Ali Nadeem on April 06, 2021, 08:57:12 AM

Title: Dashcam video Speed referene
Post by: Ali Nadeem on April 06, 2021, 08:57:12 AM
Hi Phil/all,

thank you for the lovely tool.

I have a Dashcam video, the watermark speed ref is showing mph while Exiftool speed ref is showing km/h. which one to believe?

many thanks. 
Title: Re: Dashcam video Speed referene
Post by: StarGeek on April 06, 2021, 11:05:56 AM
What model of camera was the video from?  Does it show the same speed number at the same moment in time?  For example, does the video show 50 mph while exiftool shows 50 kph at the same point in the video? Or does 50 mph while exiftool shows 80 kph?

Would you be able to share a short video, preferably at a speed where it would be easy to tell the difference between MPH and KPH?  Say 10-20 mph?
Title: Re: Dashcam video Speed referene
Post by: Phil Harvey on April 07, 2021, 09:19:10 PM
It could be that some dashcams store speeds in different units based on their settings, so ExifTool could be wrong about this.  It is fairly easy to calculate the speed from the lat/lon positions.  I can do this if you send me the output gpx.txt file from this command:

exiftool -p "$gpsdatetime $gpslatitude $gpslongitude $gpsspeed $gpstrack" -ee -n FILE > gps.txt

My email is philharvey66 at gmail.com.

- Phil