Generates spectrogram and waveform images from flac files

gen-flac-visuals

#!/bin/sh

# Requires: audiowaveform (https://github.com/bbc/audiowaveform), metaflac, sox

zoom_start=60
zoom_duration=4
zoom_end=$((zoom_start + zoom_duration))

if [ $# -lt 1 ] || [ "$1" == "--help" ] || [ "$1" == "-h" ]; then
    echo "Generates spectrogram and waveform images from flac files"
    echo ""
    echo "For each type, an image of the entire file will be made, as well as a"
    echo "more detailed analysis of $zoom_duration seconds of audio starting $zoom_start seconds in."
    echo ""
    echo "The generated files will have the same name as the input files"
    echo "with extra identifiers appended."
    echo ""
    echo "usage: `basename $0` file [file ..]"
    echo ""
    echo "positional arguments:"
    echo "  file                The flac file(s) to process"
    exit 0
fi

# Check deps
for cmd in 'audiowaveform' 'metaflac' 'sox'; do
    if ! command -v "$cmd" > /dev/null ; then
        echo "Missing dependency '$cmd'"
        exit 1
    fi
done

count=0
success=0
for x in "$@"; do
    ((count++))
    echo "Processing file $count/$#: '$x'"

    # Generate spectrograms
    sox "$x" -n remix 1 spectrogram -X 500 -y 1025 -z 120 -w Kaiser -S "$zoom_start" -d "$zoom_duration" -o "${x}_spectral_zoom.png" || continue
    sox "$x" -n remix 1 spectrogram -x 3000 -y 513 -z 120 -w Kaiser -o "${x}_spectral.png" || continue

    # Get audio length and generate waveforms
    len=`metaflac --show-total-samples --show-sample-rate "$x" | tr '\n' ' ' | awk '{print int($1/$2)}'` || continue
    audiowaveform -i "$x" -o "${x}_waveform_zoom.png"  -w 2000 -h 1024 -s "$zoom_start" -e "$zoom_end" > /dev/null || continue
    audiowaveform -i "$x" -o "${x}_waveform.png" -w 3000 -h 512 -s 0 -e "$len" > /dev/null || continue

    ((success++))
done

echo ""
echo "Sucessfully generated images for $success/$count files"