TextToSpeech.Engine
public
class
TextToSpeech.Engine
extends Object
java.lang.Object | |
↳ | android.speech.tts.TextToSpeech.Engine |
Constants and parameter names for controlling text-to-speech. These include:
- Intents to ask engine to install data or check its data and extras for a TTS engine's check data activity.
-
Keys for the parameters passed with speak commands, e.g.
Engine.KEY_PARAM_UTTERANCE_ID
,Engine.KEY_PARAM_STREAM
. -
A list of feature strings that engines might support, e.g
Engine.KEY_FEATURE_NETWORK_SYNTHESIS
. These values may be passed in toTextToSpeech.speak
andTextToSpeech.synthesizeToFile
to modify engine behaviour. The engine can be queried for the set of features it supports throughTextToSpeech.getFeatures(java.util.Locale)
.
INTENT_ACTION_TTS_SERVICE
in the queries
elements of their
manifest:
<queries> ... <intent> <action android:name="android.intent.action.TTS_SERVICE" /> </intent> </queries>
Summary
Constants | |
---|---|
String |
ACTION_CHECK_TTS_DATA
Activity Action: Starts the activity from the platform TextToSpeech engine to verify the proper installation and availability of the resource files on the system. |
String |
ACTION_GET_SAMPLE_TEXT
Activity intent for getting some sample text to use for demonstrating TTS. |
String |
ACTION_INSTALL_TTS_DATA
Activity Action: Triggers the platform TextToSpeech engine to start the activity that installs the resource files on the device that are required for TTS to be operational. |
String |
ACTION_TTS_DATA_INSTALLED
Broadcast Action: broadcast to signal the change in the list of available languages or/and their features. |
int |
CHECK_VOICE_DATA_BAD_DATA
This constant was deprecated in API level 18. Use CHECK_VOICE_DATA_FAIL instead. |
int |
CHECK_VOICE_DATA_FAIL
Indicates failure when checking the installation status of the resources used by the
TextToSpeech engine with the |
int |
CHECK_VOICE_DATA_MISSING_DATA
This constant was deprecated in API level 18. Use CHECK_VOICE_DATA_FAIL instead. |
int |
CHECK_VOICE_DATA_MISSING_VOLUME
This constant was deprecated in API level 18. Use CHECK_VOICE_DATA_FAIL instead. |
int |
CHECK_VOICE_DATA_PASS
Indicates success when checking the installation status of the resources used by the
TextToSpeech engine with the |
int |
DEFAULT_STREAM
Default audio stream used when playing synthesized speech. |
String |
EXTRA_AVAILABLE_VOICES
Extra information received with the |
String |
EXTRA_CHECK_VOICE_DATA_FOR
This constant was deprecated in API level 18. Redundant functionality, checking for existence of specific sets of voice data can be done on client side. |
String |
EXTRA_SAMPLE_TEXT
Extra information received with the |
String |
EXTRA_TTS_DATA_INSTALLED
This constant was deprecated in API level 18. No longer in use. If client is interested in information about what changed, it should use the ACTION_CHECK_TTS_DATA intent to discover available voices. |
String |
EXTRA_UNAVAILABLE_VOICES
Extra information received with the |
String |
EXTRA_VOICE_DATA_FILES
This constant was deprecated in API level 18. TTS engine implementation detail, this information has no use for text-to-speech API client. |
String |
EXTRA_VOICE_DATA_FILES_INFO
This constant was deprecated in API level 18. TTS engine implementation detail, this information has no use for text-to-speech API client. |
String |
EXTRA_VOICE_DATA_ROOT_DIRECTORY
This constant was deprecated in API level 18. TTS engine implementation detail, this information has no use for text-to-speech API client. |
String |
INTENT_ACTION_TTS_SERVICE
Intent for starting a TTS service. |
String |
KEY_FEATURE_EMBEDDED_SYNTHESIS
This constant was deprecated
in API level 21.
Starting from API level 21, to select embedded synthesis, call
( |
String |
KEY_FEATURE_NETWORK_RETRIES_COUNT
Feature key that indicates that network request retries count can be set for the request. |
String |
KEY_FEATURE_NETWORK_SYNTHESIS
This constant was deprecated
in API level 21.
