Cloud gaming has only scratched the surface of its potential, but it offers tremendous promise to those who love playing video games and those who provide gaming experiences. This service enables players to access and play a game live-streamed over the internet without downloading it on a local device. Even AAA games can be streamed with near-instantaneous response times for players without the need for expensive PCs or consoles – effectively lowering the cost of access for more gamers. Advances in bandwidth and cloud technology mean that people worldwide can join and compete, collaborate, and watch exciting gaming.
So how does cloud gaming work?
Cloud gaming is changing how gamers engage with their favorite games, allowing them to access platforms and titles hosted remotely in the cloud. With this technology, platforms are completely virtualized in a datacenter, meaning only pixel data is transmitted to the end user at a rate of 30-60 (or much more) images per second via an encrypted stream over the internet, giving gamers unparalleled access to new titles and platform experiences easily and confidently. This data is then accessed using familiar devices such as televisions, laptops, tablets, mobile phones, or purpose-built thin gaming consoles and handhelds.
Four pillars dictate the quality of experience for cloud-based gaming.
1) Bit rate is an important and complex issue when streaming video and audio across the internet. Players of modern games require smooth user experiences to fully immerse themselves in a virtual world, and different games are affected differently by the amount of data streamed to the user’s device. For example, slower-paced RPGs are happier with a lower frame rate than fast-twitch first-person-shooters (FPSs), for which an uninterrupted response time is essential.
Different settings will affect the level of information sent based on the user's particular endpoint device. For example, for a game streamed at 1080p to an HDTV set, 8-15Mbps would need to be delivered to maintain a consistent visual experience. On the other hand, higher bit rates, such as 32-60 Mbps, are necessary for 4K streaming. This poses a challenge as it takes more time to transmit the data, increasing latency and affecting game response times. Another challenge is the cost of offering higher network bandwidth services, which is required to deliver higher resolutions to many current home internet network connections. Thanks to efficient compression software like AV1 and H.265, ultra-high-resolution gaming experiences will soon be delivered at a compressed bit rate.
2) Frame rate plays an essential role in the gaming experience. It refers to the frequency of frames shown on an end-point device, delivered as frames per second (FPS). The higher the FPS, the smoother the gaming experience will feel. This requires a streaming process that entails compressing the display pixels using a codecs and transferring, decoding, and then rendering it on the endpoint device. To help ensure a good gaming experience, it's important to match the FPS with the refresh rate of the endpoint device (measured in Hz). Generally speaking, cloud gaming calls for frame rates between 30fps (for RPGs) to 60fps (for FPP), but this can vary based on each game or system settings.
3) Display resolution is a significant component of the viewing experience, as it directly influences the amount of image detail the player will see. The higher the resolution, the more pixels are used to build an image; thus, more data is needed to ensure evenness and accuracy. As technology evolves, cloud gaming providers strive for higher resolutions, often setting full HD (1080p) as a standard for their platform. Display resolution is important for many people who appreciate watching movies and playing video games at home. Knowing how resolution affects what we see on our screens can help us optimize our experiences accordingly.
4) Visual quality is a critical factor to consider when transmitting data between devices, as it can significantly impact the user experience. Client-side graphics must usually go through a lossy video compression and transmission process, which can degrade visual quality. Choosing the right software to encode, compress and decode the data sent from a data center to another such as a mobile or TV is especially important. There are many types of codecs available. Here are a few of the most commonly used:
- H.264 is a popular and powerful codec used across multiple sectors of the video and audio industry. It compresses digital data with high efficiency and consistency, making it the go-to standard for companies specializing in streaming content, such as Netflix, Amazon Prime, YouTube, and more. To ensure quality standards remain constant with H.264 streaming, users need an internet connection capable of supporting up to 32Mbps files for 4K content. H.264 is a cost-license but is generally inexpensive and the license is easy to obtain.
