¶ 1 Overview
This guide describes how to configure and use the Microsoft Azure Bot Service (ABS) plugin to the UniMRCP server. The document is intended for users having a certain knowledge of Microsoft Azure Speech APIs and UniMRCP.
¶ 1.1 Installation
For installation instructions, use one of the guides below.
RPM Installation Manual Red Hat / CentOS
Deb Installation Manual Debian / Ubuntu¶ 1.2 Applicable Versions
Instructions provided in this guide are applicable to the following versions.
UniMRCP 1.7.0 and above
UniMRCP ABS Plugin 1.0.0 and above
¶ 2 Supported Features
This is a brief check list of the features currently supported by the UniMRCP server running with the Azure SR plugin.
¶ 2.1 MRCP Methods
-
DEFINE-GRAMMAR
-
RECOGNIZE
-
START-INPUT-TIMERS
-
STOP
-
SET-PARAMS
-
GET-PARAMS
¶ 2.2 MRCP Events
-
RECOGNITION-COMPLETE
-
START-OF-INPUT
¶ 2.3 MRCP Header Fields
-
Input-Type
-
No-Input-Timeout
-
Recognition-Timeout
-
Speech-Complete-Timeout
-
Speech-Incomplete-Timeout
-
Waveform-URI
-
Media-Type
-
Completion-Cause
-
Confidence-Threshold
-
Start-Input-Timers
-
DTMF-Interdigit-Timeout
-
DTMF-Term-Timeout
-
DTMF-Term-Char
-
Save-Waveform
-
Speech-Language
-
Cancel-If-Queue
-
Sensitivity-Level
¶ 2.4 Grammars
-
Built-in speech transcription grammar
-
Built-in/embedded DTMF grammar
-
SRGS XML (limited support)
¶ 2.5 Results
-
NLSML
-
JSON
¶ 3 Configuration Format
The configuration file of the ABS plugin is located in /opt/unimrcp/conf/umsazurebot.xml. The configuration file is written in XML.
¶ 3.1 Document
The root element of the XML document must be <umsazurebot>.
Attributes
| Name | Unit | Description |
|---|---|---|
| license-file | File path | Specifies the license file. File name may include patterns containing '*' sign. If multiple files match the pattern, the most recent one gets used. |
| subscription-key-file | File path | Specifies the Microsoft subscription key file to use. File name may include patterns containing '*' sign. If multiple files match the pattern, the most recent one gets used. |
Parent
- None.
Children
| Name | Unit | Description |
|---|---|---|
| streaming-recognition | String | Specifies parameters of streaming recognition employed via Microsoft Speech WebSocket protocol. |
| results | String | Specifies parameters of recognition results set in RECOGNITION-COMPLETE events. |
| speech-contexts | String | Contains a list of speech contexts. |
| speech-dtmf-input-detector | String | Specifies parameters of the speech and DTMF input detector. |
| utterance-manager | String | Specifies parameters of the utterance manager. |
| rdr-manager | String | Specifies parameters of the Recognition Details Record (RDR) manager. |
| monitoring-agent | String | Specifies parameters of the monitoring manager. |
| license-server | String | Specifies parameters used to connect to the license server. The use of the license server is optional. |
Example
This is an example of a bare document.
<umsazurebot license-file="umsazurebot_*.lic" subscription-key-file="azbot.subscription.key">
</umsazurebot>
¶ 3.2 Streaming Recognition
This element specifies parameters of Microsoft WebSocket streaming recognition.
