Are we technologically ready for the coming era of high-definition video?

[51CTO.com original article] Almost no one doubts that the future will be the era of big video - but the big video here does not refer to the Internet video websites that provide film and television works, nor the live broadcast platforms that are in full swing, but a new media era of ubiquitous video information generation, dissemination, and on-demand. In this era, we will reproduce images from all corners of the world and the virtual world through terminals, and their real-time and clarity are not comparable to our current ordinary TVs.

This is not a fantasy! On March 22, Tian Jin, deputy director of the State Administration of Press, Publication, Radio, Film and Television, said that CCTV and provincial TV stations with conditions are encouraged to explore the establishment of a 4K ultra-high-definition television (UHDTV) program production and broadcasting system; it is planned to build a high-definition and ultra-high-definition hybrid broadcasting system by 2018, and to achieve ultra-high-definition experimental channel broadcasting by 2020.

So the question is: What technical challenges do we face in the era of HD and UHD video? Are we ready?

[[186854]]

Three major technical challenges of broadcasting and television systems in the era of high-definition video

First of all, we need to clarify a concept. What are HD and 4K ultra-high definition? This actually refers to the resolution of the video.

From a technical perspective, Ultra HD is actually a concept derived from the 4K digital standard. The standard 4K resolution can reach 4096×2160 pixels locally, while Ultra HD is slightly lower, with a resolution of 3840×2160 pixels. The high-definition that we often talk about now generally only has a resolution of 1280*720 - that is, the resolution of 4K is about 9 times that of the current high-definition.

So, if we want to have ultra-high-definition video around us, we need at least two conditions: first, broadcasting organizations (including media, broadcasting and television operators, etc.) produce video content that meets ultra-high-definition standards and transmit it to thousands of households; second, we have 4K terminals that meet the standards to display it. The latter problem is that the 4K TV, which has become popular now, can be said to have been basically solved; but the former problem, whether for media organizations or operators, faces many problems.

Wu Min from the Broadcasting and Television Media Cloud Technology Industry Alliance said in an interview with 51CTO reporters that there are still three major problems that need to be solved in order to achieve the collection, production and transmission of ultra-high-definition video content.

First of all, the shooting of original video materials needs to meet ultra-high-definition standards, including cameras, acquisition equipment, and other major equipment in the current studio, all of which need to be updated - for radio and television media, this is a considerable equipment investment.

The second problem is the editing and production of video programs. After the original material is recorded, it needs to be processed by the editing department. On the one hand, the processing capacity of the non-editing equipment is greatly increased, and on the other hand, the bandwidth for material transmission is high. The video material shooting, collection and production departments of various media are often not in the same physical location, and need to use the station network, dedicated line or public network for transmission. After the application and promotion of cloud technology, media departments began to try to use public clouds to share and transmit media material content. Material storage, transmission and content security protection are all issues that radio and television media are more concerned about in exploring the use of public clouds. As mentioned earlier, after the resolution is improved, the volume of the unit original material video file has increased by more than ten times; and the material of the video program is often very large, so new problems will arise in the matter of transmission.

In order to solve the problem of video transmission in the network, the proxy bitstream processing method is generally used to reduce bandwidth pressure. The original video material is compressed and encoded and transmitted to the editing side for editing and production. At the remote end, the operation is matched to the original material with high bitrate for one-to-one correspondence. In order to ensure the clarity of video production, it is necessary to adjust the appropriate compression and transmission parameters. Bitstream is also called bitrate (Data Rate), which is the data flow used by the video file in a unit of time. For the same resolution, the larger the bitstream, the smaller the compression ratio and the higher the quality of the transmitted picture; of course, the larger the bitstream, the larger the problem volume. The calculation formula is file volume = time * bitstream rate / 8. For example, the bitstream of a general high-definition video is 10Mb. According to this calculation, the size of a 90-minute video file is 5400 seconds * 10Mb / 8 = 6750MB, which is 6.59GB. Do you think it is much larger than the movies you watch on the Internet? That is because the resolution is much worse; and for professional radio and television media, in the era of ultra-high definition, a bitstream rate of 10Mb is far from enough. But just this bit rate is already too much for the current public cloud. Wu Min told 51CTO reporters that domestic manufacturers are also launching high-definition video editing and production products on public clouds. 20M bandwidth can support fast editing and fine editing of high-definition videos, but in the field of ultra-high-definition, the requirements for uploading and downloading content are relatively high. She once tried to use a well-known public cloud for relevant tests. With a bandwidth of 100m, ultra-high-definition lossless original materials (400M bit rate) require 2 to 3 times the transmission speed. The fast editing of ultra-high-definition content requires comprehensive GPU processing power and bandwidth. As an exploration, GPU-based ultra-high-definition content production can be realized, but from the perspective of actual application, it is still some distance away from practical use. Therefore, in order to enter the ultra-high-definition era, breakthroughs and improvements must be made in the field of media cloud.

