FreeSWITCH interfaces with http protocol for tts services

• Supporting Resources Download

I. Self-constructed tts service simulation test environment

This section can be skipped if there is already a tts service for the http protocol.

Here is a simple tts service implementation using pytts3 in a Windows 10 environment.

The overall structure is as follows:

Compile and configure the mod_tts_commandline module.

1. Compile mod_tts_commandline module

File: freeswitch-1.10.9.-release/

Open or add the following:

asr_tts/mod_tts_commandline

Compile and install:

./ 
#CFLAGS="-O3 -fPIC" ./configure --disable-signalwire (optional)
CFLAGS="-O3 -fPIC" ./configure 
make -j
make install

The key information is described here. For more information on FreeSWITCH source code compilation, please refer to the following article:

<load module="mod_tts_commandline"/>

<configuration name="tts_commandline.conf" description="TextToSpeech Commandline configuration">
    <settings>
    <!--
    Some variables will be replaced :
    ${text}: input text (quoted)
    ${rate}: sample rate (example: 8000)
    ${voice}: voice_name passed to TTS(quoted)
    ${file}: output file (quoted, including .wav extension)

    Example commands can be found at:
    /confluence/display/FREESWITCH/mod_tts_commandline#mod_tts_commandline-Examplecommands
    -->
    <!--param name="command" value="echo ${text} | text2wave -f ${rate} > ${file}"/-->
    <param name="command" value="/bin/bash /root/test/ ${text} ${file}" />
    </settings>
</configuration>

#! /bin/bash

content=$1
file=$2
echo $content
echo $file
#wget http://192.168.137.1:8091/?text='just a test' -O /tmp/
wget http://192.168.137.1:8091/?text="$content" -O $file

<extension name="ttsTest1">
<condition field="destination_number" expression="^654321$">
  <action application="log" data="INFO dialed 654321."/>
  <action application="lua" data=""/>
</condition>
</extension>

2. Add lua script

The contents of the lua script (/usr/local/freeswitch/scripts/):

session:answer()
session:setVariable("tts_engine", "tts_commandline")
session:setVariable("tts_voice", "girl")
--session:execute("speak", "just test!")
session:execute("speak", "It's a beautiful day!")

3、Registered extensions dialing verification

Registered extension: 1001
Call number: 654321

The test results are as follows:

IV. Module code analysis

module path： freeswitch-1.10.9.-release\src\mod\asr_tts\mod_tts_commandline

Module code file: mod_tts_commandline.c

1. mod_tts_commandline_load function

module entry function, the main thing to do is to initialize the tts resource and bind the callback function.

2、tts_commandline_speech_open function
Used to generate temporary audio file names.

3. tts_commandline_speech_close function
Delete the previously generated temporary audio file.

More module function analysisAvailable from the following sources:

V. Playing tts audio to a specific channel and fire playback completion event

If you want to build a higher tier application (e.g. a robotics service), you need to provide the ability to play tts sound to a specific channel, and generate an event to notify the caller when the playback is complete, so here's a simple example.

Script name: tts_to_channel.lua

The contents of the document can be obtained from the following sources:

tts_to_channel.lua {channel_uuid} {text}

/event plain CUSTOM MYTTS_TTS_DONE

VI. Downloading of resources

This article covers the source code and related documentation, which can be obtained from the following sources: