What is HEVC and why is it needed? What is the HEVC video format, what are its advantages and disadvantages? Supports hevc compression standard
20.11.2013
Over the past four years, H.264 has become the dominant video codec in the security industry, but recently a number of manufacturers and experts have begun to push H.265 very aggressively. In connection with the arrival of a new codec, a number of questions arise. First of all, the public is interested in two things: when HEVC will become commonly used and how long this will last. However, the editors are interested in slightly more deeply buried things: for example, who will receive the main benefits from the transition to a new coding standard, and whether this is another marketing trick to shift the market balance towards certain players. Undoubtedly, from the technical side, the new format differs from its predecessors. I would just like to make sure that all the reserves of the “old” H.264 have already been exhausted. After all, changing the format is, in essence, a revolution. For the success of which, as grandfather Lenin said, it is necessary that “the lower classes do not want, but the upper classes cannot.”
The declared key marketing differences - or, in simple terms, the “trick” of the codec, called both HEVC and H.265, are that with the same image quality, the H.265 video stream has half the bitrate than the stream compressed by the H codec .264. For example, if the bitrate for transmitting a 1080p video stream compressed with the H.264 codec at a frame rate of 30 frames per second is approximately 4 megabits per second, then for an image of equivalent quality compressed with the new H.265 codec, the bitrate will drop to 2 megabits per second. It looks attractive, however, as always, the question arises about the price of this transition.
Whether the game is worth the candle is, unfortunately, not for you and me to decide. The position of the Security News editors is known. We advocate the creation of a specialized codec that would take into account all the features and specific requirements imposed on the transmission of video data in security systems. Surprisingly, despite the “multimedia” origin of the H.265 codec, some of “our” needs were taken into account here (read about this below). The last word, as usual in serious industries, always belongs to large manufacturers of equipment and systems. And the “whales” of the security industry are in no hurry to add one to the name of the codec: on the one hand, the maneuverability of production facilities is not so high, and on the other, too much money has been invested in the promotion of H.264 in recent years. Don't let good things go to waste...
Technical differences of H.265
The new codec's improved performance over its predecessors is due to several significant structural improvements. Three of them are decisive: changing the maximum block size, introducing parallel decoding and implementing random access to images within the video stream.
Maximum block size in the H.264 standard it is 256 pixels (16 x16), and in the H.265 standard it can be 16 times larger (4096 = 64 x 64). Interestingly, in the H.265 standard, the block size is selected by the algorithm itself during the encoding process, depending on the content of the encoded image. According to supporters of the new standard, the variable block size and increase in the maximum limit of this size will allow more efficient processing of high-resolution images. By the way, the new standard supports pixel resolutions up to 8192 x 4320 (35 megapixels) - the highest of modern television standards, also called 8K.
Opportunity parallel decoding, provided in H.265 decoders, allows different parts of the same frame to be processed separately and simultaneously. This processing can significantly speed up playback and provides the opportunity to take advantage of multi-core processors, which have gained great popularity in IT-oriented markets today. The H.264 codec did not provide such capabilities.
The new standard provides random access to images(Clean Random Access). This means that a randomly selected frame of a video sequence is decoded without the need to decode any images preceding it in the stream. For multimedia, random access is not critical, but for video surveillance, especially real-time monitoring, this feature is highly desirable: by switching to a specific video stream for reasons of operational necessity, the operator should instantly receive an image on his screen: in security applications one or two seconds may be decisive. Omitting the complex technical details of how this is implemented in the new codec, it is worth mentioning that it does not require the mandatory insertion of intermediate reference frames (I-frames) into the video stream, due to which the bitrate significantly increases.
In terms of the technical characteristics of the encoded video signal, its “upper” Main 10 profile provides higher color quality, since it provides 10-bit color encoding, while all existing standards, including the “lower” Main 8 profile of H.265 itself, provide There are only 8 bits per pixel color attribute.
The standard provides means for automatically determining the scan type, however, unlike its predecessors, the codec is initially focused on processing video images obtained by progressive scanning. But this does not mean that H.265 is unable to work with interlaced scanning - the developers took into account the fact that a fairly large number of systems in operation generate frames from two fields.
But here's what the H.265 codec is significantly lacking: scalable encoding. It was planned to be implemented in H.264, but for some reason this could not be done in any of these standards. The presence of scaling would make it possible to transfer images to clients using relatively slow network connections without wasting additional computing power on additional processing. To some extent, scaling also contributes to a more rational use of video data storage in systems. Currently, scalable encoding is among the planned extensions of the standard. According to experts, the requirement for scalability is largely dictated by the emerging boom in cloud technologies for data storage and processing.
