parallel_process.sh

#!/usr/bin/env bash

# Associative arrays require Bash 4
if [ -z "${BASH_VERSINFO}" ] || [ -z "${BASH_VERSINFO[0]}" ] || [ ${BASH_VERSINFO[0]} -lt 4 ]; then echo "This script requires Bash version >= 4"; exit 1; fi

source logging_functions.sh

counter=1

dirs="$@"

declare -A dir_to_filecount_and_execution_time_map

files_to_process=()

shopt -s nullglob
for dir in $dirs
do
    debug "Will process all files in $dir"
    files=("$dir"/*)
    files_to_process=("${files_to_process[@]}" "${files[@]}")
done
shopt -u nullglob # Turn off nullglob to make sure it doesn't interfere with anything later

debug "Processing ${#files_to_process[@]} files..."

start_time=`date +%s`
parallel make process INPUT_FILE={} ::: ${files_to_process[@]}
end_time=`date +%s`

execution_time=$(expr $end_time - $start_time)

aggregated_runtime=0

for video in "${files_to_process[@]}"
do
    # Get the format (container) duration as per http://trac.ffmpeg.org/wiki/FFprobeTips
    runtime=$(ffprobe -v error -show_entries format=duration -of default=noprint_wrappers=1:nokey=1 $video)
    aggregated_runtime=$(python -c "print $aggregated_runtime + $runtime")
done

debug "Processing $aggregated_runtime seconds of video (${#files_to_process[@]} files) took $execution_time seconds. Finished."