Last month, “little-known singer” Stefanie Sun once again dominated the search charts, with her live concert receiving more than 100 million likes within 16 minutes of opening. In fact, Stefanie Sun is not the first to experiment with live streaming. Since the outbreak, all online and cloud-based activities have become commonplace. Not only a number of singers have held online concerts, concerts, music festivals, and even dramas that emphasize the sense of presence have begun to be carried out in the form of live broadcasting.
The mobile Internet brings us to the digital economy, and live broadcasting is a very important tool. Whether it is the enduring entertainment live broadcast or the popular answer live broadcast, live broadcast is the flow of these years. What was once a novelty has become a standard for Internet applications, and we have entered the era of “live streaming of everything”.
So how do developers implement a live streaming app? How to guarantee the user’s experience through technical means? This paper will be combined with rongyun in the segmentation of the industry in-depth research and practical experience to answer one.
Live link selection
Briefly speaking, the implementation principle of a complete live broadcast application is as follows: the host collects audio and video, pushes it to the server, and then distributes it to the audience by the server.
The host side is responsible for pushing the stream, so RTC link or CDN link should be configured to distribute live broadcast pictures. If the connection with the mic is involved, it is also necessary to consider how to do MCU convergence. The benefit of audience subscription convergence is to ensure that the dialogues of multiple anchors are basically aligned, and there will be no phenomenon of “slow shooting” caused by a certain anchor’s picture being jammed or delayed when subscribing to multiple anchors due to poor network.
(Live link flow chart)
Several issues affecting the user experience
The core of the competition of live broadcast platforms, whether the fulcrum is anchor or content, is inseparable from the “good” experience of the application itself. From the technical logic, live broadcast should be infinitely close to offline real-time communication, that is, to achieve low delay and high fluency interaction
However, faced with such complex link selection and scene switching in the implementation of live broadcast scenes, live broadcast applications often encounter “bad comments” from users, such as delay, link switching failure and long first screen time, which are also what developers need to focus on.
Latency issue
Early live streaming apps are usually single anchors, which can only interact with viewers through text. At that time, the industry did not have high requirements for real-time broadcast, and software developers generally chose RTMP push-pull stream to distribute the live broadcast images on the CDN link. In this way, the delay between the host and the audience is generally 2 ~ 5s, that is to say, when the audience sees or hears the live broadcast picture, the voice is 2 ~ 5 seconds before the host.
When the anchor interacts with the audience, such as asking what songs they want to listen to, it takes a long time to get feedback results. This situation especially affects the overall effect in the live broadcast of e-commerce. When the anchor releases commodities for the audience to buy, the purchase entrance will appear first, and then the anchor will hear the oral broadcast of “Commodities are on the shelves, quick buying”. This kind of dislocation experience is really not high quality.
To solve this problem, developers must choose a reliable CDN live broadcast acceleration service, or simply choose RTC service for live broadcast distribution. In this regard, Rongyun’s CDN link has in-depth cooperation with domestic head manufacturers to build multi-scene and multi-link switching of interactive live broadcast scenes. In RTC live broadcast, Rongyun has realized the low-delay live broadcast with the delay from the anchor to the audience within 500ms.
(Live link comparison)
Failed to switch links when connecting to mics. Procedure
If the CDN link is used for live broadcast distribution, the switch from the CDN link to the RTC link is required when the audience is switched to the host connected to the mic in the scenario with mics, and the terminal needs to switch the audio and video player. Developers need to maintain the state of the two players, often black screen, lag, etc.
Rongyun fully considers various abnormal situations when switching these two scenes to avoid switching failures, black screen and other problems affecting user experience. When using Rongyun SDK for live broadcast, the single room and the mic can be switched at any time, and the anchor can also conveniently and quickly control the picture style seen by the audience in the room.
(Multi-room anchor with mic)
The first screen takes a long time
With the development of network technology and communication technology, our tolerance for delay is becoming less and less. However, traditional CDN link involves a series of time-consuming operations such as address distribution and data request, which cannot meet users’ requirements of “opening a live broadcast and immediately loading a video screen”.
Rongyun fully considers various scenarios and integrates all kinds of data interfaces when conducting low-delay live broadcast, so that the video can be turned on in seconds, and it only takes 1 second for users to enter the live broadcast room and load the video.
Live stream stability
In terms of ensuring the stability of live broadcast, rongyun’s independently developed algorithm can ensure the reliability of the uplink data of the host’s push stream on the weak network. Even if 40% of video packets are lost and 80% of audio packets are lost, the live streaming service will not be interrupted. In addition, the voice of the anchor can be better transmitted to the audience through 3A processing and bel Canto service.
Both low-latency and CDN links on the audience side can resist weak network, supporting the audience to switch to only subscribe to audio or subscribe to smaller size videos when the network is poor.
Coming back, let’s talk about the benefits of Cloud CDN. First of all, CDN distribution cost is low, and cost consumption is often much lower than RTC link, which is very favorable for price-sensitive projects. Secondly, with the help of rongyun’s worldwide service nodes, the cross-border live broadcast of overseas business can also respond quickly. Finally, Rongyun cooperates with major CDN vendors, which can adjust links according to different project requirements and support video transcoding, encryption and other personalized requirements.
After reading the above sharing, which link do you prefer for content distribution when developing live streaming apps? Welcome to click the link to participate in the interaction, 10 seconds to get rongyun consulting services.