1: SDIF – Intro

SDIF files typically contain one or several streams of sound or signal description matrices encapsulated in time-tagged blocks called frames, and identified by signatures (corresponding to types). Type signatures allow applications to make selections and processes on data in a file or SDIF stream based on these types. The format includes standard specifications for the most commonly used descriptions (spectral envelopes, transfer functions, filters, resonances, FFT, fundamental frequency estimation, energy, additive modeling, voiced/unvoiced decision, markers, etc.) but allows users to extend these types (new description fields) or create them for new or customized uses.

Matrix or frame types are coded by a 4-character string called signature (e.g. "1ENV" for spectral envelopes, "1FQ0" for fundamental tracking, etc.) By convention the types beginning with the character '1' are standard SDIF types, as opposed to extended or new types defined by a user.

=> See http://sdif.sourceforge.net

The idea with SDIF-Edit is to allow a generic representation of SDIF data, i.e. independent of the types of data contained within a file. This tool will thus make it possible to visualize the "classic" descriptions but also non-standard data which for example would have been generated by a user.