Starting from API level 21, to select network synthesis, call
|
String |
KEY_FEATURE_NETWORK_TIMEOUT_MS
Feature key that indicate that a network timeout can be set for the request. |
String |
KEY_FEATURE_NOT_INSTALLED
Feature key that indicates that the voice may need to download additional data to be fully functional. |
String |
KEY_PARAM_PAN
Parameter key to specify how the speech is panned from left to right when speaking text. |
String |
KEY_PARAM_SESSION_ID
Parameter key to specify an audio session identifier (obtained from
|
String |
KEY_PARAM_STREAM
Parameter key to specify the audio stream type to be used when speaking text or playing back a file. |
String |
KEY_PARAM_UTTERANCE_ID
Parameter key to identify an utterance in the
|
String |
KEY_PARAM_VOLUME
Parameter key to specify the speech volume relative to the current stream type volume used when speaking text. |
String |
SERVICE_META_DATA
Name under which a text to speech engine publishes information about itself. |
Public constructors | |
---|---|
Engine()
|
Inherited methods | |
---|---|
Constants
ACTION_CHECK_TTS_DATA
public static final String ACTION_CHECK_TTS_DATA
Activity Action: Starts the activity from the platform TextToSpeech
engine to verify the proper installation and availability of the
resource files on the system. Upon completion, the activity will
return one of the following codes:
CHECK_VOICE_DATA_PASS
,
CHECK_VOICE_DATA_FAIL
,
Moreover, the data received in the activity result will contain the following fields:
EXTRA_AVAILABLE_VOICES
which contains an ArrayListof all the available voices. The format of each voice is: lang-COUNTRY-variant where COUNTRY and variant are optional (ie, "eng" or "eng-USA" or "eng-USA-FEMALE"). EXTRA_UNAVAILABLE_VOICES
which contains an ArrayListof all the unavailable voices (ones that user can install). The format of each voice is: lang-COUNTRY-variant where COUNTRY and variant are optional (ie, "eng" or "eng-USA" or "eng-USA-FEMALE").
Constant Value: "android.speech.tts.engine.CHECK_TTS_DATA"
ACTION_GET_SAMPLE_TEXT
public static final String ACTION_GET_SAMPLE_TEXT
Activity intent for getting some sample text to use for demonstrating TTS. Specific locale have to be requested by passing following extra parameters:
- language
- country
- variant
EXTRA_SAMPLE_TEXT
which contains an String with sample text.
Constant Value: "android.speech.tts.engine.GET_SAMPLE_TEXT"
ACTION_INSTALL_TTS_DATA
public static final String ACTION_INSTALL_TTS_DATA
Activity Action: Triggers the platform TextToSpeech engine to
start the activity that installs the resource files on the device
that are required for TTS to be operational. Since the installation
of the data can be interrupted or declined by the user, the application
shouldn't expect successful installation upon return from that intent,
and if need be, should check installation status with
ACTION_CHECK_TTS_DATA
.
Constant Value: "android.speech.tts.engine.INSTALL_TTS_DATA"
ACTION_TTS_DATA_INSTALLED
public static final String ACTION_TTS_DATA_INSTALLED
Broadcast Action: broadcast to signal the change in the list of available languages or/and their features.
Constant Value: "android.speech.tts.engine.TTS_DATA_INSTALLED"
CHECK_VOICE_DATA_BAD_DATA
public static final int CHECK_VOICE_DATA_BAD_DATA
This constant was deprecated
in API level 18.
Use CHECK_VOICE_DATA_FAIL instead.
Indicates erroneous data when checking the installation status of the resources used by
the TextToSpeech engine with the ACTION_CHECK_TTS_DATA
intent.
Constant Value: -1 (0xffffffff)
CHECK_VOICE_DATA_FAIL
public static final int CHECK_VOICE_DATA_FAIL
Indicates failure when checking the installation status of the resources used by the
TextToSpeech engine with the ACTION_CHECK_TTS_DATA
intent.
Constant Value: 0 (0x00000000)
CHECK_VOICE_DATA_MISSING_DATA
public static final int CHECK_VOICE_DATA_MISSING_DATA
This constant was deprecated
in API level 18.
Use CHECK_VOICE_DATA_FAIL instead.
Indicates missing resources when checking the installation status of the resources used
by the TextToSpeech engine with the ACTION_CHECK_TTS_DATA
intent.
Constant Value: -2 (0xfffffffe)
CHECK_VOICE_DATA_MISSING_VOLUME
public static final int CHECK_VOICE_DATA_MISSING_VOLUME
This constant was deprecated
in API level 18.
Use CHECK_VOICE_DATA_FAIL instead.
Indicates missing storage volume when checking the installation status of the resources
used by the TextToSpeech engine with the ACTION_CHECK_TTS_DATA
intent.
