Transcribing with the AWS SDKs - Amazon Transcribe

Transcribing with the AWS SDKs

You can use SDKs for both batch and streaming transcriptions.

To get started with batch transcriptions, refer to Batch transcriptions. Note that prior to starting a batch transcription, you must first upload your media file into an Amazon S3 bucket.

To get started with streaming transcriptions, refer to Streaming transcriptions. For streaming transcriptions, you can transcribe a streamed media file or a live media stream. Note that streaming transcriptions are not supported with all AWS SDKs.

For a list of the programming languages you can use with Amazon Transcribe, see Supported programming languages. To view supported media formats and other media requirements and constraints, see Data input and output.

Tip

For additional examples using the AWS SDKs, including feature-specific, scenario, and cross-service examples, refer to the Code examples for Amazon Transcribe using AWS SDKs chapter.

You can also find code samples in the AWS Samples repository on GitHub.

You can create batch transcriptions using the URI of a media file located in an Amazon S3 bucket. If you're unsure how to create an Amazon S3 bucket or upload your file, refer to Create your first S3 bucket and Upload an object to your bucket.

Java
import software.amazon.awssdk.auth.credentials.AwsCredentialsProvider; import software.amazon.awssdk.auth.credentials.DefaultCredentialsProvider; import software.amazon.awssdk.regions.Region; import software.amazon.awssdk.services.transcribe.TranscribeClient; import software.amazon.awssdk.services.transcribe.model.*; import software.amazon.awssdk.services.transcribestreaming.model.LanguageCode; public class TranscribeDemoApp { private static final Region REGION = Region.US_WEST_2; private static TranscribeClient client; public static void main(String args[]) { client = TranscribeClient.builder() .credentialsProvider(getCredentials()) .region(REGION) .build(); String transcriptionJobName = "my-first-transcription-job"; String mediaType = "flac"; // can be other types Media myMedia = Media.builder() .mediaFileUri("s3://DOC-EXAMPLE-BUCKET/my-input-files/my-media-file.flac") .build(); String outputS3BucketName = "s3://DOC-EXAMPLE-BUCKET"; // Create the transcription job request StartTranscriptionJobRequest request = StartTranscriptionJobRequest.builder() .transcriptionJobName(transcriptionJobName) .languageCode(LanguageCode.EN_US.toString()) .mediaSampleRateHertz(16000) .mediaFormat(mediaType) .media(myMedia) .outputBucketName(outputS3BucketName) .build(); // send the request to start the transcription job StartTranscriptionJobResponse startJobResponse = client.startTranscriptionJob(request); System.out.println("Created the transcription job"); System.out.println(startJobResponse.transcriptionJob()); // Create the get job request GetTranscriptionJobRequest getJobRequest = GetTranscriptionJobRequest.builder() .transcriptionJobName(transcriptionJobName) .build(); // send the request to get the transcription job including the job status GetTranscriptionJobResponse getJobResponse = client.getTranscriptionJob(getJobRequest); System.out.println("Get the transcription job request"); System.out.println(getJobResponse.transcriptionJob()); } private static AwsCredentialsProvider getCredentials() { return DefaultCredentialsProvider.create(); } }
JavaScript
const { TranscribeClient, StartTranscriptionJobCommand } = require("@aws-sdk/client-transcribe"); // CommonJS import const region = "us-west-2"; const credentials = { "accessKeyId": "", "secretAccessKey": "", }; const input = { TranscriptionJobName: "my-first-transcription-job", LanguageCode: "en-US", Media: { MediaFileUri: "s3://DOC-EXAMPLE-BUCKET/my-input-files/my-media-file.flac" }, OutputBucketName: "DOC-EXAMPLE-BUCKET", }; async function startTranscriptionRequest() { const transcribeConfig = { region, credentials }; const transcribeClient = new TranscribeClient(transcribeConfig); const transcribeCommand = new StartTranscriptionJobCommand(input); try { const transcribeResponse = await transcribeClient.send(transcribeCommand); console.log("Transcription job created, the details:"); console.log(transcribeResponse.TranscriptionJob); } catch(err) { console.log(err); } } startTranscriptionRequest();
Python
import time import boto3 def transcribe_file(job_name, file_uri, transcribe_client): transcribe_client.start_transcription_job( TranscriptionJobName = job_name, Media = { 'MediaFileUri': file_uri }, MediaFormat = 'flac', LanguageCode = 'en-US' ) max_tries = 60 while max_tries > 0: max_tries -= 1 job = transcribe_client.get_transcription_job(TranscriptionJobName = job_name) job_status = job['TranscriptionJob']['TranscriptionJobStatus'] if job_status in ['COMPLETED', 'FAILED']: print(f"Job {job_name} is {job_status}.") if job_status == 'COMPLETED': print( f"Download the transcript from\n" f"\t{job['TranscriptionJob']['Transcript']['TranscriptFileUri']}.") break else: print(f"Waiting for {job_name}. Current status is {job_status}.") time.sleep(10) def main(): transcribe_client = boto3.client('transcribe', region_name = 'us-west-2') file_uri = 's3://DOC-EXAMPLE-BUCKET/my-input-files/my-media-file.flac' transcribe_file('Example-job', file_uri, transcribe_client) if __name__ == '__main__': main()

You can create streaming transcriptions using a streamed media file or a live media stream.