Attributes
| Name | Unit | Description |
|---|---|---|
| language | String | Specifies the default language to use, if not set by the client. |
| max-alternatives | Integer | Specifies the maximum number of speech recognition result alternatives to be returned. Can be overridden by client by means of the header field N-Best-List-Length. |
| alternatives-below-threshold | Boolean | Specifies whether to return speech recognition result alternatives with the confidence score below the confidence threshold. |
| start-of-input | String | Specifies the source of start of input event sent to the client (use "service-originated" to rely on service-originated startDetected event and "internal" for an event determined by plugin). |
| skip-unsupported-grammars | Boolean | Specifies whether to skip or raise an error while referencing a malformed or not supported grammar. |
| skip-empty-results | Boolean | Specifies whether to implicitly initiate a new gRPC request if the current one completes with an empty result. |
| transcription-grammar | String | Specifies the name of the built-in speech transcription grammar. The grammar can be referenced as builtin:speech/transcribe or builtin:grammar/transcribe, where transcribe is the default value of this parameter. |
| word-info | Boolean | Specifies whether to return word-level time offset information. Can be overridden by client. |
| inter-result-timeout | Time interval [msec] | Specifies a timeout between interim results containing transcribed speech. If the timeout is elapsed, input is considered complete. The timeout defaults to 0 (disabled). |
| endpoint-id | String | Specifies the custom endpoint identifier, if used. Can be overridden by client. |
| http-proxy-host | String | Specifies the host name of HTTP proxy, if used. |
| http-proxy-port | Integer | Specifies the port number of HTTP proxy, if used. |
| http-proxy-username | String | Specifies the username employed for HTTP proxy authentication, if used. |
| http-proxy-password | String | Specifies the password employed for HTTP proxy authentication, if used. |
| appid | String | The application id of the LUIS model, if used. Can be overridden by client. |
| intents | String | A comma-separated list of intents to be used from the specified LUIS model, if any. Can be overridden by client. |
| sdk-log | Boolean | Specifies whether to enable SDK logging. Available since 1.1.0. |
| activity-timeout | Time interval [msec] | Specifies a timeout to wait for an activity from the bot after final transcription result is received. If the timeout is elapsed an no activity is received, the recognition will complete with no-match. The timeout defaults to 5000 msec. Available since 1.3.0. |
| initial-silence-timeout | Time interval [msec] | Sets the InitialSilenceTimeout of the SDK. The timeout defaults to 0 (not set explicitly). Available since 1.3.0. |
| end-silence-timeout | Time interval [msec] | Sets the EndSilenceTimeout of the SDK. The timeout defaults to 0 (not set explicitly). Available since 1.3.0. |
| segmentation-silence-timeout | Time interval [msec] | Sets the SegmentationSilenceTimeout of the SDK. The timeout defaults to 0 (not set explicitly). Available since 1.4.0. |
Parent
<umsazurebot>
Children
- None.
Example
This is an example of streaming recognition element.
<streaming-recognition
language="en-US"
max-alternatives="1"
alternatives-below-threshold="false"
start-of-input="service-originated"
skip-unsupported-grammars="true"
transcription-grammar="transcribe"
/>
¶ 3.3 Results
This element specifies parameters of recognition results set in RECOGNITION-COMPLETE events.
Attributes
| Name | Unit | Description |
|---|---|---|
| format | String | Specifies the format of results to be returned to the client (use "standard" for NLSML and "json" for JSON). |
| indent | Integer | Specifies the indent to use while composing the results. |
| replace-dots | Boolean | Specifies whether to replace '.' with '_' in the parameter names, used while composing an XML content. The parameter is observed only if the format is set to standard. |
| replace-dashes | Boolean | Specifies whether to replace '-' with '_' in the parameter names, used while composing an XML content. The parameter is observed only if the format is set to standard. |
| confidence-format | String | Specifies the format of the confidence score to be returned. The parameter is observed only if the format is set to standard. Use one of:
|
| tag-format | String | Specifies the format of the instance element to be returned. The parameter is observed only if the format is set to standard. Use one of:
|
| tag-encoding | String | Specifies the encoding of the instance element to be returned. The parameter is observed only if the format is set to standard and tag-format is *semantics/json. Use one of:
|
| event-input-text | String | Specifies the input text to be filled in NLSML on a triggered activity. The parameter defaults to 'null', if not specified. Available since 1.3.0. |
Parent
<umsazurebot>
Children
- None.
Example
This is an example of results element.
<results
format="standard"
indent="0"
replace-dots="true"
confidence-format="auto"
tag-format="semantics/xml"
/>
¶ 3.4 Speech Contexts
This element specifies a list of speech contexts.
Attributes
- None.
Parent
<umsazurebot>
Children
<speech-context>
Example
The example below defines a speech contexts directory.
<speech-contexts>
<speech-context id="directory" speech-complete="true" enable="true">
<phrase>call Steve</phrase>
<phrase>call John</phrase>
<phrase>dial 5</phrase>
<phrase>dial 6</phrase>
</speech-context>
</speech-contexts>
¶ 3.5 Speech Context
This element specifies a speech context.
Attributes
| Name | Unit | Description |
|---|---|---|
| id | String | Specifies a unique string identifier of the speech context to be referenced by the MRCP client. |
| enable | Boolean | Specifies whether the speech context is enabled or disabled. |
| speech-complete | Boolean | Specifies whether to complete input as soon as an interim result matches one of the specified phrases. |
| language | String | The language the phrases are defined for. |
| scope | String | Specifies a scope of the speech context, which can be set to either hint or strict. |
Parent
<speech-contexts>
Children
<phrase>
Example
This is an example of speech context element.
<speech-context id="directory" speech-complete="true" enable="true">
<phrase>call Steve</phrase>
<phrase>call John</phrase>
<phrase>dial 5</phrase>
<phrase>dial 6</phrase>
</speech-context>
¶ 3.6 Phrase
This element specifies a phrase in the speech context.
