Add real-time transcription into your application

Create a call and provide the transcription details

Define the TranscriptionOptions for ACS to know whether to start the transcription straight away or at a later time, which locale to transcribe in and the web socket connection to use for sending the transcript.

var createCallOptions = new CreateCallOptions(callInvite, callbackUri)
{
    CallIntelligenceOptions = new CallIntelligenceOptions() { CognitiveServicesEndpoint = new Uri(cognitiveServiceEndpoint) },
    TranscriptionOptions = new TranscriptionOptions(new Uri(""), "en-US", false, TranscriptionTransport.Websocket)
};
CreateCallResult createCallResult = await callAutomationClient.CreateCallAsync(createCallOptions);

Start Transcription

Once you're ready to start the transcription you can make an explicit call to Call Automation to start transcribing the call.

// Start transcription with options
StartTranscriptionOptions options = new StartTranscriptionOptions()
{
    OperationContext = "startMediaStreamingContext",
    //Locale = "en-US",
};

await callMedia.StartTranscriptionAsync(options);

// Alternative: Start transcription without options
// await callMedia.StartTranscriptionAsync();

Receiving Transcription Stream

When transcription starts, your websocket will receive the transcription metadata payload as the first packet. This payload carries the call metadata and locale for the configuration.

{
    "kind": "TranscriptionMetadata",
    "transcriptionMetadata": {
        "subscriptionId": "835be116-f750-48a4-a5a4-ab85e070e5b0",
        "locale": "en-us",
        "callConnectionId": "65c57654=f12c-4975-92a4-21668e61dd98",
        "correlationId": "65c57654=f12c-4975-92a4-21668e61dd98"
    }
}

Receiving Transcription data

After the metadata the next packets your web socket receives will be TranscriptionData for the transcribed audio.

{
    "kind": "TranscriptionData",
    "transcriptionData": {
        "text": "Testing transcription.",
        "format": "display",
        "confidence": 0.695223331451416,
        "offset": 2516998782481234400,
        "words": [
            {
                "text": "testing",
                "offset": 2516998782481234400
            },
            {
                "text": "testing",
                "offset": 2516998782481234400
            }
        ],
        "participantRawID": "8:acs:",
        "resultStatus": "Final"
    }
}

Handling transcription stream in the web socket server

using WebServerApi;

var builder = WebApplication.CreateBuilder(args);
builder.Services.AddEndpointsApiExplorer();
builder.Services.AddSwaggerGen();

var app = builder.Build();
app.UseWebSockets();
app.Map("/ws", async context =>
{
    if (context.WebSockets.IsWebSocketRequest)
    {
        using var webSocket = await context.WebSockets.AcceptWebSocketAsync();
        await HandleWebSocket.Echo(webSocket);
    }
    else
    {
        context.Response.StatusCode = StatusCodes.Status400BadRequest;
    }
});

app.Run();

Updates to your code for the websocket handler

using Azure.Communication.CallAutomation;
using System.Net.WebSockets;
using System.Text;

namespace WebServerApi
{
    public class HandleWebSocket
    {
        public static async Task Echo(WebSocket webSocket)
        {
            var buffer = new byte[1024 * 4];
            var receiveResult = await webSocket.ReceiveAsync(
                new ArraySegment(buffer), CancellationToken.None);

            while (!receiveResult.CloseStatus.HasValue)
            {
                string msg = Encoding.UTF8.GetString(buffer, 0, receiveResult.Count);
                var response = StreamingDataParser.Parse(msg);

