The STOP method from the client to the server tells the resource to stop speaking if it is speaking something.
The STOP request can be sent with an active-request-id-list header field to stop the zero or more specific SPEAK requests that may be in queue and return a response code of 200(Success). If no active-request-id-list header field is sent in the STOP request, it will terminate all outstanding SPEAK requests.
If a STOP request successfully terminated one or more PENDING or IN-PROGRESS SPEAK requests, then the response message body contains an active-request-id-list header field listing the SPEAK request-ids that were terminated. Otherwise, there will be no active-request-id-list header field in the response. No SPEAK-COMPLETE events will be sent for these terminated requests.
If a SPEAK request that was IN-PROGRESS and speaking was stopped, the next pending SPEAK request, if any, would become IN-PROGRESS and move to the speaking state.
MRCPV1 STOP Example:
C->S: SPEAK 543258 MRCP/1.0
Content-Type:application/synthesis+ssml
Content-Length:104
<?xml version="1.0"?>
<speak>
<paragraph>
<sentence>You have 4 new messages.</sentence>
<sentence>The first is from <say-as
type="name">Stephanie Williams</say-as>
and arrived at <break/>
<say-as type="time">3:45pm</say-as>.</sentence>
<sentence>The subject is <prosody
rate="0.8">ski trip</prosody></sentence>
</paragraph>
</speak>
S->C: MRCP/1.0 543258 200 IN-PROGRESS
C->S: STOP 543259 200 MRCP/1.0
S->C: MRCP/1.0 543259 200 COMPLETE
Active-Request-Id-List:543258
MRCPV2 STOP Example:
C->S: MRCP/2.0 ... SPEAK 543258
Channel-Identifier:32AECB23433802@speechsynth
Content-Type:application/ssml+xml
Content-Length:...
<?xml version="1.0"?>
<speak version="1.0"
xmlns="http://www.w3.org/2001/10/synthesis"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.w3.org/2001/10/synthesis
http://www.w3.org/TR/speech-synthesis/synthesis.xsd"
xml:lang="en-US">
<p>
<s>You have 4 new messages.</s>
<s>The first is from Stephanie Williams and arrived at
<break/>
<say-as interpret-as="vxml:time">0342p</say-as>.</s>
<s>The subject is
<prosody rate="0.8">ski trip</prosody></s>
</p>
</speak>
S->C: MRCP/2.0 ... 543258 200 IN-PROGRESS
Channel-Identifier:32AECB23433802@speechsynth
Speech-Marker:timestamp=857206027059
C->S: MRCP/2.0 ... STOP 543259
Channel-Identifier:32AECB23433802@speechsynth
S->C: MRCP/2.0 ... 543259 200 COMPLETE
Channel-Identifier:32AECB23433802@speechsynth
Active-Request-Id-List:543258
Speech-Marker:timestamp=857206039059
