Software Requirements Specification for ESpeak : Speech Synthesis Version 1.48.15 Prepared by Dimitrios Koufounakis January 10, 2018 Copyright © 2002 by Karl E. Wiegers. Permission is granted to use, modify, and distribute this document. Software Requirements Specification for <Project> Page ii Table of Contents Table of Contents .......................................................................................................................... ii Revision History ............................................................................................................................ ii 1. Introduction ..............................................................................................................................1 1.1 Purpose ............................................................................................................................................. 1 1.2 Document Conventions .................................................................................................................... 1 1.3 Intended Audience and Reading Suggestions................................................................................... 1 1.4 Project Scope .................................................................................................................................... 1 1.5 References......................................................................................................................................... 1 2. Overall Description ..................................................................................................................2 2.1 Product Perspective .......................................................................................................................... 2 2.2 Product Features ............................................................................................................................... 2 2.3 User Classes and Characteristics ...................................................................................................... 2 2.4 Operating Environment .................................................................................................................... 3 2.5 Design and Implementation Constraints ........................................................................................... 3 2.6 User Documentation ......................................................................................................................... 3 2.7 Assumptions and Dependencies ....................................................................................................... 4 3. System Features .......................................................................................................................4 3.1 System Feature 1 .............................................................................................................................. 3 3.2 System Feature 2 (and so on)............................................................................................................ 4 4. External Interface Requirements ...........................................................................................8 4.1 User Interfaces .................................................................................................................................. 8 4.2 Hardware Interfaces .......................................................................................................................... 8 4.3 Software Interfaces ........................................................................................................................... 8 4.4 Communications Interfaces .............................................................................................................. 8 5. Other Nonfunctional Requirements .......................................................................................8 5.1 Performance Requirements ............................................................................................................... 8 5.2 Safety Requirements ......................................................................................................................... 9 5.3 Security Requirements ...................................................................................................................... 9 5.4 Software Quality Attributes .............................................................................................................. 9 6. Other Requirements ................................................................................................................5 Appendix A: Glossary....................................................................................................................9 Appendix B: Analysis Models .......................................................................................................6 Appendix C: Issues List .................................................................................................................6 Software Requirements Specification for <Project> Page 1 1. Introduction 1.1 Purpose The purpose of the current document is the specification of all the requirements that eSpeak : Speech Synthesis version 1.48.15. eSpeak : Speech Synthesis is a compact open source software speech synthesizer for English and other languages,available for Linux and Windows. eSpeak can be used to create an audio file that contains the given input text file in a verbal form. 1.2 Document Conventions This SRS document follows Karl E. Wiegers standard. It is the only document describing the requirements of this software for the current version (1.48.15). Any change in the software’s requirements in the future is necessary to be made through a typical process of change and acceptance of this document. The displays from some devices may look different from the screenshots below. The screenshots in the document have been taken in Windows 10. 1.3 Intended Audience and Reading Suggestions The intended audience of this document is as follows: 1. Software engineers: It can be used for understanding and further developing the program. 2. Programmers: By reading the document, developers will be able to understand the software in depth, something that would be more difficult if their only source was the program’s code and its GUI. This way, programmers can find which elements need to be improved and what features can be added in a future release. 3. Testers: The document can provide useful information about how the program responds while using it and which are its restrictions so as to better test it and find weak spots. 4. Users: Users can get another view of the application mainly by reading chapters 3 and 4, in addition to the User Manual. 1.4 Project Scope eSpeak : Speech Synthesis is open source software distributed under the GNU General Public License version 3.0 (GPLv3) . The scope of this software is to provide a text-to-sound conversion of a file. The output sound can be played directly or saved to a .wav file for future use(Save to .wav button). Options like voice selection, voice rate and volume are available. There is also a graphical representation of the oral movement. eSpeak : Speech Synthesis windows 10 screenshot 1.5 References The information found in this document have been taken by the following links: 1. http://espeak.sourceforge.net/index.html Main Website Software Requirements Specification for <Project> Page 2 2. https://en.wikipedia.org/wiki/ESpeakNG Wikipedia page 2. Overall Description 2.1 Product Perspective In 1995, Jonathan Duddington released the Speak speech synthesizer for RISC OS computers supporting British English. On 17 February 2006, Speak 1.05 was released under the GPLv2 license, initially for Linux, with a Windows SAPI 5 version added in January 2007. Development on Speak continued until version 1.14, when it was renamed to eSpeak. From eSpeak 1.27, eSpeak was updated to use the GPLv3 license. The last official eSpeak release was 1.48.04 for Windows and Linux, 1.47.06 for RISC OS and 1.45.04 for Mac OS X. The last development release of eSpeak was 1.48.15 on 16 April 2015. To this day, eSpeak has been used from various users to listen to blogs and news sites. The eSpeak speech synthesizer supports several languages, however in many cases these are initial drafts and need more work to improve them. Assistance from native speakers is welcome for these, or other new languages. eSpeak does text to speech synthesis for several languages, some better than others. 2.2 Product Features • Includes different Voices, whose characteristics can be altered. • Can produce speech output as a WAV file. • SSML (Speech Synthesis Markup Language) is supported (not complete), and also HTML. • Compact size. The program and its data, including many languages, totals about 2 Mbytes. • Can be used as a front-end to MBROLA diphone voices, see mbrola.html. eSpeak converts text to phonemes with pitch and length information. • Can translate text into phoneme codes, so it could be adapted as a front end for another speech synthesis engine. • Potential for other languages. Several are included in varying stages of progress. Help from native speakers for these or other languages is welcome. • Development tools are available for producing and tuning phoneme data. • Written in C. 2.3 User Classes and Characteristics This software has been used, until now, mainly in proprietary or open source projects as a screen reader. Some examples are : • Windows • Linux Ubuntu and some other distributions • Android