A bash script that convert MP3 Songs into Spectrum Video Clips with Songs

spectrum.sh

#!/usr/bin/env bash

# ============================================================================
# MP3 Rainbow Spectrum Video Generator
#
# Description:
#   Generates a 1920x1080 MP4 audio spectrum visualizer with animated
#   multicolor frequency bars while reserving the bottom area for lyrics.
#
# Author:
#   Mohammad Hafiz bin Ismail
#
# Website:
#   https://blog.mypapit.net/2026/08/how-to-generate-audio-spectrum-videos-from-mp3-songs-youtube-ffmpeg.html↗
#
# Copyright:
#   Copyright (c) 2026 Mohammad Hafiz bin Ismail (mypapit.net)
#
# Requirements:
#   - Bash 4.x or later
#   - FFmpeg with:
#       * showfreqs
#       * geq
#       * alphamerge
#       * overlay
#       * volume
#       * libx264
#       * AAC encoder
#
# Usage:
#   ./spectrum.sh song.mp3
#   ./spectrum.sh song1.mp3 song2.mp3 song3.mp3
#   ./spectrum.sh *.mp3
#
# Output:
#   song.mp3 -> song-spectrum.mp4
#
# Layout:
#
#   1920x1080
#
#   +--------------------------------------+
#   |                                      |
#   |                                      |
#   |          visual/background           |
#   |                                      |
#   |     █ ███ █████ ██ ████ █           |
#   |     ██████████████████████           |
#   |          spectrum area               |
#   |                                      |
#   |--------------------------------------|
#   |                                      |
#   |          RESERVED FOR LYRICS         |
#   |                                      |
#   +--------------------------------------+
#
# ============================================================================

set -u

# ---------------------------------------------------------------------------
# Video configuration
# ---------------------------------------------------------------------------

VIDEO_WIDTH=1920
VIDEO_HEIGHT=1080

# Spectrum dimensions.
SPECTRUM_WIDTH=1600
SPECTRUM_HEIGHT=280

# Horizontal position.
SPECTRUM_X=160

# Vertical position.
#
# Spectrum occupies Y=520 through Y=800.
# Therefore approximately 280 pixels remain below it for lyrics.
SPECTRUM_Y=520

# ---------------------------------------------------------------------------

if ! command -v ffmpeg >/dev/null 2>&1; then
    echo "Error: FFmpeg is not installed or not available in PATH."
    exit 1
fi

if [ "$#" -eq 0 ]; then
    echo "Usage:"
    echo "  $0 song1.mp3 [song2.mp3 song3.mp3 ...]"
    echo
    echo "Example:"
    echo "  $0 *.mp3"
    exit 1
fi

for input in "$@"; do

    if [ ! -f "$input" ]; then
        echo "Skipping: file not found: $input"
        echo
        continue
    fi

    filename="$(basename -- "$input")"
    directory="$(dirname -- "$input")"
    basename_no_ext="${filename%.*}"

    output="${directory}/${basename_no_ext}-spectrum.mp4"

    echo "============================================================"
    echo "Processing : $input"
    echo "Output     : $output"
    echo "============================================================"

    ffmpeg -y \
        -i "$input" \
        -filter_complex "\
[0:a]volume=3,\
showfreqs=\
s=${SPECTRUM_WIDTH}x${SPECTRUM_HEIGHT}:\
mode=bar:\
ascale=sqrt:\
fscale=log:\
win_size=2048:\
overlap=0.75:\
colors=white:\
rate=30,\
format=gray[specmask];\
color=s=${SPECTRUM_WIDTH}x${SPECTRUM_HEIGHT}:c=black:r=30,\
format=rgb24,\
geq=\
r='255*clip(1.5-abs(6*X/W-3),0,1)':\
g='255*clip(1.5-abs(6*X/W-2),0,1)':\
b='255*clip(1.5-abs(6*X/W-4),0,1)'\
[gradient];\
[gradient][specmask]alphamerge[colored];\
color=s=${VIDEO_WIDTH}x${VIDEO_HEIGHT}:c=black:r=30[background];\
[background][colored]overlay=${SPECTRUM_X}:${SPECTRUM_Y}:shortest=1[v]" \
        -map "[v]" \
        -map 0:a:0 \
        -c:v libx264 \
        -preset medium \
        -crf 18 \
        -pix_fmt yuv420p \
        -c:a aac \
        -b:a 320k \
        -shortest \
        "$output"

    status=$?

    echo

    if [ "$status" -eq 0 ]; then
        echo "Completed successfully:"
        echo "  $output"
    else
        echo "ERROR: FFmpeg failed while processing:"
        echo "  $input"
    fi

    echo
done