                if (response != null)
                {
                    if (response is AudioMetadata audioMetadata)
                    {
                        Console.WriteLine("***************************************************************************************");
                        Console.WriteLine("MEDIA SUBSCRIPTION ID-->"+audioMetadata.MediaSubscriptionId);
                        Console.WriteLine("ENCODING-->"+audioMetadata.Encoding);
                        Console.WriteLine("SAMPLE RATE-->"+audioMetadata.SampleRate);
                        Console.WriteLine("CHANNELS-->"+audioMetadata.Channels);
                        Console.WriteLine("LENGTH-->"+audioMetadata.Length);
                        Console.WriteLine("***************************************************************************************");
                    }
                    if (response is AudioData audioData)
                    {
                        Console.WriteLine("***************************************************************************************");
                        Console.WriteLine("DATA-->"+audioData.Data);
                        Console.WriteLine("TIMESTAMP-->"+audioData.Timestamp);
                        Console.WriteLine("IS SILENT-->"+audioData.IsSilent);
                        Console.WriteLine("***************************************************************************************");
                    }

                    if (response is TranscriptionMetadata transcriptionMetadata)
                    {
                        Console.WriteLine("***************************************************************************************");
                        Console.WriteLine("TRANSCRIPTION SUBSCRIPTION ID-->"+transcriptionMetadata.TranscriptionSubscriptionId);
                        Console.WriteLine("LOCALE-->"+transcriptionMetadata.Locale);
                        Console.WriteLine("CALL CONNECTION ID--?"+transcriptionMetadata.CallConnectionId);
                        Console.WriteLine("CORRELATION ID-->"+transcriptionMetadata.CorrelationId);
                        Console.WriteLine("***************************************************************************************");
                    }
                    if (response is TranscriptionData transcriptionData)
                    {
                        Console.WriteLine("***************************************************************************************");
                        Console.WriteLine("TEXT-->"+transcriptionData.Text);
                        Console.WriteLine("FORMAT-->"+transcriptionData.Format);
                        Console.WriteLine("OFFSET-->"+transcriptionData.Offset);
                        Console.WriteLine("DURATION-->"+transcriptionData.Duration);
                        Console.WriteLine("PARTICIPANT-->"+transcriptionData.Participant.RawId);
                        Console.WriteLine("CONFIDENCE-->"+transcriptionData.Confidence);

                        foreach (var word in transcriptionData.Words)
                        {
                            Console.WriteLine("TEXT-->"+word.Text);
                            Console.WriteLine("OFFSET-->"+word.Offset);
                            Console.WriteLine("DURATION-->"+word.Duration);
                        }
                        Console.WriteLine("***************************************************************************************");
                    }
                }

                await webSocket.SendAsync(
                    new ArraySegment(buffer, 0, receiveResult.Count),
                    receiveResult.MessageType,
                    receiveResult.EndOfMessage,
                    CancellationToken.None);

                receiveResult = await webSocket.ReceiveAsync(
                    new ArraySegment(buffer), CancellationToken.None);
            }

            await webSocket.CloseAsync(
                receiveResult.CloseStatus.Value,
                receiveResult.CloseStatusDescription,
                CancellationToken.None);
        }
    }
}

Update Transcription

For situations where your application allows users to select their preferred language you may also want to capture the transcription in that language. To do this, Call Automation SDK allows you to update the transcription locale.

await callMedia.UpdateTranscriptionAsync("en-US-NancyNeural");

Stop Transcription

When your application needs to stop listening for the transcription, you can use the StopTranscription request to let Call Automation know to stop sending transcript data to your web socket.

StopTranscriptionOptions stopOptions = new StopTranscriptionOptions()
{
    OperationContext = "stopTranscription"
};

await callMedia.StopTranscriptionAsync(stopOptions);

Create a call and provide the transcription details

Define the TranscriptionOptions for ACS to know whether to start the transcription straight away or at a later time, which locale to transcribe in and the web socket connection to use for sending the transcript.

CallInvite callInvite = new CallInvite(target, caller); 

CallIntelligenceOptions callIntelligenceOptions = new CallIntelligenceOptions()
    .setCognitiveServicesEndpoint(appConfig.getCognitiveServiceEndpoint()); 

TranscriptionOptions transcriptionOptions = new TranscriptionOptions(
    appConfig.getWebSocketUrl(), 
    TranscriptionTransport.WEBSOCKET, 
    "en-US", 
    false
); 

CreateCallOptions createCallOptions = new CreateCallOptions(callInvite, appConfig.getCallBackUri());
createCallOptions.setCallIntelligenceOptions(callIntelligenceOptions); 
createCallOptions.setTranscriptionOptions(transcriptionOptions); 

Response result = client.createCallWithResponse(createCallOptions, Context.NONE); 
return result.getValue().getCallConnectionProperties().getCallConnectionId(); 

Start Transcription

Once you're ready to start the transcription you can make an explicit call to Call Automation to start transcribing the call.

