Mimic - The Mycroft TTS Engine

Mimic is a fast, lightweight Text-to-speech engine developed by Mycroft A.I. and VocaliD, based on Carnegie Mellon University’s Flite (Festival-Lite) software. Mimic takes in text and reads it out loud to create a high quality voice.

This repository only contains the core of mimic. If you want to get all the language support and voices, please check out the mimic-full repository, that builds mimic with all the language support and voices at once.

More information of mimic at: mimic.mycroft.ai

Supported platforms

• Linux (ARM & Intel architectures)
• Mac OS X
• Windows

Untested

• Android

Future

• iOS

Requirements

This is the list of requirements. Below there is the commands needed on the most popular distributions and supported OS.

• A C compiler:
  • Linux or Mac OSX: Recommended: gcc or clang
  • Windows: Recommended: GCC under mingw64
• ninja
• pkg-config
• An audio engine:
  • Linux: ALSA/PortAudio/PulseAudio (Recommended: ALSA)
  • Mac OSX: PortAudio
  • Windows: PortAudio or WinMME (Recommended: PortAudio)
• Optionally, PCRE2 library and headers (they are compiled otherwise)
• Optionally, The HTSEngine library and headers (they are compiled otherwise)

Dependencies:

Linux

On Debian/Ubuntu

sudo apt-get install gcc pkg-config libasound2-dev python3-pip ninja-build
pip3 install --user meson

On Fedora

sudo dnf install gcc pkgconfig alsa-lib-devel python3-pip ninja-build
pip3 install --user meson

On Arch

sudo pacman -S --needed install gcc pkg-config alsa-lib python-pip ninja
pip3 install --user meson

Mac OSX

• Install Brew

  /usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"
  

• Install python3, ninja, pkg-config, pcre2 and PortAudio

  brew install python3 ninja pkg-config pcre2 portaudio
  pip3 install --user meson
  

Windows

Cross compiling:

The fastest and most straightforward way to build mimic for windows is by cross-compilation from linux. This requires some additional packages to be installed.

On Ubuntu:

sudo apt-get install binutils-mingw-w64-x86-64 mingw-w64-x86-64-dev gcc-mingw-w64-x86-64

Native build

Install mingw-w64, ninja-build and meson. Install the portaudio library and headers optionally as well.

Build

• Regular:

meson build --prefix="$PWD/install" # Choose any installation prefix you want
ninja -C build
ninja -C build install # Depending on the prefix, this may need sudo privileges.

• Cross compilation Ubuntu -> Windows:

meson build --prefix="$PWD/install" --cross-file="cross/ubuntu-mingw64.txt"
ninja -C build install

Usage

By default mimic will play the text using an audio device. Alternatively it can output the wave file in RIFF format (often called .wav).

Read text

• To an audio device

  $ ./mimic -t TEXT
  

  Example

  $ ./mimic -t "Hello. Doctor. Name. Continue. Yesterday. Tomorrow."
  

• To an audio file

  $ ./mimic -t TEXT -o WAVEFILE
  

  Example

  $ ./mimic -t "Hello. Doctor. Name. Continue. Yesterday. Tomorrow." -o hello.wav
  

Read text from file

• To an audio device

  $ ./mimic -f TEXTFILE
  

  Example

  $ ./mimic -f doc/alice
  

• To an audio file

  $ ./mimic -f TEXTFILE -o WAVEFILE`
  

  Example

  $ ./mimic -f doc/alice -o hello.wav
  

Change voice

• List available internal voices

  $ ./mimic -lv
  

• Use an internal voice

  $ ./mimic -t TEXT -voice VOICE
  

  Example

  $ ./mimic -t "Hello" -voice slt
  

• Use an external voice file

  $ ./mimic -t TEXT -voice VOICEFILE
  

  Example

  $ ./mimic -t "Hello" -voice voices/cmu_us_slt.flitevox
  

• Use an external voice url

  $ ./mimic -t TEXT -voice VOICEURL
  

  Example

  $ ./mimic -t "Hello" -voice http://www.festvox.org/flite/packed/flite-2.0/voices/cmu_us_ksp.flitevox
  

Notes

• mimic offers several voices that can use different speech modelling techniques (diphone, clustergen, hts). Voices can differ a lot on size, naturalness and intelligibility.

  • Diphone voices are less computationally expensive and quite intelligible but they lack naturalness (sound more robotic). e.g. ./mimic -t "Hello world" -voice kal16

  • clustergen voices can sound more natural and intelligible at the expense of size and computational requirements. e.g.: e.g. ./mimic -t "Hello world" -voice slt, ./mimic -t "Hello world" -voice ap

  • hts voices usually may sound a bit more synthetic than clustergen voices, but have much smaller size. e.g.: e.g. ./mimic -t "Hello world" -voice slt_hts

• Voices can be compiled (built-in) into mimic or loaded from a .flitevox file. The only exception are hts voices. hts voices combine both a compiled function with a voice data file .htsvoice. Mimic will look for the .htsvoice file when the hts voice is loaded, looking into the current working directory, the "voices" subdirectory and the $prefix/share/mimic/voices directory if it exists.

• Voice names are identified as loadable files if the name includes a "/" (slash) otherwise they are treated as internal compiled-in voices.

• The voices/ directory contains several flitevox voices. Existing Flite voices can be found here: http://www.festvox.org/flite/packed/flite-2.0/voices/

• The voice referenced via an url will be downloaded on the fly.

