LRS3 trainval — auto_avsr mouth crops, bridged to WebDataset
The LRS3 trainval split (30 h) as [T,96,96] uint8 grayscale mouth-ROI shards with character
transcripts, produced with auto_avsr's own crop geometry so results stay comparable to that
project's published LRS3 numbers.
Derived from TheNHz/ellipsis-lrs3-raw
(itself a verified mirror of LRS3-TED, whose official distribution was discontinued).