Is the Azure-to-Oculus viseme mapping many-to-one only? No: Azure viseme 19 groups d, t, n and th, which Oculus splits across DD, nn and TH, so Azure to Oculus also needs context.
Problem. C2-B06-D-06 says many-to-one collapse is lossless in direction only from Azure to Oculus, implying Azure IDs always map to a single Oculus viseme. Conditions. Compare the Azure ID table with the Oculus viseme table. Method. Azure ID 19 covers phonemes d, t, n and the dental th; Oculus assigns t,d to DD, n,l to nn, and th to TH. A converter from Azure IDs to Oculus names cannot choose one of DD/nn/TH from the ID alone and needs phoneme or context information (or a visually acceptable default). Failure modes. A naive 22-to-15 lookup table will mislabel n/th frames as DD. Limitations. This is the auditor's inference from two vendor tables; both tables list only example phonemes ('Only a subset of phonemes are shown for each viseme' on the Oculus page), so a full mapping is not established. Version/date. Pages fetched 2026-10-23.
Structured fields
{
"citations": [
{
"url": "https://learn.microsoft.com/en-us/azure/ai-services/speech-service/how-to-speech-synthesis-viseme",
"note": "Viseme ID table, ID 19; Viseme table, nn row; Viseme table, DD row; Viseme table, TH row"
},
{
"url": "https://developers.meta.com/horizon/documentation/unity/audio-ovrlipsync-viseme-reference",
"note": "cited at https://developers.meta.com/horizon/documentation/unity/audio-ovrlipsync-viseme-reference/; Viseme ID table, ID 19; Viseme table, nn row; Viseme table, DD row; Viseme table, TH row"
},
{
"url": "https://developers.meta.com/horizon/documentation/unity/audio-ovrlipsync-viseme-reference/",
"note": "observed URL (dated/alias form of the cited catalogue source; canonical identity retained)"
}
]
}Evidence claims
- [sourced_fact] Problem. C2-B06-D-06 says many-to-one collapse is lossless in direction only from Azure to Oculus, implying Azure IDs always map to a single Oculus viseme. Conditions. Compare the Azure ID table with the Oculus viseme table. Method. Azure ID 19 covers phonemes d, t, n and the dental th; Oculus assigns t,d to DD, n,l to nn, and th to TH. A converter from Azure IDs to Oculus names cannot choose one of DD/nn/TH from the ID alone and needs phoneme or context information (or a visually acceptable default). Failure modes. A naive 22-to-15 lookup table will mislabel n/th frames as DD. Limitations. This is the auditor's inference from two vendor tables; both tables list only example phonemes ('Only a subset of phonemes are shown for each viseme' on the Oculus page), so a full mapping is not established. Version/date. Pages fetched 2026-10-23. · locator: Viseme ID table, ID 19; Viseme table, nn row; Viseme table, DD row; Viseme table, TH row source
Rights
| component | license | hosting | redistribution | modification | training | Evidence and notes |
|---|---|---|---|---|---|---|
| documentation | unknown | permitted | permitted | unknown | unknown | Applies to this original summary only, not to the cited sources. |