There are more AWS SDK examples available in the [AWS Doc SDK Examples](https://github.com/awsdocs/aws-doc-sdk-examples) GitHub repo.

# Basic examples for Amazon Transcribe Streaming using AWS SDKs
<a name="transcribe-streaming_code_examples_basics"></a>

The following code examples show how to use the basics of Amazon Transcribe Streaming with AWS SDKs. 

**Contents**
+ [Actions](transcribe-streaming_code_examples_actions.md)
  + [`StartMedicalStreamTranscription`](transcribe-streaming_example_transcribe-streaming_StartMedicalStreamTranscription_section.md)
  + [`StartStreamTranscription`](transcribe-streaming_example_transcribe-streaming_StartStreamTranscription_section.md)

# Actions for Amazon Transcribe Streaming using AWS SDKs
<a name="transcribe-streaming_code_examples_actions"></a>

The following code examples demonstrate how to perform individual Amazon Transcribe Streaming actions with AWS SDKs. Each example includes a link to GitHub, where you can find instructions for setting up and running the code. 

These excerpts call the Amazon Transcribe Streaming API and are code excerpts from larger programs that must be run in context. You can see actions in context in [Scenarios for Amazon Transcribe Streaming using AWS SDKs](transcribe-streaming_code_examples_scenarios.md). 

 The following examples include only the most commonly used actions. For a complete list, see the [Amazon Transcribe Streaming API Reference](https://docs.aws.amazon.com/transcribe/latest/APIReference/Welcome.html). 

**Topics**
+ [`StartMedicalStreamTranscription`](transcribe-streaming_example_transcribe-streaming_StartMedicalStreamTranscription_section.md)
+ [`StartStreamTranscription`](transcribe-streaming_example_transcribe-streaming_StartStreamTranscription_section.md)

# Use `StartMedicalStreamTranscription` with an AWS SDK
<a name="transcribe-streaming_example_transcribe-streaming_StartMedicalStreamTranscription_section"></a>

The following code example shows how to use `StartMedicalStreamTranscription`.

------
#### [ Java ]

