[QUESTION] Audio from Chime SDK PSTN call contains unclear audio from Kinesis

[Prince7036]

I'm trying to get the live audio out from a chime SDK PSTN call but the audio contains either silent sound / noise without any clear audio from the actual call.

I followed the approach mentioned in https://github.com/aws-samples/amazon-chime-sdk-media-streams where I do the following

1. Initiate an Outbound PSTN call using Chime SDK
2. Once call is answered, I do a JoinChimeMeeting with a meeting I created with an attendee
3. Once the call is bridged to the meeting, I start the media stream pipeline
4. I have a event bridge rule which fires when the media stream starts
5. Once I get the event, I start consuming the audio from Kinesis Video Streams
6. But the audio I receive sometimes has some noise / silent or in very rare case I hear a clear audio

Code I used for audio consumption, I'm using SERVER_TIMESTAMP

@Override
public InputStream openStream(AudioStreamRequest request) {
	var streamArn = request.getStreamIdentifier();
	var streamName = Arn.fromString(streamArn).resource().resource();
	var region = Arn.fromString(streamArn).region()
		.orElseThrow(() -> new IllegalArgumentException("Invalid stream arn"));

	var dataEndpoint = getDataEndpoint(streamName);
	var kvsMediaClient = getKinesisVideoClient(dataEndpoint, region);

	var startSelector = buildStartSelector(request);
	var mediaRequest = GetMediaRequest.builder()
		.streamName(streamName)
		.startSelector(startSelector)
		.build();

	log.info(
		"Opening KVS media stream: streamName={}, startSelectorType={}, startPosition={}",
		streamName,
		startSelector.startSelectorType(),
		request.getStartPosition()
	);

	var kvsStream = kvsMediaClient.getMedia(mediaRequest);

	return new KvsAudioInputStream(kvsStream, kvsMediaClient);
}

private StartSelector buildStartSelector(AudioStreamRequest request) {
	if (StringUtils.isNotEmpty(request.getStartPosition())) {
		return StartSelector.builder()
			.startSelectorType(StartSelectorType.SERVER_TIMESTAMP)
			.startTimestamp(Instant.parse(request.getStartPosition()))
			.build();
	}

	return StartSelector.builder()
		.startSelectorType(StartSelectorType.NOW)
		.build();
}

private KinesisVideoMediaClient getKinesisVideoClient(String dataEndpoint, String region) {
	return KinesisVideoMediaClient.builder()
		.credentialsProvider(DefaultCredentialsProvider.builder().build())
		.endpointOverride(URI.create(dataEndpoint))
		.region(Region.of(region))
		.build();
}

private String getDataEndpoint(String streamName) {
	var request = GetDataEndpointRequest.builder()
		.streamName(streamName)
		.apiName(APIName.GET_MEDIA)
		.build();

	return kinesisVideoClient.getDataEndpoint(request).dataEndpoint();
}

Has anyone faced this issue ?