How to Build a Scalable Video Streaming app architecture
There has been enormous progress in digital video processing and communication technology in recent years. These technologies have enabled the dream of high-quality and real-time video streaming over various networks. The amount of data required for streaming is enormous. Even the bandwidth of communication channels is limited. Fortunately, file compression technologies have overcome these limitations. Wired and wireless communication channels provide a platform for video streaming applications. However, even with all these technological advancements, you can build a video streaming app but still there are some challenges.
The most common issue faced by developers is making their app scalable. Scalability is your app’s ability to handle a growing number of users. It also has to do with the capacity of your current or future developer to maintain the app. If you find yourself asking the question of whether your app can scale up to exponential growth, you are in the right place. To make your app scalable, you need to be prepared to add new features. These features will make your code flexible and keep your app running smoothly.
How do Scalable Applications Work?
On the user’s device, whenever they click on a video, it loads for a few seconds and then starts playing. Let us have a look at how this process works in the backend. After the user makes a request, the app transcodes the video. Transcoding converts a video file from one format to another. This ensures that the video is in a format that works best for a particular device. Transcoding videos enables users to view videos across different platforms and devices.
The most prominent streaming services send their video to their content operation team after they receive it from their video source. Before a user can view a video, it goes through rigorous processing. The most common process includes the following three steps:
Transcoding attempts or data transmission problems can cause color changes or missing frames. Softwares analyze these videos for any digital errors. Detection of errors results in the video being rejected.
2. Parallel Encoding
Most video files are multiple terabyte-sized. It is inefficient to process such extensive data. Hence, the video is first broken down into many smaller fragments. These fragments are then encoded in parallel. Many servers are needed to process all these parts at the same time. Once these parts are encoded, they are validated to ensure no new errors have arisen. Then, they are merged back into a single file and verified again.
3. Encoding Profile
Each device has a video format that looks best on that particular device. Video streaming services use the mass of files created during encoding to support every internet-connected device. All the different formats for a video are called its encoding profile. This profile is optimized for different network speeds. The faster your network is, the higher the quality of the video you will see. Even audio and subtitles are encoded into varying levels of quality and various languages.
Technology Stacks Used by Streaming Services
There are various strategies you can employ to build a video streaming app. These are some of the strategies used by the most successful streaming service, Netflix:
1. CDN (Content Distribution Network)
The idea behind a content distribution network is to put content as close as possible to the users. When the user requests a video, the app will find the nearest server with the video. The app then streams the video from there to the device. The most significant benefits of CDN are speed and reliability. By moving the video source as close as possible to the people watching it, the viewing experience will be much faster and reliable.
Along with the optimization of page content and libraries, the use of CDN also ensures that the application has a faster load time. It loads content from the nearest location of the user. The use of AWS Cloudfront can make a significant difference in terms of loading speed along with supporting caching strategy.
2. Third-Party CDNs
Some streaming services even start their own CDNs, but this can only be done if their video catalog is small enough. If the videos are lesser, one location can store all content. As companies grow, building their CDN makes even less sense. Third-party CDNs allow them to have a global reach instantly using existing services. By outsourcing their distribution networks, services get more time to work on higher priority projects. They can utilize this time to create algorithms to adapt to changing network conditions.
3. Open Connect
In 2012, Netflix launched its dedicated CDN solution to maximize network efficiency. Its own purpose-built CDN has proven to be very advantageous for Netflix. Open Connect is less expensive compared to other third-party distribution networks. It allowed them to control the entire video path. They now have control over transcoding, CDN, and clients. It has also made the app more scalable. Higher scalability is in line with Netflix’s goal of offering its service world over. Their CDN allows them to know who their users are. They even have their own computer system for video storage called OCA (Open Connect Appliances). This helps Netflix make various optimization choices other services cannot make. Their high-performance CDN has allowed them to deliver a superior video viewing experience.
What is HLS Streaming?
HLS stands for HTTP Live Streaming. It is a video streaming protocol for delivering audiovisual media to viewers over the internet. This live streaming protocol was first launched by Apple when they launched the first iPhone. It is used to implement an adaptive bitrate streaming format. The most crucial feature that HLS offers is that it can adapt the bitrate of the video to the actual speed of the connection. HLS streaming videos are delivered from a container format such as mp4. Container formats contain an encoded video and audio track in a single file. This file is then streamed using the streaming protocol.
HTTP Live Streaming is encoded in different resolutions and bitrates. As the connection gets slower, the protocol adjusts the requested bitrate to the available bandwidth. Therefore, it can work on different bandwidths such as 3G or 4G. Hence, it provides the best UX based on the user’s bandwidth.
Check out the meditation app we built using HLS streaming
AWS for Video Streaming
AWS for Video Streaming can be implemented using a variety of protocols that are layered on top of HTTP. Many popular video streaming websites use AWS. Coursera is one of the companies that would not exist without AWS. Coursera relies on it to provide fast and reliable service to users every day. To allow users to watch videos on-demand, it uses Amazon S3 for storage. It uses Amazon Elastic Transcoder for video processing and Amazon Cloudfront for delivery.
Amazon S3 is an infinitely scalable storage facility for your videos. It has built-in redundancy and allows users to pay only for what they use. The Elastic Transcoder takes videos from one S3 bucket and transcodes it as per the users’ request. Then, it stores it in a second S3 bucket. Amazon Cloudfront caches videos at the edges. Therefore, users experience uninterrupted video playback with minimal delays due to buffering. AWS offers global, scalable delivery at a very affordable price point.
Benefits of a Scalable App
Scalability is not something that you can incorporate into an app after development. The development process needs to start with scalability as a priority. Assume that your app will gain rapid success after hitting the market. Hence, scalability is the key factor that contributes to your app’s potential to grow. The following are the benefits of scalability:
1. Maintaining User Experience
If your marketing is successful, you should expect a massive influx of traffic. If your app is scalable, you can accommodate new customers with zero downtime and without sacrificing user experience.
2. Flexible Projects
Sometimes, the code is so complicated that only the original developer can maintain it. With scalable apps, you have the flexibility to hand it off to other developers.
3. More Potential Growth
Scalability testing allows developers to identify bugs and glitches before users do. This results in positive reviews and more potential for growth.
We hope this article helped you understand how to build a video streaming app. These services can be divided into the backend, CDN, and the client. All requests from the client are handled in the cloud. Videos are transcoded into different formats for the best viewing experience. While all these are important, scalability is crucial for your app’s success. If you want to serve millions of users with your app, you need to start planning now. The primary purpose of scalability is to push your app to its limits.