Who is "affecting" video clarity? Let's start with the history of coding development
Latest update time：2024-10-21
Reads：
“
After more than a decade of technological exploration, who is “changing” the video clarity?
”
Author | Dai Congfei
Editor
| Lin Juemin
Recently, a video by the famous B station UP host Yingshi Hurricane, titled "The clarity is not as good as it was 4 years ago! Is the blurry video just your illusion?", has once again aroused the attention of the industry and the public to video clarity. As a result, related terms such as "bit rate, encoding" have also entered the public's field of vision.
Although the video has been removed from the shelves, it has brought the "bitrate" indicator to the public's attention, causing many ordinary users who do not know the reason to easily misunderstand that bitrate is positively correlated with image quality.
So, what are the factors that determine the clarity of a video?
An industry insider told Leifeng.com that bitrate is not the only factor in measuring image quality, but only a parameter that affects the user's viewing experience. In addition to bitrate, the video's frame rate, the encoding technology used, color saturation, etc. will also affect the final presentation of the video quality. Among them, with the advancement of encoding technology, the platform can reduce the bitrate by compressing the size of the video to achieve the same image quality
.
In fact, looking at the history of the development of the video industry, encoding technology is actually the key link in balancing video quality and cost.
It all starts with the history of the development of coding technology.
01
Behind the controversy over image quality: a history of coding technology development
At present, video platforms often use 1080P, 720P, 4K, etc. to simply distinguish video clarity. The number here is what we often call pixel resolution. Generally speaking, the higher the resolution, the more pixels there are, and the finer and more delicate the display effect will be.
Hurricane Video mentioned in its video that if the video data is not compressed at all, one minute of 4K video requires about 44G. This is unacceptable for both users and platforms. In fact, the technical development trend of video platforms is indeed to reduce bandwidth costs by reducing bit rates. But overall, each platform basically reduces bandwidth costs while ensuring picture quality.
Xiaohongshu users discuss related topics
At present, the most widely used encoding format for streaming media platforms is still H.264 (MPEG-4 AVC). Compared with its previous generation H.263, H.264 is more efficient, can save more than 50% of the bit rate (bit rate), provide high-quality video images at low bit rates, and has good compatibility with devices.
As people's demand for video clarity increases, from 720P to 1080P and 4K, the H.264 codec format is increasingly unable to meet the demand. In 2013, H.265, the successor of H.264, was approved by the International Telecommunication Union Telecommunication Standardization Department. Through improved technology, H.265 further saves 50% of the bit rate and supports a maximum resolution of 7680*4320. The latest coding standard H.266 can further save 50% of the bit rate.
The direct result of the upgrade of encoding technology is that, with the bandwidth cost remaining unchanged, users can see more and more 1080P content on streaming platforms.
Currently, H.265 is not widely used. One of the main reasons is that there are too many patent holders and the commercial cost is too high. Therefore, people are in urgent need of a more efficient and affordable codec format.
In 2015, Amazon, Google, Intel and other companies jointly established the Alliance for Open Media (AOMedia), which is committed to promoting the development of ultra-high-definition, data-saving technologies and improving user experience. In 2018, AOMedia announced the AV1 bitstream and decoding process specifications, which were later first applied to YouTube and Chrome browsers.
In China, AV1 is increasingly used. In 2019, Tencent announced that all Tencent Cloud live and on-demand products will support the AV1 standard. In 2020, iQiyi became the first video website in China to enable the AV1 format. Based on the AV1 standard, iQiyi also independently developed the QAV1 encoder to alleviate the problems of high computational complexity and long encoding time of AV1, and accelerate the application efficiency of AV1.
"The advancement of encoding technology is not simply due to the platform's need to reduce bandwidth costs, but also to allow users to see higher quality videos."
said an industry insider.
02
What changes have been brought about by coding technology?
What we can see is that the continuous upgrading of encoding technology, on the one hand, enables users to watch high-quality videos with low bit rates, and on the other hand, it also objectively helps the platform save bandwidth costs.
Since the birth of video platforms, bandwidth costs have always been a major headache for the platforms. As early as 2007, Youku founder Gu Yongqiang once said, "Don't make videos without 100 million yuan," mainly referring to the server and bandwidth costs.
The reason why video platforms actively participate in the research and development and upgrade of encoding technology is due to the difference in bandwidth costs among domestic and foreign operators.
Google is in an absolutely strong position abroad, and operators need to actively seek Google's use, otherwise they may lose a large number of users. At the same time, Google also purchased dark fiber and established its own broadband operator Google Fiber as a bargaining chip in negotiations with operators. This series of operations has saved Google a lot of broadband costs, and YouTube, owned by Google, has almost become a highly profitable business.
In China, the situation is exactly the opposite. Operators are in a strong position, and platforms must pay bandwidth fees to operators to ensure user experience. In other words, domestic video platforms naturally have to pay a huge amount of bandwidth costs more than YouTube, which puts great pressure on the platforms, so much so that the phenomenon of "adjusting the bit rate according to the popularity of the video" mentioned by UP host Film and Television Hurricane in the video appears.
Zhang Chaoyang once talked about the difference in bandwidth costs at home and abroad
A person in the video industry revealed to Leifeng.com that, overall, platforms basically reduce bandwidth costs while ensuring picture quality, otherwise it would be counterproductive to cause user loss. As for the phenomenon of adjusting the bitrate based on popularity, it may exist on some short video platforms because their user base is larger and it is easier for users to watch the same popular video at the same time.
