Internal utility skill for media assembly operations. NOT called directly by users. Used by producer skills (video-producer, podcast-producer, audio-producer, social-producer) to stitch, mix, and assemble final media outputs.
SkillScore100Maintained
Automatic
◆Coding pack
Last verified 8/3/2026
What it changes
Passed 23 of 23 test cases with the skill, and 3 of 23 without it.
Without skill13%
With skill100%
Checks it passed that the model alone missed
Uses video_concat.py
Uses report_to_pdf.py
Uses audio_mix.py with --no-duck
and 37 more in the full report
20 fixed3 passed either way0 still failing0 broke
Pass-rate lift
+87 pp
Tokens
-1%
Agent turns
0%
Response time
-55%
Model gemini-3.6-flashMeasured 8/3/2026v123 of 23 cases passed with skill
Tokens, turns and time describe resource use, not a dollar price.
See it in action
One of 20 test cases the skill fixed. Same model, same prompt, with and without the skill.
1 of 20
Prompt
I want to mix voice.wav and background music music.mp3 into final.mp3. I do NOT want ducking enabled when voice plays, and I want the background music level set to 0.2 instead of the standard level. What is the command?
What was checked, without and with the skill
Checked
Without skill
With skill
Uses audio_mix.py with --no-duck
Missed
Passed
Includes --music-volume 0.2 in the command
Missed
Passed
case-09 · gemini-3.6-flash · 8/3/2026 · answers are capped and redacted
What's inside
The instructions your model reads when the skill loads.
SKILL.md158 lines8 filesincludes scripts
Media Utilities
Internal utilities for media assembly. Used by producer skills.
These scripts wrap FFmpeg to provide reliable media operations.
Prerequisites
FFmpeg must be installed: brew install ffmpeg (macOS) or apt install ffmpeg (Linux)