//Option 1: Start transcription with options
StartTranscriptionOptions transcriptionOptions = new StartTranscriptionOptions()
    .setOperationContext("startMediaStreamingContext"); 

client.getCallConnection(callConnectionId)
    .getCallMedia()
    .startTranscriptionWithResponse(transcriptionOptions, Context.NONE); 

// Alternative: Start transcription without options
// client.getCallConnection(callConnectionId)
//     .getCallMedia()
//     .startTranscription();

Receiving Transcription Stream

When transcription starts, your websocket will receive the transcription metadata payload as the first packet. This payload carries the call metadata and locale for the configuration.

{
    "kind": "TranscriptionMetadata",
    "transcriptionMetadata": {
        "subscriptionId": "835be116-f750-48a4-a5a4-ab85e070e5b0",
        "locale": "en-us",
        "callConnectionId": "65c57654=f12c-4975-92a4-21668e61dd98",
        "correlationId": "65c57654=f12c-4975-92a4-21668e61dd98"
    }
}

Receiving Transcription data

After the metadata the next packets your web socket receives will be TranscriptionData for the transcribed audio.

{
    "kind": "TranscriptionData",
    "transcriptionData": {
        "text": "Testing transcription.",
        "format": "display",
        "confidence": 0.695223331451416,
        "offset": 2516998782481234400,
        "words": [
            {
                "text": "testing",
                "offset": 2516998782481234400
            },
            {
                "text": "testing",
                "offset": 2516998782481234400
            }
        ],
        "participantRawID": "8:acs:",
        "resultStatus": "Final"
    }
}

Handling transcription stream in the web socket server

package com.example;

import org.glassfish.tyrus.server.Server;

import java.io.BufferedReader;
import java.io.InputStreamReader;

public class App {
    public static void main(String[] args) {
        Server server = new Server("localhost", 8081, "/ws", null, WebSocketServer.class);

        try {
            server.start();
            System.out.println("Web socket running on port 8081...");
            System.out.println("wss://localhost:8081/ws/server");
            BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
            reader.readLine();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            server.stop();
        }
    }
}

Updates to your code for the websocket handler

package com.example;

import javax.websocket.OnMessage;
import javax.websocket.Session;
import javax.websocket.server.ServerEndpoint;

import com.azure.communication.callautomation.models.streaming.StreamingData;
import com.azure.communication.callautomation.models.streaming.StreamingDataParser;
import com.azure.communication.callautomation.models.streaming.media.AudioData;
import com.azure.communication.callautomation.models.streaming.media.AudioMetadata;
import com.azure.communication.callautomation.models.streaming.transcription.TranscriptionData;
import com.azure.communication.callautomation.models.streaming.transcription.TranscriptionMetadata;
import com.azure.communication.callautomation.models.streaming.transcription.Word;

@ServerEndpoint("/server")
public class WebSocketServer {
    @OnMessage
    public void onMessage(String message, Session session) {
        StreamingData data = StreamingDataParser.parse(message);

        if (data instanceof AudioMetadata) {
            AudioMetadata audioMetaData = (AudioMetadata) data;
            System.out.println("----------------------------------------------------------------");
            System.out.println("SUBSCRIPTION ID: --> " + audioMetaData.getMediaSubscriptionId());
            System.out.println("ENCODING: --> " + audioMetaData.getEncoding());
            System.out.println("SAMPLE RATE: --> " + audioMetaData.getSampleRate());
            System.out.println("CHANNELS: --> " + audioMetaData.getChannels());
            System.out.println("LENGTH: --> " + audioMetaData.getLength());
            System.out.println("----------------------------------------------------------------");
        }

