SenSyn Speech Synthesizer Package SenSyn UNIX

Transcription

1 SenSyn Speech Synthesizer Package SenSyn UNIX SENSIMETRICS Sensimetrics Corporation 48 Grove Street Suite 305 Somerville, MA Tel: Fax: Web:

2 SENSYN Speech Synthesizer Package UNIX Version INTRODUCTION The SenSyn Speech Synthesizer Package is based on Dennis Klatt's KLSYN88 software implementation of a cascade/parallel formant synthesizer. The KLSYN88 synthesizer is described in the chapter Description of the Cascade/Parallel Formant Synthesizer (referenced as Klatt in the text that follows), which has been supplied as part of the package. As with the version of the synthesizer published by Klatt in 1980, the current version is based on Fant's theory of speech production (Klatt: Section 3.1). Both Klatt versions embody the approach that accurate synthetic speech can be created by duplication of the acoustic patterns that appear on spectrograms. The more recent KLSYN88 synthesizer provides a number of features not found in the earlier KLSYN program, including two new source waveform models (the KLGLOTT88 "natural" waveform model and a modified version of the Liljencrants and Fant waveform model), new parameters to control these source waveforms, and a variety of new control parameters that are important for modeling female voices and "pathological" speech. It is claimed by Klatt that the current synthesizer is capable of producing male and female speech waveforms that are nearly indistinguishable from the original recording. We have tested the SenSyn software extensively and have found that it produces waveforms that are nearly identical to those produced by KLSYN88. As with the KLSYN88a University Synthesizer Package we had offered previously, Sensimetrics Corporation has undertaken to port the SenSyn program to a number of personal computer platforms and to make the program available at low cost to speech researchers on a noncommercial basis. The present document provides instructions for installation, compilation, and usage of the UNIX version of the SenSyn program, along with brief descriptions of the various synthesizer control parameters. Detailed discussions of each parameter may be found by following up on the page references to Klatt which are included in brackets. Modifications to the synthesizer algorithm that we have made for purposes of this distribution are described below. Modifications to the KLSYN88 Algorithm In preparing for our distribution of the SenSyn synthesizer, certain guidelines were followed in order to avoid patent infringement. U.S. Patent Number 4,754,485, "Digital Processor For Use In A Text To Speech System," filed on December 12, 1983 and granted on June 28, 1988, to Dennis H. Klatt assignor to Digital Equipment Corporation specifically describes the four times oversampling algorithm incorporated in KLSYN88. This algorithm, which Klatt claims contributes to the naturalness of gliding fundamental frequency changes in the synthesis of high-pitched female voices, is mentioned both in a recent ASA paper (Klatt, D.H., & Klatt, L.C. (1990). "Analysis, synthesis, and perception of voice quality variations among female and male talkers," J. Acoust. Soc. Am. 87, footnote 17, p. 855) and in the document we are providing as part of the University Synthesizer Package. Our resolution of the patent infringement problem has been to omit the sections of code that would constitute the four times oversampling algorithm. As a result, both waveform source and filtering functions in the SenSyn synthesizer are calculated at the same sampling rate. Our experience with this synthesizer indicates that the absence of waveform oversampling yields a subtle perceptual difference which is apparent only for rapid fundamental frequency changes in the 300 to 400 Hz range. Please note that the user's ability to specify the fundamental frequency in one-tenth Hertz steps, which also contributes to the naturalness of gliding fundamental frequency changes, has not been altered. Setting up the SenSyn synthesizer software UNIX Environment The software for the UNIX version of SenSyn is written in ANSI Standard C. It has been compiled using the GNU C Compiler (GCC), although any ANSI C compiler should work. To use the included Makefiles, a "make" utility is also needed. GCC and GNU make are available to the public, and can be accessed by anonymous FTP to prep.ai.mit.edu. ii

