Mod openmrcp

From FreeSWITCH Wiki

Contents 1 Introduction 2 Status 2.1 Compatibility Matrix 3 Building 4 Deploying 5 Configuration 5.1 Create and Include XML conf 5.2 Example Configuration 6 Using from FreeSWITCH 6.1 TTS 6.2 ASR 7 FAQ 7.1 If my freeswitch server is behind a NAT.. 8 Known Bugs 9 Previous Bugs 9.1 Failed to modify channel (sporadic)

Introduction

A module which allows freeswitch to interface with v1 or v2 MRCP compliant speech recognition or TTS servers. The module connects using the publicly available OpenMRCP library sponsored by Cepstral, makers of Text-to-Speech voices.

Status

The module has been released and is ready for use!

Compatibility Matrix

mod_openmrcp has been tested with the following products

• Cepstral TTS
• Voxeo

Building

• Add entry to modules.conf file

asr_tts/mod_openmrcp

• Build freeswitch with 'make install'

Deploying

• Perform steps described in Configuration section below
• Add module to modules.conf.xml
• Restart freeswitch
• Start necessary ASR/TTS MRCP servers

Configuration

Create and Include XML conf

• Create a configuration file in /usr/local/freeswitch/conf/mod_openmrcp.conf.xml using example below
• Edity freeswitch.xml to include mod_openmrcp.conf.xml

Example Configuration

<configuration name="mod_openmrcp.conf" description="mod_openmrcp configuration">
  <settings>
    <param name="asr_default_profile" value="openmrcp-v2"/>
    <param name="tts_default_profile" value="openmrcp-v2"/>
    <param name="log_level" value="0"/>
  </settings>
  <profiles>
    <profile name="openmrcp-v1" description="OpenMRCPv1 Server">
      <param name="proto_version" value="1"/>

      <param name="client_ip" value="127.0.0.1"/>
      <param name="client_port" value="8062"/>

      <param name="server_ip" value="127.0.0.1"/>
      <param name="server_port" value="1554"/>

      <param name="rtp_port_min" value="10000"/>
      <param name="rtp_port_max" value="11000"/>
    </profile>
    <profile name="openmrcp-v2" description="OpenMRCPv2 Server">
      <param name="proto_version" value="2"/>

      <param name="client_ip" value="127.0.0.1"/>
      <param name="client_port" value="8062"/>

      <param name="server_ip" value="127.0.0.1"/>
      <param name="server_port" value="8060"/>

      <param name="rtp_port_min" value="11000"/>
      <param name="rtp_port_max" value="12000"/>
    </profile>
  </profiles>
</configuration>

• asr_default_profile - what profile to use for client settings for contacting an ASR (speech recognition server). 'default' profile to use when one isn't specified.
• tts_default_profile - what profile to use for client settings for contacting a TTS (text to speech server).
• log_level - loglevel for OpenMRCP client library, valid values: 0-7 where 0 emits the least amount and 7 emits the most amount of logging.
• proto_version - whether to use MRCP v1 or v2. See OpenMRCP for more info on what this means.
• client_ip - the ip address the embedded OpenMRCP client will bind to.
• client_port - the port the embedded OpenMRCP client will bind to.
• server_ip - the ip address the embedded OpenMRCP client will connect to. There must be an MRCP compliant server running on this port. If this profile was designated as the asr_default_profile, then the MRCP server must support recognition.
• server_port - the port the embedded OpenMRCP client will connect to.

Using from FreeSWITCH

TTS

Using javascript

session.speak("openmrcp:openmrcp-v2","David","Hello from FreeSwitch"); 

• NOTE* the string after the : is the desired profile from your config.

ASR

Try changing the pizza demo to use "openmrcp" instead of "lumenvox" (no longer supported). (However, this probably won't work due to differences in grammar)

Also check out the python-based recipewizard tutorial.

FAQ

If my freeswitch server is behind a NAT..

Q: If my freeswitch server is behind a NAT, can I connect to a v2 MRCP server on the public internet? Will it use STUN?

A: By default it does not seem to use STUN, however this might be configurable.

Known Bugs

Previous Bugs

Failed to modify channel (sporadic)

Fixed in revision 465

This bug only affects MRCP v2 communication.

The bug is a sporadic failure in the client library which causes it to fail to setup a connection with the mrcp server. On the freeswitch console you will see "Modify Channel" first, then "Failed to modify channel", then finally a "Connected to MRCPv2 Server", though its not really connected.

This fix involves add a pending requests queue in the client stack.