Attributes
| Name | Unit | Description |
|---|---|---|
| tag | String | Specifies an optional arbitrary string identifier to be returned as an instance in the NLSML result, if the transcription result matches the phrase. |
Parent
<speech-context>
Children
- None.
This is an example of a speech context with phrases having tags specified.
<speech-context id="boolean" speech-complete="true" scope="strict" enable="true">
<phrase tag="true">yes</phrase>
<phrase tag="true">sure</phrase>
<phrase tag="true">correct</phrase>
<phrase tag="false">no</phrase>
<phrase tag="false">not sure</phrase>
<phrase tag="false">incorrect </phrase>
</speech-context>
¶ 3.7 Speech and DTMF Input Detector
This element specifies parameters of the speech and DTMF input detector.
Attributes
| Name | Unit | Description |
|---|---|---|
| vad-mode | Integer | Specifies an operating mode of VAD in the range of [0 ... 3]. Default is 1. |
| speech-start-timeout | Time interval [msec] | Specifies how long to wait in transition mode before triggering a start of speech input event. |
| speech-complete-timeout | Time interval [msec] | Specifies how long to wait in transition mode before triggering an end of speech input event. The complete timeout is used when there is an interim result available. |
| speech-incomplete-timeout | Time interval [msec] | Specifies how long to wait in transition mode before triggering an end of speech input event. The incomplete timeout is used as long as there is no interim result available. Afterwards, the complete timeout is used. |
| noinput-timeout | Time interval [msec] | Specifies how long to wait before triggering a no-input event. |
| input-timeout | Time interval [msec] | Specifies how long to wait for input to complete. |
| dtmf-interdigit-timeout | Time interval [msec] | Specifies a DTMF inter-digit timeout. |
| dtmf-term-timeout | Time interval [msec] | Specifies a DTMF input termination timeout. |
| dtmf-term-char | Character | Specifies a DTMF input termination character. |
| speech-leading-silence | Time interval [msec] | Specifies desired silence interval preceding spoken input. |
| speech-trailing-silence | Time interval [msec] | Specifies desired silence interval following spoken input. |
| speech-output-period | Time interval [msec] | Specifies an interval used to send speech frames to the recognizer. |
Parent
<umsazurebot>
Children
- None.
Example
The example below defines a typical speech and DTMF input detector having the default parameters set.
<speech-dtmf-input-detector
vad-mode="2"
speech-start-timeout="300"
speech-complete-timeout="1000"
speech-incomplete-timeout="3000"
noinput-timeout="5000"
input-timeout="10000"
dtmf-interdigit-timeout="5000"
dtmf-term-timeout="10000"
dtmf-term-char=""
speech-leading-silence="300"
speech-trailing-silence="300"
speech-output-period="200"
/>
¶ 3.8 Utterance Manager
This element specifies parameters of the utterance manager.
Attributes
| Name | Unit | Description |
|---|---|---|
| save-waveforms | Boolean | Specifies whether to save waveforms or not. |
| purge-existing | Boolean | Specifies whether to delete existing records on start-up. |
| max-file-age | Time interval [min] | Specifies a time interval in minutes after expiration of which a waveform is deleted. Set 0 for infinite. |
| max-file-count | Integer | Specifies the max number of waveforms to store. If reached, the oldest waveform is deleted. Set 0 for infinite. |
| waveform-base-uri | String | Specifies the base URI used to compose an absolute waveform URI. |
| waveform-folder | Dir path | Specifies a folder the waveforms should be stored in. |
| file-prefix | String | Specifies a prefix used to compose the name of the file to be stored. Defaults to 'umsazurebot-', if not specified. |
| use-logging-tag | Boolean | Specifies whether to use the MRCP header field Logging-Tag, if present, to compose the name of the file to be stored. |
Parent
<umsazurebot>
Children
- None.
Example
The example below defines a typical utterance manager having the default parameters set.
<utterance-manager
save-waveforms="false"
purge-existing="false"
max-file-age="60"
max-file-count="100"
waveform-base-uri="http://localhost/utterances/"
waveform-folder=""
/>
¶ 3.9 RDR Manager
This element specifies parameters of the Recognition Details Record (RDR) manager.
Attributes
| Name | Unit | Description |
|---|---|---|
| save-records | Boolean | Specifies whether to save recognition details records or not. |
| purge-existing | Boolean | Specifies whether to delete existing records on start-up. |
| max-file-age | Time interval [min] | Specifies a time interval in minutes after expiration of which a record is deleted. Set 0 for infinite. |
| max-file-count | Integer | Specifies the max number of records to store. If reached, the oldest record is deleted. Set 0 for infinite. |
| record-folder | Dir path | Specifies a folder to store recognition details records in. Defaults to ${UniMRCPInstallDir}/var. |
| file-prefix | String | Specifies a prefix used to compose the name of the file to be stored. Defaults to 'umsazurebot-', if not specified. |
| use-logging-tag | Boolean | Specifies whether to use the MRCP header field Logging-Tag, if present, to compose the name of the file to be stored. |
Parent
<umsazurebot>
Children
- None.
