This tool merges multiple GoPro telemetry CSV files into a single CSV file. These files are created by DashWare when merging multiple GoPro videos. It extracts the embedded telemetry data and writes them to a CSV file per video. To use them in DashWare you have to merge them and update incrementing timestamps and min and max values. Additionally, the telemetry data is not always in sync with the merged video. This tool also applies a factor to the global time to make video and telemetry in sync.

This tool is tested with videos from a GoPro Hero 7 Black. If you can not use GoPro 5 or up telemetry data in DashWare, see this link .

Compile the project to a single jar file:

mvn clean package

Run the jar file with the following parameters:

java -jar target/telemetry-csv-merger.jar <path-to-csv-files> ...

To get a help of available options, use:

java -jar target/telemetry-csv-merger.jar -h

In some cases the telemetry data is not in sync with the merged video. To fix this you have to apply a factor to the GlobalTime column. This can be done with the command line argument -f or --factor.

Example: In DashWare your merged video has a length of 37:27.500. In the "Synchronization" tab of DashWare you can see that the merged telemetry data only has a length of 36:00.950. The telemetry data is compressed by 01:26.650. To stretch the telemetry data you have to apply a factor of 1.040051829056665 to the GlobalTime field.

01:26.650 = 86.55s
36:00.950 = 2160.95s
37:27.500 = 2247.50s

1 + (86.55 / 2160.95) = 1.040051829056665
2247.50 / 2160.95 = 1.040051829056665

To apply this factor, run:

java -jar target/telemetry-csv-merger.jar -f GlobalTime=1.040051829056665 <path-to-csv-files> ...

You can also use the -f argument multiple times for other numeric fields, i.e. when your sensor data has to be adjusted.

java -jar target/telemetry-csv-merger.jar -f GlobalTime=1.040051829056665 -f "Speed KPH=1000" -f "Speed MPH=1000" <path-to-csv-files> ...

This project is based on GoPro-Telemetry-Joiner by James Desmond.