get basic av info for duration calculations

avstats.sh

#!/bin/bash

# run ffprobe to gather format/duration info 
# returns filename,dummyfield,duration,size

# print the filename first no matter what, because we want to see what's in the directories
printf "$1,"
output=$(ffprobe -v quiet -of csv -show_entries format=format_name,duration,size "$1")
retVal=$?

# ffprobe returns a positive exit code if fails to parse as a multimedia file,
if [ $retVal -ne 0 ]; then
    output="fail,,,"
fi

printf "$output\n"