media-subtitle-sync

Align SRT, ASS, and VTT subtitle timings to video audio using alass and ffsubsync.

15|4|Updated Apr 18, 2026

Search Tags:#subtitles #batch-processing #video-sync #subtitle-sync #ffsubsync #alass

Ready to run

npx skills add https://github.com/damionrashford/media-os --skill media-subtitle-sync

💬 Prompt for ChatGPT / Claude Chat▼

Please help me install this Agent Skill.
Skill: media-subtitle-sync
Source: https://github.com/damionrashford/media-os/tree/main/skills/media-subtitle-sync
Command: npx skills add https://github.com/damionrashford/media-os --skill media-subtitle-sync

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill includes scripts (resource) and references (resource) components.

What problem does it solve?

Subtitle synchronization remains a pain when captions drift, out-of-sync timing, or different encodings make alignment unreliable. This skill uses alass and ffsubsync to align SRT/ASS/VTT subtitles to video audio, fix timing drift, and batch-align seasons.

Core Features & Use Cases

Automatic subtitle alignment: syncs subtitles to video timing across common formats (SRT, ASS, VTT).
Drift and offset handling: corrects constant offsets and non-linear drift, including commercial breaks or edits.
Batch processing: processes multiple episodes in a season with a single command.

Quick Start

Run the subsync wrapper against a video file and its subtitle file to generate a synced subtitle.

Frequently Asked Questions about media-subtitle-sync

High-intent search queries and answers about installing and using this skill.

FAQPage Schema

How do I fix out-of-sync subtitles for a video file?▼

To fix out-of-sync subtitles, this skill aligns SRT, ASS, and VTT timings to video audio using alass and ffsubsync. It corrects constant offsets and non-linear drift automatically.

Can I batch sync subtitles for an entire season of episodes?▼

Yes, you can batch sync subtitles across a full season of episodes. The skill processes multiple video files in a single command to align timings efficiently.

Do I need FFmpeg installed to align subtitle timing?▼

Yes, you need FFmpeg available on your PATH to align subtitle timing. You also need alass and/or ffsubsync installed locally to perform the audio synchronization.

What subtitle formats are supported for timing drift correction?▼

Supported subtitle formats for timing drift correction include SRT, ASS, and VTT. The skill uses audio alignment to correct fixed offsets and non-linear drift across these formats.

What's the best way to correct non-linear subtitle drift caused by commercial cuts?▼

The best way to correct non-linear subtitle drift from commercial cuts is using alass or ffsubsync audio alignment. The skill matches subtitle timings to the actual video audio track.