The Luna API is defined using gRPC and protocol buffers. This section of the documentation is auto-generated from the protobuf file. It describes the data types and functions defined in the spec. The “messages” below correspond to the data structures to be used, and the “service” contains the methods that can be called.
Service that implements the Cobalt Luna Text-to-Speech API
| Method Name | Request Type | Response Type | Description |
|---|---|---|---|
| Version | VersionRequest | VersionResponse | Queries the Version of the Server. |
| ListVoices | ListVoicesRequest | ListVoicesResponse | Retrieves a list of available text-to-speech voices. |
| Synthesize | SynthesizeRequest | SynthesizeResponse | Performs synchronous text-to-speech generation. |
| SynthesizeStream | SynthesizeRequest | SynthesizeResponse | Performs streaming text-to-speech generation, where the synthesized speech is streamed to the client as it is being generated. |
The top-level message sent by the client for the ListVoices method.
This message is empty and has no fields.
The message sent by the server for the ListVoices method.
| Field | Type | Label | Description |
|---|---|---|---|
| voices | Voice | repeated | List of voices available for use that match the request. |
The top-level message sent by the client for the Synthesize and
SynthesizeStream methods.
| Field | Type | Label | Description |
|---|---|---|---|
| config | SynthesizerConfig | Provides configuration for the text-to-speech engine. | |
| text | string | The text to generate speech for. |
The message returned to the client by the Synthesize and
SynthesizeStream methods.
| Field | Type | Label | Description |
|---|---|---|---|
| audio | bytes | Audio samples of the generated speech. The samples will have the encoding specified in the SynthesizerConfig.AudioEncoding field of the request. |
Configuration for setting up the text-to-speech engine.
| Field | Type | Label | Description |
|---|---|---|---|
| voice_id | string | ||
| encoding | SynthesizerConfig.AudioEncoding | Encoding of the synthesized speech. If not specified, defaults to RAW_FLOAT32. | |
| n_samples | uint64 | Optional field for streaming synthesis. If not zero, waits until n_samples are generated before sending the audio data to the client. In the case that the entire generated audio is less than n_samples, the samples will be returned when synthesis is complete. |
The top-level message sent by the client for the Version method.
This message is empty and has no fields.
The message sent by the server for the Version method.
| Field | Type | Label | Description |
|---|---|---|---|
| version | string |
Description of a Luna Voice
| Field | Type | Label | Description |
|---|---|---|---|
| id | string | Unique identifier of the voice. This identifier is used to choose the voice during a synthesis request, and is specified in the SynthesizerConfig message. |
|
| name | string | Name of the voice. This is a concise name describing the voice, and maybe presented to the end-user, for example, to help which voice to choose for their TTS task. | |
| sample_rate | uint32 | The sample rate of this voice, returned in Hertz. | |
| language | string | The language code for this voice. |
Supported audio encodings. Unless otherwise noted, the sample rate is defined by the voice model.
| Name | Number | Description |
|---|---|---|
| RAW_LINEAR16 | 0 | Raw (headerless) uncompressed 16-bit signed little endian samples (linear PCM), single channel. |
| RAW_FLOAT32 | 1 | Raw (headerless) uncompressed 32-bit floating-point little endian samples (PCM), single channel. |
| .proto Type | Notes | Go Type | Python Type | C++ Type |
|---|---|---|---|---|
| double | float64 | float | double | |
| float | float32 | float | float | |
| int32 | Uses variable-length encoding. Inefficient for encoding negative numbers – if your field is likely to have negative values, use sint32 instead. | int32 | int | int32 |
| int64 | Uses variable-length encoding. Inefficient for encoding negative numbers – if your field is likely to have negative values, use sint64 instead. | int64 | int/long | int64 |
| uint32 | Uses variable-length encoding. | uint32 | int/long | uint32 |
| uint64 | Uses variable-length encoding. | uint64 | int/long | uint64 |
| sint32 | Uses variable-length encoding. Signed int value. These more efficiently encode negative numbers than regular int32s. | int32 | int | int32 |
| sint64 | Uses variable-length encoding. Signed int value. These more efficiently encode negative numbers than regular int64s. | int64 | int/long | int64 |
| fixed32 | Always four bytes. More efficient than uint32 if values are often greater than 2^28. | uint32 | int | uint32 |
| fixed64 | Always eight bytes. More efficient than uint64 if values are often greater than 2^56. | uint64 | int/long | uint64 |
| sfixed32 | Always four bytes. | int32 | int | int32 |
| sfixed64 | Always eight bytes. | int64 | int/long | int64 |
| bool | bool | boolean | bool | |
| string | A string must always contain UTF-8 encoded or 7-bit ASCII text. | string | str/unicode | string |
| bytes | May contain any arbitrary sequence of bytes. | []byte | str | string |