Example
The example below defines a typical utterance manager having the default parameters set.
<rdr-manager
save-records="false"
purge-existing="false"
max-file-age="60"
max-file-count="100"
waveform-folder=""
/>
¶ 3.10 Monitoring Agent
This element specifies parameters of the monitoring agent.
Attributes
| Name | Unit | Description |
|---|---|---|
| refresh-period | Time interval [sec] | Specifies a time interval in seconds used to periodically refresh usage details. See <usage-refresh-handler>. |
Parent
<umsazurebot>
Children
<usage-change-handler><usage-refresh-handler>
Example
The example below defines a monitoring agent with usage change and refresh handlers.
<monitoring-agent refresh-period="60">
<usage-change-handler>
<log-usage enable="true" priority="NOTICE"/>
</usage-change-handler>
<usage-refresh-handler>
<dump-channels enable="true" status-file="umsazurebot-channels.status"/>
</usage-refresh-handler >
</monitoring-agent>
¶ 3.11 Usage Change Handler
This element specifies an event handler called on every usage change.
Attributes
- None.
Parent
<monitoring-agent>
Children
<log-usage><update-usage><dump-channels>
Example
This is an example of the usage change event handler.
<usage-change-handler>
<log-usage enable="true" priority="NOTICE"/>
<update-usage enable="false" status-file="umsazurebot-usage.status"/>
<dump-channels enable="false" status-file="umsazurebot-channels.status"/>
</usage-change-handler>
¶ 3.12 Usage Refresh Handler
This element specifies an event handler called periodically to update usage details.
Attributes
- None.
Parent
<monitoring-agent>
Children
<log-usage><update-usage><dump-channels>
Example
This is an example of the usage change event handler.
<usage-refresh-handler>
<log-usage enable="true" priority="NOTICE"/>
<update-usage enable="false" status-file="umsazurebot-usage.status"/>
<dump-channels enable="false" status-file="umsazurebot-channels.status"/>
</usage-refresh-handler>
¶ 3.13 License Server
This element specifies parameters used to connect to the license server.
Attributes
| Name | Unit | Description |
|---|---|---|
| enable | Boolean | Specifies whether the use of license server is enabled or not. If enabled, the license-file attribute is not honored. |
| server-address | String | Specifies the IP address or host name of the license server. |
| certificate-file | File path | Specifies the client certificate used to connect to the license server. File name may include patterns containing a * sign. If multiple files match the pattern, the most recent one gets used. |
| ca-file | File path | Specifies the certificate authority used to validate the license server. |
| channel-count | Integer | Specifies the number of channels to check out from the license server. If not specified or set to 0, either all available channels or a pool of channels will be checked based on the configuration of the license server. |
| http-proxy-address | String | Specifies the IP address or host name of the HTTP proxy server, if used. |
| http-proxy-port | Integer | Specifies the port number of the HTTP proxy server, if used. |
| security-level | Integer | Specifies the SSL security level, which defaults to 1. Applicable since OpenSSL 1.1.0. Available since 1.2.0. |
Parent
<umsazurebot>
Children
- None.
Example
The example below defines a typical configuration which can be used to connect to a license server located, for example, at 10.0.0.1.
<license-server
enable="true"
server-address="10.0.0.1"
certificate-file="unilic_client_*.crt"
ca-file="unilic_ca.crt"
/>
For further reference to the license server, visit
License Server Check out the concepts¶ 4 Configuration Steps
This section outlines common configuration steps.
¶ 4.1 Using Default Configuration
The default configuration should be sufficient for the general use.
¶ 4.2 Specifying LUIS Model
A LUIS model is referenced by the corresponding App ID.
The App ID can be specified globally in the configuration file umsazurebot.xml by means of the parameter appid in the element <streaming-recognition>. For example:
<streaming-recognition
interim-results="true"
start-of-input="service-originated"
language="en-US"
max-alternatives="1"
appid="abcdefgh-ijkl-mnop-qrst-vwxyz12345678"
/>
The App ID can also be specified per individual MRCP RECOGNIZE request using one of the alternate methods listed below.