Note that the standard AWS SDK for Python (Boto3) is not supported for Amazon Transcribe streaming. To start a streaming transcription using Python, use this async Python SDK for Amazon Transcribe.

Java

The following example is a Java program that transcribes streaming audio.

To run this example, note the following:

See also: Retry client for Amazon Transcribe streaming (Java SDK). This code manages the connection to Amazon Transcribe and retries sending data when there are errors on the connection. For example, if there is a transient error on the network, this client resends the request that failed.

public class TranscribeStreamingDemoApp { private static final Region REGION = Region.US_WEST_2; 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.toString()); }) .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 InputStream getStreamFromFile(String myMediaFileName) { try { File inputFile = new File(getClass().getClassLoader().getResource(myMediaFileName).getFile()); InputStream audioStream = new FileInputStream(inputFile); return audioStream; } catch (FileNotFoundException e) { throw new RuntimeException(e); } } 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(); } } }
JavaScript
const { TranscribeStreamingClient, StartStreamTranscriptionCommand, } = require("@aws-sdk/client-transcribe-streaming"); const { createReadStream } = require("fs"); const { join } = require("path"); const audio = createReadStream(join(__dirname, "my-media-file.flac"), { highWaterMark: 1024 * 16}); const LanguageCode = "en-US"; const MediaEncoding = "pcm"; const MediaSampleRateHertz = "16000"; const credentials = { "accessKeyId": "", "secretAccessKey": "", }; async function startRequest() { const client = new TranscribeStreamingClient({ region: "us-west-2", credentials }); const params = { LanguageCode, MediaEncoding, MediaSampleRateHertz, AudioStream: (async function* () { for await (const chunk of audio) { yield {AudioEvent: {AudioChunk: chunk}}; } })(), }; const command = new StartStreamTranscriptionCommand(params); // Send transcription request const response = await client.send(command); // Start to print response try { for await (const event of response.TranscriptResultStream) { console.log(JSON.stringify(event)); } } catch(err) { console.log("error") console.log(err) } } startRequest();
Python

The following example is a Python program that transcribes streaming audio.

To run this example, note the following:

  • You must use this SDK for Python .

  • The sample rate you specify must match the actual sample rate of your audio stream.

import asyncio # This example uses aiofile for asynchronous file reads. # It's not a dependency of the project but can be installed # with `pip install aiofile`. import aiofile from amazon_transcribe.client import TranscribeStreamingClient from amazon_transcribe.handlers import TranscriptResultStreamHandler from amazon_transcribe.model import TranscriptEvent """ Here's an example of a custom event handler you can extend to process the returned transcription results as needed. This handler will simply print the text out to your interpreter. """ class MyEventHandler(TranscriptResultStreamHandler): async def handle_transcript_event(self, transcript_event: TranscriptEvent): # This handler can be implemented to handle transcriptions as needed. # Here's an example to get started. results = transcript_event.transcript.results for result in results: for alt in result.alternatives: print(alt.transcript) async def basic_transcribe(): # Set up our client with your chosen Region client = TranscribeStreamingClient(region = "us-west-2") # Start transcription to generate async stream stream = await client.start_stream_transcription( language_code = "en-US", media_sample_rate_hz = 16000, media_encoding = "pcm", ) async def write_chunks(): # NOTE: For pre-recorded files longer than 5 minutes, the sent audio # chunks should be rate limited to match the real-time bitrate of the # audio stream to avoid signing issues. async with aiofile.AIOFile('filepath/my-media-file.flac', 'rb') as afp: reader = aiofile.Reader(afp, chunk_size = 1024 * 16) async for chunk in reader: await stream.input_stream.send_audio_event(audio_chunk = chunk) await stream.input_stream.end_stream() # Instantiate our handler and start processing events handler = MyEventHandler(stream.output_stream) await asyncio.gather(write_chunks(), handler.handle_events()) loop = asyncio.get_event_loop() loop.run_until_complete(basic_transcribe()) loop.close()

Using this service with an AWS SDK

AWS software development kits (SDKs) are available for many popular programming languages. Each SDK provides an API, code examples, and documentation that make it easier for developers to build applications in their preferred language.

For examples specific to this service, see Code examples for Amazon Transcribe using AWS SDKs.

Example availability

Can't find what you need? Request a code example by using the Provide feedback link at the bottom of this page.