On the educational clip, lip sync was absent as well; the report measured 2.5-4/255 pixel differences over the 9-second clip, including a wide-open 'oo' frame where the English and Spanish mouths were frame-identical.
What was measured
Lip Sync Accuracy
Does the dubbed audio visually match lip movements in the original video?
decisive for this rankingtransformation
The ranking is specifically about lip sync, so visual alignment of speech to mouth movement is a core success criterion. (3 of 3 judges)
What was given, what came back
Test input: Educational airport conversation short (English → Spanish) · video · group: video-translation-voice-clone-lip-sync
Input — what we sent
Input not captured
This run recorded no prompt or input file for the test, so we cannot show you what produced the result below. Capture gaps are tracked, not hidden.
A structured educational/conversation-style English short video used to test translation into Spanish with clear narration, steadier pacing, and easier lip-sync alignment than the other scenarios.
Why this input is hard
- · Structured speech translation accuracy
- · English-to-Spanish narration quality
- · Longer-phrase lip-sync consistency
- · Clear voice rendering for informational content
- · Export/download reliability in a simple speaking scenario
Output — unretouched
Also checked on this input — same tool, 1 other criterion
Provenance
- Observation
- c5ea41b6-dfb4-47bc-891d-b2edfd343d96
- Evidence run
- ec1dd100-6af8-4f49-8f19-b78492702b14
- Study
- Translate Videos with Voice Cloning and Lip Sync Using AI
- Research task
- 86b96dfpf
- Tested at
- not recorded
- Source
- first-party
- Evidence state
- verified
- Proof shown
- output only
- Cost / latency
- not captured
- Repeat run
- not captured
- Tester
- not captured
The last three rows are honest blanks, not placeholders — our capture has no field for them yet.
Query this
get_evidence({
tool: "camb-ai",
scenario: "video-translation-voice-clone-lip-sync"
})MCP · mcp.aidemos.com/api/mcp
Free with attribution.
Same input, same check — 8 other tools
measured on Lip Sync Accuracy
Akool✓ WorkedA content-matched frame comparison confirmed genuine mouth regeneration, with the output mouth shape differing from the source.Dubverse✓ WorkedLip sync is described as more precise than on the other inputs.ElevenLabs✗ FailedThe tool provides no built-in lip sync, so the Spanish educational output would need external video editing to align audio with the mouth movements.HeyGen✗ FailedAt the matched "Unripe" moment, the mouth shape, eyebrows, and expression were essentially identical between input and output, showing no visible lip-sync change.Rask AI✗ FailedAt t=4.0s the input and output are frame-for-frame identical, with the same mouth shape, so no lip sync or face regeneration is visible on the free tier.Sync Labs◐ MixedLip sync is better on the slower educational clip, although slight lag in lip movement remains.Synthesia◐ MixedThe dubbed mouth movement roughly tracks the source at the compared timestamps in the English→Spanish test, so lip sync appears visually usable but not perfect.VEED✓ WorkedTest 2 does regenerate mouth motion: the report measures 6-38/255 pixel differences in the face region, and at one matched timestamp the English source has her mouth open while the Spanish output has it closed.
This evidence is published in
From the same study (page rebuilt from a later run)
Real inputs and real outputs, no retouching · every cell queryable via API & MCP · aidemos.com