Speech to Text

Subtitle Edit can automatically transcribe audio to text using Whisper-based speech recognition engines.

• Menu: Video → Speech to text (Whisper)...

<!-- Screenshot: Speech to text window -->

Supported Engines

Engine	Platform	GPU Support
Whisper.cpp	Windows, Linux, macOS	CPU only
Whisper.cpp (cuBLAS)	Windows	NVIDIA CUDA
Whisper.cpp (Vulkan)	Windows	Vulkan GPU
Purfview's Faster Whisper XXL	Windows, Linux	NVIDIA CUDA
Whisper CTranslate2	Windows, Linux, macOs	CPU only / NVIDIA CUDA (requires CUDA 12.x)
Const-me's Whisper	Windows	DirectX
OpenAI Whisper	All (Python required)	NVIDIA CUDA
Chat LLM cpp	Windows, Linux	CPU/GPU

Engines and models are downloaded automatically on first use.

How to Use

1. Open a video file in Subtitle Edit
2. Go to Video → Speech to text (Whisper)...
3. Select an Engine from the dropdown
4. Select a Model (larger models = better accuracy but slower)
5. Select the Language of the audio
6. Optionally enable:
   • Translate to English — Translate non-English audio to English
   • Adjust timings — Post-process timing using waveform data
   • Post-processing — Fix casing, merge lines, add periods, etc.
7. Click Transcribe

Models

Each engine has its own set of models. Common model sizes:

• tiny — Fastest, least accurate
• base — Good balance for quick work
• small — Better accuracy
• medium — High accuracy
• large / large-v2 / large-v3 — Best accuracy, slowest

Models ending in .en are English-only and perform better for English audio.

Batch Mode

Transcribe multiple video files at once:

1. Click Batch mode
2. Add video files
3. Click Transcribe
4. Results are saved as .srt files next to the video files

Advanced Settings

Click the Advanced button to configure custom command-line arguments for the Whisper engine:

• Use VAD (voice activity detection) for better timing
• Highlight spoken words in the transcript
• Adjust temperature or other model parameters

Post-Processing Settings

Click the Post-processing button to configure:

• Adjust timings (using waveform peak data)
• Fix short durations
• Fix casing
• Add periods
• Merge short lines
• Split long lines
• Change underline to color (useful for highlight spoken words)

Console Log

The console log at the bottom shows real-time output from the Whisper process, useful for debugging issues.

Tips

• For NVIDIA GPU users, use Whisper.cpp (cuBLAS) or Purfview's Faster Whisper XXL for fastest transcription
• If you get "CUDA out of memory" errors, try a smaller model
• The --standard parameter is automatically added for Purfview's Faster Whisper XXL
• You can re-download an engine by right-clicking the engine area