Getting started

We only support the MRCP recognizer service as a gateway to our ASR for users who need to leverage their legacy MRCPv2 tools.
Please keep in mind that this gateway only implements a sub-set of the MRCPv2 specifications that are compatible with our native ASR API: this isn't a port of our ASR engine to cover all of MRCPv2, in any way.

Input protocol

Commands

• SET_PARAMS
• GET_PARAMS
• DEFINE-GRAMMAR (Only builtin grammars are supported, not custom grammars sent as SRGS XML)
• RECOGNIZE (multiple active grammars supported without weights)
• STOP
• START_INPUT_TIMERS

Resource headers

• Confidence-Threshold
• No-Input-Timeout
• Recognition-Timeout
• Start-Input-Timers
• Speech-Complete-Timeout
• Speech-Incomplete-Timeout
• Content-Type
• Content-ID
• Sensitivity-Level
• Speech-Language (2-letter ISO codes, only "fr" and "en" for the moment)
• Hotword-Min-Duration (RECOGNIZE method only)
• Hotword-Max-Duration (RECOGNIZE method only)
• Recognition-Mode (RECOGNIZE method only)

Output protocol

Output sample

MRCP/2.0 544 RECOGNITION-COMPLETE 2 COMPLETE
Channel-Identifier: 39ac4ea9750a4790@speechrecog
Completion-Cause: 000 success
Completion-Reason: success
Content-Type: application/x-nlsml
Content-Length: 331
<?xml version="1.0" encoding="UTF-8"?>
<result>
  <interpretation grammar="session:demo-grammar-0" confidence="1.00">
    <instance>je veux changer mon billet</instance>
    <input mode="speech" timestamp-start="2020-12-22T11:11:45.620+01:00" timestamp-end="2020-12-22T11:11:47.060+01:00" confidence="1.00">je veux changer mon billet</input>
  </interpretation>
</result>

Events

• START-OF-INPUT
• RECOGNITION-COMPLETE

Headers & statuses

• Completion-Cause:

  • success
  • no-input-timeout
  • partial-match
  • no-match-maxtime
  • no-match
  • success-maxtime,
  • hotword-maxtime,
  • partial-match-maxtime

• Completion-Reason

For GET-PARAMS replies:

• Confidence-Threshold
• No-Input-Timeout
• Recognition-Timeout
• Start-Input-Timers
• Speech-Complete-Timeout
• Speech-Incomplete-Timeout
• Sensitivity-Level
• Speech-Language

For STOP replies:

• Active-Request-Id-List