**SDK for Java 2.x**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/example_code/transcribe-streaming#code-examples). 

```
/*
To run this AWS code example, ensure that you have set up your development
 environment, including your AWS credentials.

 For information, see this documentation topic:

 https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html

This code demonstrates the process of starting a medical transcription job using the AWS Transcribe
Streaming service, including setting up the audio input stream, configuring the transcription request,
and handling the transcription response.
 */

public class TranscribeMedicalStreamingDemoApp {
    private static TranscribeStreamingAsyncClient client;

    public static void main(String args[])
        throws ExecutionException, InterruptedException, LineUnavailableException {

        client = TranscribeStreamingAsyncClient.builder()
            .credentialsProvider(getCredentials())
            .build();

        CompletableFuture<Void> result = client.startMedicalStreamTranscription(getMedicalRequest(16_000),
            new AudioStreamPublisher(getStreamFromMic()),
            getMedicalResponseHandler());

        result.get();
        client.close();
    }

    private static InputStream getStreamFromMic() throws LineUnavailableException {

        // Signed PCM AudioFormat with 16kHz, 16 bit sample size, mono
        int sampleRate = 16000;
        AudioFormat format = new AudioFormat(sampleRate, 16, 1, true, false);
        DataLine.Info info = new DataLine.Info(TargetDataLine.class, format);

        if (!AudioSystem.isLineSupported(info)) {
            System.out.println("Line not supported");
            throw new LineUnavailableException("The audio system microphone line is not supported.");
        }

        TargetDataLine line = (TargetDataLine) AudioSystem.getLine(info);
        line.open(format);
        line.start();

        InputStream audioStream = new AudioInputStream(line);
        return audioStream;
    }

    private static AwsCredentialsProvider getCredentials() {
        return DefaultCredentialsProvider.create();
    }

    private static StartMedicalStreamTranscriptionRequest getMedicalRequest(Integer mediaSampleRateHertz) {
        return StartMedicalStreamTranscriptionRequest.builder()
            .languageCode(LanguageCode.EN_US.toString()) // For medical transcription, EN_US is typically used.
            .mediaEncoding(MediaEncoding.PCM)
            .mediaSampleRateHertz(mediaSampleRateHertz)
            .specialty(Specialty.PRIMARYCARE) // Specify the medical specialty.
            .type(Type.CONVERSATION) // Set the type as CONVERSATION or DICTATION.
            .build();
    }

    private static StartMedicalStreamTranscriptionResponseHandler getMedicalResponseHandler() {
        return StartMedicalStreamTranscriptionResponseHandler.builder()
            .onResponse(r -> {
                System.out.println("Received Initial response");
            })
            .onError(e -> {
                System.out.println(e.getMessage());
                StringWriter sw = new StringWriter();
                e.printStackTrace(new PrintWriter(sw));
                System.out.println("Error Occurred: " + sw.toString());
            })
            .onComplete(() -> {
                System.out.println("=== All records streamed successfully ===");
            })
            .subscriber(event -> {
                List<MedicalResult> results = ((MedicalTranscriptEvent) event).transcript().results();
                if (results.size() > 0) {
                    if (!results.get(0).alternatives().get(0).transcript().isEmpty()) {
                        System.out.println(results.get(0).alternatives().get(0).transcript());
                    }
                }
            })
            .build();
    }

    private static class AudioStreamPublisher implements Publisher<AudioStream> {
        private final InputStream inputStream;
        private static Subscription currentSubscription;

        private AudioStreamPublisher(InputStream inputStream) {
            this.inputStream = inputStream;
        }

        @Override
        public void subscribe(Subscriber<? super AudioStream> s) {

            if (this.currentSubscription == null) {
                this.currentSubscription = new SubscriptionImpl(s, inputStream);
            } else {
                this.currentSubscription.cancel();
                this.currentSubscription = new SubscriptionImpl(s, inputStream);
            }
            s.onSubscribe(currentSubscription);
        }
    }

    public static class SubscriptionImpl implements Subscription {
        private static final int CHUNK_SIZE_IN_BYTES = 1024 * 1;
        private final Subscriber<? super AudioStream> subscriber;
        private final InputStream inputStream;
        private ExecutorService executor = Executors.newFixedThreadPool(1);
        private AtomicLong demand = new AtomicLong(0);

        SubscriptionImpl(Subscriber<? super AudioStream> s, InputStream inputStream) {
            this.subscriber = s;
            this.inputStream = inputStream;
        }

        @Override
        public void request(long n) {
            if (n <= 0) {
                subscriber.onError(new IllegalArgumentException("Demand must be positive"));
            }

            demand.getAndAdd(n);
            executor.submit(() -> {
                try {
                    do {
                        ByteBuffer audioBuffer = getNextEvent();
                        if (audioBuffer.remaining() > 0) {
                            AudioEvent audioEvent = audioEventFromBuffer(audioBuffer);
                            subscriber.onNext(audioEvent);
                        } else {
                            subscriber.onComplete();
                            break;
                        }
                    } while (demand.decrementAndGet() > 0);
                } catch (Exception e) {
                    subscriber.onError(e);
                }
            });
        }

        @Override
        public void cancel() {
            executor.shutdown();
        }

        private ByteBuffer getNextEvent() {
            ByteBuffer audioBuffer = null;
            byte[] audioBytes = new byte[CHUNK_SIZE_IN_BYTES];

            int len = 0;
            try {
                len = inputStream.read(audioBytes);

                if (len <= 0) {
                    audioBuffer = ByteBuffer.allocate(0);
                } else {
                    audioBuffer = ByteBuffer.wrap(audioBytes, 0, len);
                }
            } catch (IOException e) {
                throw new UncheckedIOException(e);
            }

            return audioBuffer;
        }

        private AudioEvent audioEventFromBuffer(ByteBuffer bb) {
            return AudioEvent.builder()
                .audioChunk(SdkBytes.fromByteBuffer(bb))
                .build();
        }
    }
}
```
+  For API details, see [StartMedicalStreamTranscription](https://docs.aws.amazon.com/goto/SdkForJavaV2/transcribe-streaming-2017-10-26/StartMedicalStreamTranscription) in *AWS SDK for Java 2.x API Reference*. 

