package google.cloud.texttospeech.v1

Get desktop application:
View/edit binary Protocol Buffers messages

Service that implements Google Cloud Text-to-Speech API.

• rpc ListVoices (ListVoicesRequest, ListVoicesResponse)

  cloud_tts.proto:34

  Returns a list of [Voice][google.cloud.texttospeech.v1.Voice] supported for synthesis.

  message ListVoicesRequest

  cloud_tts.proto:51

  The top-level message sent by the client for the `ListVoices` method.

  • string language_code = 1

    Optional (but recommended) [BCP-47](https://www.rfc-editor.org/rfc/bcp/bcp47.txt) language tag. If specified, the ListVoices call will only return voices that can be used to synthesize this language_code. E.g. when specifying "en-NZ", you will get supported "en-*" voices; when specifying "no", you will get supported "no-*" (Norwegian) and "nb-*" (Norwegian Bokmal) voices; specifying "zh" will also get supported "cmn-*" voices; specifying "zh-hk" will also get supported "yue-*" voices.

  message ListVoicesResponse

  cloud_tts.proto:64

  The message returned to the client by the `ListVoices` method.

  • repeated Voice voices = 1

    The list of voices.

• rpc SynthesizeSpeech (SynthesizeSpeechRequest, SynthesizeSpeechResponse)

  cloud_tts.proto:42

  Synthesizes speech synchronously: receive results after all text input has been processed.

  message SynthesizeSpeechRequest

  cloud_tts.proto:87

  The top-level message sent by the client for the `SynthesizeSpeech` method.

  • optional SynthesisInput input = 1

    Required. The Synthesizer requires either plain text or SSML as input.

  • optional VoiceSelectionParams voice = 2

    Required. The desired voice of the synthesized audio.

  • optional AudioConfig audio_config = 3

    Required. The configuration of the synthesized audio.

  message SynthesizeSpeechResponse

  cloud_tts.proto:179

  The message returned to the client by the `SynthesizeSpeech` method.

  • bytes audio_content = 1

    The audio data bytes encoded as specified in the request, including the header (For LINEAR16 audio, we include the WAV header). Note: as with all bytes fields, protobuffers use a pure binary representation, whereas JSON representations use base64.

Description of audio data to be synthesized.

Used in: SynthesizeSpeechRequest

• AudioEncoding audio_encoding = 1

  Required. The format of the requested audio byte stream.

• double speaking_rate = 2

  Optional speaking rate/speed, in the range [0.25, 4.0]. 1.0 is the normal native speed supported by the specific voice. 2.0 is twice as fast, and 0.5 is half as fast. If unset(0.0), defaults to the native 1.0 speed. Any other values < 0.25 or > 4.0 will return an error.

• double pitch = 3

  Optional speaking pitch, in the range [-20.0, 20.0]. 20 means increase 20 semitones from the original pitch. -20 means decrease 20 semitones from the original pitch.

• double volume_gain_db = 4

  Optional volume gain (in dB) of the normal native volume supported by the specific voice, in the range [-96.0, 16.0]. If unset, or set to a value of 0.0 (dB), will play at normal native signal amplitude. A value of -6.0 (dB) will play at approximately half the amplitude of the normal native signal amplitude. A value of +6.0 (dB) will play at approximately twice the amplitude of the normal native signal amplitude. Strongly recommend not to exceed +10 (dB) as there's usually no effective increase in loudness for any value greater than that.

• int32 sample_rate_hertz = 5

  The synthesis sample rate (in hertz) for this audio. Optional. If this is different from the voice's natural sample rate, then the synthesizer will honor this request by converting to the desired sample rate (which might result in worse audio quality), unless the specified sample rate is not supported for the encoding chosen, in which case it will fail the request and return [google.rpc.Code.INVALID_ARGUMENT][].

Configuration to set up audio encoder. The encoding determines the output audio format that we'd like.

Used in: AudioConfig

• AUDIO_ENCODING_UNSPECIFIED = 0

  Not specified. Will return result [google.rpc.Code.INVALID_ARGUMENT][].

• LINEAR16 = 1

  Uncompressed 16-bit signed little-endian samples (Linear PCM). Audio content returned as LINEAR16 also contains a WAV header.

• MP3 = 2

  MP3 audio.

• OGG_OPUS = 3

  Opus encoded audio wrapped in an ogg container. The result will be a file which can be played natively on Android, and in browsers (at least Chrome and Firefox). The quality of the encoding is considerably higher than MP3 while using approximately the same bitrate.

Gender of the voice as described in [SSML voice element](https://www.w3.org/TR/speech-synthesis11/#edef_voice).

Used in: Voice, VoiceSelectionParams

• SSML_VOICE_GENDER_UNSPECIFIED = 0

  An unspecified gender. In VoiceSelectionParams, this means that the client doesn't care which gender the selected voice will have. In the Voice field of ListVoicesResponse, this may mean that the voice doesn't fit any of the other categories in this enum, or that the gender of the voice isn't known.

• MALE = 1

  A male voice.

• FEMALE = 2

  A female voice.

• NEUTRAL = 3

  A gender-neutral voice.

Contains text input to be synthesized. Either `text` or `ssml` must be supplied. Supplying both or neither returns [google.rpc.Code.INVALID_ARGUMENT][]. The input size is limited to 5000 characters.

Used in: SynthesizeSpeechRequest

• oneof input_source

  The input source, which is either plain text or SSML.

  • string text = 1

    The raw text to be synthesized.

  • string ssml = 2

    The SSML document to be synthesized. The SSML document must be valid and well-formed. Otherwise the RPC will fail and return [google.rpc.Code.INVALID_ARGUMENT][]. For more information, see [SSML](/speech/text-to-speech/docs/ssml).

Description of a voice supported by the TTS service.

Used in: ListVoicesResponse

• repeated string language_codes = 1

  The languages that this voice supports, expressed as [BCP-47](https://www.rfc-editor.org/rfc/bcp/bcp47.txt) language tags (e.g. "en-US", "es-419", "cmn-tw").

• string name = 2

  The name of this voice. Each distinct voice has a unique name.

• SsmlVoiceGender ssml_gender = 3

  The gender of this voice.

• int32 natural_sample_rate_hertz = 4

  The natural sample rate (in hertz) for this voice.

Description of which voice to use for a synthesis request.

Used in: SynthesizeSpeechRequest

• string language_code = 1

  The language (and optionally also the region) of the voice expressed as a [BCP-47](https://www.rfc-editor.org/rfc/bcp/bcp47.txt) language tag, e.g. "en-US". Required. This should not include a script tag (e.g. use "cmn-cn" rather than "cmn-Hant-cn"), because the script will be inferred from the input provided in the SynthesisInput. The TTS service will use this parameter to help choose an appropriate voice. Note that the TTS service may choose a voice with a slightly different language code than the one selected; it may substitute a different region (e.g. using en-US rather than en-CA if there isn't a Canadian voice available), or even a different language, e.g. using "nb" (Norwegian Bokmal) instead of "no" (Norwegian)".

• string name = 2

  The name of the voice. Optional; if not set, the service will choose a voice based on the other parameters such as language_code and gender.

• SsmlVoiceGender ssml_gender = 3

  The preferred gender of the voice. Optional; if not set, the service will choose a voice based on the other parameters such as language_code and name. Note that this is only a preference, not requirement; if a voice of the appropriate gender is not available, the synthesizer should substitute a voice with a different gender rather than failing the request.