Download Twitch Broadcasts

spasm

#!/bin/sh
# This is a shell script to download a 'past broadcast' from twitch.tv and
# convert it to an MP4. Takes a channel and a number parameter, which is the
# which is the number in the url http://twitch.tv/<channel>/b/<number>
# 
# If no parameter is provided, a list of up to 10 video ids combined with their
# dates and the game played will be printed.
# 
# This requires the following tools:
# curl
# ffmpeg
# jq
# 
# This script was written to work on OS X. It may work on other platforms.
# Feel free to modify this to take additional arguments like 'limits' and such

TMPDIR=`mktemp -d -t spasm`
OUTPUT=$2
trap "rm -rf ${TMPDIR}" EXIT
trap "exit" SIGINT

function broadcasts {
  url="https://api.twitch.tv/kraken/channels/$1/videos?broadcasts=true"
  filter='.videos|.[]|"\(.game), \(._id|ltrimstr("a")), \(.recorded_at)"'
  curl -s -X GET $url | jq -r "$filter"
  exit
}

function download {
  : ${OUTPUT:="output"}
  url="http://download.twitchapps.com/listparts.php?id=a$1&playlist=true"
  pushd $TMPDIR > /dev/null
  curl -s $url | grep "flv\$" | xargs -n 1 curl --progress-bar -O
  ls -A1 | grep "flv$" | xargs printf "file './%s'\n" > list.txt
  ffmpeg -v 0 -f concat -i list.txt -c copy ${OUTPUT}.mp4
  popd > /dev/null
  mv ${TMPDIR}/${OUTPUT}.mp4 ./
  echo "Finished"
  exit
}

if [[ $# -eq 0 ]]; then
  echo "usage: spasm <channel|broadcast-id> [output-name]" && exit
fi

case $1 in
    ''|*[!0-9]*) broadcasts $1;;
    *) download $1;;
esac