Apply advanced crossfeed using Redline Monitor

apply_crossfeed.bash

#!/bin/bash

# Set up parameters
in=`realpath "${1}"`
echo $in
indir="${in%/*}"
infile="${in##*/}"
outdir="${indir}_headphone"
tmpin="/tmp/in_${infile}.flac"
tmpout="/tmp/out_${infile}.flac"
out="crossfed_${infile}"
# Get the original bit depth for later
original_bit_depth=`file -b "${in}" | cut -d " " -f 5`
if [ "${original_bit_depth}" == "24" ]; then
  sample_fmt="s32"
else
  sample_fmt="s16"
fi

function remove_temp_files() {
  rm "${tmpin}"
  rm "${tmpout}"
}

function die() {
  echo $*
  remove_temp_files
  exit 1
}

# Note - I'm using a bunch of temp files because I couldn't get streaming processing at high bit depths to work well with mrswatson64

# Reduce level to leave processing headroom for mrwatson
ffmpeg -loglevel quiet -y -i "${in}" -filter:a "volume=-6dB" -sample_fmt s32 "${tmpin}" || die "unable to reduce input level"

# Apply advanced crossfeed
SLIGHTLY_LESS_CENTER=0.333
SLIGHTLY_MORE_CENTER=0.667
MOST_CENTER=1
WIDE_SOUNDSTAGE=0.75 # 75% vs default of 60%
WIDEST_SOUNDSTAGE=1

mrswatson64 --quiet --bit-depth 24 -p /Library/Audio/Plug-Ins/VST/Redline\ Monitor.vst --parameter 0,${SLIGHTLY_MORE_CENTER} --parameter 1,${WIDE_SOUNDSTAGE} --input "${tmpin}" --output "${tmpout}" 2>&1|| die "unable to apply crossfeed"

# Normalize to 0dB peak to reduce the amount of amplification needed at playback
vol=`ffmpeg -i "${tmpout}" -af "volumedetect" -vn -sn -dn -f null /dev/null 2>&1 | grep "max_volume" | cut -d ' ' -f 5 | sed 's/\-//'` || die "unable to determine max volume"

# Note, I'm using the highest compression level to save space, but this slows down encoding
ffmpeg -loglevel quiet -y -i "${tmpout}" -filter:a "volume=+${vol}dB" "${out}" || die "unable to encode final output"

remove_temp_files