download-videos.sh

#!/bin/sh
# ------------- Script INFOs -------------
# Script Name:  download-videos.sh
# Create Date:  2021-02-25
# Version #:    1.2
# Author:       github@ushio-cheng

# Description:  - Accept 2 parameter <path to a list of video links> [path to output video]
#               - Downloads all videos in the list by spawning screen session
#               - Will retry if youtube-dl failed

# Remark:       - This is sketchy but simple way to download a list of stuff
#               - configure youtube-dl to use aria to avoid downloading the 
#                 same video segment multiple times
# ----------------------------------------

function mainScript() {

    workerUID=0
    if [ ! $1 ]
    then
        echo "ERROR: videolist file not provided"
        exit
    fi

    for line in $(cat $1)
    do
        spawnDownloadWorker "$2" "$(basename -s .txt $1)-$workerUID" $line
        workerUID=$(( $workerUID + 1 ));
    done
}

# spawn workers
# param1: work dir
# param2: workerName
# param3: assignedUrl
spawnDownloadWorker () {
    if [ $1 ]
    then
        cd $1
    fi
    workerTaskUID=$(uuidgen)
    echo "while ! youtube-dl --recode-video mp4 -o \"[%(id)s] %(title)s.%(ext)s\" "$3";" >> $workerTaskUID.sh
    echo "do sleep 3;done" >> $workerTaskUID.sh # wait 3s before try again
    echo "rm $workerTaskUID.sh" >> $workerTaskUID.sh
    screen -dmLS "$2" sh $workerTaskUID.sh
}

# Run
mainScript $1 $2