Other options

Voices accept additional debug options. specified as --setf feature=value in the command line. Wrong values can prevent mimic from working. Some speech modelling techniques may not implement support for changing these features so at some point some voices may not provide support for these options. Here are some examples:

• Use simple concatenation of diphones without prosodic modification

  ./mimic --sets join_type=simple_join doc/intro.txt
  

• Print sentences as they are said

  ./mimic -pw doc/alice
  

• Make it speak slower

  ./mimic --setf duration_stretch=1.5 doc/alice
  

• Make it speak faster

  ./mimic --setf duration_stretch=0.8 doc/alice
  

• Make it speak higher

  ./mimic --setf int_f0_target_mean=145 doc/alice
  

See lang/cmu_us_kal/cmu_us_kal.c) to see some other features and values.

Say the hour

• The talking clock requires a single argument HH:MM. Under Unix you can call it

  ./mimic_time `date +%H:%M` 
  

Benchmarking

• For benchmarking, "none" can be used to discard the generated audio and give a summary of the speed:

  ./mimic -f doc/alice none
  

How to Contribute

For those who wish to help contribute to the development of mimic there are a few things to keep in mind.

Git branching structure

We will be using a branching struture similar to the one described in this article

In short

• master branch is for stable releases,

• development branch is where development work is done between releases,

• Any feature branch should branch off from development, and when complete will be merged back into development.

• Once enough features are added or a new release is complete those changes in development will be merged into master, then work can continue on development for the next release.

Coding Style Requirements

To keep the code in mimic coherent a simple coding style/guide is used. It should be noted that the current codebase as a whole does not meet some of these guidlines,this is a result of coming from the flite codebase. As different parts of the codebase are touched, it is the hope that these inconsistancies will diminish as time goes on.

• Indentation

  Each level of indentation is 4 spaces.

• Braces

  Braces always comes on the line following the statement.

  Example

  void cool_function(void)
  {
      int cool;
      for (cool = 0; cool < COOL_LIMIT; cool++)
      {
          [...]
          if (cool == AWESOME)
          {
              [...]
          }
      }
  }

• If-statements

  Always use curly braces.

  Example

  if(condition)
  {                             /*always use curly braces even if the 'if' only has one statement*/
      DoJustThisOneThing();        
  }
  
  if(argv[i][2] == 'h' &&      /*split 'if' conditions to multiple lines if the conditions are long */
     argv[i][3] == 'e' &&      /*or if it makes things more readable. */
     argv[i][4] == 'l' && 
     argv[i][5] == 'p')
  {
        /*example taken from args parsing code*/
        /* code */
  }
  else if(condition)
  {
        /* code */
  }
  else
  {
      /* code */
  }

• Switch-statements

  Always keep the break statement last in the case, after any code blocks.

  Example

  switch(state)
  {
      case 1:
      {               /* even if the case only has one line, use curly braces (similar reasoning as with if's) */ 
          doA(1);
      } break;
                          /* separate cases with a line */
      case 2:             /* unless it falls into the next one */
      case 3:
      {
          DoThisFirst();
      }                   /* no break, this one also falls through */
      case 4:
      {                   /* notice that curly braces line up with 'case' on line above */
          int b = 2;
          doA(b);
      } break;        /* putting 'break' on this line saves some room and makes it look a little nicer */
  
      case 5:
      {
          /* more code */
      } break;
  
      default:        /* It is nice to always have a default case, even if it does nothing */
      {
          InvalidDefaultCase(); /* or whatever, it depends on what you are trying to do. */
      }
  }

• Line length

  There's no hard limit but if possible keep lines shorter than 80 characters.

Vimrc

For those of you who use vim, add this to your vimrc to ensure proper indenting.

"####Indentation settings
:filetype plugin indent on
" show existing tab with 4 spaces width
:set tabstop=4
" when indenting with '>', use 4 spaces width
:set shiftwidth=4
" On pressing tab, insert 4 spaces
:set expandtab
" fix indentation problem with types above function name
:set cinoptions+=t0
" fix indentation of { after case
:set cinoptions+==0
" fix indentation of multiline if
:set cinoptions+=(0   "closing ) to let vimrc hylighting work after this line

"see http://vimdoc.sourceforge.net/htmldoc/indent.html#cinoptions-values
"for more indent options

Indent command (currently does not indent switch/cases properly)

indent [FILE] -npcs -i4 -bl -Tcst_wave -Tcst_wave_header -Tcst_rateconv \
      -Tcst_voice -Tcst_item -Tcst_features -Tcst_val -Tcst_va -Tcst_viterbi \
      -Tcst_utterance -Tcst_vit_cand_f_t -Tcst_vit_path_f_t -Tcst_vit_path \
      -Tcst_vit_point -Tcst_string -Tcst_lexicon -Tcst_relation \
      -Tcst_voice_struct -Tcst_track -Tcst_viterbi_struct -Tcst_vit_cand \
      -Tcst_tokenstream -Tcst_tokenstream_struct -Tcst_synth_module \
      -Tcst_sts_list -Tcst_lpcres -Tcst_ss -Tcst_regex -Tcst_regstate \
      -Twchar_t -Tcst_phoneset -Tcst_lts_rewrites -Tlexicon_struct \
      -Tcst_filemap -Tcst_lts_rules -Tcst_clunit_db -Tcst_cg_db \
      -Tcst_audio_streaming_info -Tcst_audio_streaming_info_struct -Tcst_cart \
      -Tcst_audiodev -TVocoderSetup -npsl -brs -bli0 -nut

Acknowledgements

see ACKNOWLEDGEMENTS

License

See COPYING