Speech Port Properties

Various Speech Port Properties can be set via the API at a Scope of the client level or the port level. In the C API they are set through LV_SRE_SetPropertyEx. In the C++ API, they are set through SetPropertyEx at the port or client level, or SetClientPropertyEx at the client level. SetClientPropertyEx is a static function that allows for client level properties to be applied without opening a port.

The properties that were set can be queried with the following functions:

C API

Scope: Port and Client

C++ API

Scope: Port and Client

Scope: Client only static functions

Network Properties

PROP_EX_SRE_SERVERS

Description: This property sets which Speech Engine servers are used for processing decodes. 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 5730, and a server at 10.0.0.1 using the port 5721.

Scope: Client

Value Type: PROP_EX_VALUE_TYPE_STRING

Possible Values: Strings of IP addresses.

Default Value: "127.0.0.1:5730"

PROP_EX_LICENSE_SERVERS

Description: This property sets which License server is used to check for available licenses. 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 7569, and a server at 10.0.0.1 using the port 5721.

Scope: Client

Value Type: PROP_EX_VALUE_TYPE_STRING

Possible Values: Strings of IP addresses.

Default Value: "127.0.0.1:7569"

Pre-Processing Properties

PROP_EX_TRIM_SILENCE_VALUE

Description: Sets how aggressively silence is trimmed from the audio during pre-processing. Values range from 0 to 1000; lower values corresponding to more aggressive trimming.

Scope: Port, Client

Value Type: PROP_EX_VALUE_TYPE_INT, PROP_EX_VALUE_TYPE_INT_PTR

Possible Values: 0 - 1000

Default Value: 970

PROP_EX_NOISE_REDUCTION_ENABLE

Description: Specifies the noise reduction algorithm used. For most users the default noise reduction algorithm should work best. For certain noise conditions the Alternate noise reduction algorithm has shown better results. Hence, advanced users can try switching the algorithm to see if it improves their performance in noisy conditions. The Adaptive noise reduction algorithm works best only when the noise is constantly changing such as car or highway noise. For more stationary noises like fan noise, the default algorithm will show the best performance

Scope: Port, Client

Value Type: PROP_EX_VALUE_TYPE_INT, PROP_EX_VALUE_TYPE_INT_PTR

Possible Values: NOISE_REDUCTION_NONE, NOISE_REDUCTION_DEFAULT, NOISE_REDUCTION_ALTERNATE, NOISE_REDUCTION_ADAPTIVE

Default Value: NOISE_REDUCTION_DEFAULT

Decode Properties

PROP_EX_MAX_NBEST_RETURNED

Description: Specifies the maximum number of n-best results to be returned by the Engine.

Scope: Port, Client

Value Type: PROP_EX_VALUE_TYPE_INT, PROP_EX_VALUE_TYPE_INT_PTR

Possible Values: Number of n-best results.

Default Value: 1

PROP_EX_DECODE_TIMEOUT

Description: In a non-blocking decode, this is the timeout value, in milliseconds, used by LV_SRE_WaitForDecode and LVSpeechPort::WaitForDecode functions. In blocking decode, this is the time to wait until the decode times out and returns an error from LV_SRE_Decode and LVSpeechPort::Decode.

Scope: Port, Client

Value Type: PROP_EX_VALUE_TYPE_INT, PROP_EX_VALUE_TYPE_INT_PTR

Possible Values: Time in milliseconds.

Default Value: 20000

PROP_EX_LOAD_GRAMMAR_TIMEOUT

Description: Specifies how long, in milliseconds, the client should wait for a grammar to load. If the timeout is reached before the grammar is loaded, the LoadGrammar function returns error code -37, LV_LOAD_GRAMMAR_TIMEOUT.

Scope: Port, Client

Value Type: PROP_EX_VALUE_TYPE_INT, PROP_EX_VALUE_TYPE_INT_PTR

Possible Values: Time in milliseconds.

Default Value: 200000

PROP_EX_ACOUSTIC_MODEL_RESOLUTION

Description: An enumerated type that specifies the resolution of acoustic model that would be used in decode. Higher resolution models may improve accuracy at the cost of speed.

Scope: Port, Client

Value Type: PROP_EX_VALUE_TYPE_INT, PROP_EX_VALUE_TYPE_INT_PTR

Possible Values: PROP_EX_LOW_RESOLUTION_ACOUSTIC_MODEL, PROP_EX_MIDDLE_RESOLUTION_ACOUSTIC_MODEL, PROP_EX_HIGH_RESOLUTION_ACOUSTIC_MODEL

Default Value: PROP_EX_LOW_RESOLUTION_ACOUSTIC_MODEL

PROP_EX_SPEED_VS_ACCURACY

Description: An integer between 0-100 specifiying how much accuracy will be valued in an SRE decode, at the cost of speed. Lower values correspond to faster decodes; 100 means maximum accuracy.