Understanding the HEVC (H.265) standardThe HEVC (High Efficiency Video Coding) standard defines a video compression format intended to replace the previously adopted H.264/MPEG-4 AVC (Advanced Video Coding) standard, jointly developed by the video industry expert group. ISO's Moving Picture Experts Group (MPEG) and the International Telecommunications Union's Video Coding Experts Group (VCEG). The first group of developers gave the standard the internal name ISO/IEC 23008-2 MPEG-H, part 2, and the second - H.265. It is claimed that the HEVC standard allows doubling the compression ratio of digital video data compared to its predecessor or significantly improving image quality while maintaining the data bit density. The new compression algorithm supports the 8K ultra-high definition standard and image pixel resolutions up to 8192 x 4320. The areas of application of the standard are broadcast television, multimedia, industrial television and video surveillance. The official publication date of the first version of the standard is April 13, 2013. A number of positions intended for implementation in the standard remained unrealized at the time of its release, and currently a joint team of experts is working on further extensions of the standard, the most important of which are scalable encoding and 3D video. |
What helps improve image quality
A large number of IT product manufacturers are promoting the H.265 compression format as a means of improving image quality. It should be noted that this is to a certain extent disingenuous. In reality, images compressed with an H.265 encoder have no higher quality than those processed with the H.264 algorithm, which, in turn, is no better in terms of quality than MPEG-4. Since all of the mentioned codecs provide the ability to arbitrarily set the compression level, the quality of the compressed image depends only on the user’s preferences. It’s another matter to fit the video image into the realities of the technical environment. First of all, this concerns network bandwidth resources.
If your network has enough bandwidth to support H.264-compressed images, switching to H.265 compression will not provide any improvement in image quality. Such a transition can only reduce the bitrate, that is, somewhat relieve your network. The only case when switching to a new codec will help improve image quality is if, for reasons of saving bitrate, images were obviously excessively compressed by the H.264 codec, and compression artifacts interfered with the efficient reading of details by operators and video analysts.
Doubts and limitations
Like most modern video codecs, H.265 is most effective (that is, it is able to confirm marketing expectations) in relatively simple surveillance scenes, where there are no sharp changes in contrast and there is no intense movement of objects and backgrounds. The promised saving of 50% in bitrate/storage volume primarily concerns such scenes. That is, in real conditions - at a busy intersection or in a supermarket sales area - the savings figures will be significantly smaller.
In addition, today all the “economic” advantages of the predecessor codec are not really in demand. Most equipment and system manufacturers, in particular, have not made the transition to more advanced versions of H.264 profiles. In video surveillance, three profiles of this standard are most often used. The Baseline profile is the minimum bandwidth savings and the minimum load on computing resources. In the last few years, it has gained the greatest popularity among vendors. The main profile (Main) provides, according to the results of independent tests, a 10-30% improvement in performance compared to the basic one. Over the past few months, manufacturers have shown increasing interest in this particular profile. The High profile provides even more significant benefits, but today the number of vendors that have provided compatibility with this profile can literally be counted on one hand.
In other words, manufacturers have room to develop even without a new codec, without experiencing unnecessary risks and moving along a relatively well-established path. Since the industry, with the transition to IP video, is increasingly becoming “IT”, considerations typical of system administrators begin to work here: what works normally is better not to change or touch at all.
New H.265 HEVC codec
In the near future, all consumer DSLR cameras will be equipped with the H.265 HEVC codec, and it is also planned to use it for streaming 4K movies and videos on servers like Netflix, YouTube and Vimeo . Video editors and simply lovers of high-quality video have the opportunity to encode and watch video in a completely different format.
HEVC is a new codec , which is gaining popularity faster than anyone could have imagined. It turned out to be faster and much more efficient than H.264 and there is every chance that we will all be using it in the next few years. Here are a few things you should know about HEVC:
— HEVC is also known as H.265 . H.265 will replace the H.264 codec, which, according to the ITU, is now used in eighty percent of videos published on the Internet.
— High Efficiency Video Coding (HEVC) is a more successful video compression format than H.264 and AVC HD. The new codec will almost double the encoding efficiency, and this, when compared with H.264, means that when comparing two videos of similar quality, a video encoded with the H.265 codec will need a much lower data transfer rate (lower bitrate), and with the same bitrate, if encoded with the H.265 codec, you can get higher quality video .
