Quickstart: Create and manage a media composition resource


Functionality described on this section is currently in private preview. Private preview includes access to SDKs and documentation for testing purposes that are not yet available publicly. Apply to become an early adopter by filling out the form for preview access to Azure Communication Services.

Get started with Azure Communication Services by using the Communication Services C# Media Composition SDK to compose and stream videos.


Prerequisite check

  • In a terminal or command window, run the dotnet command to check that the .NET SDK is installed.

Set up the application environment

To set up an environment for using media composition, take the steps in the following sections.

Create a new C# application

  1. In a console window, such as cmd, PowerShell, or Bash, use the dotnet new command to create a new console app with the name MediaCompositionQuickstart. This command creates a simple "Hello World" C# project with a single source file, Program.cs.

    dotnet new console -o MediaCompositionQuickstart
  2. Change your directory to the newly created app folder and use the dotnet build command to compile your application.

    cd MediaCompositionQuickstart
    dotnet build

Install the package

  1. While still in the application directory, install the Azure Communication Services MediaComposition SDK for .NET package by using the following command.

    dotnet add package Azure.Communication.MediaCompositionQuickstart --version 1.0.0-beta.1
  2. Add a using directive to the top of Program.cs to include the Azure.Communication namespace.

    using System;
    using System.Collections.Generic;
    using Azure;
    using Azure.Communication;
    using Azure.Communication.MediaComposition;

Authenticate the media composition client

Open Program.cs in a text editor and replace the body of the Main method with code to initialize a MediaCompositionClient with your connection string. The MediaCompositionClient will be used to create and manage media composition objects.

You can find your Communication Services resource connection string in the Azure portal. For more information on connection strings, see this page.

// Find your Communication Services resource in the Azure portal
var connectionString = "<connection_string>";
var mediaCompositionClient = new MediaCompositionClient(connectionString);

Create a media composition

Create a new media composition by defining the inputs, layout, outputs, and a user-friendly mediaCompositionId. For more information on how to define the values, see this page. These values are passed into the CreateAsync function exposed on the client. The code snippet below shows and example of defining a simple two by two grid layout:

var layout = new GridLayout(
    rows: 2,
    columns: 2,
    inputIds: new List<List<string>>
        new List<string> { "Jill", "Jack" }, new List<string> { "Jane", "Jerry" }
        Resolution = new(1920, 1080)

var inputs = new Dictionary<string, MediaInput>()
    ["Jill"] = new ParticipantInput
        id: new CommunicationUserIdentifier("8:acs:5110fbea-014a-45aa-a839-d6dc967b4175_00000080-fa91-402b-a3a5-42d74e113351"),
        call: "meeting")
    ["Jack"] = new ParticipantInput
        id: new CommunicationUserIdentifier("8:acs:5110fbea-014a-45aa-a839-d6dc967b4175_00000090-20e2-430d-9c34-0e4b72c98636"),
        call: "meeting")
    ["Jane"] = new ParticipantInput
        id: new CommunicationUserIdentifier("8:acs:5110fbea-014a-45aa-a839-d6dc967b4175_00000030-45lk-9dp0-04c8-3ed0023d0ds"),
        call: "meeting"
    ["Jerry"] = new ParticipantInput
        id: new CommunicationUserIdentifier("8:acs:5110fbea-014a-45aa-a839-d6dc967b4175_00000080-09ce-4ac2-8dbf-00533d606db8"),
        call: "meeting"
    ["meeting"] = new GroupCallInput("d12d2277-ffec-4e22-9979-8c0d8c13d193")

var outputs = new Dictionary<string, MediaOutput>()
    ["acsGroupCall"] = new GroupCallOutput("d12d2277-ffec-4e22-9979-8c0d8c13d193")

var mediaCompositionId = "twoByTwoGridLayout"
var response = await mediaCompositionClient.CreateAsync(mediaCompositionId, layout, inputs, outputs);

You can use the mediaCompositionId to view or update the properties of a media composition object. Therefore, it is important to keep track of and persist the mediaCompositionId in your storage medium of choice.

Get properties of an existing media composition

Retrieve the details of an existing media composition by referencing the mediaCompositionId.

var gridMediaComposition = await mediaCompositionClient.GetAsync(mediaCompositionId);


Updating the layout of a media composition can happen on-the-fly as the media composition is running. However, input updates while the media composition is running are not supported. The media composition will need to be stopped and restarted before any changes to the inputs are applied.

Update layout

Updating the layout can be issued by passing in the new layout object and the mediaCompositionId. For example, we can update the grid layout to an auto-grid layout following the snippet below:

var layout = new AutoGridLayout(new List<string>() { "meeting" })
    Resolution = new(720, 480),

var response = await mediaCompositionClient.UpdateLayoutAsync(mediaCompositionId, layout);

Upsert or remove inputs

To upsert inputs from the media composition object, use the UpsertInputsAsync function exposed in the client. Note that multi-source inputs such as group call or rooms cannot be upserted or removed when the media composition is running.

var inputsToUpsert = new Dictionary<string, MediaInput>()
    ["James"] = new ParticipantInput
        id: new CommunicationUserIdentifier("8:acs:5110fbea-014a-45aa-a839-d6dc967b4175_00000030-91cc-4b24-9ae2-505161ad3ca7"),
        call: "meeting"

var response = await mediaCompositionClient.UpsertInputsAsync(mediaCompositionId, inputsToUpsert);

You can also explicitly remove inputs from the list.

var inputIdsToRemove = new List<string>()
    "Jane", "Jerry"
var response = await mediaCompositionClient.RemoveInputsAsync(mediaCompositionId, inputIdsToRemove);

Upsert or remove outputs

To upsert outputs, you can use the UpsertOutputsAsync function from the client. Note that outputs cannot be upserted or removed when the media composition is running.

var outputsToUpsert = new Dictionary<string, MediaOutput>()
    ["youtube"] = new RtmpOutput("key", new(1920, 1080), "rtmp://a.rtmp.youtube.com/live2")

var response = await mediaCompositionClient.UpsertOutputsAsync(mediaCompositionId, outputsToUpsert);

You can remove outputs by following the snippet below:

var outputIdsToRemove = new List<string>()
var response = await mediaCompositionClient.RemoveOutputsAsync(mediaCompositionId, outputIdsToRemove);

Start running a media composition

After defining the media composition with the correct properties, you can start composing the media by calling the StartAsync function using the mediaCompositionId.

var compositionSteamState = await mediaCompositionClient.StartAsync(mediaCompositionId);

Stop running a media composition

To stop a media composition, call the StopAsync function using the mediaCompositionId.

var compositionSteamState = await mediaCompositionClient.StopAsync(mediaCompositionId);

Delete a media composition

If you wish to delete a media composition, you may issue a delete request:

await mediaCompositionClient.DeleteAsync(mediaCompositionId);

Object model

The table below lists the main properties of media composition objects:

Name Description
mediaCompositionId Media composition identifier that can be a user-friendly string. Must be unique across a Communication Service resource.
layout Specifies how the media sources will be composed into a single frame.
inputs Defines which media sources will be used in the layout composition.
outputs Defines where to send the composed streams to.

Next steps

In this section you learned how to:

  • Create a new media composition
  • Get the properties of a media composition
  • Update layout
  • Upsert and remove inputs
  • Upsert and remove outputs
  • Start and stop a media composition
  • Delete a media composition

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