Can an automatic audio-visual sync detector or lip-sync metric (Synchformer offset classes, SyncNet-style LSE-D/LSE-C) certify that generated video and separately generated audio are in sync, and at what resolution?

Published sync models are benchmarked far more coarsely than human perception: Synchformer scores offsets in 21 classes of 0.2 s and counts a prediction correct within +/-0.2 s, on inputs resampled to 25 fps and 16 kHz; on sparse in-the-wild clips its top-1 accuracy was 43.7% (60.2% within one class). Wav2Lip's LSE-D/LSE-C are SyncNet distance and confidence scores, not milliseconds, and generated faces scored as better matched than real videos on LRW. So these tools can flag gross offsets and rank candidates but the sources do not support using them to certify the 30-170 ms perceptual ranges. Curator qualifications: 21 classes of 0.2 s, the 86.5/99.6 dense result and the 43.7/60.2 VGGSound-trained sparse result are verified. Correction: the producer calls 43.7/60.2 the authors' best model (citing the Table 4 ablation), but Table 1 lists the AudioSet-trained Synchformer at 46.8/67.1 on VGGSound-Sparse (54.6/77.6 on the cleaned subset). The conclusion stands: benchmarks run at 0.2 s granularity cannot certify offsets of tens of ms. Rights/verification notes are shown as limitations (L00 0019/ADR-0011): they restrict reuse of the cited material or record what was not verified; they are not cleared by this summary. Limitations: [component_reuse_restriction] Curator readbacks of Love et al. 2013 (PMC3549984), Schwartz & Savariaux 2014 (PMC4117430) and Synchformer arXiv 2401.16423v1 HTML, all byte-identical to producer pins; all three CC BY 4.0 per their XML/HTML licence links. Evidence status: statements located in the cited sources by a correlated desk review (Claude); not executed; not independently reviewed.

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      "url": "https://arxiv.org/html/2401.16423v1",
      "note": "Synchformer arXiv HTML Table 1 (sparse block) and metrics paragraph"
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      "url": "https://github.com/v-iashin/Synchformer/blob/b66668a1521d7567cc760e5544b2b5b53179b687/README.md",
      "note": "Synchformer arXiv HTML Table 1 (sparse block) and metrics paragraph"
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      "url": "https://arxiv.org/html/2008.10010v1",
      "note": "Synchformer arXiv HTML Table 1 (sparse block) and metrics paragraph"
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