Bash script to convert the DJI Googles SRT file to a CSV which can be used in spreadsheets.

srt2csv.sh

#!/bin/bash

outputFile=${1/.srt/.csv}

# initialize statistics
totalLines=$( cat ${1} |wc -l | sed 's/ //g;' )

# loop over the whole file
echo "timestamp;latency;bitrate;voltage;avg. voltage" > "${outputFile}"
currentLine=0
while read line; do
  ((currentLine++))
  echo -ne "Processing ${1}... (${currentLine}/${totalLines} lines)\r"
  if [[ "${line}" =~ ^0.:.* ]]; then
    timestamp=${line:0:12}
  fi

  if [[ "${line}" =~ ^signal:.* ]]; then
    echo ${line} |\
         sed 's/ /:/g;s/ms//g;s/Mbps//g;s/V//g' |\
         awk -F: -v timestamp="${timestamp}" '{ print timestamp";"$16";"$18";"$8";"$8/$12 }' |\
         sed 's/,/\./g' \
         >> ${outputFile}
  fi
done < ${1}
echo -e "\n${outputFile} generated.\n"

# statistics summary
awk -F\; '
BEGIN{
  maxLatency=0
  lowerLatency=999
  maxBitrate=0
  lowerBitrate=999
}

(NR>1){
  sumLatency += $2
  if ($2 <= lowerLatency) lowerLatency=$2
  if ($2 >= maxLatency) maxLatency=$2
  sumBitrate += $3

  if ($3 <= lowerBitrate) lowerBitrate=$3
  if ($3 >= maxBitrate) maxBitrate=$3
}

END {
  print "Statistics:"
  print "  Input data:"
  print "  - Total meassures: " NR - 1
  print "  - Flight time: " $1
  print "\n  Latency:"
  print "  - Lower Latency: " lowerLatency "ms"
  print "  - Max Latency: " maxLatency "ms"
  print "  - Average Latency: " sumLatency/NR "Mbps"
  print "\n  Bitrate:"
  print "  - Lower Bitrate: " lowerBitrate "Mbps"
  print "  - Max Bitrate: " maxBitrate "Mbps"
  print "  - Average Bitrate: " sumBitrate/NR "Mbps"
}' ${outputFile}

Description
It produces a CSV file including the timestamp, latency, bitrate, total voltage and average voltage per cell in the UAV.

Has been tested in the next environment:

• macOS BigSur
• the SRT files created by the DJI Googles V1 with v01.00.06.00 firmware

Newer versions might generate different SRT files which may include other fields and make this parser fail. Contact me if that happens to you so I can help and fix the parser.

How to use it
Download it:

$ wget -q https://bit.ly/str2csv_sh -O str2csv.sh 
$ chmod +x str2csv.sh

Run it:

$ ./srt2csv.sh DJIG0000.srt
Processing DJIG0000.srt... (7080/7080 lines)
DJIG0000.csv generated.

Statistics:
  Input data:
  - Total meassures: 1771
  - Flight time: 00:04:41.950

  Latency:
  - Lower Latency: 20ms
  - Max Latency: 50ms
  - Average Latency: 25,6358Mbps

  Bitrate:
  - Lower Bitrate: 1.3Mbps
  - Max Bitrate: 9.3Mbps
  - Average Bitrate: 42,9684Mbps