The third question is how to deliver the produced high-definition programs to the majority of users through operating organizations (such as Gehua Cable), or how users can realize video on demand through operating organizations. Unlike what some people think, the bottleneck here is not the network bandwidth - in fact, the produced videos will be transmitted as video streams according to standard encoding (such as H.265), and the existing coaxial cables and so on can basically meet the application. The main bottleneck in the process of video transmission to users is actually the bandwidth resources occupied by the existing broadcast content. Each operating organization allocates bandwidth resources in advance according to the business structure. If these resources are used for previous high-definition, standard-definition and 3D businesses, there may not be enough space to transmit ultra-high-definition programs. Therefore, in order to ensure the online broadcast of ultra-high-definition programs, some existing businesses must be cleared.

Technical solutions for the media dedicated cloud era

From the above analysis, we can conclude that the first difficulty is mainly related to the image recording equipment. At present, the technical problem has been solved, and the main problem is money. The third problem is mainly about resources and business strategy. The second problem involves the construction of the basic platform in the ICT field, which is also our concern: Are we ready for the technology?

Wu Min told me that in fact, in the past one or two years, both globally and domestically, the deployment of corresponding solutions has been accelerated to prepare for the arrival of the ultra-high-definition video era. As for specific technical issues, Huawei is the most authoritative to explain this issue globally! As far as China is concerned, whether it is coaxial, FTTH optical fiber transmission or even long-distance microwave transmission in the transmission field, or in the field of servers and storage, Huawei has been at the forefront of the market. Recently, Huawei has also been working with the radio and television industry to build a variety of new business models such as media cloud, government cloud, and smart cities. Therefore, 51CTO reporters found Zhang Weijun, director of Huawei's China Radio and Television Media Business Department, to understand the future technological changes in the two major trends of the ultra-high-definition video era and all-media integration.

Zhang Weijun said that the radio and television industry is indeed facing many new business challenges, including integrated editing and production, 4K ultra-high-definition video, new value-added services, etc. Analyzing the technical requirements behind these business levels, there should be three major technical changes:

***It should be said that it is a storage challenge. Video is the most important resource of traditional radio and television media. Previous video resources and future ultra-high-definition videos will bring greater capacity and faster response speed requirements for video resource storage, retrieval, and playback, which is a huge challenge for storage technology.

Second, as Wu Min introduced above, it is the IPization of the matrix on both ends of gathering, editing and broadcasting. Due to the high requirements for network response speed and transmission quality, this challenge is very great.

The third is media cloud. Previously, all media used private cloud, but with the market demand, public cloud has become a direction that media must consider, especially in the news field. The urgent need now is to achieve multiple ways of collection and distribution, and to put the collection and rough editing on the cloud.

The reporter asked Zhang Weijun, what did Huawei do in the face of this change?

Zhang Weijun said that Huawei actually only focused on two things: first, improving coding to reduce the pressure on bandwidth in the era of ultra-high-definition video. In fact, Huawei is one of the developers of the next-generation video compression standard in the world. Second, expanding the infrastructure pipeline to "prepare for a flood like the Pacific Ocean."

The so-called expansion of pipelines actually includes many aspects. At the backbone network level, China has entered the 100G era a few years ago. Currently, 400G has been commercialized and 800G is also being tested. It can be said that Huawei has made preparations to ensure that there will be no problems at the "backbone road" level in the 4K era. At the same time, Huawei is also preparing for network transformation from the input end to the master control broadcast end, and has launched corresponding solutions in areas with relatively high video requirements such as CDN and transcoding functions. In terms of storage, Huawei has also become the leader in the new share of the domestic market and is actively helping many media customers build video resource libraries. It can be said that Huawei is ready for pipelines in the era of ultra-high-definition video.

The reporter noticed that in these preparations, the application level was not mentioned. Zhang Weijun introduced that Huawei's strategy is "not to touch applications, not to touch data", but Huawei provides open and advanced IaaS and PaaS platforms, and actively cooperates with ISVs in the media and broadcasting industries, opening up various platform interfaces to them to jointly provide better solutions. So far, Huawei has more than 570 partners in the broadcasting industry, and has formed in-depth cooperation with almost all major solution providers in the video industry. It has also established many successful cases in the broadcasting field across the country, which can even be said to be model projects.

Zhang Weijun said that the big video industry will arrive in the next two to three years, not only ultra-high-definition video, but also smart cities and smart homes will be promoted simultaneously. The corresponding ICT technology platform is ready, and only the east wind is needed!

[51CTO original article, please indicate the original author and source as 51CTO.com when reprinting on partner sites]