The Master Guide / 10 Voice and lip sync · Speaking shots and lip sync
Lip-sync failures and fixes
Find the symptom, read its cause, and change that one thing.
Find the symptom, read its cause, and change that one thing.
Symptom | Cause | Fix |
The plate's mouth is closed, or murmurs, through a spoken stretch (lips mushy after Sync) | The plate called "silent", or the mouth lines missing | "Sound-off", never "silent"; the manner line; lips closed only in the pauses; rewrite the beats (see Speaking shots and lip sync → Route 2, the Arabic default). If both drafts fail the first-plates check, take it to the batch review |
The mouth opens in the pauses after Sync | The room-tone stretches | Trim the plate and the take to their in and out points before Sync |
The offset rounds beyond ±1 frame | The take misplaced in the plate-length file | Rebuild the file from the measured first-word time |
English-shaped mouth movements | The plate mouthed the English meaning | Write the meaning as behaviour, never quoted |
The gate fails on the audio-driven plate | Seedance re-timed the line | Change one thing and make another take within budget; otherwise the default plate |
The face's emotion drifts from the voice | Picture and voice made in two passes | Put the take's emotion into the timed beats; for a close-up hero line, Route 1 if you choose it |
Lips warp at the widest point of the move | The move turns the face past about 45°, or runs too fast | A smaller arc or a slower push, the move kept; never a lock by default |
A speaking shot reads stiff, the line flat | Too little life in the frame or the face | A breathing frame or a very slow push through the words, written large enough to show; for a hero line, the delivery map option |
A listener's lips move with the speaker's words | No listening line | A line saying the listener speaks no words in this beat, and an action for them (see Performance → Listening) |
The scene feels cut up and stiff | Every line its own single, no shared moment | The two-hander pattern: a moving master nobody speaks in, the singles cut into it |
A refusal with an audio reference | Moderation | A clean, voice-only reference |