------

# Use `StartStreamTranscription` with an AWS SDK
<a name="transcribe-streaming_example_transcribe-streaming_StartStreamTranscription_section"></a>

The following code examples show how to use `StartStreamTranscription`.

Action examples are code excerpts from larger programs and must be run in context. You can see this action in context in the following code examples: 
+  [Transcribe an audio file](transcribe-streaming_example_transcribe-streaming_Scenario_StreamEvents_File_section.md) 
+  [Transcribe audio from a microphone](transcribe-streaming_example_transcribe-streaming_Scenario_StreamEvents_Microphone_section.md) 

------
#### [ C\$1\$1 ]

**SDK for C\$1\$1**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/cpp/example_code/transcribe-streaming#code-examples). 

```
int main() {
    Aws::SDKOptions options;

    Aws::InitAPI(options);
    {
        //TODO(User): Set to the region of your AWS account.
        const Aws::String region = Aws::Region::US_WEST_2;

        //Load a profile that has been granted AmazonTranscribeFullAccess AWS managed permission policy.
        Aws::Client::ClientConfiguration config;
#ifdef _WIN32
        // ATTENTION: On Windows with the AWS C++ SDK, this example only runs if the SDK is built
        // with the curl library. 
        // For more information, see the accompanying ReadMe.
        // For more information, see "Building the SDK for Windows with curl".
        // https://docs.aws.amazon.com/sdk-for-cpp/v1/developer-guide/setup-windows.html
        //TODO(User): Update to the location of your .crt file.
        config.caFile = "C:/curl/bin/curl-ca-bundle.crt";
#endif
        config.region = region;

        TranscribeStreamingServiceClient client(config);
        StartStreamTranscriptionHandler handler;
        handler.SetOnErrorCallback(
                [](const Aws::Client::AWSError<TranscribeStreamingServiceErrors> &error) {
                        std::cerr << "ERROR: " + error.GetMessage() << std::endl;
                });
        //SetTranscriptEventCallback called for every 'chunk' of file transcripted.
        // Partial results are returned in real time.
        handler.SetTranscriptEventCallback([](const TranscriptEvent &ev) {
                for (auto &&r: ev.GetTranscript().GetResults()) {
                    if (r.GetIsPartial()) {
                        std::cout << "[partial] ";
                    }
                    else {
                        std::cout << "[Final] ";
                    }
                    for (auto &&alt: r.GetAlternatives()) {
                        std::cout << alt.GetTranscript() << std::endl;
                    }
                }
        });

        StartStreamTranscriptionRequest request;
        request.SetMediaSampleRateHertz(SAMPLE_RATE);
        request.SetLanguageCode(LanguageCode::en_US);
        request.SetMediaEncoding(
                MediaEncoding::pcm); // wav and aiff files are PCM formats.
        request.SetEventStreamHandler(handler);

        auto OnStreamReady = [](AudioStream &stream) {
                Aws::FStream file(FILE_NAME, std::ios_base::in | std::ios_base::binary);
                if (!file.is_open()) {
                    std::cerr << "Failed to open " << FILE_NAME << '\n';
                }
                std::array<char, BUFFER_SIZE> buf;
                int i = 0;
                while (file) {
                    file.read(&buf[0], buf.size());

                    if (!file)
                        std::cout << "File: only " << file.gcount() << " could be read"
                                  << std::endl;

                    Aws::Vector<unsigned char> bits{buf.begin(), buf.end()};
                    AudioEvent event(std::move(bits));
                    if (!stream) {
                        std::cerr << "Failed to create a stream" << std::endl;
                        break;
                    }
                    //The std::basic_istream::gcount() is used to count the characters in the given string. It returns
                    //the number of characters extracted by the last read() operation.
                    if (file.gcount() > 0) {
                        if (!stream.WriteAudioEvent(event)) {
                            std::cerr << "Failed to write an audio event" << std::endl;
                            break;
                        }
                    }
                    else {
                        break;
                    }
                    std::this_thread::sleep_for(std::chrono::milliseconds(
                            25)); // Slow down because we are streaming from a file.
                }
                if (!stream.WriteAudioEvent(
                        AudioEvent())) {
                    // Per the spec, we have to send an empty event (an event without a payload) at the end.
                    std::cerr << "Failed to send an empty frame" << std::endl;
                }
                else {
                    std::cout << "Successfully sent the empty frame" << std::endl;
                }
                stream.flush();
                stream.Close();
        };

        Aws::Utils::Threading::Semaphore signaling(0 /*initialCount*/, 1 /*maxCount*/);
        auto OnResponseCallback = [&signaling](
                const TranscribeStreamingServiceClient * /*unused*/,
                const Model::StartStreamTranscriptionRequest & /*unused*/,
                const Model::StartStreamTranscriptionOutcome &outcome,
                const std::shared_ptr<const Aws::Client::AsyncCallerContext> & /*unused*/) {

                if (!outcome.IsSuccess()) {
                    std::cerr << "Transcribe streaming error "
                              << outcome.GetError().GetMessage() << std::endl;
                }

                signaling.Release();
        };

        std::cout << "Starting..." << std::endl;
        client.StartStreamTranscriptionAsync(request, OnStreamReady, OnResponseCallback,
                                             nullptr /*context*/);
        signaling.WaitOne(); // Prevent the application from exiting until we're done.
        std::cout << "Done" << std::endl;
    }

    Aws::ShutdownAPI(options);

    return 0;
}
```
+  For API details, see [StartStreamTranscription](https://docs.aws.amazon.com/goto/SdkForCpp/transcribe-streaming-2017-10-26/StartStreamTranscription) in *AWS SDK for C\$1\$1 API Reference*. 

