Using the Amazon Chime SDK - Amazon Chime

Using the Amazon Chime SDK

Developers can use the Amazon Chime SDK to build real-time media applications that can send and receive audio and video and allow screen sharing. The Amazon Chime SDK works independently of any Amazon Chime administrator accounts, and it does not affect meetings hosted on Amazon Chime. Instead, the Amazon Chime SDK provides builder tools for developers to use to build their own meeting applications.

Amazon Chime SDK Prerequisites

Using the Amazon Chime SDK requires the following:

  • The ability to program.

  • An AWS account.

  • An IAM role with a policy that grants permission to access Amazon Chime API actions used by the Amazon Chime SDK, such as the AWS managed AmazonChimeSDK policy. For more information, see How Amazon Chime Works with IAM and Allow Users to Access Amazon Chime SDK Actions in the Amazon Chime Administrator Guide.

  • For the majority of use cases, you also need the following:

    • Server application – Manages meeting and attendee resources, and serves those resources to the client application. The server application is created in the AWS account and must have access to the IAM role mentioned previously.

    • Client application – Receives meeting and attendee information from the server application, and uses that information to make media connections.

Amazon Chime SDK Concepts

The following terminology and concepts are central to understanding how to use the Amazon Chime SDK.

meeting

An ephemeral resource identified by a unique MeetingId. The MeetingId is placed onto a group of media services that host the active meeting.

media service group

The group of media services that hosts an active meeting.

media placement

A set of regionalized URLs that represents a media service group. Attendees connect to the media service group with their clients to send and receive real-time audio and video, and share their screens.

attendee

A meeting participant that is identified by a unique AttendeeId. Attendees may freely join and leave meetings using a client application built with an Amazon Chime SDK client library.

join token

A unique token assigned to each attendee. Attendees use the join token to authenticate with the media service group.

Amazon Chime SDK Architecture

The following list describes how the different components of the Amazon Chime SDK architecture work together to support meetings and attendees, audio, video, and screen sharing.

Meetings and attendees

When the server application creates a meeting using the Amazon Chime SDK, the meeting is assigned to a region-specific media service group. The hosts in this group are responsible for securely transferring real-time media between attendee clients. Each created attendee is assigned a unique join token, an opaque secret key that your server application must securely transfer to the client authorized to join the meeting on behalf of an attendee. Each client uses a join token to authenticate with the media service group. Clients use a combination of secure WebSockets and DTLS to securely signal the media service group, and to send and receive media to and from other attendees through the media service group.

Audio

The media service group mixes audio together from each attendee and sends the mix to each recipient, after subtracting their own audio from the mix. Audio is sampled at a rate of 16 kHz and encoded using the Opus Codec.

Video

The media service group acts as a Selective Forwarding Unit (SFU) using a publish and subscribe model. Each attendee can publish one video source, up to a total of 16 simultaneous videos per meeting. Each attendee can also subscribe to all other videos in the meeting except for their own. Video is sampled at a rate of 15 frames per second and encoded with a variable bitrate codec.

Screen sharing

The client application samples screen shares at a rate of 3 frames per second. The media service group republishes the stream to screen share viewers as a stream of difference-based macro blocks.

Amazon Chime SDK Quotas

Resource Quota

Attendees per meeting

100

Audio streams per meeting

100

Video streams per meeting

16

Screen shares per meeting

1

Video resolution up to 1280x720 is supported, depending on CPU and bandwidth availability. Video limits are dependent on camera capabilities. For more information, see Bandwidth Requirements in the Amazon Chime Administrator Guide.

Amazon Chime SDK System Requirements

The following system requirements apply to applications created with the Amazon Chime SDK.

Amazon Chime SDK for JavaScript – Supported browsers

  • Mozilla Firefox (version 60 and later), for macOS and Windows

  • Google Chrome (version 78 and later), for macOS and Windows

  • Chromium-based Edge (version 79 and later), for Windows

  • Chromium-based Electron (Electron 7 and later, with Chromium version 78 and later)

  • Safari (version 12 and later, audio and video only, no screen sharing)

  • Opera (version 66 and later)

Amazon Chime SDK for iOS

  • iOS (version 10.0 and later)

Amazon Chime SDK for Android

  • Android OS (version 5.0 and later)