Unlike traditional one-way live streaming, which often results in low viewer engagement and conversion rates, ApsaraVideo Real-time Communication (ARTC) transforms passive viewers into active participants with features like voice chat, video co-streaming, and interactive gaming, enhancing user engagement and connection. This topic introduces the product architecture, use cases, and features of ARTC.
Product architecture
Powered by an advanced technical architecture and optimized algorithms, ApsaraVideo Real-time Communication (ARTC) provides developers and enterprises with efficient, stable, and easy-to-use SDKs and APIs. It supports seamless integration across platforms, including iOS, Android, Web, and Windows. You can also integrate ARTC with other Alibaba Cloud services to create solutions for a wider range of business scenarios.
Use cases
Social voice chat
Supports up to 50 simultaneous speakers with an end-to-end latency of 150–400 ms. Audio features include voice effects, reverberation, and vocal enhancement. To ensure content compliance, ARTC provides content moderation services and third-party integration capabilities, helping you quickly launch a complete solution. For more information, see Voice chat room, Online karaoke, and Real-time audio and video calls.
Voice chat room
| Online karaoke
| Real-time audio and video call
|
Interactive co-streaming
Enable interactive scenarios like streamer-viewer co-streaming, streamer battles, and multi-host sessions. This feature provides an end-to-end latency of 150–400 ms and allows viewers to seamlessly join or leave the stage. It integrates with Alibaba Cloud's standard live streaming and Real-Time Streaming (RTS) to support over 100,000 concurrent viewers. For more information, see Interactive co-streaming.
Streamer-viewer co-streaming
| Streamer battle
|
AI-powered real-time interaction
Quickly build AI-powered audio and video calling applications. With a simple, no-code workflow, you can create a dedicated AI agent in as little as 10 minutes to interact with end users in real time over the Global Realtime Transport Network (GRTN). For more information, see AI-powered real-time interaction overview.
Voice call
| Avatar call
| Vision call
|
Features
Feature | Description | Common use cases | Billing |
Video call | One-on-one or group video calls with support for HD resolutions including 480p, 720p, and 1080p. | 1-on-1 video calls, multi-person video conferences, video customer service, and real-time audio and video calls. | |
Voice call | One-on-one or group voice calls. | 1-on-1 voice calls, multi-person voice conferences, and voice chat. | |
Interactive video | Multi-person video interaction with resolutions up to 1080p and end-to-end latency within 300 ms. | Real-Time Streaming (RTS), streamer battles across channels. | |
Interactive audio | High-fidelity voice interaction with a 48 kHz sampling rate. | Voice chat rooms, online karaoke, and co-streaming. | |
Cloud recording | Records audio and video streams to Object Storage Service (OSS) or ApsaraVideo VOD. | Archiving, compliance reviews, etc. | |
Cloud transcoding | Ensures smooth, high-quality transmission and playback of audio and video content across various environments. | Recording format conversion. | |
Stream mixing and relay | Mixes multiple streams based on defined rules and relays the output to ApsaraVideo Live or third-party platforms. | Multi-view live streaming, large-scale multi-party conferences, and multi-teacher collaborative classes. | |
Audio moderation | Seamlessly integrates with Alibaba Cloud's audio moderation service or supports manual integration with third-party moderation services. | Business security checks, content compliance, etc. | |
Video moderation | Seamlessly integrates with Alibaba Cloud's video moderation service or supports manual integration with third-party moderation services. | Business security checks, content compliance, etc. | |
Face retouching | Provides multiple editions of the Queen SDK with retouching and special effects. | Video calls, interactive streaming, online classes, etc. | |
Reverberation | Supports various reverberation effects, such as hallway, church, studio, basement, and concert hall. | Voice calls, video calls, voice chat rooms, online karaoke, etc. | Free of charge |
Voice effects | Supports various voice effects, such as electronic, elderly, deep male, and high-pitched female voices. | Online karaoke, voice chat rooms, etc. | |
Smart noise reduction | Intelligently eliminates ambient noise, suppresses sudden sounds, and cancels feedback from multiple devices while maintaining high-fidelity voice reproduction. | Voice calls, multi-person conferences, etc. | |
Low-latency in-ear monitoring | Feeds a user's real-time voice back to their headphones or other output devices with minimal delay during audio capture, processing, and playback. | Interactive streaming, online karaoke, recording studios, etc. | |
Audio 3A processing | Includes Acoustic Echo Cancellation (AEC), Automatic Noise Suppression (ANS), and Automatic Gain Control (AGC). | All scenarios involving voice communication. | |
Screen sharing | Shares a user's desktop, a specific window, or a selected region with other users and supports simultaneous display of the camera feed. | Online classes, remote assistance, etc. | |
Spatial audio | Uses specialized audio technology to simulate how sound propagates in a three-dimensional space, creating an immersive audio experience with a sense of space, direction, and depth. | Online karaoke, voice chat rooms, etc. | |
Custom audio and video input | Allows users to input audio and video data from external sources. | Custom face retouching, custom sound effects, etc. |
Core advantages
High-quality global service: A global network of over 3,200 PoPs supports ARTC, ApsaraVideo Live, and ApsaraVideo VOD, ensuring high availability worldwide. This network includes 9 media centers in Beijing, Shenzhen, Shanghai, Qingdao, Singapore, Germany, Japan, Indonesia, and Saudi Arabia, and 3 stream mixing and relay centers in Shanghai, Singapore, and Riyadh.
