Free Video Subtitle Generation with Whisper & Shotcut

Why Add Subtitles?

• SEO: Video pages with subtitles rank higher on Google
• Accessibility: Helps viewers who are deaf or hard of hearing
• Engagement: 80%+ of social media videos are watched muted
• Reach: Captions help non-native speakers understand content

Step-by-Step: Generate Subtitles for Free

1. Install Whisper CLI — Use the open-source Whisper model from OpenAI or community forks (whisper.cpp, whisperx)
2. Transcribe your video — Whisper works directly on audio tracks extracted from video files
3. Edit the SRT file — Minor timing adjustments in any text editor for perfect sync
4. Burn subtitles into video — Use Shotcut MLT to embed the SRT as burned-in captions

Copy-Ready Commands

Step 1: Transcribe with Whisper

# Extract audio and transcribe
whisper "input.mp4" --task transcribe --model medium --output_format srt
# Output: input.srt

Step 2: Burn Subtitles into Video with Shotcut MLT

melt "input.mp4" in=0 out=360 \
  -attach-track subtitle:"input.srt" \
  -consumer avformat:"output_with_subs.mp4" vcodec=libx264 crf=23

Alternative: Extract only the subtitles (SRT file)

# Whisper outputs SRT — use for YouTube uploads, Vimeo subtitles, etc.
whisper "input.mp4" --task transcribe --model large-v3 --output_format vtt

Subtitle Format Quick Reference

• YouTube Compression Guide: YouTube Compression Guide
• Trim clips before captioning: Video Trimming Guide
• Pick the right format for captions: Format Conversion Guide
• Optimize quality with CRF values: CRF Calculator