Built-in grammar
builtin:speech/transcribe?appid=abcdefgh-ijkl-mnop-qrst-vwxyz12345678
Vendor-Specific-Parameters
Vendor-Specific-Parameters: appid=abcdefgh-ijkl-mnop-qrst-vwxyz12345678
SRGS XML grammar
<grammar mode="voice" root="transcribe" version="1.0"
xml:lang="en-US"
xmlns="http://www.w3.org/2001/06/grammar">
<meta name="scope" content="builtin"/>
<meta name="appid" content="abcdefgh-ijkl-mnop-qrst-vwxyz12345678"/>
<rule id="main"><one-of/></rule>
</grammar>
¶ 4.3 Specifying Intents
A particular intent or a list of intents in the LUIS model can optionally be specified in the configuration file umsazurebot.xml by means of the parameter intents in the element <streaming-recognition>. For example:
<streaming-recognition
interim-results="true"
start-of-input="service-originated"
language="en-US"
max-alternatives="1"
appid="abcdefgh-ijkl-mnop-qrst-vwxyz12345678"
intents="BookFlight, RoomReservation"
/>
The intents can also be specified per individual MRCP RECOGNIZE request using one of the alternate methods listed below.
Built-in grammar
builtin:speech/transcribe?intents=BookFlight, RoomReservation
Vendor-Specific-Parameters
Vendor-Specific-Parameters: intents=BookFlight, RoomReservation
SRGS XML grammar
<grammar mode="voice" root="transcribe" version="1.0"
xml:lang="en-US"
xmlns="http://www.w3.org/2001/06/grammar">
<meta name="scope" content="builtin"/>
<meta name="intents" content="BookFlight, RoomReservation"/>
<rule id="main"><one-of/></rule>
</grammar>
¶ 4.4 Specifying Recognition Language
Recognition language can be specified by the client per MRCP session by means of the header field Speech-Language set in a SET-PARAMS or RECOGNIZE request. Otherwise, the parameter language set in the configuration file umsazurebot.xml is used. The parameter defaults to en-US.
The recognition language can also be set by the attribute xml:lang specified in the SRGS XML grammar. For example:
<?xml version="1.0" encoding="UTF-8"?>
<grammar mode="voice" root="transcribe" version="1.0"
xml:lang="en-AU"
xmlns="http://www.w3.org/2001/06/grammar">
<meta name="scope" content="builtin"/>
<rule id="transcribe"><one-of/></rule>
</grammar>
¶ 4.5 Specifying Sampling Rate
Sampling rate is determined based on the SDP negotiation. Refer to the configuration guide of the UniMRCP server on how to specify supported encodings and sampling rates to be used in communication between the client and server.
¶ 4.6 Specifying Speech Input Parameters
While the default parameters specified for the speech input detector are sufficient for the general use, various parameters can be adjusted to better suit a particular requirement.
- speech-start-timeout
This parameter is used to trigger a start of speech input. The shorter is the timeout, the sooner a START-OF-INPUT event is delivered to the client. However, a short timeout may also lead to a false positive. Note that if the start-of-input parameter in the ws-streaming-recognition is set to service-originated, then a START-OF-INPUT event is sent to the client at a later stage, upon reception of a speech.startDetected response from the service.
- speech-complete-timeout
This parameter is used to trigger an end of speech input. The shorter is the timeout, the shorter is the response time. However, a short timeout may also lead to a false positive.
Note that both events, an expiration of the speech complete timeout and a speech.endDetected response delivered from the service, are monitored to trigger an end of speech input, on whichever comes first basis. In order to rely solely on an event delivered from the speech service, the parameter speech-complete-timeout needs to be set to a higher value.
- vad-mode
This parameter is used to specify an operating mode of the Voice Activity Detector (VAD) within an integer range of [0 … 3]. A higher mode is more aggressive and, as a result, is more restrictive in reporting speech. The parameter can be overridden per MRCP session by setting the header field Sensitivity-Level in a SET-PARAMS or RECOGNIZE request. The following table shows how the Sensitivity-Level is mapped to the vad-mode.
| Sensitivity-Level | Vad-Mode |
|---|---|
| [0.00 ... 0.25) | 0 |
| [0.25 … 0.50) | 1 |
| [0.50 ... 0.75) | 2 |
| [0.75 ... 1.00] | 3 |
¶ 4.7 Specifying DTMF Input Parameters
While the default parameters specified for the DTMF input detector are sufficient for the general use, various parameters can be adjusted to better suit a particular requirement.
- dtmf-interdigit-timeout
This parameter is used to set an inter-digit timeout on DTMF input. The parameter can be overridden per MRCP session by setting the header field DTMF-Interdigit-Timeout in a SET-PARAMS or RECOGNIZE request.
- dtmf-term-timeout
This parameter is used to set a termination timeout on DTMF input and is in effect when dtmf-term-char is set and there is a match for an input grammar. The parameter can be overridden per MRCP session by setting the header field DTMF-Term-Timeout in a SET-PARAMS or RECOGNIZE request.
- dtmf-term-char
This parameter is used to set a character terminating DTMF input. The parameter can be overridden per MRCP session by setting the header field DTMF-Term-Char in a SET-PARAMS or RECOGNIZE request.
