New experience of mlvb cloud live broadcast: millisecond low latency live broadcast solution (with live broadcast performance comparison)

With the continuous expansion of mobile live broadcast scenes , From the beginning of the traditional scene , For example, outdoor exploration 、 Online online classes have gradually appeared in selfie talent or game live broadcast 、 New types of scenes such as interactive answer or live broadcast of sports competitions . meanwhile , These new scenarios have a common requirement for mobile live broadcast, that is, lower latency .

Based on this demand , Extended based on Tencent cloud MLVB Mobile live broadcast low delay live broadcast scheme —— Live broadcast , The full name is Live Event Broadcasting perhaps LEB. Today, Zhimi technology will analyze the advantages and specific performance of this low latency live broadcast scheme .

Advantages of fast live broadcast

• Millisecond delay

because MLVB The live broadcast plug-in adopts UDP Communication protocol of , Therefore, it can still be implemented in the case of high concurrency 1 Delay within seconds , That is, the delay reaches the millisecond level . Compared with ordinary mobile live broadcast, it may be as high as 5 Second is more fluent . At the same time, it can also take into account the situation of second opening and Caton .

• Strong compatibility

Fast live broadcast products have low latency , It is still compatible with the push-pull stream in the standard mobile live broadcast 、 transcoding 、 Recording 、 Screenshot 、 Chi Huang 、 Play and other full functions . Therefore, engineers can develop from ordinary MLVB Move live broadcast to LEB Fast live Application .

• High coverage of server nodes

Because the product is backed by Tencent cloud , Therefore, fast live broadcast has also distributed server acceleration nodes all over the world , Currently, there are 2 Thousands of nodes , covers 25 A country . meanwhile , The supported bandwidth also exceeds 100T

• Quick start

As a mobile live broadcast MLVB A product branch of , Fast live also uses standard protocols , Therefore, connect with other platforms and APP It's also relatively simple . In Google browser and Apple's own Safari Can be played directly in .

• Network fluctuation resistance

It is also due to fast live broadcast and MLVB They are all under Tencent cloud product line , Therefore, high-quality cloud servers can ensure the quality of video streams in a relatively weak network environment .

• Web Low delay

at present CDN Live broadcast only supports HLS Format stream , But the playback delay of this format is also up to several seconds . And fast live broadcast can also support web side playback , And there is only a delay of hundreds of milliseconds .

• Seamless multi rate switching

Seamlessly switch transcoding streams with different bit rates , There will be no interruption or jump in the switching process , Realize the smooth transition between appearance and hearing .

• Adaptive rate control

Adaptively adjust and switch different code streams according to the network bandwidth , Ensure smooth playback experience when different network conditions change

Effect comparison ： Normal network environment vs Weak network environment

• Test scenarios

The host side uses RTMP Push flow , The audience plays separately FLV And fast live streaming , Statistics of Caton rate and other indicators . The anchor is a lossless network , Different weak networks are set on the audience side for testing . The main test indicators are frame rate and Caton rate .

• Streaming parameter configuration

The resolution of the ：1080P

Bit rate ：1800 kbp

Frame rate ：15 frame / second

• Comparison of key indicators of live broadcast

Video frame rate

• Video card frame rate

•   Audio card frame rate

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Parameter description  

Video card frame rate ： The video rendering interval is greater than 500 Milliseconds are regarded as stuck , The total of all the jam times divided by the total playback time is the jam rate

Audio card frame rate ： The audio playback interval is greater than 500 Milliseconds are regarded as stuck , The total of all the jam times divided by the total playback time is the jam rate

Video frame rate ： Video frames per second

Data sources ： live broadcast SDK Advantages of fast live broadcast