# Transcribing multi-channel audio If your audio has two channels, you can use channel identification to transcribe the speech from each channel separately. Amazon Transcribe doesn't currently support audio with more than two channels. In your transcript, channels are assigned the labels `ch_0` and `ch_1`. In addition to the [standard transcript sections](how-input.md#how-it-works-output) (`transcripts` and `items`), requests with channel identification enabled include a `channel_labels` section. This section contains each utterance or punctuation mark, grouped by channel, and its associated channel label, timestamps, and confidence score. ``` "channel_labels": { "channels": [ { "channel_label": "ch_0", "items": [ { "channel_label": "ch_0", "start_time": "4.86", "end_time": "5.01", "alternatives": [ { "confidence": "1.0", "content": "I've" } ], "type": "pronunciation" }, ... "channel_label": "ch_1", "items": [ { "channel_label": "ch_1", "start_time": "8.5", "end_time": "8.89", "alternatives": [ { "confidence": "1.0", "content": "Sorry" } ], "type": "pronunciation" }, ... "number_of_channels": 2 }, ``` Note that if a person on one channel speaks at the same time as a person on a separate channel, timestamps for each channel overlap while the individuals are speaking over each other. To view a complete example transcript with channel identification, see [Example channel identification output (batch)](channel-id-output-batch.md). ## Using channel identification in a batch transcription To identify channels in a batch transcription, you can use the **AWS Management Console**, **AWS CLI**, or **AWS SDKs**; see the following for examples: ### AWS Management Console 1. Sign in to the [AWS Management Console](https://console.aws.amazon.com/transcribe/). 1. In the navigation pane, choose **Transcription jobs**, then select **Create job** (top right). This opens the **Specify job details** page. ![\[Amazon Transcribe console 'Specify job details' page. In the 'Job settings' panel, you can specify a name for your transcription job, select a Model type, and specify your language settings.\]](http://docs.aws.amazon.com/transcribe/latest/dg/images/console-batch-job-details-1.png) 1. Fill in any fields you want to include on the **Specify job details** page, then select **Next**. This takes you to the **Configure job - *optional*** page. In the **Audio settings** panel, select **Channel identification** (under the 'Audio identification type' heading). ![\[Amazon Transcribe console 'Configure job' page. In the 'Audio settings' panel, you can enable Channel identification.\]](http://docs.aws.amazon.com/transcribe/latest/dg/images/channel-id-batch.png) 1. Select **Create job** to run your transcription job. ### AWS CLI This example uses the [start-transcription-job](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/transcribe/start-transcription-job.html). For more information, see [https://docs.aws.amazon.com/transcribe/latest/APIReference/API_StartTranscriptionJob.html](https://docs.aws.amazon.com/transcribe/latest/APIReference/API_StartTranscriptionJob.html). ``` aws transcribe start-transcription-job \ --region us-west-2 \ --transcription-job-name my-first-transcription-job \ --media MediaFileUri=s3://amzn-s3-demo-bucket/my-input-files/my-media-file.flac \ --output-bucket-name amzn-s3-demo-bucket \ --output-key my-output-files/ \ --language-code en-US \ --settings ChannelIdentification=true ``` Here's another example using the [start-transcription-job](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/transcribe/start-transcription-job.html) command, and a request body that enables channel identification with that job. ``` aws transcribe start-transcription-job \ --region us-west-2 \ --cli-input-json file://my-first-transcription-job.json ``` The file *my-first-transcription-job.json* contains the following request body. ``` { "TranscriptionJobName": "my-first-transcription-job", "Media": { "MediaFileUri": "s3://amzn-s3-demo-bucket/my-input-files/my-media-file.flac" }, "OutputBucketName": "amzn-s3-demo-bucket", "OutputKey": "my-output-files/", "LanguageCode": "en-US", "Settings": { "ChannelIdentification": true } } ``` ### AWS SDK for Python (Boto3) This example uses the AWS SDK for Python (Boto3) to identify channels using the [start\$1transcription\$1job](https://boto3.amazonaws.com/v1/documentation/api/latest/reference/services/transcribe.html#TranscribeService.Client.start_transcription_job) method. For more information, see [StartTranscriptionJob](https://docs.aws.amazon.com/transcribe/latest/APIReference/API_StartTranscriptionJob.html). ``` from __future__ import print_function import time import boto3 transcribe = boto3.client('transcribe', 'us-west-2') job_name = "my-first-transcription-job" job_uri = "s3://amzn-s3-demo-bucket/my-input-files/my-media-file.flac" transcribe.start_transcription_job( TranscriptionJobName = job_name, Media = { 'MediaFileUri': job_uri }, OutputBucketName = 'amzn-s3-demo-bucket', OutputKey = 'my-output-files/', LanguageCode = 'en-US', Settings = { 'ChannelIdentification':True } ) while True: status = transcribe.get_transcription_job(TranscriptionJobName = job_name) if status['TranscriptionJob']['TranscriptionJobStatus'] in ['COMPLETED', 'FAILED']: break print("Not ready yet...") time.sleep(5) print(status) ``` ## Using channel identification in a streaming transcription To identify channels in a streaming transcription, you can use **HTTP/2** or **WebSockets**; see the following for examples: ### HTTP/2 stream This example creates an HTTP/2 request that separates channels in your transcription output. For more information on using HTTP/2 streaming with Amazon Transcribe, see [Setting up an HTTP/2 stream](streaming-setting-up.md#streaming-http2). For more detail on parameters and headers specific to Amazon Transcribe, see [StartStreamTranscription](https://docs.aws.amazon.com/transcribe/latest/APIReference/API_streaming_StartStreamTranscription.html). ``` POST /stream-transcription HTTP/2 host: transcribestreaming.us-west-2.amazonaws.com X-Amz-Target: com.amazonaws.transcribe.Transcribe.StartStreamTranscription Content-Type: application/vnd.amazon.eventstream X-Amz-Content-Sha256: string X-Amz-Date: 20220208T235959Z Authorization: AWS4-HMAC-SHA256 Credential=access-key/20220208/us-west-2/transcribe/aws4_request, SignedHeaders=content-type;host;x-amz-content-sha256;x-amz-date;x-amz-target;x-amz-security-token, Signature=string x-amzn-transcribe-language-code: en-US x-amzn-transcribe-media-encoding: flac x-amzn-transcribe-sample-rate: 16000 x-amzn-channel-identification: TRUE transfer-encoding: chunked ``` Parameter definitions can be found in the [API Reference](https://docs.aws.amazon.com/transcribe/latest/APIReference/API_Reference.html); parameters common to all AWS API operations are listed in the [Common Parameters](https://docs.aws.amazon.com/transcribe/latest/APIReference/CommonParameters.html) section. ### WebSocket stream This example creates a presigned URL that separates channels in your transcription output. Line breaks have been added for readability. For more information on using WebSocket streams with Amazon Transcribe, see [Setting up a WebSocket stream](streaming-setting-up.md#streaming-websocket). For more detail on parameters, see [https://docs.aws.amazon.com/transcribe/latest/APIReference/API_streaming_StartStreamTranscription.html](https://docs.aws.amazon.com/transcribe/latest/APIReference/API_streaming_StartStreamTranscription.html). ``` GET wss://transcribestreaming.us-west-2.amazonaws.com:8443/stream-transcription-websocket? &X-Amz-Algorithm=AWS4-HMAC-SHA256 &X-Amz-Credential=AKIAIOSFODNN7EXAMPLE%2F20220208%2Fus-west-2%2Ftranscribe%2Faws4_request &X-Amz-Date=20220208T235959Z &X-Amz-Expires=300 &X-Amz-Security-Token=security-token &X-Amz-Signature=string &X-Amz-SignedHeaders=content-type%3Bhost%3Bx-amz-date &language-code=en-US &specialty=PRIMARYCARE &type=DICTATION &media-encoding=flac &sample-rate=16000 &channel-identification=TRUE ``` Parameter definitions can be found in the [API Reference](https://docs.aws.amazon.com/transcribe/latest/APIReference/API_Reference.html); parameters common to all AWS API operations are listed in the [Common Parameters](https://docs.aws.amazon.com/transcribe/latest/APIReference/CommonParameters.html) section. # Example channel identification output (batch) Example output Here's an output example for a batch transcription with channel identification enabled. ``` { "jobName": "my-first-transcription-job", "accountId": "111122223333", "results": { "transcripts": [ { "transcript": "I've been on hold for an