¶ 4.8 Specifying No-Input and Recognition Timeouts
- noinput-timeout
This parameter is used to trigger a no-input event. The parameter can be overridden per MRCP session by setting the header field No-Input-Timeout in a SET-PARAMS or RECOGNIZE request.
- input-timeout
This parameter is used to limit input (recognition) time. The parameter can be overridden per MRCP session by setting the header field Recognition-Timeout in a SET-PARAMS or RECOGNIZE request.
¶ 4.9 Specifying Vendor-Specific Parameters
The following parameters can optionally be specified by the MRCP client in SET-PARAMS, DEFINE-GRAMMAR and RECOGNIZE requests via the MRCP header field Vendor-Specific-Parameters.
| Name | Unit | Description |
|---|---|---|
| start-of-input | String | Specifies the source of start of input event sent to the client (use "service-originated" for an event originated based on a first-received interim result and "internal" for an event determined by plugin). |
| alternatives-below-threshold | Boolean | Specifies whether to return speech recognition result alternatives with the confidence score below the confidence threshold. |
| speech-start-timeout | Time interval [msec] | Specifies how long to wait in transition mode before triggering a start of speech input event. |
| interim-result-timeout | Time interval [msec] | Specifies a timeout between interim results containing transcribed speech. If the timeout is elapsed, input is considered complete. The timeout defaults to 0 (disabled). |
| appid | String | The application id of the LUIS model, if used. |
| intents | String | A comma-separated list of intents to be used from the specified LUIS model, if any. |
| method | String | Specifies the method to be executed. One of:
|
| payload | String | Specifies the JSON payload used when the method is set to send-activity. Available since 1.3.0. |
| payload-encoding | String | Specifies the encoding of the payload. One of:
|
| payload-text | String | Specifies the payload text. Either payload or payload-text is supposed to be used. Available since 1.3.0. |
| tag-format | String | Specifies the format of the instance element to be returned. The parameter is observed only if the format is set to standard. Use one of:
|
| tag-encoding | String | Specifies the encoding of the instance element to be returned. The parameter is observed only if the format is set to standard and tag-format is *semantics/json. Use one of:
|
| event-input-text | String | Specifies the input text to be filled in NLSML on a triggered activity. The parameter defaults to 'null', if not specified. Available since 1.3.0. |
| activity-timeout | Time interval [msec] | Specifies a timeout to wait for an activity from the bot after final transcription result is received. If the timeout is elapsed an no activity is received, the recognition will complete with no-match. The timeout defaults to 5000 msec. Available since 1.3.0. |
| initial-silence-timeout | Time interval [msec] | Sets the InitialSilenceTimeout of the SDK. The timeout defaults to 0 (not set explicitly). Available since 1.3.0. |
| end-silence-timeout | Time interval [msec] | Sets the EndSilenceTimeout of the SDK. The timeout defaults to 0 (not set explicitly). Available since 1.3.0. |
All the vendor-specific parameters can also be specified at the grammar-level via a built-in or SRGS XML grammar.
The following example demonstrates the use of a built-in grammar with the vendor-specific parameters alternatives-below-threshold and speech-start-timeout set to true and 100 correspondingly.
builtin:speech/transcribe?alternatives-below-threshold=true;speech-start-timeout=100
The following example demonstrates the use of an SRGS XML grammar with the vendor-specific parameters alternatives-below-threshold and speech-start-timeout set to true and 100 correspondingly.
<grammar mode="voice" root="transcribe" version="1.0" xml:lang="en-US" xmlns="http://www.w3.org/2001/06/grammar">
<meta name="scope" content="builtin"/>
<meta name="alternatives-below-threshold" content="true"/>
<meta name="speech-start-timeout" content="100"/>
<rule id="transcribe">
<one-of ><item>blank</item></one-of>
</rule>
</grammar>
¶ 4.10 Triggering Activity
¶ Prime Action
This scenario assumes that a new conversation starts by sending an activity message from the user application to the bot. The bot is supposed to respond with an activity in return.
builtin:speech/transcribe?tag-format=semantics/json;method=send-activity;event-input-text=null;payload={"type":"message","text":"Trigger Event|123456|abcdef"}
Note: the payload shall conform to the JSON structure described in this link.