Constant Value: -3 (0xfffffffd)
CHECK_VOICE_DATA_PASS
public static final int CHECK_VOICE_DATA_PASS
Indicates success when checking the installation status of the resources used by the
TextToSpeech engine with the ACTION_CHECK_TTS_DATA
intent.
Constant Value: 1 (0x00000001)
DEFAULT_STREAM
public static final int DEFAULT_STREAM
Default audio stream used when playing synthesized speech.
Constant Value: 3 (0x00000003)
EXTRA_AVAILABLE_VOICES
public static final String EXTRA_AVAILABLE_VOICES
Extra information received with the ACTION_CHECK_TTS_DATA
intent result where
the TextToSpeech engine returns an ArrayList
Constant Value: "availableVoices"
EXTRA_CHECK_VOICE_DATA_FOR
public static final String EXTRA_CHECK_VOICE_DATA_FOR
This constant was deprecated
in API level 18.
Redundant functionality, checking for existence of specific sets of voice
data can be done on client side.
Extra information sent with the ACTION_CHECK_TTS_DATA
intent where the
caller indicates to the TextToSpeech engine which specific sets of voice data to
check for by sending an ArrayList
Constant Value: "checkVoiceDataFor"
EXTRA_SAMPLE_TEXT
public static final String EXTRA_SAMPLE_TEXT
Extra information received with the ACTION_GET_SAMPLE_TEXT
intent result where
the TextToSpeech engine returns an String with sample text for requested voice
Constant Value: "sampleText"
EXTRA_TTS_DATA_INSTALLED
public static final String EXTRA_TTS_DATA_INSTALLED
This constant was deprecated
in API level 18.
No longer in use. If client is interested in information about what
changed, it should use the ACTION_CHECK_TTS_DATA
intent to discover available voices.
Extra information received with the ACTION_TTS_DATA_INSTALLED
intent result.
It indicates whether the data files for the synthesis engine were successfully
installed. The installation was initiated with the ACTION_INSTALL_TTS_DATA
intent. The possible values for this extra are
TextToSpeech.SUCCESS
and TextToSpeech.ERROR
.
Constant Value: "dataInstalled"
EXTRA_UNAVAILABLE_VOICES
public static final String EXTRA_UNAVAILABLE_VOICES
Extra information received with the ACTION_CHECK_TTS_DATA
intent result where
the TextToSpeech engine returns an ArrayList
Constant Value: "unavailableVoices"
EXTRA_VOICE_DATA_FILES
public static final String EXTRA_VOICE_DATA_FILES
This constant was deprecated
in API level 18.
TTS engine implementation detail, this information has no use for
text-to-speech API client.
Extra information received with the ACTION_CHECK_TTS_DATA
intent result where
the TextToSpeech engine specifies the file names of its resources under the
resource path.
Constant Value: "dataFiles"
EXTRA_VOICE_DATA_FILES_INFO
public static final String EXTRA_VOICE_DATA_FILES_INFO
This constant was deprecated
in API level 18.
TTS engine implementation detail, this information has no use for
text-to-speech API client.
Extra information received with the ACTION_CHECK_TTS_DATA
intent result where
the TextToSpeech engine specifies the locale associated with each resource file.
Constant Value: "dataFilesInfo"
EXTRA_VOICE_DATA_ROOT_DIRECTORY
public static final String EXTRA_VOICE_DATA_ROOT_DIRECTORY
This constant was deprecated
in API level 18.
TTS engine implementation detail, this information has no use for
text-to-speech API client.
Extra information received with the ACTION_CHECK_TTS_DATA
intent result where
the TextToSpeech engine specifies the path to its resources.
It may be used by language packages to find out where to put their data.
Constant Value: "dataRoot"
INTENT_ACTION_TTS_SERVICE
public static final String INTENT_ACTION_TTS_SERVICE
Intent for starting a TTS service. Services that handle this intent must
extend TextToSpeechService
. Normal applications should not use this intent
directly, instead they should talk to the TTS service using the the methods in this
class.
Constant Value: "android.intent.action.TTS_SERVICE"
KEY_FEATURE_EMBEDDED_SYNTHESIS
public static final String KEY_FEATURE_EMBEDDED_SYNTHESIS
This constant was deprecated
in API level 21.
Starting from API level 21, to select embedded synthesis, call
(TextToSpeech.getVoices()
, find a suitable embedded voice
(Voice.isNetworkConnectionRequired()
) and pass it
to TextToSpeech.setVoice(Voice)
).
