FFmpeg Loudness Normalization Workflow for n8n Form Trigger

Normalize audio loudness automatically from an n8n Form upload

This n8n workflow takes an uploaded audio file from an n8n Form Trigger, runs FFmpeg loudness normalization to match a selected LUFS target, and returns the normalized audio plus a parsed loudness report (input/output LUFS and true peak).

What this workflow does

• Receives your audio upload and a target loudness selection from an n8n Form Trigger.
• Creates a unique per-run temp directory and derives the input/output file paths and numeric LUFS target from the form submission.
• Saves the uploaded audio to disk so FFmpeg can process it.
• Runs FFmpeg with the loudnorm filter to:
  • measure input loudness/true peak,
  • normalize to the chosen LUFS target,
  • output loudness stats as JSON.
• Parses FFmpeg’s loudnorm JSON from stderr into a clean report including:
  • configured target loudness,
  • input/output LUFS,
  • input/output true peak.
• Reads the normalized file back from disk and outputs:
  • the normalized audio,
  • the structured loudness report.

Use cases

• SaaS operators who need consistent loudness for user-uploaded audio assets.
• Automation engineers building pipelines for podcasts, audiobooks, or streaming previews.
• Content teams standardizing multiple audio sources to a single LUFS target for quality control.

Technical details

• Workflow trigger: Form Trigger
• Processing & logic: Code, Sticky Note
• File handling: Read Write File
• Audio processing: Execute Command (FFmpeg on the host)
• Requirements: self-hosted n8n (n8n Cloud does not support Execute Command), ensure ffmpeg is on PATH, and set N8N_RESTRICT_FILE_ACCESS_TO="/tmp" so files can be created/read in /tmp.