Various Speech Port Properties can be set via the API at a scope of the application level or the client port level. In the C API they are set through LV_TTS_SetPropertyEx. In the C++ API, they are set through LVTTSClient::SetPropertyEx at the client port or application level, or LVTTSClient::SetClientPropertyEx at the application level. LVTTSClient::SetClientPropertyEx is a static function that allows for application level properties to be applied without creating an instance.
The properties that were set can be queried with the following functions/methods:
C API
- Scope: Client Port (PROP_EX_TARGET_PORT) and Application (PROP_EX_TARGET_CLIENT)
C++ API
- Scope: Client Port (PROP_EX_TARGET_PORT) and Application (PROP_EX_TARGET_CLIENT)
- Scope: Application (PROP_EX_TARGET_CLIENT) only static functions
Synthesis Process Control Properties
Setting of these properties prior to calling LV_TTS_Synthesize / LVTTSClient::Synthesize only provides a hint about the desired settings to the synthesizer. If the input to LV_TTS_Synthesize / LVTTSClient::Synthesize is plain text, then these settings may have an effect. If the input were SSML, then the properties defined in the SSML document override these settings.
All of the properties listed in this section are based on SSML settings. For a description of possible values and corresponding defaults, please consult the SSML specification.
PROP_EX_TTS_SERVERS
Description: This property sets which TTS servers are used for processing synthesis requests. The value is a string containing IP addresses and optional ports separated by semicolons. For instance, "127.0.0.1;10.0.0.1:5721" specifies a server at 127.0.0.1 using the default port of 7579, and a server at 10.0.0.1 using the port 5721..
Scope: PROP_EX_TARGET_CLIENT
Value Type: PROP_EX_VALUE_TYPE_STRING
PROP_EX_SYNTH_PROSODY_PITCH
Description: Controls the pitch of the audio produced.
Scope: PROP_EX_TARGET_PORT, PROP_EX_TARGET_CLIENT
Value Type: PROP_EX_VALUE_TYPE_STRING
PROP_EX_SYNTH_PROSODY_CONTOUR
Description: Controls the contour of the sound pitch produced.
Scope: PROP_EX_TARGET_PORT, PROP_EX_TARGET_CLIENT
Value Type: PROP_EX_VALUE_TYPE_STRING
PROP_EX_SYNTH_PROSODY_RANGE
Description: Controls the range of the sound produced.
Scope: PROP_EX_TARGET_PORT, PROP_EX_TARGET_CLIENT
Value Type: PROP_EX_VALUE_TYPE_STRING
PROP_EX_SYNTH_PROSODY_RATE
Description: Controls the speaking rate of the sound produced.
Scope: PROP_EX_TARGET_PORT, PROP_EX_TARGET_CLIENT
Value Type: PROP_EX_VALUE_TYPE_STRING
PROP_EX_SYNTH_PROSODY_DURATION
Description: Controls the duration of time it takes for the texts to play.
Scope: PROP_EX_TARGET_PORT, PROP_EX_TARGET_CLIENT
Value Type: PROP_EX_VALUE_TYPE_STRING
PROP_EX_SYNTH_PROSODY_VOLUME
Description: Controls the volume of the audio produced.
Scope: PROP_EX_TARGET_PORT, PROP_EX_TARGET_CLIENT
Value Type: PROP_EX_VALUE_TYPE_STRING
PROP_EX_SYNTH_VOICE_GENDER
Description: Controls the gender of the voice timbre of the audio produced.
Scope: PROP_EX_TARGET_PORT, PROP_EX_TARGET_CLIENT
Value Type: PROP_EX_VALUE_TYPE_STRING
PROP_EX_SYNTH_VOICE_AGE
Description: Controls the age of the voice timbre of the audio produced.
Scope: PROP_EX_TARGET_PORT, PROP_EX_TARGET_CLIENT
Value Type: PROP_EX_VALUE_TYPE_STRING
PROP_EX_SYNTH_VOICE_VARIANT
Description: Sets the preferred voice variant of the audio produced.
Scope: PROP_EX_TARGET_PORT, PROP_EX_TARGET_CLIENT
Value Type: PROP_EX_VALUE_TYPE_STRING
PROP_EX_SYNTH_VOICE_NAME
Description: Sets the synthesis processor-specific voice name of the audio produced.