The continuous upgrading of encoding technology has actually helped the platform save bandwidth costs, which also gives video platforms the confidence to invest more in high-quality content and production.
In the past few years, the industry has seen the emergence of high-quality dramas such as "Bianshui Past", "My Altay", "Tang Dynasty Strange Stories" series, and the Zijin Chen trilogy. In terms of image quality, in addition to upgrading encoding technology, the platform is also exploring more cutting-edge technologies, such as HDR (high dynamic range) image technology, to meet users' pursuit of audio-visual experience. Compared with SDR (standard dynamic range), HDR can provide more dynamic performance and image details, reflecting the visual effects in a real environment.
In 2024, after the broadcast of iQiyi's self-produced drama "My Altay", it sparked widespread heated discussions and even boosted Altay's tourism economy. In addition to the healing power conveyed by the excellent original work, the screenwriter's adaptation closely followed the core of the original work, and the series producer's pursuit of video images are also inseparable.
Regarding the "movie-level" texture and lens aesthetics highly praised by the audience, "My Altay" director of photography Liu Yizeng pointed out that Xinjiang's natural scenery and the actors' precise performances have provided a good creative soil for lens expression.
During the broadcast of the TV series, #我的阿勒泰壁纸# was also on the hot search list, which was inseparable from the use of HDR technology. When talking about the color creation of the show, colorist Huang Qian pointed out that "我的阿勒泰" prepared the HDR color version during the filming, which opened up unlimited possibilities for creation in the later stage. It is understood that "我的阿勒泰" opened up the native HDR shooting and production process for the first time, realizing full-link quality control covering shooting, production, production, and broadcasting.
03
Better audio-visual experience is the future
To date, many video platforms are still stuck in the dilemma of user experience and profitability. However, with the advancement of technology, such as the emergence of encoding technology, it is possible to achieve a balance between the two to a large extent - the platform saves some bandwidth costs, and users reduce traffic costs and get a better experience.
Looking back, both the user experience needs and the platform cost control are inseparable from the progress of technology.
From this perspective, the current coding technology upgrade undoubtedly provides a good start and demonstration for the development of the industry.
In fact, over the past decade of development, the platform has not only been exploring how to update encoding technology, but also introduced color adjustment algorithm models, terminal equipment certification standards, etc. to improve user experience.
For example, in 2021, iQIYI announced that all HDR content can support the HDR Vivid high dynamic range video standard released by the World Ultra High Definition Video Industry Alliance (UWA Alliance). This is also the first platform in the industry that can broadcast all HDR content in support of the HDR Vivid high dynamic range video standard.
In addition, iQIYI has also launched the terminal image quality certification standard "FrameQi Yinghua MAX" in recent years, which is committed to exploring how to restore the artist's intention as much as possible from the last link of content playback. During the equipment certification and testing process, directors, producers, colorists and iQIYI FrameQi Yinghua MAX algorithm engineers are almost all involved, not only checking the film source
, but also including the calibration of different terminal device parameters to ensure the final presentation effect of the picture.
For example, the ZREAL frame-sharing standard launched by Youku supports the generation of images at up to 120 frames per second, ensuring sufficient smoothness of the picture, no jitter at high speeds, and a smooth and enjoyable viewing experience.
In recent years, AI technology has entered a golden period of rapid development, and related technologies have also been used in fields such as old movie restoration, allowing users to see classic film and television works in higher definition.
In 2023, the China Film Archive, TikTok, and Volcano Engine launched the "Classic Hong Kong Film Restoration Project" to restore 100 classic Hong Kong films in 4K, improving the film quality in all aspects, including clarity, color, smoothness, and defects.
The head of iQiyi's ZoomAI restoration team said that the application of AI technology has increased the restoration efficiency of classic old films by 500 times. So far, iQiyi has used its self-developed ZoomAI intelligent restoration technology to restore more than 100 classic films released in the last century, including "Scented Soul Girl", "Mu Guiying in Command", "The East is Red", "Li Shuangshuang", "Little Soldier Zhang Ga", etc. Combined with post-production manual retouching, 90% of the restored films have reached 4K high-definition quality.
Not only video platforms are committed to improving picture quality, but also the entire audio-visual industry. The State Administration of Radio and Television has also taken the acceleration of the development of ultra-high definition as an important strategic task. It has taken the lead in pilot projects in Beijing, Shanghai, and Guangdong, and has selected multiple regions to promote the ultra-high definition broadcasting of provincial satellite TV stations. In September this year, the State Administration of Radio and Television mentioned in a press conference that by 2026, the proportion of ultra-high definition in the annual new programs of platforms including iQiyi, Youku, Tencent, Mango TV, Bilibili, and Migu will exceed 50%. Ultra-high definition will become the main presentation mode of radio, television, and online audio-visual.
In general, the development direction of the industry is standardization, standardization and high definition. As for the three dilemmas of bandwidth pressure, user experience and platform profitability, video websites may need more time to explore, and the ultimate solution to this problem may still be technology.
After all, in the long run, as technology continues to upgrade, there is no doubt that users will get better and better audio-visual experience.
//
Recent Hot Articles
京公网安备 11010802033920号