Coefontuber

Coefontuber, which is named after CoeFont + YouTuber, is an interactive and cross-platform CUI client for CoeFont.

As a vtuber streams a live with his/her virtual appearance, Coefontuber lets you speak with a virtual voice. Even dictionary and sound effects such as echo are supported.

It is written in Go.

_{In addition to CoeFont API, VOICEVOX API is supported. Currently this is experimental and not documented.}

Demo

1. Requirements

1.1 Sign Up

1. Sign up for CoeFont.

2. Visit https://coefont.cloud/account/api to generate a key for CoeFont API.

1.2 Requirements

• SoX (We call play command bundled with SoX.)

2. Configurations

2.1 Configuration File

Coefontuber reads ./config.json as the configuration file.

You don't need to write ./config.json from scratch; just

cp ./template_config.json ./config.json

Here is an example configuration:

{
    "coefont": { //Normally, this is the only section you might want to edit.
        "access_key":    "vWuJOxgUZcJGNV4aCZA0dXHlK",
        "client_secret": "y5Fsd7GDfspJnFaqszqOsxSF729je6SecIkevyC6",
        "font_uuid":     "6c0540f7-9639-4d2b-ae8c-43572d9d7f79",
        "speed":         1.0
    },
    "readline": { //Never edit this section unless you know what is GNU Readline.
        "vim_mode":     false,
        "history_file": "./.history"
    },
    "output_dir":  "./wav",
    "timeout_sec": 10,
    "custom_prefix_list": [
        {
            "prefix": "echo",
            "args": [
                "echo",
                "0.8",
                "0.88",
                "60",
                "0.4"
            ]
        }
    ]
}

2.2 custom_prefix_list (Sound Effects)

See also: 3.3 Special Commands

The configuration field custom_prefix_list registers additional arguments to the play command used to play generated WAV files.

With the example configuration above, if you for example input

!echo hello world

in an interactive session, then

play hello_world.wav echo 0.8 0.88 60 0.4

is executed under the hood.

Using this, you can apply any effects supported by SoX.

You can type !list to list all of the prefixes you've registered.

3. Usage

3.1 Build

go build

3.2 Run

./coefontuber #starts an interactive session

3.3 Special Commands

In an interactive session, each input of the form

!<word>[ <arg(s)>]

is interpreted as a special command.

3.3.1 Built-In Special Commands

Syntax	Description
!help	Shows help about all of the built-in special commands.
!list	Shows the list of all of the user-defined special commands.
!dict	Shows the list of the words registered to CoeFont dictionary.
!dict <word> <reading>	Registers the word <word> with its pronunciation <reading> to CoeFont dictionary.
!dict del <word>	Removes the word <word> from CoeFont dictionary.

3.3.2 User-Defined Special Commands

User-define special commands are supported in a limited manner. See 2.2 custom_prefix_list (Sound Effects) for the detail.

4. Development Notes

Run ./lint.sh before you commit.

5. How It Works

Say you want to make Coefontuber speak "hello", "world" and "bye". Here is what is happening under the hood:

1. main() reads your inputs (i.e. "hello", "world" and "bye") using GNU Readline.

2. main() spawns a pair of APICall() and Play() for each input. All of such functions start running right away, and they are all asynchronous.

3. APICall() sends a string to CoeFont and passes the resultant .wav file to the corresponding Play() using a channel. CoeFont works as a text-to-speech converter. Note that which APICall() returns first is undefined. It is possible (E) or (F) in the figure below returns before (D) returns though (D) is spawned first.

4. Play() waits for the corresponding APICall() to give it a .wav file. In addition, it waits for the adjacent Play() which has been spawned right before it to return. This implies that, before Play() returns, it notifies "I'm done." to the adjacent Play(). By that, even if sequentially spawned APICall()s don't return in that order, it is guaranteed that Play()s speak in that order. These "I'm done." communications are also done via channels named batonIn (for listening) and batonOut (for notifying). Each instance of batonIn or batonOut is shared only by two adjacent Play()s. For example, if a batonOut is passed to (B) in the figure below as an argument, it is copied only once and passed to (C) as batonIn.

Figure: How Coefontuber Works