Security and compliance: ARTC meets global calling regulations and holds comprehensive certifications for privacy protection standards.
Diverse product integration: Combine with other Alibaba Cloud products such as ECS, OSS, security services, ApsaraVideo Live, ApsaraVideo VOD, digital avatars, and AI to build one-stop solutions.
Easy integration:
UI Kit Integration: Provides open-source UI sample code and components to simplify the development process. For more information, see Interactive streaming scenarios.
Scenario-based API integration: Encapsulates low-level, atomic API calls into business-centric interfaces to reduce development complexity. For more information, see Client-side API.
Multi-scenario best practices: Provides solutions for a wide range of scenarios, including 1-on-1 calls, interactive co-streaming, voice chat rooms, and online karaoke. For more information, see Scenario-specific solutions.
Usage limits
User capacity per channel:
Interactive mode: By default, a channel supports up to 17 users on stage (streamer role) and 1,000 users off stage (viewer role).
NoteIn interactive streaming scenarios, you can relay the stream to ApsaraVideo Live to support an unlimited number of viewers.
Communication mode: By default, a channel supports up to 50 users.
Each user can simultaneously publish one main stream (audio-video, audio-only, or video-only) and one screen sharing stream.
Key concepts
This section describes key concepts related to ApsaraVideo Real-time Communication.
Concept | Description |
SDKAppID | ApsaraVideo Real-time Communication uses applications, identified by an SDKAppID, to manage your services. You should create a separate SDKAppID for each of your services to isolate business logic and configurations. |
ChannelID | A channel, identified by a ChannelID, is an audio and video space defined by ARTC. Users in the same channel can interact with each other. ARTC also supports cross-channel interaction in specific scenarios. |
UserID | A UserID is a unique identifier for a user within an ARTC application. Each UserID must be globally unique within the same application. |
Token | A Token is a security signature designed by Alibaba Cloud to prevent unauthorized use of your cloud services. You must provide the SDKAppID, UserID, ChannelID, Timestamp, and Token in the login function of the relevant SDK. |
Stream | A stream is a continuous flow of audio and video data that is compressed, encoded, and transmitted over a network for real-time playback. |
Publish | The process of uploading a user's local audio and video data to ARTC servers. This action is also known as stream ingest. |
Subscribe | The process of pulling audio and video data from ARTC servers to a user's local device. This action is also known as stream pulling. |
Role | ARTC has two user roles: streamer and viewer. A streamer can both publish and subscribe to streams, while a viewer can only subscribe. Users can switch roles during a session. |
Stream mixing and relay | You can use stream mixing and relay to combine multiple audio and video streams, configure the layout and encoding parameters, and then relay the processed stream to ApsaraVideo Live or a third-party live streaming platform. After relaying the stream to ApsaraVideo Live, you can leverage its features for transcoding, recording, and live playback. |
SEI | Supplemental Enhancement Information (SEI) is a component of video encoding standards like H.264/AVC and H.265/HEVC. It is used to carry additional information related to the video content. |