- H.265, also known as High-Efficiency Video Coding (HEVC), is the successor to the popular H.264 encoding standard and features significant improvements in compression capabilities. It can compress video streams by up to 50% compared to H.264 at the same quality level, allowing 4K footage to be streamed with only 15MB of bandwidth. Additionally, H.265 offers a more practical means of encoding 8K footage for a genuinely high-definition viewing experience. The use of H.265 will also require a license.
- Initially, Advance Video Coding (AVC) and H.264 were the preferred codecs for streaming since they exhibited excellent efficiency and performance while broadcasting content across networks. But with the coming of VP9 in 2013 and AV1 in 2018, the industry gained open-source, royalty-free video codecs that offered better performance than before. AV1 has become particularly popular due to its similar efficiencies to H.265 while not having the same issues around patent and royalty concerns of H.265.
To overcome current internet networks' latency and quality reduction, cloud gaming leaders have been experimenting with compression software such as AV1 and H.265 to facilitate high frame rate, high quality, and high-resolution streaming. That said, due to H.265 royalty concerns this is not looked on favorably compared to AV1 or H.264. H.264 is widely adopted at this time offering more compatible and available hardware to use this codec. AV1 and its future iterations offer high efficiency and provides a royalty-free implementation. However, its success depends on the adoption of hardware encoding and decoding providers, which, admittedly, the market is seeing a good pace in the market.
There is one more area of consideration which falls closely to visual quality. lets call this pillar 4.5.
4.5) Another aspect of visual quality is the color model and depth of an image or video consist of its brightness (Luma) and color (Chroma) information. A technique called sub-sampling takes advantage of the fact that the human eye can detect brightness more easily than colors to provide a way to reduce the data sizes of images and videos further. Viewers can still perceive visuals as high quality if we retain brightness but decrease the amount of color information that needs compression. Cloud gaming streaming currently offers 4:2:0 (quarter the color data), resulting in less sent data and lower latency. However, with technology improving and customer demand for higher quality visuals increasing, considering 4:4:4 for the future of cloud gaming might be necessary. The primary benefit is less blurring and discoloration of text and thin lines resulting in a crisp and sharp gaming experience.
AMD Radeon™ Pro V620 graphics designed for cloud gaming:
- Dedicated dual encode engines – The inclusion of two VCN engines enables each V620 GPU to process double the encode/decode/transcode operations. Those engines take full advantage of AMD infinity Cache technology, which provides each graphics engine with the bandwidth it needs to access data instantaneously. Two VCN engines can provide faster rendering during gameplay, greater efficiency for encoding and decoding live-streamed content, and concurrent transcoding. The result is low latency, high-performance content streaming for a range of different sized end-point devices.
- GPU architecture - AMD RDNA™ 2 architecture delivers exceptional performance and efficiency while the V620’s 72 compute units deliver powerful simultaneous graphics processing. With two VCN engines built directly on the V620, each engine can be dedicated to encode/decode for a single eye of a VR headset, reducing latency and processing times. AMD is working hard with its VR/AR technology partners to further optimize these capabilities.
- Built-in hardware ray tracing - Powered by 72 Ray accelerator engines, the same capabilities in the latest generation of consoles, and the graphics engine support of the latest Vulkan® and DirectX® 12 compounds the ways the V620 GPU can leverage this technology to deliver deeper shadows and crisper reflections in games for the best cinematic experiences.
Cloud gaming offers many benefits for both video gamers and game developers. From a gaming standpoint, cloud gaming could eliminate the need to purchase gaming consoles and PCs: all of the necessary hardware is installed in off-site datacenters. This makes it easy for gamers to jump right into their latest titles without waiting for lengthy game updates. Furthermore, since many of the processes are standardized within these datacenters, game development becomes more efficient and streamlined. Developers can now rapidly code, test, and publish games on one platform to bring their new games to the public more quickly.
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George Watkins is a Product Marketing Manager for AMD. His postings are his own opinions and may not represent AMD’s positions, strategies or opinions. Links to third party sites are provided for convenience and unless explicitly stated, AMD is not responsible for the contents of such linked sites and no endorsement is implied. Third party marks are for informational purposes only and no endorsement of or by AMD is intended or implied.