------
#### [ Java ]

**SDK for Java 2.x**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/example_code/transcribe-streaming#code-examples). 

```
public class TranscribeStreamingDemoApp {
    private static final Region REGION = Region.US_EAST_1;
    private static TranscribeStreamingAsyncClient client;

    public static void main(String[] args)
            throws URISyntaxException, ExecutionException, InterruptedException, LineUnavailableException {

        client = TranscribeStreamingAsyncClient.builder()
                .credentialsProvider(getCredentials())
                .region(REGION)
                .build();

        CompletableFuture<Void> result = client.startStreamTranscription(getRequest(16_000),
                new AudioStreamPublisher(getStreamFromMic()),
                getResponseHandler());

        result.get();
        client.close();
    }

    private static InputStream getStreamFromMic() throws LineUnavailableException {

        // Signed PCM AudioFormat with 16kHz, 16 bit sample size, mono
        int sampleRate = 16000;
        AudioFormat format = new AudioFormat(sampleRate, 16, 1, true, false);
        DataLine.Info info = new DataLine.Info(TargetDataLine.class, format);

        if (!AudioSystem.isLineSupported(info)) {
            System.out.println("Line not supported");
            System.exit(0);
        }

        TargetDataLine line = (TargetDataLine) AudioSystem.getLine(info);
        line.open(format);
        line.start();

        InputStream audioStream = new AudioInputStream(line);
        return audioStream;
    }

    private static AwsCredentialsProvider getCredentials() {
        return DefaultCredentialsProvider.create();
    }

    private static StartStreamTranscriptionRequest getRequest(Integer mediaSampleRateHertz) {
        return StartStreamTranscriptionRequest.builder()
                .languageCode(LanguageCode.EN_US.toString())
                .mediaEncoding(MediaEncoding.PCM)
                .mediaSampleRateHertz(mediaSampleRateHertz)
                .build();
    }

    private static StartStreamTranscriptionResponseHandler getResponseHandler() {
        return StartStreamTranscriptionResponseHandler.builder()
                .onResponse(r -> {
                    System.out.println("Received Initial response");
                })
                .onError(e -> {
                    System.out.println(e.getMessage());
                    StringWriter sw = new StringWriter();
                    e.printStackTrace(new PrintWriter(sw));
                    System.out.println("Error Occurred: " + sw);
                })
                .onComplete(() -> {
                    System.out.println("=== All records stream successfully ===");
                })
                .subscriber(event -> {
                    List<Result> results = ((TranscriptEvent) event).transcript().results();
                    if (results.size() > 0) {
                        if (!results.get(0).alternatives().get(0).transcript().isEmpty()) {
                            System.out.println(results.get(0).alternatives().get(0).transcript());
                        }
                    }
                })
                .build();
    }

    
    private static class AudioStreamPublisher implements Publisher<AudioStream> {
        private static Subscription currentSubscription;
        private final InputStream inputStream;

        private AudioStreamPublisher(InputStream inputStream) {
            this.inputStream = inputStream;
        }

        @Override
        public void subscribe(Subscriber<? super AudioStream> s) {

            if (currentSubscription == null) {
                currentSubscription = new SubscriptionImpl(s, inputStream);
            } else {
                currentSubscription.cancel();
