OutputAudioConfig

Instructs the speech synthesizer how to generate the output audio content.

JSON representation
{
  "audioEncoding": enum(OutputAudioEncoding),
  "sampleRateHertz": number,
  "synthesizeSpeechConfig": {
    object(SynthesizeSpeechConfig)
  }
}
Fields
audioEncoding

enum(OutputAudioEncoding)

Required. Audio encoding of the synthesized audio content.

sampleRateHertz

number

Optional. The synthesis sample rate (in hertz) for this audio. If not provided, then the synthesizer will use the default sample rate based on the audio encoding. 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).

synthesizeSpeechConfig

object(SynthesizeSpeechConfig)

Optional. Configuration of how speech should be synthesized.

OutputAudioEncoding

Audio encoding of the output audio format in Text-To-Speech.

Enums
OUTPUT_AUDIO_ENCODING_UNSPECIFIED Not specified.
OUTPUT_AUDIO_ENCODING_LINEAR_16 Uncompressed 16-bit signed little-endian samples (Linear PCM). Audio content returned as LINEAR16 also contains a WAV header.
OUTPUT_AUDIO_ENCODING_MP3 MP3 audio.
OUTPUT_AUDIO_ENCODING_OGG_OPUS 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.

SynthesizeSpeechConfig

Configuration of how speech should be synthesized.

JSON representation
{
  "speakingRate": number,
  "pitch": number,
  "volumeGainDb": number,
  "effectsProfileId": [
    string
  ],
  "voice": {
    object(VoiceSelectionParams)
  }
}
Fields
speakingRate

number

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.

pitch

number

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.

volumeGainDb

number

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. We strongly recommend not to exceed +10 (dB) as there's usually no effective increase in loudness for any value greater than that.

effectsProfileId[]

string

Optional. An identifier which selects 'audio effects' profiles that are applied on (post synthesized) text to speech. Effects are applied on top of each other in the order they are given.

voice

object(VoiceSelectionParams)

Optional. The desired voice of the synthesized audio.

VoiceSelectionParams

Description of which voice to use for speech synthesis.

JSON representation
{
  "name": string,
  "ssmlGender": enum(SsmlVoiceGender)
}
Fields
name

string

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

ssmlGender

enum(SsmlVoiceGender)

Optional. The preferred gender of the voice. If not set, the service will choose a voice based on the other parameters such as languageCode 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.

SsmlVoiceGender

Gender of the voice as described in SSML voice element.

Enums
SSML_VOICE_GENDER_UNSPECIFIED An unspecified gender, which means that the client doesn't care which gender the selected voice will have.
SSML_VOICE_GENDER_MALE A male voice.
SSML_VOICE_GENDER_FEMALE A female voice.
SSML_VOICE_GENDER_NEUTRAL A gender-neutral voice.