tts

This example demonstrates how to use text to speech (TTS) in Flutter with sherpa-onnx.

It works on the following platforms:

• Android
• iOS
• Linux
• macOS (both arm64 and x86_64 are supported)
• Windows

How to build

Before you run flutter build, you have to select a TTS model and change the code to use your selected model.

1. Select a TTS model

We have a list of TTS models at

https://github.com/k2-fsa/sherpa-onnx/releases/tag/tts-models

You can select any of them. If you feel that there are so many that you don't know which one is the best, please visit http://huggingface.co/spaces/k2-fsa/text-to-speech and try each one by yourself and select the one you consider the best.

Suppose you select

https://github.com/k2-fsa/sherpa-onnx/releases/download/tts-models/vits-piper-en_US-libritts_r-medium.tar.bz2

Then please do the following:

• 1. Download and unzip the model

cd flutter-examples/tts/assets
wget https://github.com/k2-fsa/sherpa-onnx/releases/download/tts-models/vits-piper-en_US-libritts_r-medium.tar.bz2
tar xf vits-piper-en_US-libritts_r-medium.tar.bz2
rm vits-piper-en_US-libritts_r-medium.tar.bz2
cd ..

./generate-asset-list.py

Note that you have to run ./generate-asset-list.py so that Flutter knows where to find the model.

• 1. Change the code to use the downloaded model.

  We have given several examples for different models in ./lib/model.dart. For our selected model, we need to change ./lib/model.dart so that it looks like below:

// Example 6
// https://github.com/k2-fsa/sherpa-onnx/releases/tag/tts-models
// https://github.com/k2-fsa/sherpa-onnx/releases/download/tts-models/vits-piper-en_US-libritts_r-medium.tar.bz2
modelDir = 'vits-piper-en_US-libritts_r-medium';
modelName = 'en_US-libritts_r-medium.onnx';
dataDir = 'vits-piper-en_US-libritts_r-medium/espeak-ng-data';

• 3. That's it.

Build the APP

• 1. For Linux

flutter build linux

# See below if you get any errors

• 2. For macOS

To build a universal2 APP, use

flutter build macos

To build for x86_64, use

export FLUTTER_XCODE_ARCHS=x86_64
flutter build macos

To build for arm64, use

export FLUTTER_XCODE_ARCHS=arm64
flutter build macos

• 3. For Windows

flutter build windows

• 4. For Android

flutter build apk --split-per-abi

• 5. For iOS

flutter build ios

Fix for Linux

If you get the following errors on Linux,

Building Linux application...
CMake Error at /usr/local/share/cmake-3.29/Modules/FindPkgConfig.cmake:634 (message):
  The following required packages were not found:

   - gstreamer-1.0

Call Stack (most recent call first):
  /usr/local/share/cmake-3.29/Modules/FindPkgConfig.cmake:862 (_pkg_check_modules_internal)
  flutter/ephemeral/.plugin_symlinks/audioplayers_linux/linux/CMakeLists.txt:24 (pkg_check_modules)

please run:

sudo apt-get install -y libgstreamer1.0-dev libgstreamer-plugins-base1.0-dev libunwind-dev

See also https://github.com/bluefireteam/audioplayers/tree/main/packages/audioplayers_linux#setup-for-linux for the above error.