3 The program does not include graphics, or options for audio playback of synthesized waveform files or for printing files. The UNIX version of the SenSyn program has been set up so that the waveform file can be written in several different ways. The software includes a routine, in the file writwave.c, for writing waveform files in 16-bit linear PCM raw (.sw) format, which may be converted to any desired format via the free software SoX (available at Note that it is necessary to supply SoX with the sample rate at which the waveform was created, as this information is not stored in the.sw file. Also included as a courtesy, but without technical support, are routines for directly writing 8-bit waveform files in NeXT.snd format (writwave.next) and.au format (writwave.sun). While this is more convenient than using a separate utility to convert the output files, be aware that the quality of 8-bit audio may be noticeably less than that of 16-bit audio. For users with the Entropics ESPS toolkit, we include a routine (writwave.esps) to write waveform files in Entropics..sd format, however, Sensimetrics cannot provide technical support for the use of this toolkit. Check files on the disk Check your disk to make sure that all relevant files are present. The UNIX version comprises the files listed below. These include a make (compilation) file, the source code and header files, and the default60.con default configuration file. Executable and object files are not included with the UNIX version of SenSyn in order to permit the software to be used with a wider range of UNIX machines. List of SenSyn synthesizer software files for the UNIX version 1. Command files for compilation Makefile Makefile.esps (Make command file) (Make command file for use with ESPS) 2. SenSyn program components default60.con sensyn.c sensyn.h dbconver.c frame.c init_syn.c reson.c reson.h sample.c synth.h voice.c writwave.c writwave.next writwave.sun 3. Other files FILELIST README SU (Current parameter configuration) (Command handler for SenSyn software synthesizer) (Declarations for sensyn.c) (Converts db to linear amplitude) (Synthesize one frame) (Synthesizer data structures and initialization) (Implements a second order resonator) (Resonator declarations) (Synthesize one sample) (Synthesizer support declarations) (Synthesize one voice sample) (Function for writing the 16-bit raw.sw format waveform file) (Function for writing the 8-bit.snd format waveform file) (Function for writing the 8-bit.au format waveform file) (File list) (Read me text document) (SU Directory, optional files for use with ESPS) Installing the SenSyn software a. Create a directory for the synthesizer program files. b. Insert the disk into your CD drive, and (if necessary) mount the CD volume. Your SenSyn CD is formatted with an ISO9660 filesystem. Your Unix system may be set up to automatically mount inserted compact disks with this format; if not you will need to issue a mount command manually. iii

4 c. Copy all of the files from your disk to the newly created directory. Be sure that each of the files listed above is present. If not, you should notify Sensimetrics Corporation immediately. Compiling the SenSyn source code a. Prior to compiling the SenSyn program, it is necessary to have an ANSI Standard "C" compiler and the "make" utility installed on your computer. The Makefile supplied with the source code assumes you are using the gcc compiler; if you have another compiler you may need to edit the Makefile, changing the value of the macro CC from gcc to the name of the compiler you wish to use. By default the program will output audio files in raw (headerless) 16-bit linear format, with a file extension of.sw. If your Unix platform uses a big-endian byte ordering you may want to edit the Makefile, changing the flag -DSENS_LITTLE_ENDIAN defined in the CFLAGS to -DSENS_BIG_ENDIAN. (The only effect of this flag is to set the byte order in which 16-bit samples are written to the output file.) If you wish the program to output.snd or.au format audio files remove the file writwave.c and rename the file writwave.next or the file writwave.sun to writwave.c. If you have installed the Entropics ESPS software and wish to output.sd format files, remove the Makefile and writwave.c, and rename Makefile.esps to Makefile and writwave.esps to writwave.c. b. To compile the program, open a command shell, change your current working directory to the directory containing the SenSyn source files, then type the make command at the prompt followed by a carriage return: File Formats > make sensyn In the UNIX version of SenSyn, two types of files may be created: parameter files and waveform files. The file extensions are:.doc synthesis parameter files, and, depending on how the program was compiled, either.sw raw waveform files,.sd sampled data files (ESPS),.snd waveform files (NeXT) or.au (Sun audio) files. 1).doc synthesis parameter document file. This ASCII text file contains the user-specified numerical values which specify the constant and variable parameter values. The file default60.con, which is the default configuration file, is in.doc format. The default utterance is a schwa-like steady state "vowel," 500 msec in duration. Note: the default60.con file must be present in your synthesizer directory in order for the program to run. If it is not present, an error message is printed and the program terminates. Upon entering the program, the default60.con file is loaded. One can synthesize the default utterance by typing "s" and then providing a save name. If values of the variable parameters have been changed, the.doc file then includes the values for the constant parameters followed by a list of the varied parameters with frame numbers as row markers. 2).sw raw waveform data file. The synthesis command creates and stores a binary file containing the sequence of 16-bit samples, and no header information. 3) sd sampled data (utterance waveform) file. If you have compiled the ESPS version of SenSyn, the synthesis command creates and stores in binary file format a sampled data file that is compatible with the ENTROPICS ESPS and WAVES+ signal analysis programs. More information about the.sd file format may be found by examining the ESPS documentation. 4).snd waveform files. If you have compiled the NeXT version of SenSyn, the synthesis command creates and stores a binary waveform file with the appropriate sound file header. 5).au files. If you have compiled the Sun version of SenSyn, the synthesis command creates and stores a binary waveform file with the appropriate sound file header. iv