hour. Sorry about that." } ], "channel_labels": { "channels": [ { "channel_label": "ch_0", "items": [ { "channel_label": "ch_0", "start_time": "4.86", "end_time": "5.01", "alternatives": [ { "confidence": "1.0", "content": "I've" } ], "type": "pronunciation" }, { "channel_label": "ch_0", "start_time": "5.01", "end_time": "5.16", "alternatives": [ { "confidence": "1.0", "content": "been" } ], "type": "pronunciation" }, { "channel_label": "ch_0", "start_time": "5.16", "end_time": "5.28", "alternatives": [ { "confidence": "1.0", "content": "on" } ], "type": "pronunciation" }, { "channel_label": "ch_0", "start_time": "5.28", "end_time": "5.62", "alternatives": [ { "confidence": "1.0", "content": "hold" } ], "type": "pronunciation" }, { "channel_label": "ch_0", "start_time": "5.62", "end_time": "5.83", "alternatives": [ { "confidence": "1.0", "content": "for" } ], "type": "pronunciation" }, { "channel_label": "ch_0", "start_time": "6.1", "end_time": "6.25", "alternatives": [ { "confidence": "1.0", "content": "an" } ], "type": "pronunciation" }, { "channel_label": "ch_0", "start_time": "6.25", "end_time": "6.87", "alternatives": [ { "confidence": "1.0", "content": "hour" } ], "type": "pronunciation" }, { "channel_label": "ch_0", "language_code": "en-US", "alternatives": [ { "confidence": "0.0", "content": "." } ], "type": "punctuation" } ] }, { "channel_label": "ch_1", "items": [ { "channel_label": "ch_1", "start_time": "8.5", "end_time": "8.89", "alternatives": [ { "confidence": "1.0", "content": "Sorry" } ], "type": "pronunciation" }, { "channel_label": "ch_1", "start_time": "8.89", "end_time": "9.06", "alternatives": [ { "confidence": "0.9176", "content": "about" } ], "type": "pronunciation" }, { "channel_label": "ch_1", "start_time": "9.06", "end_time": "9.25", "alternatives": [ { "confidence": "1.0", "content": "that" } ], "type": "pronunciation" }, { "channel_label": "ch_1", "alternatives": [ { "confidence": "0.0", "content": "." } ], "type": "punctuation" } ] } ], "number_of_channels": 2 }, "items": [ { "id": 0, "channel_label": "ch_0", "start_time": "4.86", "end_time": "5.01", "alternatives": [ { "confidence": "1.0", "content": "I've" } ], "type": "pronunciation" }, { "id": 1, "channel_label": "ch_0", "start_time": "5.01", "end_time": "5.16", "alternatives": [ { "confidence": "1.0", "content": "been" } ], "type": "pronunciation" }, { "id": 2, "channel_label": "ch_0", "start_time": "5.16", "end_time": "5.28", "alternatives": [ { "confidence": "1.0", "content": "on" } ], "type": "pronunciation" }, { "id": 3, "channel_label": "ch_0", "start_time": "5.28", "end_time": "5.62", "alternatives": [ { "confidence": "1.0", "content": "hold" } ], "type": "pronunciation" }, { "id": 4, "channel_label": "ch_0", "start_time": "5.62", "end_time": "5.83", "alternatives": [ { "confidence": "1.0", "content": "for" } ], "type": "pronunciation" }, { "id": 5, "channel_label": "ch_0", "start_time": "6.1", "end_time": "6.25", "alternatives": [ { "confidence": "1.0", "content": "an" } ], "type": "pronunciation" }, { "id": 6, "channel_label": "ch_0", "start_time": "6.25", "end_time": "6.87", "alternatives": [ { "confidence": "1.0", "content": "hour" } ], "type": "pronunciation" }, { "id": 7, "channel_label": "ch_0", "alternatives": [ { "confidence": "0.0", "content": "." } ], "type": "punctuation" }, { "id": 8, "channel_label": "ch_1", "start_time": "8.5", "end_time": "8.89", "alternatives": [ { "confidence": "1.0", "content": "Sorry" } ], "type": "pronunciation" }, { "id": 9, "channel_label": "ch_1", "start_time": "8.89", "end_time": "9.06", "alternatives": [ { "confidence": "0.9176", "content": "about" } ], "type": "pronunciation" }, { "id": 10, "channel_label": "ch_1", "start_time": "9.06", "end_time": "9.25", "alternatives": [ { "confidence": "1.0", "content": "that" } ], "type": "pronunciation" }, { "id": 11, "channel_label": "ch_1", "alternatives": [ { "confidence": "0.0", "content": "." } ], "type": "punctuation" } ], "audio_segments": [ { "id": 0, "transcript": "I've been on hold for an hour.", "start_time": "4.86", "end_time": "6.87", "channel_label": "ch_0", "items": [ 0, 1, 2, 3, 4, 5, 6, 7 ] }, { "id": 1, "transcript": "Sorry about that.", "start_time": "8.5", "end_time": "9.25", "channel_label": "ch_1", "items": [ 8, 9, 10, 11 ] } ] }, "status": "COMPLETED" } ```