Kingsoft Cloud Launches World’s First H5-based KSC265 Decoding Project

Live game streaming platforms has spawned more and more smash-hit games. A playing mode called "Great Escape" has prevailed in the entire game industry. PlayerUnknown’s Battlegrounds ignites the whole world’s passion for competition in a flash, like a fire that faces the wind. Fortnite has carried all before it, and, together with God of War, has set a new record for console games’ monthly income from in-game purchases. Of course, League of Legends remains the most popular game. The scale of PC games continues to skyrocket and will reach $33.6 billion in 2020.

FPS (First Person Shooter) games such as PlayerUnknown’s Battlegrounds are pretty popular and are more suitable for team battles. These games have relatively high requirements on PC hardware configuration. Games like LOL, PlayerUnknown’s Battlegrounds, Fortnite, etc. have extremely complex scenes, therefore, watching live game streaming on PCs which have bigger screen and higher definition will produce a better viewing effect. As a result, these games sweep small and large Internet cafes around China very soon, just like a raging fire. A large number of game players crowd into Internet cafes or stay at home to play the games with their teams on PCs.


But, for live game streaming platforms, the feeling is mixed. The good point is the soaring popularity of the platforms, the bad point is constantly high bandwidth costs. When streamers are live streaming games, the resolution and bitrate of live streams are generally high in order to ensure a high screen definition on PCs. The resolution and bitrate basically reach 1080P and 6Mbps-12Mbps respectively. The high bitrate causes expensive bandwidth costs, laying a heavy burden on lots of live streaming platforms.


Recently, journalists from the telecommunications industry interviewed Huang Huan, the CTO of Panda TV, which is a leader among live streaming platforms, about the problems universally faced by the live streaming industry. Huang Huan said that live streaming platforms have a very high requirement on network conditions, and the high bandwidth costs have become a significant impediment to the development of live streaming platforms. For us, in order to change the status quo, a new technology is in urgent need.

The Replacement of H.264 by H.265 Is an Irresistible Trend

Unlike recorded on-demand videos, live streaming requires the player to acquire and play real-time streaming videos. It is known that, at present, technologies involved in the acceleration of live streaming mainly include CDN, P2P and H.265. For CDN and P2P, the consumption of bandwidth should be reduced without doubt. For H.265, although it’s been popularized on a large scale on mobile phones, it hasn’t had a uniform standard on PCs. Most CDN manufacturers have expressed support for H.265 in their advertisement, but few have a complete solution.


It has been learned that H.265 adopts a hybrid coding framework similar to H.264, based on which it has made a large quantity of technological improvements. Typical technological improvements include: large-size quadtree coding structure, multi-angle intra prediction, motion estimation and fusion technology, self-adaptive motion vector prediction and compensation technology, loop filtering and entropy coding. H.265 possesses excellent network adaptability, parallel processing capability and high compression efficiency. However, its algorithm is 2~10 times more complex than H.264. Thus, real-time coding in H.265 standard has a higher requirement on terminal hardware performance. In addition, when we live stream on PC browsers using H.265 standard, on one hand, the transmission of video streams is better for the same video quality; on the other hand, the video quality is almost doubled for the same bitrate. 


In order to achieve a clear and smooth playing of live streaming on PC browsers, we will need to rely on the HTML5 (hereinafter H5) technology, which is used in the player’s kernel. With the advancement and reforms of technologies in recent years, media players such as Flash have been gradually replaced by H5, meanwhile, there are an increasing number of H5-supporting PC browsers. It is highly possible that the brand new coding protocol H.265 will replace H.264.

Kingsoft Cloud Becomes the First H.265-supporting PCs Service Provider

At the moment, Kingsoft Cloud is known to be the only service provider who is able to apply H.265 to PC browsers in the industry and thus brings benefits to a vast amount of users. Kingsoft Cloud can apply H.265 to various PC browsers, such as Google's Chrome, Microsoft's Edge, Firefox and Apple's Safari, etc. Kingsoft Cloud’s H5-based KSC265 decoding solution has become the first choice for customers of live streaming and video on demand, for its well application to live streaming that requires a high video quality, such as games, sports, and shows, etc.


The WebAssembly technology is now supported by the new versions of the four major browsers. WebAssembly is a bytecode technology applied to web pages. It defines a universal, compact, and fast-loading binary format, and can run nearly as fast as running native machine code with its performance of universal hardware. To decode the videos encoded using H.265 on browsers is a very challenging task, which JavaScript and other scripting languages are not capable of doing. While the WASM generated by WebAssembly can complete this task well. Kingsoft Cloud first developed decoder with WASM format in the industry, enabling PC browsers to decode H.265-encoded videos. This is Kingsoft Cloud’s H5-based KSC265 decoding solution.


It is reported that the entire process of Kingsoft Cloud’s decoding solution is the H5-base software decoding playing plan, that is, to compile the high-performance decoder developed by Kingsoft Cloud into a WASM library using WebAssembly technology. The WASM files exist in a binary form and contain virtual instructions (similar to assembly instructions) which are irrelevant to the platform. The “naked” video streams are sent to the WASM decoder for decoding using JS. Videos in YUV format are produced and then converted to those in RGB format, which are then transmitted to the canvas tag for playing. At the same time, audio files are sent to the audio tag for playing. And the audio and video are synchronized.

Panda TV is to Implement Kingsoft Cloud’s PC KSC265 Decoding Solution in Near Future

In the interview, Huang Huan told the author that Panda TV has successfully conducted internal testing on the decoding solution of Kingsoft Cloud on PCs. In the internal testing, Kingsoft Cloud’s H5-based KSC265 solution can save 30%-50% bandwidth costs and produce videos with higher definition.


In the testing, major PC browsers that support WASM include Edge16 and above, Chrome57 and above, Firefox52 and above, Safari11 and above, Opera44 and above, QQ Browser 10.0, 360 Extreme 9.5 and Sogou 8.0. And major PC browsers that support webGL (webGL is used to call GPU resources in the process of converting YUV format to RGB format after decoding) include: Edge12 and above, Chrome8 and above, Firefox4 and above, Safafi5.1 and above, Opera12.1 and above and China’s browsers.


As for a large-scale promotion in the later stage, Huang Huan said that Panda TV will first promote the decoder on users’ decoding end, and will continue to promote it on the coding end if the promotion on decoding is satisfactory. Huang Huan also admitted that, for live streaming platforms, a stable watching experience is a prerequisite. But, if there are new technologies that can improve efficiency and reduce the consumption of bandwidth while ensuring stability, we are more than willing to try. Since Kingsoft Cloud's H.265 can be applied to PCs, if it is widely popularized, it will undoubtedly have a greater prospect for development.