        if (data instanceof AudioData) {
            AudioData audioData = (AudioData) data;
            System.out.println("----------------------------------------------------------------");
            System.out.println("DATA: --> " + audioData.getData());
            System.out.println("TIMESTAMP: --> " + audioData.getTimestamp());
            System.out.println("IS SILENT: --> " + audioData.isSilent());
            System.out.println("----------------------------------------------------------------");
        }

        if (data instanceof TranscriptionMetadata) {
            TranscriptionMetadata transcriptionMetadata = (TranscriptionMetadata) data;
            System.out.println("----------------------------------------------------------------");
            System.out.println("TRANSCRIPTION SUBSCRIPTION ID: --> " + transcriptionMetadata.getTranscriptionSubscriptionId());
            System.out.println("IS SILENT: --> " + transcriptionMetadata.getLocale());
            System.out.println("CALL CONNECTION ID: --> " + transcriptionMetadata.getCallConnectionId());
            System.out.println("CORRELATION ID: --> " + transcriptionMetadata.getCorrelationId());
            System.out.println("----------------------------------------------------------------");
        }

        if (data instanceof TranscriptionData) {
            TranscriptionData transcriptionData = (TranscriptionData) data;
            System.out.println("----------------------------------------------------------------");
            System.out.println("TEXT: --> " + transcriptionData.getText());
            System.out.println("FORMAT: --> " + transcriptionData.getFormat());
            System.out.println("CONFIDENCE: --> " + transcriptionData.getConfidence());
            System.out.println("OFFSET: --> " + transcriptionData.getOffset());
            System.out.println("DURATION: --> " + transcriptionData.getDuration());
            System.out.println("RESULT STATUS: --> " + transcriptionData.getResultStatus());
            for (Word word : transcriptionData.getWords()) {
                System.out.println("Text: --> " + word.getText());
                System.out.println("Offset: --> " + word.getOffset());
                System.out.println("Duration: --> " + word.getDuration());
            }
            System.out.println("----------------------------------------------------------------");
        }
    }
}

Update Transcription

For situations where your application allows users to select their preferred language you may also want to capture the transcription in that language. To do this, Call Automation SDK allows you to update the transcription locale.

client.getCallConnection(callConnectionId)
    .getCallMedia()
    .updateTranscription("en-US-NancyNeural");

Stop Transcription

When your application needs to stop listening for the transcription, you can use the StopTranscription request to let Call Automation know to stop sending transcript data to your web socket.

// Option 1: Stop transcription with options
StopTranscriptionOptions stopTranscriptionOptions = new StopTranscriptionOptions()
    .setOperationContext("stopTranscription");

client.getCallConnection(callConnectionId)
    .getCallMedia()
    .stopTranscriptionWithResponse(stopTranscriptionOptions, Context.NONE);

// Alternative: Stop transcription without options
// client.getCallConnection(callConnectionId)
//     .getCallMedia()
//     .stopTranscription();

Create a call and provide the transcription details

Define the TranscriptionOptions for ACS to know whether to start the transcription straight away or at a later time, which locale to transcribe in, and the web socket connection to use for sending the transcript.

const transcriptionOptions = {
    transportUrl: "",
    transportType: "websocket",
    locale: "en-US",
    startTranscription: false
};

const options = {
    callIntelligenceOptions: {
        cognitiveServicesEndpoint: process.env.COGNITIVE_SERVICES_ENDPOINT
    },
    transcriptionOptions: transcriptionOptions
};

console.log("Placing outbound call...");
acsClient.createCall(callInvite, process.env.CALLBACK_URI + "/api/callbacks", options);

Start Transcription

Once you're ready to start the transcription, you can make an explicit call to Call Automation to start transcribing the call.

const startTranscriptionOptions = {
    locale: "en-AU",
    operationContext: "startTranscriptionContext"
};

// Start transcription with options
await callMedia.startTranscription(startTranscriptionOptions);

// Alternative: Start transcription without options
// await callMedia.startTranscription();

Receiving Transcription Stream

When transcription starts, your websocket will receive the transcription metadata payload as the first packet. This payload carries the call metadata and locale for the configuration.

