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How to Choose Live Video Call SDK

How to Choose Live Video Call SDK

You may use live video calls every day, including live video conferences in Zoom, live video chats for random dating, interactive live video calls with the host in a live streaming room, or live video calls through Whatsapp with your family. Live video calls have been so common that you have got so used to them as an alternative to telephone calls.

If one day your company assigned you a task to build a live video call feature for your company’s app, how would you proceed? You start with a few things, such as reasoning, and research, and finally, come to a preliminary resolution.

What is the technology behind a live streaming call? It offers real-time voice and video communication for a one-on-one session or multi-party session. Video and video data are pretty bulky but can tolerate losses, so they can be transmitted with UDP. The transmission must be coordinated and routed dynamically, with an intelligent algorithm, so there must be a signaling center.

After thinking hard and drafting a few architecture diagrams on the whiteboard, you start to research with Google and read through some blogs and solution slides. You may find it very hard to build real-time video technology from the ground up. The feasible ways to proceed include using live video call SDKs from vendors, or building the RTC technology based on open-sourced projects like WebRTC or FFmpeg.

Why Shall We Use Live Video Call SDK

Cracking WebRTC or FFmpeg requires a large amount of time and human resources, and the learning curve of multi-media theory and technology is very steep. It won’t be easy for your team, whose expertise is in business application development. It won’t be a good idea to hire a new team with the right expertise to develop the technology in-house because of the high cost of human resources. Even if you are determined to invest the time and money, the quality of an RTC technology based on open-sourced projects cannot be guaranteed.

The most feasible choice for you would be to choose a good live video call SDK from technology vendors and build the live video call feature by calling video call APIs, while focusing on your own business. There are four great advantages of using live video SDK to build the live video call feature:

  1. No investment in human resource

You have to set up at least a 6-member team to develop live video technology. And it is a long term matter to maintain and grow the team. The investment in the team would be stunning.

  1. No investment in backend infrastructure

To accelerate data transmission and guarantee live video call quality, you have to construct a data transmission network to transmit multi-media data. The data network will consist of a large number of data centers and dedicated leased lines.

  1. No investment in system maintenance

System maintenance is an ongoing task, and it will involve continuous investment in a maintenance team. System accidents like breakdowns are inevitable headaches.

  1. Fast go-to-market

It is paramount to be quick in market competition. When you observe a trend, or you come up with an idea, it is important to implement and verify the idea promptly. Your fortune will be gone if it is delayed for a long time.

There are many great choices of live video call SDK on the market. The best of them include ZEGOCLOUD, Twilio, and Vonage, who provide easy-to-use and powerful live video call SDK to help you build live video call features within a couple of hours. In particular, ZEGOCLOUD even offers UIKit edition of its live video SDK. It can help you customize the GUI of your APP quickly.

What Are The Use Cases of Live Video Call SDK

There are many use cases of live video SDK. The way that you are going to use it will fall into one of the categories.

  1. Online Social and Entertainment

Live video dating and live video streaming both fall into this category. In the live video dating scenario, a live video call allows the two people to see each other through interactive video, and build up stronger relations that lead to meeting offline. In a live video streaming scenario, a live video call allows the host to speak with audience members or guests interactively. The interactive live video streaming helps hosts to build a more sticky and interactive atmosphere, and drive revenue to grow.

  1. Online Education

Small classes and medium classes require interaction between teachers and students. The teacher asks questions, and students compete to “stand up” and answer the question through a live video call. Students raise their hands for questions, and the teacher allows a student to “stand up” and ask questions. The whole class will be able to see the teacher and the speaking student in conversation on video.

  1. Video Conferencing

Video conference is a typical scenario where all participants expect to see and hear anybody in the conference. Therefore, it is essentially a multi-party live video call. What makes video conferencing different is that it allows participants to turn on or off their video camera, and mute or unmute their microphones; of course, the hosts have permission to control participants’ voice and video status.

  1. Video Customer Services

Traditional customer services are based on telephone calls. One typical pain point is that it is very inconvenient for the customer to submit documentation to the customer service staff. Another typical pain point would be that the customer service staff cannot do identity authentication by looking at the customer’s face. Live video calls can help online customer services become more effective and efficient. For example, It has become popular that stock brokers adopt video customer services to help new customers to sign contracts and open new trading accounts.

  1. Telehealth

Normally, the telehealth scenario requires a one-on-one live video call. The doctor and patient can speak plainly in the live video call for diagnosis. What makes it different is that the patient might need to submit historical reports to the doctor. If it is a diagnosis conference among doctors, it will require sharing of medical reports that are of super high definition. And it is possible that doctors want to look at the extra sound scanning video remotely through the live video call. ZEGOCLOUD has successful customer cases like this in the telehealth field.