                currentSubscription = new SubscriptionImpl(s, inputStream);
            }
            s.onSubscribe(currentSubscription);
        }
    }

    public static class SubscriptionImpl implements Subscription {
        private static final int CHUNK_SIZE_IN_BYTES = 1024;
        private final Subscriber<? super AudioStream> subscriber;
        private final InputStream inputStream;
        private final ExecutorService executor = Executors.newFixedThreadPool(1);
        private final AtomicLong demand = new AtomicLong(0);

        SubscriptionImpl(Subscriber<? super AudioStream> s, InputStream inputStream) {
            this.subscriber = s;
            this.inputStream = inputStream;
        }

        @Override
        public void request(long n) {
            if (n <= 0) {
                subscriber.onError(new IllegalArgumentException("Demand must be positive"));
            }

            demand.getAndAdd(n);

            executor.submit(() -> {
                try {
                    do {
                        ByteBuffer audioBuffer = getNextEvent();
                        if (audioBuffer.remaining() > 0) {
                            AudioEvent audioEvent = audioEventFromBuffer(audioBuffer);
                            subscriber.onNext(audioEvent);
                        } else {
                            subscriber.onComplete();
                            break;
                        }
                    } while (demand.decrementAndGet() > 0);
                } catch (Exception e) {
                    subscriber.onError(e);
                }
            });
        }

        @Override
        public void cancel() {
            executor.shutdown();
        }

        private ByteBuffer getNextEvent() {
            ByteBuffer audioBuffer = null;
            byte[] audioBytes = new byte[CHUNK_SIZE_IN_BYTES];

            int len = 0;
            try {
                len = inputStream.read(audioBytes);

                if (len <= 0) {
                    audioBuffer = ByteBuffer.allocate(0);
                } else {
                    audioBuffer = ByteBuffer.wrap(audioBytes, 0, len);
                }
            } catch (IOException e) {
                throw new UncheckedIOException(e);
            }

            return audioBuffer;
        }

        private AudioEvent audioEventFromBuffer(ByteBuffer bb) {
            return AudioEvent.builder()
                    .audioChunk(SdkBytes.fromByteBuffer(bb))
                    .build();
        }
    }
}
```
+  For API details, see [StartStreamTranscription](https://docs.aws.amazon.com/goto/SdkForJavaV2/transcribe-streaming-2017-10-26/StartStreamTranscription) in *AWS SDK for Java 2.x API Reference*. 

------
#### [ Swift ]

**SDK for Swift**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/swift/example_code/transcribe-streaming#code-examples). 

```
        let client = TranscribeStreamingClient(
            config: try await TranscribeStreamingClient.TranscribeStreamingClientConfiguration(
                region: region
            )
        )

        // Start the transcription running on the audio stream.

        let output = try await client.startStreamTranscription(
            input: StartStreamTranscriptionInput(
                audioStream: try await createAudioStream(),
                languageCode: TranscribeStreamingClientTypes.LanguageCode(rawValue: lang),
                mediaEncoding: encoding,
                mediaSampleRateHertz: sampleRate
            )
        )
```
+  For API details, see [StartStreamTranscription](https://sdk.amazonaws.com/swift/api/awstranscribestreaming/latest/documentation/awstranscribestreaming/transcribestreamingclient/startstreamtranscription(input:)) in *AWS SDK for Swift API reference*. 

------