An ESPS/waves+ label file is a text file with one label stored per line. Each label indicates a segment boundary. A complete description of the ESPS/waves+ label format is given in the ESPS/waves+ manual pages xwaves (1-ESPS) and xlabel (1-ESPS). Only details required for use with HTK are given here.
The label data follows a header which ends with a line containing only a #. The header contents are generally ignored by HLABEL. The labels follow the header in the form
time ccode namewhere time is a floating point number which denotes the boundary location in seconds, ccode is an integer color map entry used by ESPS/waves+ in drawing segment boundaries and name is the name of the segment boundary. A typical value for ccode is 121.
While each HTK label can contain both a start and an end time which indicate the boundaries of a labeled segment, ESPS/waves+ labels contain a single time in seconds which (by convention) refers to the end of the labeled segment. The starting time of the segment is taken to be the end of the previous segment and 0 initially.
ESPS/waves+ label files may have several boundary names per line. However, HLABEL only reads ESPS/waves+ label files with a single name per boundary. Multiple-alternative and/or multiple-level HTK label data structures cannot be saved using ESPS/waves+ format label files.