Scope: PROP_EX_TARGET_PORT, PROP_EX_TARGET_CLIENT
Value Type: PROP_EX_VALUE_TYPE_STRING
PROP_EX_SYNTH_EMPHASIS_LEVEL
Description: Controls the strength of emphasis of the audio produced.
Scope: PROP_EX_TARGET_PORT, PROP_EX_TARGET_CLIENT
Value Type: PROP_EX_VALUE_TYPE_STRING
Synthesis Output Properties
PROP_EX_SYNTH_SOUND_FORMAT
Description: Controls the format of the sound that the synthesized audio will be produced in.
Scope: PROP_EX_TARGET_PORT, PROP_EX_TARGET_CLIENT
Value Type: PROP_EX_VALUE_TYPE_INT, PROP_EX_VALUE_TYPE_INT_PTR
Possible Values:
- SFMT_ULAW
- SFMT_PCM
- SFMT_ALAW
Default Value: SFMT_ULAW
PROP_EX_SYNTHESIS_LANGUAGE
Description: Set the language that the synthesized audio is to be produced in.
Scope: PROP_EX_TARGET_PORT, PROP_EX_TARGET_CLIENT
Value Type: PROP_EX_VALUE_TYPE_STRING
Possible Values: A supported TTS language code, for example: "en-US", "en-GB", "es-LA"
Default Value: "en-US"
PROP_EX_SYNTHESIS_SAMPLING_RATE
Description: Sets the sampling rate that the audio is to be synthesized in.
Scope: PROP_EX_TARGET_PORT, PROP_EX_TARGET_CLIENT
Value Type: PROP_EX_VALUE_TYPE_INT, PROP_EX_VALUE_TYPE_INT_PTR
Possible Values: 8000, 22050
Default Value: 8000
PROP_EX_GENERATE_VISEMES
Description: Controls the generation of visemes during synthesis.
Scope: PROP_EX_TARGET_PORT, PROP_EX_TARGET_CLIENT
Value Type: PROP_EX_VALUE_TYPE_INT, PROP_EX_VALUE_TYPE_INT_PTR
Possible Values: PROP_EX_VISEMES_DISABLED (0), PROP_EX_VISEMES_ENABLED (1)
Default Value: 0
Logging Properties
PROP_EX_LOGGING_VERBOSITY
Description: Controls the verbosity of event logging. This can be used to increase or decrease the amount of log events that are generated. Note that increasing logging verbosity uses more CPU, and should therefore be avoided wherever possible in production systems where optimal performance is critical.
Scope: Client
Value Type: PROP_EX_VALUE_TYPE_INT, PROP_EX_VALUE_TYPE_INT_PTR
Possible Values:
- 1 - Minimal logging. Logs only errors and critical issues.
- 2 - Medium logging. Logs all non-debug information as events occur.
- 3 - Maximum logging. Logs all types of events. This will include any and all informational and debugging activity.
Default Value: 1
PROP_EX_LOG_TTS_EVENTS
Description: Controls whether the application will save off call log files used with the LumenVox Speech Tuner. Turn this on to capture audio and more information related to each synthesis.
- 0 - Deactivates saving of call log files.
- 1 - Enables saving of call log files
Scope: PROP_EX_TARGET_PORT, PROP_EX_TARGET_CLIENT
Value Type: PROP_EX_VALUE_TYPE_INT, PROP_EX_VALUE_TYPE_INT_PTR
Possible Values: 0 and 1
Default Value: 0
PROP_EX_SECURE_CONTEXT
Description: Controls the suppression of event logging. This can be used to suppress potentially sensitive data from logged events that are generated. This setting may be used with either ASR or TTS clients. When enabled, this setting will prevent logging of results or any other data to either the log files, or the callsre files. Wherever sensitive data would have appeared, this will be replaced with the word _SUPPRESSED, so indicate that data was suppressed. In the case of recorded audio, these will not be placed into the callsre file when this secure_context mode is enabled.
This functionality was introduced with LumenVox version 11.0.300 (November 2012) as part of our ongoing enhancements to support secure application development.
- 0 - Disabled. Regular logging will occur as normal
- 1 - Secure context mode enabled. Logging of potentially sensitive data will be suppressed
Scope: PROP_EX_TARGET_PORT, PROP_EX_TARGET_CLIENT
Value Type: PROP_EX_VALUE_TYPE_INT, PROP_EX_VALUE_TYPE_INT_PTR
Possible Values: 0 and 1
Default Value: 0
