E-commerce: Ultra-low latency live streaming (400–800 ms)

Industry overview

In recent years, an increasing number of e-commerce businesses have adopted live streaming. However, standard live streaming technology often has a latency of 3 to 6 seconds or even longer, which cannot meet the demand for frequent interaction between hosts and buyers. Furthermore, the stability and continuity of audio and video streams can directly impact business conversion rates.

Pain points

• High latency: When viewers ask questions about products, high latency prevents the host from responding in real time, which degrades the viewing experience.

• Frequent buffering: Frequent buffering complaints from viewers often force hosts to switch networks or restart the stream, which reduces efficiency.

• Long wait times when switching streams: Swiping between live streams on a mobile device can cause a multi-second delay before the next video loads.

Solution

RTS uses the UDP protocol and leverages Alibaba Cloud's global network of over 3,200 points of presence (POPs) and full-link optimization technology to reduce the latency of e-commerce live streaming to the sub-second level, down from over 3 seconds with standard live streaming. RTS features low latency, easy integration, and low stuttering.

Advantages

Demonstration

Use case

Taobao Live: Taobao Live has evolved into a new industry for e-commerce in the modern era. Merchants, streamers, and consumers have all embraced the platform. Currently, Taobao Live uses RTS at a large scale. RTS helps Taobao Live reduce latency, minimize buffering, and support tens of millions of concurrent users, boosting its business conversion efficiency.

Prerequisites

• Ensure that ApsaraVideo Live is activated. If not, activate it now.

• An ingest domain must be associated with a streaming domain. For more information, see Associate an ingest domain with a streaming domain.

Limitations

• Web RTS SDK limitations: The SDK does not support video streams that contain B-frames or audio streams that use AAC encoding. If you enable RTS and select Sub-second latency (400ms-800ms end-to-end), the system automatically transcodes streams that contain B-frames or use AAC audio to ensure compatibility. This process incurs a live stream transcoding fee.

• Player requirements: RTS uses the UDP protocol, and the player version requirements are shown in the table below:

  Player type	Description
  ApsaraVideo Player SDK	Version 5.4.5.0 or later
  ApsaraVideo Player SDK	Version 2.0.3 or later

Configuration

1. Log in to the ApsaraVideo Live console.

2. In the left-side navigation pane, choose Live + > RTS.

3. Select a streaming domain.

4. Enable the RTS toggle and select Sub-second (End-to-End Latency: 400-800 ms).

5. To deploy in a production environment, you can integrate the SDK or follow the RTS signaling protocol.

   Note

   You can enable both RTS and standard live streaming (RTMP, FLV, and HLS) on a single playback domain. You can differentiate between them by using the playback URL.

   • An example of a playback URL for RTS is: artc://PlaybackDomain/AppName/StreamName?AuthenticationString.

   • Example of a standard live streaming playback URL: rtmp://{streaming_domain}/{AppName}/{StreamName}?{auth_string}.

Step 1: Generate ingest and playback URLs

Step 2: Ingest stream with OBS

• Open OBS Studio. In the settings, select Stream. In the Server field, enter the generated ingest URL. Example: rtmp://***push1.ialicdn.com/test***/test?auth_key=1643******-0-0-a922892e06ee18016640e0fe14******.

• In the settings, select Output. Set Keyframe Interval to 3 seconds or less, and set the Profile to baseline. Return to the main screen, select a video source, and start streaming.

  Note

  These settings help achieve an ultra-low latency of 700–900 ms.

Step 3: Play the RTS stream

Billing rules

Unlike standard live streaming, RTS is billed according to a new pricing system as follows:

• You are billed based on the RTS billable item, and are not additionally charged for the standard live streaming billable item.

• The billing methods for RTS are the same as those for standard live streaming: billing by data transfer and billing by bandwidth.

• When the billing method for standard live streaming is changed, the RTS billing method is also updated accordingly.

For more information about billing for RTS, see Billing for Ultra-Low Latency Live Streaming.

Promotional offers

For more information, see Free trial for RTS!

• Enterprise users with real-name registration can receive a 10 TB free package. Individual users with real-name registration can receive a 1 TB free package.

• Each Alibaba Cloud account (UID) is eligible for one free trial package. To use the free package, you must select the pay-by-data-transfer billing method.

Can standard live streaming and RTS be used simultaneously for the same live stream?

Yes. For a single live stream, separate playback URLs are generated for standard live streaming and RTS. For example, standard live streaming uses rtmp://PlaybackDomain/AppName/StreamName?AuthenticationString for playback, and RTS uses artc://PlaybackDomain/AppName/StreamName?AuthenticationString for playback.

Can I use a self-developed SDK to access RTS?

Yes. You must follow the specifications of the Alibaba Cloud RTS signaling protocol.

RTS: Which browsers are supported for playback?

RTS allows access via standard WebRTC, which enables playback in any WebRTC-compatible browser. For more information about browser compatibility, see Browser compatibility with WebRTC.