Back t nd

The video won't open, or no speech is found

Checked against v1.1.5, 12 September 2026.

tondi reads .mp4, .mov and most common video formats, and needs an audio track with someone talking. Three different messages cover the ways that can go wrong; each has a different fix.

“Couldn't read this video file”

Couldn't read this video file — it may be corrupted or in a format the app doesn't support. Try a .mp4 or .mov.

  1. Check it plays in QuickTime. If QuickTime can't open it either, the file is damaged or in a format macOS doesn't know; re-export it from wherever it came from.
  2. Re-export as .mp4 (H.264). From your editor, recorder or phone. This fixes almost every case.
  3. Audio-only files aren't supported. An .mp3 or .m4a episode with no picture won't open. tondi needs a video track to make clips from.
  4. Check it finished copying. A file still transferring from a card or a drive reads as corrupted.

“This video has no audio track”

This video has no audio track, so there's nothing to transcribe. Try a video with speech.

The file has a picture but no sound at all — common with screen recordings made without a microphone, or exports where the audio track was left unchecked. Re-export with the audio included.

“No speech was detected”

No speech was detected in this video, so there are no captions to add. Try a video with talking.

  1. Check the audio isn't silent or music only. Play it back. tondi needs talking.
  2. Very quiet or very noisy recordings. If the voice is buried, raise the level in your editor and re-export. Best accuracy tier copes with more noise than Standard.
  3. Non-English speech works — the language is detected automatically — but a heavily accented or mixed-language recording can slip past Standard. Try Best.

Common questions

Which formats does tondi accept?

Anything ffmpeg can read: .mp4, .mov, .m4v, .mkv, .webm and most others. When in doubt, .mp4 with H.264 video and AAC audio always works.

Can I clip an audio-only podcast?

Not yet. tondi needs a video file. If your recorder gives you a video track — even a static one — use that.

Is there a size or length limit?

No. Longer videos take proportionally longer to transcribe; a 60-minute episode is normal use.