Extracting BSL-1k clips from BOBSL

[hshreeshail]

This issue is in reference to extracting the video clips of individual signs from BOBSL that form the BSL-1k dataset. In mouthing_spottings.json, the global_times annotation is a single timestamp value (instead of a (start, end) range). How, do I extract the corresponding clip from this? Are all the clips of same length?