The release of the open source speech synthesis system RHVoice 1.2.4 has been published, initially developed to provide high-quality support for the Russian language, but then adapted for other languages, including English, Portuguese, Ukrainian, Kyrgyz, Tatar and Georgian. The code is written in C++ and distributed under the LGPL 2.1 license. Work is supported in GNU/Linux, Windows and Android. The program is compatible with typical TTS (text-to-speech) interfaces for text-to-speech: SAPI5 (Windows), Speech Dispatcher (GNU/Linux) and Android Text-To-Speech API, but can also be used in the NVDA screen reader.
The program uses a parametric synthesis method with statistical models (Statistical Parametric Synthesis based on HMM - Hidden Markov Model). The advantage of the statistical model is low overhead and undemanding CPU power. All operations are performed locally on the user's system. Three levels of speech quality are supported (the lower the quality, the higher the performance and the shorter the response time).
Supports customization and change of voices. For the Russian language, 9 voice options are available, for English - 5. Voices are formed based on natural speech recordings. Due to the use of a statistical model, the quality of pronunciation does not reach the level of synthesizers that generate speech based on a combination of fragments of natural speech, but nevertheless the result is quite intelligible and resembles a broadcast recording from a loudspeaker.
In the settings you can change the speed, pitch and volume. The Sonic library can be used to change the tempo. It is possible to automatically detect and switch the language based on the analysis of the input text (for example, for words and quotes in another language, a native synthesis model for this language can be used). Voice profiles are supported that define combinations of voices for different languages.
Source: opennet.ru