{
    "kind": "TranscriptionMetadata",
    "transcriptionMetadata": {
        "subscriptionId": "835be116-f750-48a4-a5a4-ab85e070e5b0",
        "locale": "en-us",
        "callConnectionId": "65c57654=f12c-4975-92a4-21668e61dd98",
        "correlationId": "65c57654=f12c-4975-92a4-21668e61dd98"
    }
}

Receiving Transcription Data

After the metadata, the next packets your web socket receives will be TranscriptionData for the transcribed audio.

{
    "kind": "TranscriptionData",
    "transcriptionData": {
        "text": "Testing transcription.",
        "format": "display",
        "confidence": 0.695223331451416,
        "offset": 2516998782481234400,
        "words": [
            {
                "text": "testing",
                "offset": 2516998782481234400
            },
            {
                "text": "testing",
                "offset": 2516998782481234400
            }
        ],
        "participantRawID": "8:acs:",
        "resultStatus": "Final"
    }
}

Handling transcription stream in the web socket server

import WebSocket from 'ws';
import { streamingData } from '@azure/communication-call-automation/src/util/streamingDataParser';

const wss = new WebSocket.Server({ port: 8081 });

wss.on('connection', (ws) => {
    console.log('Client connected');

    ws.on('message', (packetData) => {
        const decoder = new TextDecoder();
        const stringJson = decoder.decode(packetData);
        console.log("STRING JSON => " + stringJson);

        const response = streamingData(packetData);
        
        if ('locale' in response) {
            console.log("Transcription Metadata");
            console.log(response.callConnectionId);
            console.log(response.correlationId);
            console.log(response.locale);
            console.log(response.subscriptionId);
        }
        
        if ('text' in response) {
            console.log("Transcription Data");
            console.log(response.text);
            console.log(response.format);
            console.log(response.confidence);
            console.log(response.offset);
            console.log(response.duration);
            console.log(response.resultStatus);

            if ('phoneNumber' in response.participant) {
                console.log(response.participant.phoneNumber);
            }

            response.words.forEach((word) => {
                console.log(word.text);
                console.log(word.duration);
                console.log(word.offset);
            });
        }
    });

    ws.on('close', () => {
        console.log('Client disconnected');
    });
});

console.log('WebSocket server running on port 8081');

Update Transcription

For situations where your application allows users to select their preferred language, you may also want to capture the transcription in that language. To do this, the Call Automation SDK allows you to update the transcription locale.

await callMedia.updateTranscription("en-US-NancyNeural");

Stop Transcription

When your application needs to stop listening for the transcription, you can use the StopTranscription request to let Call Automation know to stop sending transcript data to your web socket.

const stopTranscriptionOptions = {
    operationContext: "stopTranscriptionContext"
};

// Stop transcription with options
await callMedia.stopTranscription(stopTranscriptionOptions);

// Alternative: Stop transcription without options
// await callMedia.stopTranscription();

Create a call and provide the transcription details

Define the TranscriptionOptions for ACS to know whether to start the transcription straight away or at a later time, which locale to transcribe in, and the web socket connection to use for sending the transcript.

transcription_options = TranscriptionOptions(
    transport_url=" ",
    transport_type=TranscriptionTransportType.WEBSOCKET,
    locale="en-US",
    start_transcription=False
)

call_connection_properties = call_automation_client.create_call(
    target_participant,
    CALLBACK_EVENTS_URI,
    cognitive_services_endpoint=COGNITIVE_SERVICES_ENDPOINT,
    source_caller_id_number=source_caller,
    transcription=transcription_options
)

Start Transcription

Once you're ready to start the transcription, you can make an explicit call to Call Automation to start transcribing the call.

