nhldl.sh

#!/bin/bash

# NHL.DL
# A script for downloading and assembling NHL.tv video streams. See README.md.

exit_route () {
    echo "$1"
    exit 1
}

VERBOSITY="--quiet"

which ffmpeg 1>/dev/null || exit_route "Please install ffmpeg 3.x"

# @todo: Scrape the nhl.tv login process and add user/pass to script arguments.
ls cookies.txt > /dev/null 2>&1 || exit_route "Missing cookies.txt file."

master_m3u8_url="$1"
stream_directory=$(basename $(dirname $master_m3u8_url))
mkdir -p $stream_directory
master_m3u8_file="$stream_directory/$(basename $master_m3u8_url)"

echo ">>> Fetching master m3u8 file: $master_m3u8_url"
wget $VERBOSITY --load-cookies cookies.txt \
     --output-document $master_m3u8_file \
     $master_m3u8_url || exit_route ">>> Failed."
echo ">>> Done."

# Fetch stream m3u8 file
quality="$2"

if [ -n "$quality" ]
then
    stream_m3u8_url="$(dirname $master_m3u8_url)/$(grep ${quality}K $master_m3u8_file)"
else
    stream_m3u8_url="$(dirname $master_m3u8_url)/$(tail -1 $master_m3u8_file)"
    quality=$(tail -1 $master_m3u8_file | cut -c1-4)
fi

stream_m3u8_file="$stream_directory/$(basename $stream_m3u8_url)"

echo ">>> Fetching ${quality}K stream m3u8 file: $stream_m3u8_url"
wget $VERBOSITY --load-cookies cookies.txt \
     --output-document $stream_m3u8_file \
     $stream_m3u8_url || exit_route ">>> Failed"
echo ">>> Done."

# Fetch all the keyfiles
stream_key_urls=$(grep -o "https://mf[^\"]*" $stream_m3u8_file | uniq)

mkdir -p $stream_directory/keys

echo ">>> Fetching stream keys."
while read -r line; do
    wget $VERBOSITY \
         --load-cookies cookies.txt \
         --output-document "$stream_directory/keys/$(basename $line)" \
         $line
done <<< "$stream_key_urls"
echo ">>> Done."

# @todo: Download all of the stream segments first. Parallelise it.

concat_file=$stream_directory/stream_files.txt
: > $concat_file

counter=1
num_of_segments=$(grep "^[0-9]" $stream_m3u8_file | wc -l)

# For each line in stream m3u8 file.
while read -r line; do
    # If line is a new key and IV
    if echo $line | grep -q "^#EXT-X-KEY:METHOD=AES"; then
        # Extract key.
        key_url=$(echo "$line" | grep -o "https://mf[^\"]*")
	echo ">>> Key URL: $key_url"
        key_file="$stream_directory/keys/$(basename $key_url)"
        key=$(xxd -p $key_file)

        # Extract IV.
        iv=$(echo "$line" | grep -o "IV=[^$]*" | cut -c 6-)

    # If line is a video segment.
    elif echo $line | grep -q "^[0-9]"; then
        # Make directory for segment
        mkdir -p "$stream_directory/$(dirname $line)"

        # While stream file doesn't exist, or is zero length.
        while [ ! -s "$stream_directory/$line" ]; do
            # Download encrypted segment.
            echo ">>> Downloading stream segment: $line [$counter/$num_of_segments]"
            wget $VERBOSITY --load-cookies cookies.txt \
                 --timeout 3 \
                 --output-document "$stream_directory/$line.enc" \
                 $(dirname $stream_m3u8_url)/$line
            echo ">>> Done."

            # Decrypt segment.
            echo ">>> Decrypting segment."
            openssl enc -aes-128-cbc \
                    -in "$stream_directory/$line.enc" \
                    -out "$stream_directory/$line.dec" \
                    -d -K "$key" -iv "$iv"

            # If decryption failed, delete bad segment,
            # otherwise replace it with decrypted version.
            if [ $? -ne 0 ]; then
                rm "$stream_directory/$line.enc"
                echo ">>> Failed. Fetching segment again."
            else
                rm "$stream_directory/$line.enc"
                mv "$stream_directory/$line.dec" "$stream_directory/$line"
                echo ">>> Done."
            fi
        done

        # Add segment to ffmpeg concatenation file.
        echo "file '$line'" >> $concat_file

        # Increment counter
        counter=$((counter+1))
    fi
done < "$stream_m3u8_file"

echo ">>> Concatenating stream."
ffmpeg -loglevel error -f concat -i $concat_file -c copy -bsf:a aac_adtstoasc \
    $stream_directory/concatenated.mp4

echo ">>> Stripping blanked-out ads."
# Detect silences that indicate ads.
# |& not working on osx 10.10.5 converted to two stage

ffmpeg -nostats -i $stream_directory/concatenated.mp4 -filter_complex \
"[0:a]silencedetect=n=-50dB:d=1[outa]" -map [outa] -f s16le -y /dev/null &>$stream_directory/silence_raw.txt

grep "^\[silence" $stream_directory/silence_raw.txt > $stream_directory/silence.txt
rm -f $stream_directory/silence_raw.txt

# Add a final silence_start to the slience file, ensuring last segment is kept.
echo "silence_start: $(ffprobe -v error -show_entries format=duration -of default=noprint_wrappers=1:nokey=1 $stream_directory/concatenated.mp4)" >> $stream_directory/silence.txt

# Split into segments without ads.
mkdir -p $stream_directory/gapless
cat $stream_directory/silence.txt | F='-codec copy -loglevel error' D=$stream_directory perl -ne 'INIT { $ss=0; $se=0; }
  if (/silence_start: (\S+)/) { $ss=$1; $ctr+=1; printf "ffmpeg -nostdin -i $ENV{D}/concatenated.mp4 -ss %f -t %f $ENV{F} -y $ENV{D}/gapless/%03d.mp4\n", $se, ($ss-$se), $ctr; }
  if (/silence_end: (\S+)/) { $se=$1; }' | sh

# Merge segments into final gapless video.
printf "file 'gapless/%s'\n" $(ls $stream_directory/gapless) > $stream_directory/gapless_files.txt
ffmpeg -y -loglevel error -f concat -i $stream_directory/gapless_files.txt -c copy $stream_directory.mp4

echo ">>> Finished. You can now delete the $stream_directory directory."