Hi, everyone. Welcome to the tenth and last chapter in our Tencent Cloud SysOps Associate course. Tencent Cloud Video Services. At the end of this chapter; you'll be able to explain the basics of video services, describe Tencent Cloud's Cloud Streaming Services CSS service and describe Tencent Cloud's video On Demand VOD service. In this chapter we'll cover three sections; Basic video knowledge, Tencent Cloud's CSS service and Tencent Cloud's VOD service. This video will cover the first section, basic video knowledge. Subsequent videos will cover the remaining sections. Let's get started with Section 1, basic video knowledge. In this video we'll cover; an introduction to video services and Tencent Cloud's video services. Let's start with an introduction to video services. In this subsection we'll cover; the development of video services, the categories of video services and the key elements of video services. Video services have changed substantially in the last 100 years. In the 1940s the dominant video platform was the Black-and-white TV. In the 1950s the dominant video platform was the Color TV. Later in the 1990s the dominant video platform was the Digital TV. Finally, in the 2000s the definition of a dominant video platform expanded it to include various types of devices such as the HD or UHD digital TV, tablets, phones, virtual reality headsets and more. These devices provide media content to users via streaming over the internet. At the beginning of the 21st century many end user devices started to support videos. With the development and popularization of these end user devices, video services also became diversified. Examples of video services include Cable TV, which is a traditional method of acquiring video streams via TV. Live Broadcasting, which involves live streaming on multiple devices. Video On Demand, which distributes pre-recorded videos to multiple devices anytime and anywhere and Time-Shifting, which is a combination of live broadcasting and video on-demand equipped with additional features such as replaying and editing. As video services have developed, the demand for higher resolution has increased with advancements in graphic quality. Now let's compare traditional video services and Cloud-based video services. Traditional video services must focus on IT infrastructure construction, IT infrastructure operation management, application development, recording, uploading, transcoding, storage, distribution and playback and video content. In contrast, Cloud-based video services only need to focus on video content production and operations. As a result, traditional video services are inflexible and not secure, and involve high costs and complex Ops. In contrast, Cloud-based services are elastic and secure, and involve low costs and simple Ops. There are four main categories of video services; live broadcasting, video on demand, video processing and real time video. Live Broadcasting use cases include; live game broadcasting, live show broadcasting, live the e-commerce broadcasting, online education, radio, TV and new media. Video on demand use cases include; video portals, e-commerce, copyright protection, the radio and TV industry or OTT users and short video applications. Video processing use cases include; video websites, online videos, the radio and TV industry, OTT smart TVs and e-commerce. Real time videos use cases include; video calls and low latency live broadcasting. Now let's move on to the key elements of video services. Each video has a corresponding resolution, frame rate and a bitrate. The table on the right lists several common resolutions such as 4K, 2K, FHD, HD and SD. Within a video, each pixel contains color space and bit depth information. Color space information is stored according to the RGB system or the CMYK system. The bit depth is determined by how colorful an image is. Because videos are often too large to be efficiently transmitted to the end-user, they first need to be compressed, necessitating the use of encoders and containers. Encoders compress videos by encoding them. Examples of encoders include; mpeg-1, mpeg-2, mpeg-4, h.264 and h.265. Containers wrap the encoded videos into different file formats such as.mp4,.mkv and.rmvb. Lastly, since videos are made up of numerous images, or in other words frames, frames per second is a metric used to measure the number of images a video contains. Finally, let's take a look at Tencent Cloud's video services. Tencent Cloud's video services include services for the cloud and services for end-users. Services for the cloud include; real-time video, cloud communication, cloud transcoding, VOD, live broadcasting, TESHD and video analysis. Services for the end-user include; the short video SDK, the beauty special effects SDK, the mobile broadcasting SDK and the video player. Tencent cloud also offers several video solutions including; commercial live broadcasting, slow live broadcasting, interactive live broadcasting, Tencent extreme speed high definition, TESHD, video analysis, digital copyright protection, video alarms, VR videos and online knowledge contests.