Month: October 2018

I wanted to try my hand at using the AWS Polly text-to-speech service.  Polly offers several different voices and supports multiple languages, most of which sound pretty good, especially if you use SSML when passing text.  SSML is where the character of the speech (rate, tone, pitch, etc) come into play.  See here for more detail.

What I’ve done is created a script to interact with the AWS Polly API using PHP and store the output into an S3 bucket.  Click here to try it out.

Step 1: Creating the IAM User

This has been outlined in many prior posts so I won’t go into detail.  We’ll be using the AmazonS3FullAccess and AmazonPollyFullAccess permission policies (screenshot of my user summary here).  If you don’t plan on saving the results to S3, you don’t need the S3 policy attached (obviously).

Step 2:  Converting our text to speech

<?php
require '/home/bitnami/vendor/autoload.php'; 

//Prep the Polly client and plug in our IAM credentials
use Aws\Polly\PollyClient;
$clientPolly = new PollyClient([
'version' => 'latest',
'region' => 'us-west-2', //I have all of my AWS stuff in USW2 but it's merely preference given my location.
'credentials' => [
  'key' => '', //IAM user key
  'secret' => '', //IAM user secret
 ]]);

//Configure our inputs and desired output details
$resultPolly = $clientPolly->synthesizeSpeech([
'OutputFormat' => 'mp3',
'Text' => "<speak>This is my example.</speak>",
'TextType' => 'ssml',
'VoiceId' => 'Joey', //A list of voices is available here: https://docs.aws.amazon.com/polly/latest/dg/voicelist.html
]);

//Get our results
$resultPollyData = $resultPolly->get('AudioStream')->getContents();

?>

Step 3: Saving the MP3 file to S3

<?php
//Set timezone to use in the file name
date_default_timezone_set('America/Los_Angeles');

//Prep S3 client and plug in the IAM credentials
$clientS3 = new Aws\S3\S3Client([
'version' => 'latest',
'region' => 'us-west-2', //Region of your S3 bucket
'credentials' => [
  'key' => '', //Same IAM user as above
  'secret' => '',  //Same as above
 ]]);

//Put the Polly MP3 file to S3
$resultS3 = $clientS3->putObject([
  'Key'         => date("Y-m-d_H:i:s").'.mp3',
  'ACL'         => 'public-read',
  'Body'        => $resultPollyData,
  'Bucket'      => 'fkpolly',
  'ContentType' => 'audio/mpeg',
  'SampleRate'  => '22050'
]);

//Return a link to the file
echo "<a href=\"".$resultS3['ObjectURL']."\">Listen</a>";
?>

Try It Out

I’ve saved my example for ongoing tinkering.  Click here to try it out.