— Recent studies say that HEVC is visually better than H264 Tests conducted by independent researchers have shown that the use of H.265 already makes it possible to reduce the bitrate by 25-30%, but at the same time maintain HD video quality identical to that obtained with a higher bitrate when encoding with the H.264 codec.
—File sizes are 50% smaller than H.264
A lower bitrate allows you to get a smaller file size, but at the same time maintain the highest quality, which will allow you to stream or transmit high-resolution video (up to 4K) even over low-bandwidth lines. In other words, if you do not have high-speed Internet, but want to watch movies in high quality, then in this case the H.265 codec will be very useful. To view 4K video encoded in H.265, an Internet connection with a speed of 20-30 megabits per second is sufficient. 
— It can support 4k resolutions up to 8192 x 4320. — The video service Netflix and Amazon are already filming original programs in HEVC 4k for streaming. — No, of course, you shouldn’t expect that tomorrow a new standard will replace the existing H.264, the implementation of which took about ten years. Broadcasters won't be able to deliver HEVC 4K content for several years yet. Tests show that both playback and encoding of video compressed with the new codec require computing resources far greater than those required by H.264. And this, in turn, means that time is needed to prepare and implement new technologies. So we'll have to wait.
- For streaming HEVC 4K content, a 15Mbps stream will be recommended. — You can try HVEC encoding today by downloading DivX software. For high-quality video playback in DivX, DivX Plus HD and DivX HEVC formats with resolutions up to 4K, you will need to install it on your computer DivX HEVC plugin - download from Yandex disk
Additionally, along with codecs, you can install a good converter, for example, you can convert videos to format Plus HD or just saying MKV/H.264, naturally there is support for receiving formats DivX/MPEG-4, but you will have to pay for this, and since the medicine is in the archive, you will not have problems with this. I would like to note that the codec package includes a good DivX H.264 Decoder, it will help accelerate hardware performance using DXVA technology, so you can watch high-definition videos without worrying about the CPU being overloaded.
DivX Plus Converter
In addition to high-quality output of DivX (AVI, DIVX) and DivX Plus ® (H.264 video in MKV container) video, for PC and DivX Certified ® devices, the converter now has convert to MP4
format for good playback on iPhone, iPad and beyond. and with hardware video acceleration*, delivers fast encoding performance that doesn't overload your processor or drain your battery. Designed to quickly and easily convert most popular video formats, the web converter also allows you to customize encoding settings (resolution, file size and bitrate), combine multiple videos into one file, create game tricks for smooth rewinding, and add up to multiple subtitles and audio tracks. Added support for MPG, TS, VOB and SVCD files with MPEG-2/DVD plugin.
The package also includes Plus Player and Web Player
DivX Plus Player Provides the best playback of movies, TV shows and popular web video formats (AVI, DIVX, MKV, MP4, MOV, WMV). With support for advanced features (multiple subtitles, audio tracks, smooth and fast forward), fast transfer to DivX Certified ® devices and new data transfer to DLNA-compatible devices, the player with DivX To Go ® is the only tool you need for high-quality playback HD video from your collection on your computer, or throughout the house.
DivX Plus Web Player Efficiently and smoothly play streaming video, including MKV, right in your browser**. Provides superior HD video quality with 5.1 channel surround sound, multiple subtitles and audio, smooth playback with hardware video acceleration, and the ability to download what you watch on the Internet. Supporting DivX, AVI, MKV, MP4 and MOV video formats, Web Player is an excellent choice for publishing your videos on a website or blog. Adaptive bitrate playback with experimental support for DivX HEVC streams* Supports smooth forward/rewind, episode markers, subtitles and audio tracks Hardware-accelerated H.264 DXVA uses less CPU and battery power *Requires DivX HEVC plugin
DivX Plus Codec Pack Codec Pack includes the latest and most complete set of codecs, filters and splitters for the converter, player and web player. And you can also use Codec Pack profiles to output video to your DivX Certified Home Theater, HD or mobile devices, and use it in conjunction with your video editing applications. With additional encoding settings and hardware video acceleration, this Codec Pack from DivX ensures high-quality HD video viewing on your computer.
High Efficiency Video Coding (HEVC), a video codec also known as the H 265 codec, which compresses more than twice as much as the best video codec for Blu-ray.
