Real-Time Streaming (RTS) is a value-added feature in ApsaraVideo Live. This feature provides easy-to-access live streaming services characterized by low latency, high concurrency, high definition, and smooth playback. This topic describes basic information about the RTS feature and shows you how to use the feature.

Introduction

The RTS feature is developed based on ApsaraVideo Live. This feature supports latency monitoring during the entire live streaming process, reconstructed CDN transmission protocol, and optimized underlying technologies such as UDP. The RTS SDK is integrated with ApsaraVideo Player SDK. Compared with conventional live streaming that has a latency of 3 to 6 seconds, RTS supports the playback of tens of millions of concurrent streams at a low latency of milliseconds. You can use RTS to reduce the latency and video stuttering, and ensure instant loading and smooth playback for live streaming.

Architecture

To use the RTS feature, you need to only add an RTS streaming domain to your ApsaraVideo Live service. This way, you can pull streams over various protocols. The following figure shows the architecture of RTS.

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Note
  • Streams are ingested based on Real-Time Messaging Protocol (RTMP). The network quality of the stream ingest client, group of pictures (GOP) size of the stream, and player cache all affect the latency of the entire live streaming process.
  • The streaming URL for standard streaming over RTMP starts with rtmp://. The streaming URL for standard streaming over FLV or HLS starts with http://. The streaming URL for RTS over UDP starts with artc://.

Differences between RTS and standard streaming

You can smoothly upgrade from standard streaming to Real-Time Streaming (RTS). If you are using standard streaming, you can enable RTS in the ApsaraVideo Live console to use the standard streaming and RTS services at the same time. If you fail to use RTS to play a stream, you can use standard streaming to play the stream. This ensures the reliability of your business.

Differences

Item RTS Standard streaming
Streaming protocol Playback of streams over the Alibaba Real-Time Communication (ARTC) protocol, which is based on Web Real-Time Communication (WebRTC), is supported. Playback of streams over the Real-Time Messaging Protocol (RTMP), Flash Video (FLV), and HTTP Live Streaming (HLS) protocols is supported.
End-to-end latency Streams over ARTC are transmitted by using the User Datagram Protocol (UDP) protocol and have a latency of less than 1 second.
  • Streams over RTMP or FLV are transmitted by using the Transmission Control Protocol (TCP) protocol and have a latency of more than 3 seconds.
  • Streams over HLS are transmitted by using the TCP protocol and have a latency of more than 6 seconds.
Resistance to poor networks RTS has a strong capability to perform under poor network conditions. You can smoothly play streams even at a packet loss rate of 30%. Standard streaming has a limited capability to perform under poor network conditions.
Compatibility
  • Native: RTS is compatible with iOS, Android, macOS, and Windows.
  • Web: The compatibility rate for devices is greater than 94%.
The compatibility of standard streaming varies based on the protocol.
Stuttering rate Compared with standard streaming, RTS significantly reduces the end-to-end latency, while keeping the stuttering rate unchanged or slightly lower.
Concurrency Tens of millions of concurrent streams are supported.

Scenarios

Type Scenario
RTS
  • Highly interactive scenarios: RTS is commonly used in e-commerce live streaming, group live streaming, education live streaming, and enterprise live streaming. The low latency and high interactivity of RTS help improve business conversion and user engagement.
  • Scenarios that require screen consistency among multiple viewers: RTS is also commonly used in live streaming of events. RTS allows audience to know situations in the field in real time and avoids screen inconsistency among the audience.
Standard streaming Weakly interactive scenarios: Standard streaming allows audience to watch streams. However, inconsistent screens may be shown to the audience due to different network conditions.

Effect comparison

The following video compares the effects of RTS and regular live streaming.

Scenarios

Scenario Description
Educational live streaming RTS supports online large classes, in which a large number of students can interact with teachers online at a low latency.
E-commerce live streaming RTS allows sellers to communicate with buyers, answer questions from buyers, and exchange product information with buyers in real time.
Sports live streaming RTS can be used to broadcast events such as sports and e-sports in real time.
Interactive entertainment RTS allows streamers to give real-time response when viewers send virtual gifts. This delivers a more interactive and engaging experience to streamers and viewers.

Billing

The billing for RTS is different from that for standard streaming. The following rules apply:

  • You are charged based on the billable items of RTS rather than those of standard streaming. This way, you are charged for the streams only once.
  • The billing method used for RTS and standard streaming must be the same. The pay-by-data-transfer or pay-by-bandwidth metering method is supported.
  • If you change the billing method of standard streaming, the billing method of RTS also changes.

For more information about the billing of RTS, see RTS fees.

Demos

You can scan the following QR codes to install RTS demos. Alternatively, you can copy the URL that is displayed after you scan the QR code to a browser to download and install the demos.

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Consultation

If you have questions or suggestions when you use RTS, join the DingTalk group by searching for the group number 44533142 or scanning the following QR code. This group is used for RTS technical support. For troubleshooting and quality tuning, submit a ticket.

DingTalk group for technical support