Esempio per Android

Nel seguente esempio viene utilizzato l'SDK di Android per consentire a Amazon Polly di leggere il testo specificato utilizzando una voce selezionata da un elenco di voci.

Il codice mostrato di seguito copre i principali processi, ma non gestisce gli errori. Per il codice completo, consulta AWS Mobile SDK for Android Amazon Polly demo.

Inizializzazione

// Cognito pool ID. Pool needs to be unauthenticated pool with
// Amazon Polly permissions.
String COGNITO_POOL_ID = "YourCognitoIdentityPoolId";

// Region of Amazon Polly.
Regions MY_REGION = Regions.US_EAST_1;
 
// Initialize the Amazon Cognito credentials provider.
CognitoCachingCredentialsProvider credentialsProvider = new CognitoCachingCredentialsProvider(
        getApplicationContext(),
        COGNITO_POOL_ID,
        MY_REGION
);

// Create a client that supports generation of presigned URLs.
AmazonPollyPresigningClient client = new AmazonPollyPresigningClient(credentialsProvider);

Visualizza elenco di voci disponibili

// Create describe voices request.
DescribeVoicesRequest describeVoicesRequest = new DescribeVoicesRequest();

// Synchronously ask Amazon Polly to describe available TTS voices.
DescribeVoicesResult describeVoicesResult = client.describeVoices(describeVoicesRequest);
List<Voice> voices = describeVoicesResult.getVoices();

Visualizzazione dell'URL per lo streaming audio

// Create speech synthesis request.
SynthesizeSpeechPresignRequest synthesizeSpeechPresignRequest =
        new SynthesizeSpeechPresignRequest()
        // Set the text to synthesize.
        .withText("Hello world!")
        // Select voice for synthesis.
        .withVoiceId(voices.get(0).getId()) // "Joanna"
        // Set format to MP3.
        .withOutputFormat(OutputFormat.Mp3);

// Get the presigned URL for synthesized speech audio stream.
URL presignedSynthesizeSpeechUrl =
        client.getPresignedSynthesizeSpeechUrl(synthesizeSpeechPresignRequest);

Riproduzione dell'audio sintetizzato

// Use MediaPlayer: https://developer.android.com/guide/topics/media/mediaplayer.html

// Create a media player to play the synthesized audio stream.
MediaPlayer mediaPlayer = new MediaPlayer();
mediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);

try {
    // Set media player's data source to previously obtained URL.
    mediaPlayer.setDataSource(presignedSynthesizeSpeechUrl.toString());
} catch (IOException e) {
    Log.e(TAG, "Unable to set data source for the media player! " + e.getMessage());
}

// Prepare the MediaPlayer asynchronously (since the data source is a network stream).
mediaPlayer.prepareAsync();

// Set the callback to start the MediaPlayer when it's prepared.
mediaPlayer.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {
    @Override
    public void onPrepared(MediaPlayer mp) {
        mp.start();
    }
});

// Set the callback to release the MediaPlayer after playback is completed.
mediaPlayer.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
    @Override
    public void onCompletion(MediaPlayer mp) {
	mp.release();
    }
});