Added in API level 15

UtteranceProgressListener

abstract class UtteranceProgressListener
kotlin.Any
   ↳ android.speech.tts.UtteranceProgressListener

Listener for events relating to the progress of an utterance through the synthesis queue. Each utterance is associated with a call to android.speech.tts.TextToSpeech#speak or android.speech.tts.TextToSpeech#synthesizeToFile with an associated utterance identifier, as per TextToSpeech.Engine.KEY_PARAM_UTTERANCE_ID. The callbacks specified in this method can be called from multiple threads.

Summary

Public constructors

Public methods
open Unit
onAudioAvailable(utteranceId: String!, audio: ByteArray!)

This is called when a chunk of audio is ready for consumption.
open Unit
onBeginSynthesis(utteranceId: String!, sampleRateInHz: Int, audioFormat: Int, channelCount: Int)

Called when the TTS engine begins to synthesize the audio for a request.
abstract Unit
onDone(utteranceId: String!)

Called when an utterance has successfully completed processing.
abstract Unit
onError(utteranceId: String!)

Called when an error has occurred during processing.
open Unit
onError(utteranceId: String!, errorCode: Int)

Called when an error has occurred during processing.
open Unit
onRangeStart(utteranceId: String!, start: Int, end: Int, frame: Int)

This is called when the TTS service is about to speak the specified range of the utterance with the given utteranceId.
abstract Unit
onStart(utteranceId: String!)

Called when an utterance "starts" as perceived by the caller.
open Unit
onStop(utteranceId: String!, interrupted: Boolean)

Called when an utterance has been stopped while in progress or flushed from the synthesis queue.

Public constructors

UtteranceProgressListener

UtteranceProgressListener()

Public methods

onAudioAvailable

Added in API level 24
open fun onAudioAvailable(
    utteranceId: String!, 
    audio: ByteArray!
): Unit

This is called when a chunk of audio is ready for consumption.

The audio parameter is a copy of what will be synthesized to the speakers (when synthesis was initiated with a android.speech.tts.TextToSpeech#speak call) or written to the file system (for android.speech.tts.TextToSpeech#synthesizeToFile). The audio bytes are delivered in one or more chunks; if onDone or #onError is called all chunks have been received.

The audio received here may not be played for some time depending on buffer sizes and the amount of items on the synthesis queue.

Parameters
utteranceId String!: The utterance ID of the utterance.
audio ByteArray!: A chunk of audio; the format can be known by listening to onBeginSynthesis(java.lang.String,int,int,int).

onBeginSynthesis

Added in API level 24
open fun onBeginSynthesis(
    utteranceId: String!, 
    sampleRateInHz: Int, 
    audioFormat: Int, 
    channelCount: Int
): Unit

Called when the TTS engine begins to synthesize the audio for a request.

It provides information about the format of the byte array for subsequent onAudioAvailable calls.

This is called when the TTS engine starts synthesizing audio for the request. If an application wishes to know when the audio is about to start playing, {#onStart(String)} should be used instead.

Parameters
utteranceId String!: The utterance ID of the utterance.
sampleRateInHz Int: Sample rate in hertz of the generated audio.
audioFormat Int: Audio format of the generated audio. Should be one of AudioFormat.ENCODING_PCM_8BIT, AudioFormat.ENCODING_PCM_16BIT or AudioFormat.ENCODING_PCM_FLOAT.
channelCount Int: The number of channels.

onDone

Added in API level 15
abstract fun onDone(utteranceId: String!): Unit

Called when an utterance has successfully completed processing. All audio will have been played back by this point for audible output, and all output will have been written to disk for file synthesis requests. This request is guaranteed to be called after onStart(java.lang.String).

Parameters
utteranceId String!: The utterance ID of the utterance.

onError

Added in API level 15
Deprecated in API level 21
abstract fun onError(utteranceId: String!): Unit

Deprecated: Use onError(java.lang.String,int) instead

Called when an error has occurred during processing. This can be called at any point in the synthesis process. Note that there might be calls to onStart(java.lang.String) for specified utteranceId but there will never be a call to both onDone(java.lang.String) and onError(java.lang.String) for the same utterance.

Parameters
utteranceId String!: The utterance ID of the utterance.

onError

Added in API level 21
open fun onError(
    utteranceId: String!, 
    errorCode: Int
): Unit

Called when an error has occurred during processing. This can be called at any point in the synthesis process. Note that there might be calls to onStart(java.lang.String) for specified utteranceId but there will never be a call to both onDone(java.lang.String) and onError(java.lang.String,int) for the same utterance. The default implementation calls onError(java.lang.String).

Parameters
utteranceId String!: The utterance ID of the utterance.
errorCode Int: one of the ERROR_* codes from TextToSpeech

onRangeStart

Added in API level 26
open fun onRangeStart(
    utteranceId: String!, 
    start: Int, 
    end: Int, 
    frame: Int
): Unit

This is called when the TTS service is about to speak the specified range of the utterance with the given utteranceId.

This method is called when the audio is expected to start playing on the speaker. Note that this is different from onAudioAvailable which is called as soon as the audio is generated.

This information can be used, for example, to highlight ranges of the text while it is spoken.

Only called if the engine supplies timing information by calling android.speech.tts.SynthesisCallback#rangeStart(int,int,int).

Parameters
utteranceId String!: Unique id identifying the synthesis request.
start Int: The start index of the range in the utterance text.
end Int: The end index of the range (exclusive) in the utterance text.
frame Int: The position in frames in the audio of the request where this range is spoken.

onStart

Added in API level 15
abstract fun onStart(utteranceId: String!): Unit

Called when an utterance "starts" as perceived by the caller. This will be soon before audio is played back in the case of a android.speech.tts.TextToSpeech#speak or before the first bytes of a file are written to the file system in the case of android.speech.tts.TextToSpeech#synthesizeToFile.

Parameters
utteranceId String!: The utterance ID of the utterance.

onStop

Added in API level 23
open fun onStop(
    utteranceId: String!, 
    interrupted: Boolean
): Unit

Called when an utterance has been stopped while in progress or flushed from the synthesis queue. This can happen if a client calls TextToSpeech.stop() or uses TextToSpeech.QUEUE_FLUSH as an argument with the android.speech.tts.TextToSpeech#speak or android.speech.tts.TextToSpeech#synthesizeToFile methods.

Parameters
utteranceId String!: The utterance ID of the utterance.
interrupted Boolean: If true, then the utterance was interrupted while being synthesized and its output is incomplete. If false, then the utterance was flushed before the synthesis started.