  1. Live Online Events

Normally, events are hosted offline for advertisement and branding purposes. However, in the prolonged pandemic circumstances, it has become popular to host live events online through live streaming. Well-design events invite audience members or VIP guests to go on stage to speak. In live online events, interactive live streaming technology allows hosts to invite audience members or other VIP guests to join an interactive video call. All the audience members can see the video conversation.

The Typical Features of Live Video Call SDK

It is pretty straightforward to understand what typical features a live video call SDK shall offer. Basically, it must be able to support one-on-one and multi-party live video calls, and voice calls are supported at the same time by default.

There are implicit demands for the qualities of real-time video and voice. In terms of the quality of the real-time video, it must allow adjustment of various levels of definition, high definition such as 1080P and even 4K should be supported. Regarding the quality of real-time voice, acoustic processing, including acoustic noise suppression, acoustic echo cancellation, and automatic gain control, must be done nicely.

There are other typical features that won’t be seen obviously. We are going to cover a few of them. For more information, please refer to the real-time voice section of the ZEGOCLOUD documentation center as a reference.

  1. Video Stream Mixing

It allows you to mix two or even more video streams into one single video stream (voice stream is included by default). Normally, stream mixing is used in a broadcasting scenario, i.e. Live video streaming to a large audience.

Stream mixing consists of a few steps. First, multiple streams are decoded and de-capsulated. Second, they are mixed and synchronized with time stamp alignment. Finally, the mixed streams are encoded and capsulated in the form of an RTMP stream. The mixed stream will be forwarded to a CDN for high concurrency distribution.

There are a few benefits of video stream mixing. First, it reduces the complexity of receiver end development since there is only one stream to proceed, and the video layout is fixed already. Second, it reduces the processing workload at the receiver end, and more importantly the cost of bandwidth. Finally, it makes stream processing, like forwarding to CDN, easier. Anyway, it is simpler to process one single stream than many streams individually.

  1. Playing Stream From Media Files

Normally, Live video call SDK providers, like ZEGOCLOUD, will offer you a media player that is much more powerful than an ordinary media player. For example, the ZEGOCLOUD media player can allow you to play a media file loaded from local storage, and publish it to ZEGOCLOUD’s real-time data transmission network simultaneously. In addition, during a live video call, if you load a background music file to play by the media player, it will mix the music audio stream with the vocal audio stream captured from the microphone, and then publish the mixed stream to the real-time data network.

  1. Playing Stream From Network URL

ZEGOCLOUD’s media player can also play voice/video streams with network URLs. It works similarly to playing streams loaded from local files. If the network resource is a video one, then the media player can play and render it. In addition, the media player will mix it with the live video captured from a local camera device and publish the mixed stream to the real-time data network. In that sense, you can implement a scenario where users can watch a movie together while they are on a live video call session. Please refer to the “watch together scenario” in the “Our UIKits” section for more information if you are interested.

  1. Screen Sharing

It has been a standard feature of video conference systems or online classrooms. It seems so ordinary but you may not know what is behind it. It looks similar to the remote screen control feature, but in fact, it is totally different. The remote screen control feature offers a screen view where the remote screen is rendered in a progressive manner. The screen sharing feature actually captures the screen pictures and generates a stream to be played at the receiver end. The sender screen will be used as a video source or a virtual camera . The receiver is actually watching the live video stream on the sender’s screen.

  1. Local Media Recording

The feature allows you to record streams and save them as media files locally. You can start previewing and recording the video source as a media file without publishing the video as a stream. Of course, it will give you the freedom to publish the stream while recording during the live video call. ZEGOCLOUD offers a flexible function that allows you to start and stop recording anytime and generate a short video clip of the ongoing live video call.

The Advanced Features of Live Video Call SDK

There are many advanced features offered by live video call SDK, but we are not going to go through all of them. I will introduce a few important ones. To learn more, please refer to the real-time video section of the ZEGOCLOUD documentation center.

  1. Video Watermark

It allows you to display text or image content on video frames as the watermark. You can pass text or image files into the live video call APIs to achieve that. Video watermarks can help you to demonstrate your brand, and also make it difficult to steal or edit the content of the video.

  1. Video Snapshot

It allows you to generate video snapshots of ongoing video calls. It can let you determine the definition level of the snapshot pictures. If the bit rate and definition of the ongoing video call cannot satisfy your requirement, the feature will increase the bit rate and definition temporarily to create the snapshot.