The same activity message will be composed and send to the bot by the plugin if the parameter payload-text below is used instead of the parameter payload above.
builtin:speech/transcribe?tag-format=semantics/json;method=send-activity;event-input-text=null;payload-text=Trigger Event|123456|abcdef
If the payload contains special characters, then the payload shall be base64-encoded, for example, as follows.
builtin:speech/transcribe?tag-format=semantics/json;method=send-activity;event-input-text=null;payload-encoding=base64; payload=eyJ0eXBlIjogIm1lc3NhZ2UiLCAidGV4dCI6ICJ0cmlnZ2VyIn0=
¶ Main Loop
Afterwards, the conversation shall progress in a regular loop.
builtin:speech/transcribe?tag-format=semantics/json;method=listen
¶ 4.11 Retrieving Activity
¶ Prime Action
This scenario assumes that a new conversation starts by the bot sending an activity message to the user application.
builtin:speech/transcribe?tag-format=semantics/json;method=get-activity;event-input-text=null
¶ Main Loop
Afterwards, the conversation shall progress in a regular loop.
builtin:speech/transcribe?tag-format=semantics/json;method=listen
¶ 4.12 Maintaining Utterances
Saving of utterances is not required for regular operation and is disabled by default. However, enabling this functionality allows to save utterances sent to the service and later listen to them offline.
The relevant settings can be specified via the element utterance-manager.
- save-waveforms
Utterances can optionally be recorded and stored if the configuration parameter save-waveforms is set to true. The parameter can be overridden per MRCP session by setting the header field Save-Waveforms in a SET-PARAMS or RECOGNIZE request.
- purge-existing
This parameter specifies whether to delete existing waveforms on start-up.
- max-file-age
This parameter specifies a time interval in minutes after expiration of which a waveform is deleted. If set to 0, there is no expiration time specified.
- max-file-count
This parameter specifies the maximum number of waveforms to store. If the specified number is reached, the oldest waveform is deleted. If set to 0, there is no limit specified.
- waveform-base-uri
This parameter specifies the base URI used to compose an absolute waveform URI returned in the header field Waveform-Uri in response to a RECOGNIZE request.
- waveform-folder
This parameter specifies a path to the directory used to store waveforms in. The directory defaults to ${UniMRCPInstallDir}/var.
¶ 4.13 Maintaining Recognition Details Records
Producing of recognition details records (RDR) is not required for regular operation and is disabled by default. However, enabling this functionality allows to store details of each recognition attempt in a separate file and analyze them later offline. The RDRs ate stored in the JSON format.
The relevant settings can be specified via the element rdr-manager.
- save-records
This parameter specifies whether to save recognition details records or not.
- purge-existing
This parameter specifies whether to delete existing records on start-up.
- max-file-age
This parameter specifies a time interval in minutes after expiration of which a record is deleted. If set to 0, there is no expiration time specified.
- max-file-count
This parameter specifies the maximum number of records to store. If the specified number is reached, the oldest record is deleted. If set to 0, there is no limit specified.
- record-folder
This parameter specifies a path to the directory used to store records in. The directory defaults to ${UniMRCPInstallDir}/var.
¶ 5 Recognition Grammars and Results
¶ 5.1 Using Built-in Speech Transcription
For generic speech transcription, having no speech contexts defined, a pre-set identifier transcribe must be used by the MRCP client in a RECOGNIZE request as follows:
builtin:speech/transcribe
The name of the identifier transcribe can be changed from the configuration file umsazurebot.xml.
Speech contexts are defined in the configuration file umsazurebot.xml and available since Azure SR 1.5.0. A speech context is assigned a unique string identifier and holds a list of phrases.
Below is a definition of a sample speech context directory:
<speech-context id="directory" speech-complete="true">
<phrase>call Steve</phrase>
<phrase>call John</phrase>
<phrase>dial 5</phrase>
<phrase>dial 6</phrase>
</speech-context>
Which can be referenced in a RECOGNIZE request as follows:
builtin:speech/directory
The prefixes builtin:speech and builtin:grammar can be used interchangeably as follows:
builtin:grammar/directory
¶ 5.2 Using Built-in DTMF Grammars
Pre-set built-in DTMF grammars can be referenced by the MRCP client in a RECOGNIZE request as follows:
builtin:dtmf/$id
Where $id is a unique string identifier of the built-in DTMF grammar.
Note that only a DTMF grammar identifier digits is currently supported.
Built-in DTMF digits can also be referenced by metadata in SRGS XML grammar. The following example is equivalent to the built-in grammar above.
<grammar mode="dtmf" root="digits" version="1.0"
xml:lang="en-US"
xmlns="http://www.w3.org/2001/06/grammar">
<meta name="scope" content="builtin"/>
<rule id="digits"><one-of/></rule>
</grammar>
Where the root rule name identifies a built-in DTMF grammar.
¶ 5.3 Retrieving Results
Results received from the Azure service are transformed to a certain data structure and sent to the MRCP client in a RECOGNITION-COMPLETE event. The way results are composed can be adjusted via the <results> element in the configuration file umsazurebot.xml.
NLSML Format
If the format attribute is set to standard, which is the default setting, then the header filed Content-Type is set to application/x-nlsml and the body of a RECOGNITION-COMPLETE event is set to an NSLML result composed as follows.
input
The <input> element in an NLSML result is set to the transcribed text.
instance
By default, the <instance> element in the NLSML result is composed based on an XML representation of the returned intent. This behavior can be adjusted via the tag-format attribute, which accepts the following values.