# Start transcription without options
call_connection_client.start_transcription()

# Option 1: Start transcription with locale and operation context
# call_connection_client.start_transcription(locale="en-AU", operation_context="startTranscriptionContext")

# Option 2: Start transcription with operation context
# call_connection_client.start_transcription(operation_context="startTranscriptionContext")

Receiving Transcription Stream

When transcription starts, your websocket will receive the transcription metadata payload as the first packet. This payload carries the call metadata and locale for the configuration.

{
    "kind": "TranscriptionMetadata",
    "transcriptionMetadata": {
        "subscriptionId": "835be116-f750-48a4-a5a4-ab85e070e5b0",
        "locale": "en-us",
        "callConnectionId": "65c57654=f12c-4975-92a4-21668e61dd98",
        "correlationId": "65c57654=f12c-4975-92a4-21668e61dd98"
    }
}

Receiving Transcription Data

After the metadata, the next packets your websocket receives will be TranscriptionData for the transcribed audio.

{
    "kind": "TranscriptionData",
    "transcriptionData": {
        "text": "Testing transcription.",
        "format": "display",
        "confidence": 0.695223331451416,
        "offset": 2516998782481234400,
        "words": [
            {
                "text": "testing",
                "offset": 2516998782481234400
            },
            {
                "text": "testing",
                "offset": 2516998782481234400
            }
        ],
        "participantRawID": "8:acs:",
        "resultStatus": "Final"
    }
}

Handling transcription stream in the web socket server

import asyncio
import json
import websockets
from azure.communication.callautomation._shared.models import identifier_from_raw_id

async def handle_client(websocket, path):
    print("Client connected")
    try:
        async for message in websocket:
            json_object = json.loads(message)
            kind = json_object['kind']
            if kind == 'TranscriptionMetadata':
                print("Transcription metadata")
                print("-------------------------")
                print("Subscription ID:", json_object['transcriptionMetadata']['subscriptionId'])
                print("Locale:", json_object['transcriptionMetadata']['locale'])
                print("Call Connection ID:", json_object['transcriptionMetadata']['callConnectionId'])
                print("Correlation ID:", json_object['transcriptionMetadata']['correlationId'])
            if kind == 'TranscriptionData':
                participant = identifier_from_raw_id(json_object['transcriptionData']['participantRawID'])
                word_data_list = json_object['transcriptionData']['words']
                print("Transcription data")
                print("-------------------------")
                print("Text:", json_object['transcriptionData']['text'])
                print("Format:", json_object['transcriptionData']['format'])
                print("Confidence:", json_object['transcriptionData']['confidence'])
                print("Offset:", json_object['transcriptionData']['offset'])
                print("Duration:", json_object['transcriptionData']['duration'])
                print("Participant:", participant.raw_id)
                print("Result Status:", json_object['transcriptionData']['resultStatus'])
                for word in word_data_list:
                    print("Word:", word['text'])
                    print("Offset:", word['offset'])
                    print("Duration:", word['duration'])
            
    except websockets.exceptions.ConnectionClosedOK:
        print("Client disconnected")
    except websockets.exceptions.ConnectionClosedError as e:
        print("Connection closed with error: %s", e)
    except Exception as e:
        print("Unexpected error: %s", e)

start_server = websockets.serve(handle_client, "localhost", 8081)

print('WebSocket server running on port 8081')

asyncio.get_event_loop().run_until_complete(start_server)
asyncio.get_event_loop().run_forever()

Update Transcription

For situations where your application allows users to select their preferred language, you may also want to capture the transcription in that language. To do this, the Call Automation SDK allows you to update the transcription locale.

await call_connection_client.update_transcription(locale="en-US-NancyNeural")

Stop Transcription

When your application needs to stop listening for the transcription, you can use the StopTranscription request to let Call Automation know to stop sending transcript data to your web socket.

# Stop transcription without options
call_connection_client.stop_transcription()

# Alternative: Stop transcription with operation context
# call_connection_client.stop_transcription(operation_context="stopTranscriptionContext")