Scope: Port, Client

Value Type: PROP_EX_VALUE_TYPE_INT, PROP_EX_VALUE_TYPE_INT_PTR

Possible Values: 0-100

Default Value: 50

Grammar Properties

PROP_EX_STRICT_SISR_COMPLIANCE

Description: Controls whether LumenVox will strictly implement the final SISR 1.0 standard for adding tags to grammars. This value must be changed to 0 in order to run in a backward-compatibile mode able to read the older tag format.

Scope: Port, Client

Value Type: PROP_EX_VALUE_TYPE_INT, PROP_EX_VALUE_TYPE_INT_PTR

Possible Values: 0 (disabled) or 1 (enabled)

Default Value: 1

PROP_EX_BUILTIN_GRAMMAR_LANGUAGE

Description: Accepts a string that specifies the language that builtin grammars default to. Currently only "en-US" and "es-MX" are supported.

Scope: Port, Client

Value Type: PROP_EX_VALUE_TYPE_STRING

Possible Values: "en-US", "es-MX"

Default Value: "en-US"

Licensing Properties

PROP_EX_LICENSE_TYPE

Description:The license type sets the default license type to used when opening any port on that client. The value options are PROP_EX_LICENSE_VOXLITE, PROP_EX_LICENSE_SPEECHPORT. If the value is set to PROP_EX_LICENSE_VOXLITE, the client will get the license from the Lite license pool (these licenses only allow up to 500 vocabulary items per recognition). If the value is set to PROP_EX_LICENSE_SPEECHPORT, the client will get the license from the Full license pool. By default, the client will auto-pick the license; it will use up Full licenses before using Lite licenses.

Scope: Client

Value Type: PROP_EX_VALUE_TYPE_STRING

Possible Values: PROP_EX_LICENSE_VOXLITE, PROP_EX_LICENSE_SPEECHPORT, PROP_EX_LICENSE_AMD, PROP_EX_LICENSE_SLM

Default Value: "AUTO"

Logging Properties

PROP_EX_SAVE_SOUND_FILES

Description: Controls whether the application will save off .callsre files used with the LumenVox Speech Tuner. Turn this on to capture audio and more information related to each decode.

SAVE_SOUND_FILES_NONE - Deactivates saving of .callsre files.
SAVE_SOUND_FILES_BASIC - Saves basic information in .callsre files. This includes the audio from when BARGE_IN occured up to the END_OF_SPEECH.
SAVE_SOUND_FILES_ADVANCED - In addition to the information stored with the SAVE_SOUND_FILES_BASIC setting, when speech is streamed in to the Voice Activity Detection module, all of the collected data prior to a StreamCancel command is saved. This is usually when a NO_INPUT or TIMEOUT event occurs. This option collects data only when there is something to debug, which offers a balance between disk usage and retaining important information for debugging and is particularly useful when diagnosing NO-INPUT problems.
SAVE_SOUND_FILES_ALL - Used to collect all streamed data in all cases. This option collects all streamed data, whether there was a NO_INPUT or TIMEOUT event or not, including untrimmed audio from 'good' decodes. This option can be useful in diagnosing barge-in problems as well as other potential issues

Scope: Port, Client

Value Type: PROP_EX_VALUE_TYPE_INT, PROP_EX_VALUE_TYPE_INT_PTR

Possible Values: SAVE_SOUND_FILES_NONE, SAVE_SOUND_FILES_BASIC, SAVE_SOUND_FILES_ADVANCED, SAVE_SOUND_FILES_ALL

Default Value: SAVE_SOUND_FILES_NONE

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

Deprecated or Non-Functional Properties

PROP_EX_LIC_SERVER_HOSTNAME

Description: A string specifying the ip address of the machine hosting the LumenVox license server. This will be removed.

Scope: Client

Value Type: PROP_EX_VALUE_TYPE_STRING

Status: Deprecated since 10.0

Possible Values: Strings of IP addresses.

Default Value: "127.0.0.1"

PROP_EX_LIC_SERVER_PORTNUM

Description: An integer specifying the port number used by the LumenVox license server. This will be removed.

Scope: Client

Value Type: PROP_EX_VALUE_TYPE_INT, PROP_EX_VALUE_TYPE_INT_PTR

Status: Deprecated since 10.0

Possible Values: Port Number

Default Value: 7569

PROP_EX_DECODE_THREAD_PRIORITY

Description: Specifies the priority for the decode thread on the server. Higher priority threads will be processed before other applications on the same machine. Adjusting this parameter is useful for troubleshooting load issues on a machine.

Status: Deprecated and non functional since 9.5

PROP_EX_DECODE_OPTIMIZATION

Description: Sets whether the Engine should prioritize speed or accuracy while performing a decode. By default, it will switch between modes depending on how much load is happening on the server machine; when the server becomes too busy it will begin optimizing speed over accuracy.

Status: Deprecated and non functional since 9.5

PROP_EX_LANGUAGE

Description: A string specifying the default language to be used for the deprecated Concept/Phrase type grammars. This is no longer supported.

Status: Deprecated and non functional since 10.0

PROP_EX_NOISE_REDUCTION_AUTO_ADAPTIVE