Error “Cannot read property '0' of undefined” when parsing output from Transcribe

[michaelcafiero02]

Hello! I am using AWS SDK v3 to integrate a Node.js application with AWS Transcribe. I create an audio stream according to this documentation: https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/clients/client-transcribe-streaming/. The audio stream is then passed to transcribe with all of the syntax from the official docs. I receive a response 200 from the API, but upon parsing it I get the error “Cannot read property '0' of undefined”.

I've tried several methods for creating the audio stream, but am finding it difficult to debug since I am getting a 200 response from the API, and no errors until I parse the output. I am parsing according to the function described in the documentation. The error seems to be on line 2190 of this code
https://github.com/aws/aws-sdk-js-v3/blob/eea8b2e3/clients/client-transcribe-streaming/src/models/models_0.ts#L2063

and similar to the issue #3365.

Thanks!!

[yenfryherrerafeliz]

Hi @michaelcafiero02, could you please provide a sample code that we can use to reproduce this issue and understand your implementation.

Thanks!

[fvisticot]

I have the same issue / error message with the following code:
The audio file is a .flac 44.1k (I can play the file on my computer it seems a correct file)

async function transcribeAudio() {
  const audioStream=fs.ReadStream('test.flac')
  const command = new StartStreamTranscriptionCommand({
    LanguageCode: "fr-FR",
    MediaEncoding: "flac",
    MediaSampleRateHertz: 44100,
    AudioStream: audioStream,
  });

  try {
    const response = await transcribeClient.send(command)
  
    //const transcriptsStream = Readable.from(response.TranscriptResultStream);
    //transcriptsStream.pipe(process.stdout);

    for await (const event of response.TranscriptResultStream) {
      console.log("====>" + event)
      if (event.TranscriptEvent) {
        console.log(event)
        const message = event.TranscriptEvent;
        const results = event.TranscriptEvent.Transcript.Results;
        results.map((result) => {
          (result.Alternatives || []).map((alternative) => {
            const transcript = alternative.Items.map((item) => item.Content).join(" ");
            console.log(transcript);
          });
        });
      }
    }
  } catch (e) {
    console.error('====>Error: ' + e)
  }

}

Error returned:

/Users//development//node_modules/@aws-sdk/eventstream-handler-node/dist-cjs/EventStreamPayloadHandler.js:39
                throw err;
                ^

TypeError: Cannot read properties of undefined (reading '0')
    at AudioStream.visit (/Users//development//node_modules/@aws-sdk/client-transcribe-streaming/dist-cjs/models/models_0.js:24:40)
    at eventMarshallingVisitor (/Users//development//node_modules/@aws-sdk/client-transcribe-streaming/dist-cjs/protocols/Aws_restJson1.js:429:71)
    at Object.serializedIterator (/Users//development//node_modules/@aws-sdk/eventstream-serde-universal/dist-cjs/EventStreamMarshaller.js:25:65)
    at process.processTicksAndRejections (node:internal/process/task_queues:95:5)
    at async next (node:internal/streams/from:85:11)

[ameysj]

i am facing the same issue

................\node_modules@aws-sdk\eventstream-handler-node\dist-cjs\EventStreamPayloadHandler.js:39
throw err;
^

TypeError: Cannot read properties of undefined (reading '0')
at Object.AudioStream.visit (C:\public_html\livetranslationserver\node_modules@aws-sdk\client-transcribe-streaming\dist-cjs\models\models_0.js:24:40)
at Object.eventMarshallingVisitor [as serializer] (C:\public_html\livetranslationserver\node_modules@aws-sdk\client-transcribe-streaming\dist-cjs\protocols\Aws_restJson1.js:429:71)
at SmithyMessageEncoderStream.asyncIterator (C:\public_html\livetranslationserver\node_modules@aws-sdk\eventstream-serde-universal\node_modules@aws-sdk\eventstream-codec\dist-cjs\SmithyMessageEncoderStream.js:13:45)
at processTicksAndRejections (node:internal/process/task_queues:96:5)
at async MessageEncoderStream.asyncIterator (C:\public_html\livetranslationserver\node_modules@aws-sdk\eventstream-serde-universal\node_modules@aws-sdk\eventstream-codec\dist-cjs\MessageEncoderStream.js:12:26)
at async next (node:internal/streams/from:85:11)

here is my code :

import {
    TranscribeStreamingClient,
    StartMedicalStreamTranscriptionCommand,
    StartStreamTranscriptionCommand
} from "@aws-sdk/client-transcribe-streaming";
import fs from 'fs'
const client = new TranscribeStreamingClient();
const command = new StartStreamTranscriptionCommand({
    LanguageCode: "en-US",
    MediaEncoding: "pcm",
    MediaSampleRateHertz: 44100,
    AudioStream: audioStream(),
});

const response = client.send(command);
console.log('tyep res', typeof (response))
console.log('res', response)

function* audioStream() {
    const filePath = './100_1.en.pcm';
    const chunkSize = 8820;

    const data = fs.readFileSync(filePath);
    const pcmBuffer = Buffer.from(data);

    for (let i = 0; i < pcmBuffer.length; i += chunkSize) {
        const chunk = Buffer.alloc(chunkSize);
        pcmBuffer.copy(chunk, 0, i, i + chunkSize);
        yield chunk;
    }
}

please provide a proper code if it is working for you , btw the pcm audio data here i am taking from a file ./100_1.en.pcm

[JOS394]

Has anyone been able to solve it?