I would just call it H 265 because it sounds cool, but its full name is High Efficiency Video Coding (HEVC). It is the new successor to Advanced Video Coding (AVC), a codec also known as H.264, which is one of the main compression schemes used by Blu-ray.
The idea behind HEVC is to offer the same level of image quality as AVC, but with improved compression, so a video file compressed with this codec will be half the size. This is important for 4K/Ultra HD broadcasting (Internet and satellite), 4K Blu-ray and other purposes.
But is it good enough in this regard, how does it work?
Compression (good, bad, lossy)
The amount of raw data coming out of a professional HD camera is enormous. There is no way to conveniently deliver it to your home. Instead, the video is compressed to reduce the amount of data into a more manageable form.
There are many ways to do this, one of the simplest is to reduce quality. In some cases this is normal. Think of YouTube videos with low quality. Not really, right? This is often due to the video being highly compressed (before or during upload).
High compression by different codecs may be technically the same, but depending on the codec, the image may appear softer, noisier, or have strange, distracting artifacts (as shown above).
But that's not a good idea if you want to preserve the director's intent or show off your brand new 77-inch TV.
So another option is to use the best compression. In this case, you can basically think of "better" compression as "smarter" compression. It takes the same original (video) and finds better ways to reduce the amount of data without sacrificing quality. Every few years, transmission processing power has improved enough to allow more processor-intensive compression algorithms to be used, and data to be compressed without degrading quality.
This distinction between "more" compression and "better" compression is important because the terms are not really interchangeable in this context. You can reduce the amount of data required for a signal, either by compressing and degrading the image, or by using more efficient compression ("better" compression).
Let me put it this way. Say you have a bushel of apples. You need to place 100 apples inside. You can do this with more compression (reducing the apples to puree) or with better compression (finding a better way to make them whole while reducing the amount of space they take up).
More Compression: Applesauce
Better compression: more apples, in the same space.
As you can see from this amazing example, "more" compression is easier to do, while "better" compression requires smarter and/or better technology.
Codec H.265
The data flow in 4K video is much stronger than in HD video. While most of us were still getting used to the idea of the H.264 codec being superior to MPEG-2, the Motion Picture Experts Group and the International Telecommunication Union's Telecommunication Standardization Sector (ITU-T) had already begun work on the next generation of video compression. .
Without wanting to make small, cosmetic improvements, whenever a new compression standard is introduced it must be a significant change. With each transition to a new standard, either the video volume becomes two times smaller with the same quality, or the image quality is higher for the same volume.
How did you achieve this? Thanks in large part to the increased use of AVC (and other compression methods).
First, the new codec looks at multiple frames at once to see what hasn't changed in the frame. In most scenes in a TV show or movie, the vast majority of shots don't change much. Think about a scene with someone talking. Mostly the head is in the frame. The background won't change much for many shots. In this regard, most of the pixels that make up the face probably won't change much (except for the lips, of course). So instead of encoding every pixel from every frame, the starting frame is encoded and then (mostly) only the changes are encoded after that.
HEVC then expands the size of the area that these changes are looking at. Larger and smaller "blocks" are essential, providing additional efficiency. They can be larger, smaller, and differently shaped in HEVC than in previous codecs. Larger blocks, for example, have proven to be more efficient.
On the left is AVC/H.264 macroblocking. As you can see on the right there is a lot more flexibility, not to mention larger sizes, for an HEVC/H.265 encoder.
Then other things were improved, such as motion compensation, spatial prediction, etc. All of this would have been done in AVC or even earlier, but it required more processing power than was economically feasible at the time.
During the development phase, the compression algorithm is objectively tested against the effectiveness of its source video. It is also tested subjectively, by video professionals comparing different compression methods in a “blind” test, where they do not know which method is in front of them. Human comparison is critical. Just because the computer says one compression level is better than another doesn't mean it looks better than another.
Since H.265 is much more intensive, don't expect a simple firmware update to get your device to decode it. In fact, this is part of the problem. You need a hardware decoder. Your TV or media player must initially have a decoder; firmware is not enough. Can a high end PC decode it using software? May be.
is that enough?
Well, technically yes, but with a big caveat. Like AVC (and other compression standards), H.265 is configurable based on the required bandwidth. Want 4K on low-speed internet? No problem; increase the compression ratio (remember applesauce?). Want better image quality? No problem; reduce the compression ratio.
