hls.sh

#!/usr/bin/env bash

# An oversimplistic HLS player
# Usage:
#       $ hls.sh http://example.com/path/to/list.m3u8

CURLOPTS="--buffer --connect-timeout 2 --retry 3 --retry-max-time 3"
F="/tmp/.hls.$(mcookie).ts"
L="$(tempfile -d /tmp/ -p .hls.)"
LL="$(tempfile -d /tmp/ -p .hls.)"

# Download the segment and feed it to VLC
play_segment()
{
	# The segment URLs can be absolute or relative to the current path
	echo $1 | grep -q http
	if [ $? -eq 1 ]; then
		SS="$(dirname $P)/$1"
	else
		SS="$1"
	fi

	echo "Getting $SS"
	curl $CURLOPTS $SS > $F
}

# On termination cleanup temporary files
exit_cleanup()
{
	trap '' 0 1 2 15
	rm -f $F $L $LL
	exit 0
}

trap "exit_cleanup" 0 1 2 15

# Detect whether it's a master or variant playlist
curl $CURLOPTS "$1" > $L
M=$(grep m3u8$ $L)

if [ $? -eq 0 ]; then
	# If it's a master, typically the first variant entry has the lower
	# bitrate, play it safe
	V=$(echo $M | tr ' ' '\n' | head -1)
	P="$(dirname $1)/$V"
else
	P="$1"
fi

echo "Using playlist: $P"

# Use a named pipe to pass the TS data from curl to VLC
mkfifo $F

vlc $F > /dev/null 2>&1 &

S=""
SS=""

while :; do
	# Get the playlist and find the new/unused segments
	curl $CURLOPTS $P > $L
	S=$(diff -u $LL $L | grep -v ^+# | grep ^+ | grep -v ^+++ | sed -r 's/^\+//')
	cat $L > $LL

	if [ ! -z $SS ]; then
		N="$(echo $S | tr ' ' '\n' | grep -n $SS | cut -f1 -d:)"
		N=$((N+1))
		T="$(echo $S | tr ' ' '\n' | tail -n +${N})"
	fi

	if [ ! -z "$T" ]; then
		S="$T"
	else
		sleep 1
	fi

	for SS in $S; do
		play_segment $SS
	done
done

exit 0