Quick Example
Walk through processing a 14-minute TED talk from start to finish. See how VideoCaptioner handles transcription, optimization, translation, and synthesis.
Processing Pipeline
Step 1: Speech Transcription
Using Faster Whisper Large-v2 model with Silero V4 VAD (Voice Activity Detection), the system generates initial subtitles from the audio track.
videocaptioner transcribe ted-talk.mp4 --asr faster-whisper --model large-v2
The raw output has high recognition accuracy, but the sentence breaking is mechanical with basic punctuation — this is normal for raw ASR output.
Step 2: Intelligent Enhancement
Enable smart segmentation, optimization, and translation. The LLM performs semantic-based segmentation, producing fluid natural-language subtitles.
videocaptioner subtitle ted-talk.srt \
--optimizer llm \
--translator llm \
--target-language zh \
--enable-reflection
Reflection Translation
The system uses a two-pass "translate-reflect-translate" approach for each subtitle:
- Removes redundant words for conciseness
- Naturalizes expressions to sound native
- Compacts phrasing while preserving meaning
- Optimizes verb selection and word order
Step 3: Video Synthesis
Burn the optimized subtitles into the video with a professional dual-language layout:
videocaptioner synthesize ted-talk.mp4 -s ted-talk_optimized.srt
Step 4: All-in-One Command
Or simply run the entire pipeline with a single command:
videocaptioner process ted-talk.mp4 --target-language zh
Performance
| Stage | Duration |
|---|---|
| Transcription | ~2 min |
| Segmentation | ~30 sec |
| Translation | ~1 min |
| Synthesis | ~30 sec |
| Total | ~4 min |
Cost Analysis
Incredibly affordable
For a 14-minute video with ~50 subtitle segments using gpt-4o-mini: approximately 5,000 tokens consumed, total cost < $0.002. The LLM only processes text (no timeline data), so token usage is minimal.
Ideal Use Cases
- Educational content — Create bilingual learning materials
- Content creators — Multi-language versions for global reach
- Business — Video localization for international markets
- Conferences — Documentation with accurate subtitles