- semantics/xml
The default setting. The intent is represented in XML.
- semantics/json
The intent is represented in JSON.
- swi-semantics/xml
The intent is set in an inner <SWI_meaning> element being represented in XML.
- swi-semantics/json
The intent is set in an inner <SWI_meaning> element being represented in JSON.
JSON Format
If the format attribute is set to json, then the header filed Content-Type is set to application/json and the body of a RECOGNITION-COMPLETE event is set to a JSON representation of the intent.
The format attribute can be specified by the MRCP client per individual MRCP RECOGNIZE request as a query input attribute to the built-in speech grammar. For example:
builtin:speech/transcribe?format=json
The format attribute can also be specified in SRGS XML grammar. For example:
<grammar mode="voice" root="transcribe" version="1.0"
xml:lang="en-US"
xmlns="http://www.w3.org/2001/06/grammar">
<meta name="scope" content="builtin"/>
<meta name="format" content="json"/>
<rule id="main"><one-of/></rule>
</grammar>
¶ 6 Monitoring Usage Details
The number of in-use and total licensed channels can be monitored in several alternate ways. There is a set of actions which can take place on certain events. The behavior is configurable via the element monitoring-agent, which contains two event handlers: usage-change-handler and usage-refresh-handler.
While the usage-change-handler is invoked on every acquisition and release of a licensed channel, the usage-refresh-handler is invoked periodically on expiration of a timeout specified by the attribute refresh-period.
The following actions can be specified for either of the two handlers.
¶ 6.1 Log Usage
The action log-usage logs the following data in the order specified.
-
The number of currently in-use channels.
-
The maximum number of channels used concurrently.
-
The total number of licensed channels.
The following is a sample log statement, indicating 0 in-use, 0 max-used and 2 total channels.
[NOTICE] AZUREBOT Usage: 0/0/2
¶ 6.2 Update Usage
The action update-usage writes the following data to a status file umsazurebot-usage.status, located by default in the directory ${UniMRCPInstallDir}/var/status.
-
The number of currently in-use channels.
-
The maximum number of channels used concurrently.
-
The total number of licensed channels.
-
The current status of the license permit.
-
The license server alarm. Set to on, if the license server is not available for more than one hour; otherwise, set to off. This parameter is maintained only if the license server is used.
The following is a sample content of the status file.
in-use channels: 0
max used channels: 0
total channels: 2
license permit: true
licserver alarm: off
¶ 6.3 Dump Channels
The action dump-channels writes the identifiers of in-use channels to a status file umsazurebot-channels.status, located by default in the directory ${UniMRCPInstallDir}/var/status.
¶ 7 Usage Examples
¶ 7.1 Speech Transcription
This examples demonstrates how to perform speech recognition by using a RECOGNIZE request.
C->S:
MRCP/2.0 336 RECOGNIZE 1
Channel-Identifier: 6e1a2e4e54ae11e7@speechrecog
Content-Id: request1@form-level
Content-Type: text/uri-list
Cancel-If-Queue: false
No-Input-Timeout: 5000
Recognition-Timeout: 10000
Start-Input-Timers: true
Confidence-Threshold: 0.87
Save-Waveform: true
Content-Length: 25
builtin:speech/transcribe
S->C:
MRCP/2.0 83 1 200 IN-PROGRESS
Channel-Identifier: 6e1a2e4e54ae11e7@speechrecog
S->C:
MRCP/2.0 115 START-OF-INPUT 1 IN-PROGRESS
Channel-Identifier: 6e1a2e4e54ae11e7@speechrecog
Input-Type: speech
S->C:
MRCP/2.0 498 RECOGNITION-COMPLETE 1 COMPLETE
Channel-Identifier: 6e1a2e4e54ae11e7@speechrecog
Completion-Cause: 000 success
Waveform-Uri: <http://localhost/utterances/utter-6e1a2e4e54ae11e7-1.wav>;size=20480;duration=1280
Content-Type: application/x-nlsml
Content-Length: 214
<?xml version="1.0"?>
<result>
<interpretation grammar="builtin:speech/transcribe" confidence="0.777">
<instance>
<object><string name="query">book a room</string>
<object name="topScoringIntent">
<string name="intent">RoomReservation.Reserve</string>
<number name="score">0.77710616600000004</number>
</object>
<array name="entities"></array>
</object>
</instance><input mode="speech">book a room</input>
</interpretation>
</result>
¶ 8 Sequence Diagram
The following sequence diagram outlines common interactions between all the main components involved in a typical recognition session performed over MRCPv1 and MRCPv2 respectively.
¶ 8.1 MRCPv1
¶ 8.2 MRCPv2