  1. CDN Distribution

To support high concurrency at a low cost, CDN is an economic choice. The feature allows you to publish a stream directly to a CDN, or forward a stream from the real-time data network to a CDN. ZEGOCLOUD supports the aforementioned functionalities. In addition, ZEGOCLOUD provides a unified live streaming solution that combines the real-time data network and CDNs together. ZEGOCLOUD’s live video call SDK allows you to forward live video streams to a ZEGOCLOUD-selected CDN. If the performance of the CDN cannot satisfy the service level, ZEGOCLOUD will use its real-time data network to support content distribution. In that way, the quality of live streaming is guaranteed, and the cost of distribution is well-managed.

  1. H.265 Encoding and Decoding

H.265 is the new generation of video encoding and decoding standards. ZEGOCLOUD’s live video call SDK supports H.265 since September 2021 ( version 2.12.0). With H.265, the live video call SDK can reduce the cost of bandwidth significantly at the same level of quality requirement, and can improve the quality of video significantly at the same level of bandwidth budgeting.

  1. Stream Encryption

ZEGOCLOUD gives you the right to decide if you want to encrypt video streams. In fact, video stream data with ZEGOCLOUD is safe even without encryption since ZEGOCLOUD uses a proprietary UDP-based protocol to transmit data, and very strict authentications are conducted. If you want to encrypt, you encrypt at the sender’s end, and you have to decrypt with the decryption key at the receiver’s end. While the streams are encrypted, in-stream level processing, such as stream mixing and video beautification, cannot be done.

  1. Customized Video Processing

There are various kinds of customized video processing, including customized video capturing, customized video pre-processing, and customized video rendering. Customized video capturing means that the live video call SDK doesn’t capture video from the physical camera, but it obtains video data from a different source, and the video data is processed for purpose. Customized video pre-processing means that you can get raw video data from the SDK, process it, and then put it back to the SDK. Normally, it is designed for video beautification or enhancement. Customized video rendering means the live video call SDK won’t render video for you, and you want to get video data from the SDK to render video on your own. Normally, you want to process the video data before rendering, or you have a special way to render the video better.

How to Choose Best Video Call SDK

After going through the above sections, you have already developed a pretty comprehensive overview of the live video call SDK, and you should be already savvy about how to choose the live video call SDK itself. However, to make a good decision, you have to think outside of the box and look at a few other dimensions.

  1. Quality and Performance

Live video call technology is a tough one, and it is difficult to test either. The good thing is that ZEGOCLOUD has provided comprehensive demo APPs for you to compile and test right away, and those demo APPs are not open-source. You have to design comprehensive test cases to test the demo APPs, compare various vendors’ metrics, and evaluate them. For example, you might need to simulate weak network conditions to different stress levels and see how the demo APPs perform. At the end of the day, it is the quality and performance of the solution that counts the most.

  1. Successful Customer Cases

If you are an entrepreneur who owns a startup, it is very difficult for you to test the demo APPs thoroughly. Testing itself posts some cost, and it requires technological expertise. In that case, you can surely leverage the vendor’s successful customer cases. Big customers are strong in technology, experienced in business requirements, and very strict with vendor evaluation. If they choose a vendor, you follow their steps and take less risk. For example, ZEGOCLOUD has been on the market for more than 7 years, it has served more than 4000 customers globally, including big brand names like Uplive, Liveme, Yalla, Mico and TAL.

  1. Easy to Integrate

It is very important to make sure that the live video call SDK is easy to integrate. At the startup stage, the market is changing rapidly, and competition is hot. It is paramount for you to verify your idea, get funding, or convince big customers. You cannot bear that burden of wasting weeks integrating. ZEGOCLOUD has offered a better way to accelerate integration. It provides a UIKit edition for its live video call SDK, which allows you to build power live video calls into your app easier and quicker. More importantly, it allows you to customize the GUI of your app freely, saving a lot of time in developing the GUI yourself.

  1. Comprehensive Support

This aspect is quite hidden, however, it is very important. To make integration quick and easy, you need comprehensive documentation, nicely designed demo APPs and their source code, and a professional technical support team. ZEGOCLOUD is savvy about the client’s requirements, and makes great arrangements, and offers the aforementioned support to you.


It is a complicated process to choose a good live video call SDK. ZEGOCLOUD offers you abundant documentation for research and a great demo APP to trial. Even better, ZEGOCLOUD offers 10000 minutes of usage for free each month. If you want to know more about live video call SDK, and want to speak with an expert, please don’t hesitate to contact us.

ZEGOCLOUD With our fully customizable and easy-to-integrate Live SDK, you can quickly build reliable, scalable, and interactive live streaming into your mobile, web, and desktop apps.

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