Feature key for embedded synthesis. See TextToSpeech.getFeatures(Locale)
for a description of how feature keys work. If set and supported by the engine
as per TextToSpeech.getFeatures(Locale)
, the engine must synthesize
text on-device (without making network requests).
See also:
Constant Value: "embeddedTts"
KEY_FEATURE_NETWORK_RETRIES_COUNT
public static final String KEY_FEATURE_NETWORK_RETRIES_COUNT
Feature key that indicates that network request retries count can be set for the request.
If set and supported as per TextToSpeech.getFeatures(Locale)
or
Voice.getFeatures()
, it can be used as a request parameter to set the
number of network request retries that are attempted in case of failure. When used as
a key of a request parameter, its value should be a string with an integer value.
Constant Value: "networkRetriesCount"
KEY_FEATURE_NETWORK_SYNTHESIS
public static final String KEY_FEATURE_NETWORK_SYNTHESIS
This constant was deprecated
in API level 21.
Starting from API level 21, to select network synthesis, call
TextToSpeech.getVoices()
, find a suitable network voice
(Voice.isNetworkConnectionRequired()
) and pass it
to TextToSpeech.setVoice(Voice)
.
Feature key for network synthesis. See TextToSpeech.getFeatures(Locale)
for a description of how feature keys work. If set (and supported by the engine
as per TextToSpeech.getFeatures(Locale)
, the engine must
use network based synthesis.
See also:
Constant Value: "networkTts"
KEY_FEATURE_NETWORK_TIMEOUT_MS
public static final String KEY_FEATURE_NETWORK_TIMEOUT_MS
Feature key that indicate that a network timeout can be set for the request. If set and
supported as per TextToSpeech.getFeatures(Locale)
or Voice.getFeatures()
,
it can be used as request parameter to set the maximum allowed time for a single
request attempt, in milliseconds, before synthesis fails. When used as a key of
a request parameter, its value should be a string with an integer value.
Constant Value: "networkTimeoutMs"
KEY_FEATURE_NOT_INSTALLED
public static final String KEY_FEATURE_NOT_INSTALLED
Feature key that indicates that the voice may need to download additional data to be fully
functional. The download will be triggered by calling
TextToSpeech.setVoice(Voice)
or TextToSpeech.setLanguage(Locale)
.
Until download is complete, each synthesis request will either report
TextToSpeech.ERROR_NOT_INSTALLED_YET
error, or use a different voice to synthesize
the request. This feature should NOT be used as a key of a request parameter.
Constant Value: "notInstalled"
KEY_PARAM_PAN
public static final String KEY_PARAM_PAN
Parameter key to specify how the speech is panned from left to right when speaking text. Pan is specified as a float ranging from -1 to +1 where -1 maps to a hard-left pan, 0 to center (the default behavior), and +1 to hard-right.
See also:
Constant Value: "pan"
KEY_PARAM_SESSION_ID
public static final String KEY_PARAM_SESSION_ID
Parameter key to specify an audio session identifier (obtained from
AudioManager.generateAudioSessionId()
) that will be used by the request audio
output. It can be used to associate one of the AudioEffect
objects with the synthesis (or earcon) output.
See also:
Constant Value: "sessionId"
KEY_PARAM_STREAM
public static final String KEY_PARAM_STREAM
Parameter key to specify the audio stream type to be used when speaking text
or playing back a file. The value should be one of the STREAM_ constants
defined in AudioManager
.
See also:
Constant Value: "streamType"
KEY_PARAM_UTTERANCE_ID
public static final String KEY_PARAM_UTTERANCE_ID
Parameter key to identify an utterance in the
TextToSpeech.OnUtteranceCompletedListener
after text has been
spoken, a file has been played back or a silence duration has elapsed.
See also:
Constant Value: "utteranceId"
KEY_PARAM_VOLUME
public static final String KEY_PARAM_VOLUME
Parameter key to specify the speech volume relative to the current stream type volume used when speaking text. Volume is specified as a float ranging from 0 to 1 where 0 is silence, and 1 is the maximum volume (the default behavior).
See also:
Constant Value: "volume"
SERVICE_META_DATA
public static final String SERVICE_META_DATA
Name under which a text to speech engine publishes information about itself.
This meta-data should reference an XML resource containing a
<
tag.tts-engine
>
Constant Value: "android.speech.tts"
Public constructors
Engine
public Engine ()