Powered by Universal Speech Solutions LLC


Watson SR Plugin 1.3.0 Released

IBM Watson Speech Recognition (SR) Plugin 1.3.0 to the UniMRCP Server (UMS) has been released.

The plugin is based on the following components:

  • UniMRCP Server 1.5.0
  • IBM Watson Speech to Text API v1
  • Libevent 2.1.8
  • Rapidjson 1.1.0

The binaries are currently available for the following Linux distributions:

  • Red Hat / CentOS 7
  • Ubuntu 16.04 LTS

This release addresses broken access token retrieval routine. The release also allows for new alternate ways of specifying recognition language and referencing speech context.

Everyone MUST upgrade in order to be able to retrieve an access token. Otherwise, authentication results in 405 error if a former version of the plugin is used.

The detailed list of changes introduced in this release follows.
New Features
  • Implemented an alternate way of referencing built-in grammars via 'special' ruleref in SRGS XML grammars. See Section 5.1 in the Usage Guide.
  • Added support for 'xml:lang' attribute optionally specified in SRGS XML grammars. This method has the highest precedence in selection of recognition language. The language can be otherwise specified either by the global configuration parameter or the header field 'Speech-Language'. See Section 4.2 in the Usage Guide.
  • Added a new attribute 'language' to individual speech contexts, which allows to define speech contexts for various languages regardless of the global configuration parameter.
Fixed Problems
  • Using HTTP GET instead of HTTP POST to retrieve an access token. Although both methods were apparently accepted by IBM Watson in the past, only HTTP GET has always been documented and is currently functional.
  • If retrieval of an access token fails, reattempt the procedure in 60 seconds. Otherwise, an intermittent error in network could result in an recoverable error.
  • Speech input is considered complete only when an interim result uniquely matches one of the phrases in the used speech context.
  • All the internal common class names are declared under a unique namespace not to cause a conflict with other speech recognition plugins being loaded in to the same instance of UniMRCP server.
  • In case of DTMF input, allow both 'maxlength' and 'term char' be specified at the same time. Before, 'malxength' was not observed, if 'term char' was specified.
Configuration Parameters
  • Added a new attribute 'language' to individual speech contexts.
  • Fixed the digit format output in a log statement 'Detected Start of Event'.
  • Updated the Usage Guide to reflect the changes introduced in this release.

Visit the Watson SR plugin page for more information.


Thank you for using UniMRCP.

Arsen Chaloyan
Author of UniMRCP

Announcement Group

Subscribe to the Announcements Group if you prefer to receive news and press releases only. Please note that announcements are normally posted to the Discussion Group as well.