audio-mix-maker

audio-mix-maker is a skill for Claude Code from Mikefluff/skills. It costs 86 tokens per session (1,595 once invoked), scanned A, original, MIT.

An audio-mixing utility that uses ffmpeg to combine an existing video with music, sound effects, or a voice recording.

In plain words
What is it for?
Use it to replace or layer audio, lower music under speech, control volume, and add fades to an existing MP4, MOV, or WebM video.
Why use it?
It removes the need to build the audio filter command by hand and supports different volume and fade treatments.

Skill for Claude Code

Written for Claude Code: allowed-tools in frontmatter. Also seen: positional $N argument.

Part of the mikefluff-skills plugin — 44 skills, 2 commands shipped together

Good fit Use it to replace or layer audio, lower music under speech, control volume, and add fades to an existing MP4, MOV, or WebM video.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/mikefluff/skills/audio-mix-maker
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add Mikefluff/skills --skill audio-mix-maker
Clone the repo
git clone --depth 1 https://github.com/Mikefluff/skills

Made for: Claude Code.

Or install mikefluff-skills, the plugin that ships this one along with the rest of its 44 skills, 2 commands.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for audio-mix-maker

README.md
[![agentmods](https://agentmods.dev/badge/skills/mikefluff/skills/audio-mix-maker.svg)](https://agentmods.dev/skills/mikefluff/skills/audio-mix-maker)
Your own site
<a href="https://agentmods.dev/skills/mikefluff/skills/audio-mix-maker"><img src="https://agentmods.dev/badge/skills/mikefluff/skills/audio-mix-maker.svg" alt="Measured on agentmods" height="20"></a>
Per session 86 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,595 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00086 $0.01595
Opus 5 $0.00043 $0.00797
Sonnet 5 $0.00017 $0.00319
Haiku 4.5 $0.00009 $0.00160

Measured 7d ago against content hash add8be440f3c, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

audio-mix-maker scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 7d ago.

The scan reads SKILL.md. This mod also ships 1 executable file (scripts/run.py), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/audio-mix-maker/SKILL.md · 142 lines

How it starts

The opening of the file, as written. The whole thing — 142 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Distinct from reel-builder:

  • reel-builder ORCHESTRATES generation + stitching from scratch (script → shots → music → stitch). This skill is JUST the final-mix step on assets you already have.
  • No script / no video / music generation — bring your own.

Distinct from subtitle-burner:

  • subtitle-burner adds CAPTIONS. This skill adds AUDIO MIX.
  • Both are pure-ffmpeg utilities — they share the lightweight wrapper pattern.

Distinct from voiceover-maker:

  • voiceover-maker GENERATES TTS. This skill MIXES audio onto video.

This skill does NOT:

  • Generate music (use music-prompt --execute first)
  • Generate voiceover (use voiceover-maker --execute first)
  • Stitch multiple video clips (use reel-builder for that, or raw ffmpeg concat)
  • Cut / trim video segments (use ffmpeg / DaVinci Resolve / Premiere)
  • Sync audio to specific moments (use a NLE — Final Cut / Premiere / DaVinci)

ROLE

Read video + music + mode + volume/fade controls → run ffmpeg with the right filter chain → save mixed MP4.

PIPELINE

  1. Resolve inputs:

    • --video <path> — source MP4 / MOV / WebM (required)
    • --audio <path> — music / SFX / voiceover (required)
  2. Pick mode:

    • --mode replace (default) — drop the video's original audio, use music as sole track
    • --mode overlay — mix music ON TOP of original audio (both audible at constant volume)
    • --mode duck — overlay with sidechain compression (music auto-lowers when speech detected)
  3. Volume + fade controls:

    • --volume <multiplier> — 0.0-2.0 music volume (default 0.8)
    • --fade-in <seconds> — fade in duration (default 0)
    • --fade-out <seconds> — fade out duration (default 0.5)
    • --duck-amount <0-1> — duck mode only: how much music attenuates (default 0.6)
  4. Detect ffmpeg — print install instructions if missing.

Read the full file on GitHub · 142 lines

Files

What ships with it

4 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 7d ago First seen · 142 lines · 86 tokens per session scan A add8be440f3c

Subscribe to this mod's changes

audio-mix-maker is a skill published in the GitHub repository Mikefluff/skills (19 stars, last pushed 1mo ago), licensed MIT. It adds 86 tokens to every session and 1,595 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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