Creating long audio files - Amazon Polly
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Creating long audio files

You can use the Amazon Polly console to create long speeches using asynchronous synthesis with the same functionality as you can use with the Amazon CLI. This is done using the Text-to-Speech tab much like any other synthesis.

Console

The other asynchronous synthesis functionality is also available via the console. The S3 synthesis tasks tab reflects the ListSpeechSynthesisTasks functionality, displaying all tasks saved to the S3 bucket and enabling you to filter them if you want. Clicking on a specific single task shows its details, reflecting GetSpeechSynthesisTask functionality.

To synthesize a large text using the Amazon Polly console

  1. Sign in to the Amazon Web Services Management Console and open the Amazon Polly console at https://console.amazonaws.cn/polly/.

  2. Choose the Text-to-Speech tab. Select Long Form as the engine if appropriate.

  3. With SSML on or off, type or paste your text into the input box.

  4. Choose the language, region, and voice for your text.

  5. Choose Save to S3.

    Note

    Both the Download and Listen options are greyed out if the text length is above the 3,000 character limit for the real-time SynthesizeSpeech operation.

  6. The console opens a form so that you can choose where to store the output file.

    1. Fill in the name of the destination Amazon S3 bucket.

    2. Optionally, fill in the prefix key of the output.

      Note

      The output S3 bucket must be writable.

    3. If you want to be notified when the synthesis task is complete, provide an optional SNS topic identifier.

      Note

      The SNS must be open for publication by the current console user to use this option. For more information, see Amazon Simple Notification Service (SNS)

    4. Choose Save to S3.

To retrieve information on your speech synthesis tasks

  1. In the console, choose the S3 Synthesis Tasks tab.

  2. The tasks are displayed in date order. To filter the tasks, by status, choose All statuses and then choose the status to use.

  3. To view the details of a specific task, choose the linked Task ID.

Amazon CLI

Amazon Polly asynchronous synthesis functionality uses three SpeechSynthesisTask APIs to work with large amounts of text:

  • StartSpeechSynthesisTask: starts a new synthesis task.

  • GetSpeechSynthesisTask: returns details about a previously submitted synthesis task.

  • ListSpeechSynthesisTasks: lists all submitted synthesis tasks.

Synthesizing large amounts of text (StartSpeechSynthesisTask)

When you want to create an audio file larger than one that you can create with the real-time SynthesizeSpeech, use the StartSpeechSynthesisTask operation. In addition to the arguments needed for the SynthesizeSpeech operation, StartSpeechSynthesisTask also requires the name of an Amazon S3 bucket. Two other optional arguments are also available: a key prefix for the output file and the ARN for an SNS Topic if you want to receive status notification about the task.

  • OutputS3BucketName: The name of the Amazon S3 bucket where the synthesis should be uploaded. This bucket should be in the same region as the Amazon Polly service. Additionally, the IAM user being used to make the call should have access to the bucket. [Required]

  • OutputS3KeyPrefix: Key prefix for the output file. Use this parameter if you want to save the output speech file in a custom directory-like key in your bucket. [Optional]

  • SnsTopicArn: The SNS topic ARN to use if you want to receive notifications about status of the task. This SNS topic should be in the same region as the Amazon Polly service. Additionally, the IAM user being used to make the call should have access to the topic. [Optional]

For example, the following example can be used to run the start-speech-synthesis-task Amazon CLI command in the US East (Ohio) region:

The following Amazon CLI example is formatted for Unix, Linux, and macOS. For Windows, replace the backslash (\) Unix continuation character at the end of each line with a caret (^) and use full quotation marks (") around the input text with single quotes (') for interior tags.

aws polly start-speech-synthesis-task \
  --region us-east-2 \
  --endpoint-url "https://polly.us-east-2.amazonaws.com/" \
  --output-format mp3 \
  --output-s3-bucket-name your-bucket-name \
  --output-s3-key-prefix optional/prefix/path/file \
  --voice-id Joanna \
  --text file://text_file.txt

This will result in a response that looks similar to this: 

"SynthesisTask": 
{
     "OutputFormat": "mp3",
     "OutputUri": "https://s3.us-east-2.amazonaws.com/your-bucket-name/optional/prefix/path/file.<task_id>.mp3",
     "TextType": "text",
     "CreationTime": [..],
     "RequestCharacters": [..],
     "TaskStatus": "scheduled",
     "TaskId": [task_id],
     "VoiceId": "Joanna"
 }

The start-speech-synthesis-task operation returns several new fields:

  • OutputUri: the location of your output speech file.

  • TaskId: a unique identifier for the speech synthesis task generated by Amazon Polly.

  • CreationTime: a timestamp for when the task was initially submitted.

  • RequestCharacters: the number of billable characters in the task.

  • TaskStatus: provides information on the status of the submitted task.

    When your task is submitted, the initial status will show scheduled. When Amazon Polly starts processing the task, the status will change to inProgress and later, to completed or failed. If the task fails, an error message will be returned when calling either the GetSpeechSynthesisTask or ListSpeechSynthesisTasks operation.

When the task is completed, the speech file is available at the location specified in OutputUri.

Retrieving information on your speech synthesis task

You can get information on a task, such as errors, status, and so on, using the GetSpeechSynthesisTask operation. To do this, you will need the task-id returned by the StartSpeechSynthesisTask.

For example, the following example can be used to run the get-speech-synthesis-task Amazon CLI command: 

aws polly get-speech-synthesis-task \
--region us-east-2 \
--endpoint-url "https:// polly.us-east-2.amazonaws.com/" \
--task-id task identifier

You can also list all speech synthesis tasks that you've run in the current region using the ListSpeechSynthesisTasks operation.

For example, the following example can be used to run the list-speech-synthesis-tasks Amazon CLI command: 

aws polly list-speech-synthesis-tasks \
--region us-east-2 \
--endpoint-url "https:// polly.us-east-2.amazonaws.com/"