Skill: Raw Video Processing
Post-process raw screen recordings to improve pacing — remove silent segments, then speed up the result.
Prerequisite: FFmpeg and Python 3 must be installed.
When to Use
The user has recorded a screencast and wants to clean it up before publishing. Typical issues in raw recordings:
- Long pauses / dead air while thinking or waiting for loading
- Overall pacing feels slow and could benefit from a slight speed boost
Default Workflow
When the user provides a raw video file, run both scripts in sequence by default:
Step 1: Remove Silent Segments
python /path/to/skills/raw-video-processing/scripts/remove_silence.py <input.mp4>
This detects and cuts out silent portions, producing <input>_nosilence.mp4.
Default parameters (good for most screencasts):
--threshold -30dB— silence detection sensitivity--duration 0.8— minimum silence length (seconds) to remove--padding 0.2— seconds of breathing room kept around speech boundaries
The script prints a detailed summary: number of silent segments found, total silence removed, and all kept segments with timestamps. Review this output to confirm the result looks reasonable.
Step 2: Speed Up the Video
python /path/to/skills/raw-video-processing/scripts/speed_video.py <input>_nosilence.mp4
This applies a speed multiplier to the silence-removed video, producing <input>_nosilence_1.2x.mp4.
Default parameters:
--speed 1.2— 1.2x playback speed (a subtle boost that doesn't feel rushed)
Script Options
remove_silence.py
| Flag | Default | Description |
|---|---|---|
-o, --output | <input>_nosilence.mp4 | Custom output path |
-t, --threshold | -30dB | Silence threshold in dB (lower = more sensitive) |
-d, --duration | 0.8 | Minimum silence duration in seconds to remove |
-p, --padding | 0.2 | Padding kept around non-silent segments |
--dry-run | off | Only print detected segments, don't export |
speed_video.py
| Flag | Default | Description |
|---|---|---|
-o, --output | <input>_<speed>x.mp4 | Custom output path |
-s, --speed | 1.2 | Playback speed multiplier |
Custom Scenarios
- Only remove silence — run just Step 1.
- Only speed up — run just Step 2 directly on the input file.
- Aggressive cleanup — use
--threshold -25dB --duration 0.5for stricter silence removal, and--speed 1.5for faster playback. - Preview before committing — use
--dry-runon remove_silence.py to see what would be cut without creating a file. - Custom output name — use
-oon either script to control the output path.
Important Notes
- Always run remove_silence before speed_video. Silence detection works on the original audio; speeding up first would alter the audio characteristics and make silence detection less accurate.
- For long videos (>30 min), the silence removal step may take a few minutes as it processes each segment individually.
- Both scripts preserve video quality — remove_silence uses stream copy (no re-encoding), while speed_video re-encodes with FFmpeg defaults.