5 Running the SenSyn program Command line options After you have loaded the SenSyn module and other software files into your synthesizer directory, you may run the program by typing: > sensyn The program also provides for certain command line options which are indicated by the format below: {?} > sensyn {-n} {filename} A description of the optional arguments may be displayed by typing the following command: > sensyn? After the options display is printed, the program terminates. You have to type the program name and command line argument(s) again if you actually want to run the synthesizer. The optional argument {-n} specifies that the user is a novice. The result of including this argument is what Klatt referred to as a "verbose printout." This means that informational text is written to the screen when the user selects various synthesizer commands. The information is more complete than if the {-n} option was not included. After using the synthesizer for a short amount of time, the user should be able to forego this option. The optional {filename} argument refers to a previously created.doc (synthesis configuration/varied parameter) file. This.doc file is loaded when the program begins and becomes the current file. If no filename is specified, the default parameter file, default60.con is loaded. If a non-existing filename is specified as the command line argument, an error message is displayed and the program terminates. Synthesizer commands The commands included with the synthesizer allow the user to examine and change the configuration and the variable parameters, to create, edit, and save a new parameter (.doc) file, to synthesize an utterance and save the waveform as a file and to view the help list of legal commands. The legal commands are listed below. p PRINT (to the screen) the default parameter values for the current synthesizer configuration (60 parameters). Current minimum, default and maximum values of the 60 parameters are displayed one page (20 parameters) at a time. This command helps the user determine whether or not the default value of any parameter has been altered previously by using the c command. c CHANGE the default value for a configuration parameter. This command allows the user to alter the global default value of a parameter within the current configuration. The specified value is in effect for the entire utterance duration (unless altered by using the e command). If the parameter has already been altered using the e command, then a message indicating that the parameter is already time-varied is displayed. e ENTER time varying parameter values. The user is prompted for the symbol of a time-varying parameter following by prompts for time and value pairs. Parameter values are interpolated linearly between the last specified time and value an the current time and value. Use <CR> to step out of the menu. At the top level of this command, the values for all time varied parameters are displayed. s Synthesize a waveform file, save it, quit. After specifying the name for the output waveform file (no extension needed), and typing <CR>, the waveform file is created from the resident configuration file. The program automatically saves the current.doc file as well. Afterwards, the program is terminated. v

6 S Save current configuration/varied parameters as.doc file. This command does not create a synthesized waveform file. q QUIT program, after verification. Nothing further is saved.? Please show the legal commands for the SenSyn synthesizer interface. vi