22.2 MBROLA

As an example of how Festival may use a completely external synthesis method we support the free system MBROLA. MBROLA is both a diphone synthesis technique and an actual system that constructs waveforms from segment, duration and F0 target information. For details see the MBROLA home page at http://tcts.fpms.ac.be/synthesis/mbrola.html. MBROLA already supports a number of diphone sets including French, Spanish, German and Romanian.

Festival support for MBROLA is in the file lib/mbrola.scm. It is all in Scheme. The function MBROLA_Synth is called when parameter Synth_Method is MBROLA. The function simply saves the segment, duration and target information from the utterance, calls the external mbrola program with the selected diphone database, and reloads the generated waveform back into the utterance.

An MBROLA-ized version of the Roger diphoneset is available from the MBROLA site. The simple Festival end is distributed as part of the system in festvox_en1.tar.gz. The following variables are used by the process

mbrola_progname

the pathname of the mbrola executable.

mbrola_database

the name of the database to use. This variable is switched between different speakers.