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 User Datagram Protocol (UDP). 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 only to add an RTS streaming domain to ApsaraVideo Live. This way, you can pull streams over various protocols. The following figure shows the architecture of RTS.
- 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 Flash Video (FLV) or HTTP Live Streaming (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 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 | |
| RTS 2.0 | RTS 1.0 | ||
| 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 ARTC protocol, which is based on WebRTC, is supported. | Playback of streams over the RTMP, FLV, and HLS protocols is supported. |
| End-to-end latency | 200 to 400 ms | 500 to 1000 ms |
|
| Requirement | RTS SDK must be integrated on the stream ingest and playback sides. | RTS SDK must be integrated on the playback side. | None. |
| Resistance to poor networks | You can smoothly play streams even at an end-to-end packet loss rate of 30%. | You can smoothly play streams even at a playback-side packet loss rate of 30%. | Standard streaming has a limited capability to perform under poor network conditions. |
| Compatibility |
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| Coverage | Global | Global | Global |
| Best practices | A live streaming latency of 200 to 400 ms is achieved. For more information, see Reduce the latency to 200 to 400 ms. | A live streaming latency of 500 to 100 ms is achieved. For more information, see Use RTS. | For more information, see Get started with ApsaraVideo Live. |
Scenarios
| Type | Scenario |
| RTS |
|
| 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 figure compares the effects of RTS and standard streaming.
Applicable scenarios
| Scenario | Description |
| Education 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 of RTS is different from that of standard streaming. The following rules apply:
- You are charged based on the billable items of RTS rather than those of standard streaming.
- The billing options used for RTS and standard streaming are the same. You can pay for RTS by traffic or bandwidth.
- If you change the billing option of standard streaming, the billing option of RTS also changes.
For more information about the billing of RTS, see Billing of RTS.
Demos
You can scan the following QR codes to install RTS demos. Alternatively, you can copy the URLs that are displayed after you scan the QR codes to a browser to download and install the demos.
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 to contact Alibaba Cloud technical support. For more information, see Contact us.