While this design provides flexibility, it also means that "4K" and "UHD" do not necessarily guarantee better picture quality than "1080p" or "HD" today. The highly compressed 4K signal looked worse in many ways than the less highly compressed HD signal.
In other words, a 4K stream may look worse than a current 1080p Blu-ray, depending on how much compression is used
And although the processing speed on all devices follows Moore's Law, the Internet bandwidth is limited.
Another advantage
While most of HEVC's potential benefits are focused on 4K, its better compression provides benefits for HD. Lower bandwidth with HD means more people can get HD. People who have low Internet speeds will be able to watch HD video with the new codec. If you have a pay-per-megabyte plan, lower data speeds also mean cheaper HD viewing.
How to watch HEVC.
Clearly, the question immediately arises of how to watch HEVC. There are several solutions, depending on what you have.
If you have a PC and Windows 10, then you can use the application released by Microsoft. is an application that allows you to watch videos in HEVC format on computers. However, it is worth noting that in order for this application to work, you must have a fairly powerful computer, with seventh generation Intel processors. Well, the operating system itself should be Windows 10.
If your PC meets these requirements, then you can get this extension when updating Windows. But if you have not updated your OS, but want to watch movies in HEVC format, then you can download applications from the official Microsoft website.
Player for HEVC.
If you either have a different OS, for example Windows 7, or your computer is simply not so powerful, then you can download a player with HEVC support, for example WindowsPlayer. You can download this player from the official website of the program.
Conclusion
Start looking for HEVC (or H.265) as a feature on TVs, Blu-ray players and other media players in the future. Almost all major models since the 2014 models include the necessary hardware decoder, although it is better to immediately make sure that it really is there than to regret the purchase later.
There was a lot of grumbling about the move to H.264/AVC when Blu-ray arrived. Now the same thing is happening with the advent of HEVC. But lower data rates while maintaining quality are good for everyone.
In this article we will try to understand whether the new generation video codec meets the expectations placed on it?
The next-generation High Efficiency Video codec (HEVC), also known as H.265, was a major milestone for the video industry in 2013. There's been a lot said about H.265 and new video encoding technologies over the past 12 months, but today is the first time you can actually sit down and take a closer look at this next generation encoder (even though it's only in pre-alpha version) and test it out. quality in terms of working with video. We will look at the video display quality and stream compression sizes of the new codec in a single key, comparing it with the previous one - H.264, and also study performance in Sandy Bridge-E, Ivy Bridge and Haswell.
Benefits of H.265
The H.264 codec was quite a successful project. This is a very flexible codec that is widely used in video streaming networks, satellite platforms, and when recording Blu-ray discs. It is quite good at upscaling, which is why it has been proposed as a standard for 3D at 48-60 fps, and even for 4K. And he copes with these tasks quite well. The standard adopted for Blu-ray discs does not yet include any recommendations regarding these technologies, but the H.264 codec itself is capable of supporting them.
The problem with the H.264 codec is that while it is in principle capable of encoding video in these formats, it cannot provide a compression ratio that would make the resulting file sizes acceptable. A new standard was needed that could significantly reduce the size of the resulting files after compression and thereby earn international recognition as a means of promoting new video formats. This is how H.265 was born. It was designed in such a way that using new compression technologies and a smarter encoding/decoding model, the most economical use of channel resources.
Unlike H.264, which although can be used to support 4K television, it was not created for this format, and H.265 was developed taking into account all the features of 4K, including support for 10-bit video and high frame rates. This is just the beginning, and the current, embryonic version of the codec has some limitations. It supports 8-bit color and provides the YUV color model, however, many people would like to see this test version in action. Therefore, a group of researchers, armed only with a compiled encoder and a few test clips, decided to check what the new codec is capable of?
The first thing they were interested in was the file sizes. The researchers decided to compare the sizes of elementary video streams. It should be taken into account that we were talking exclusively about video - the sound was not encoded in any of the cases.
Encoding sizes were determined by the quantizer settings, with lower q-scores corresponding to higher quality (and larger file sizes). The base encoded file consists of 500 frames, its size is 1.5 GB, YUV 4:2:0, frame rate is 50 per second. The raw file size of the stream file was used for comparison because it represents what is passed to the decoder to create the output image. The researchers worked with elementary streams because at this stage of the project (pre-alpha testing), the size of the decoded file is always 1.5 GB, regardless of the quality level chosen when creating it.
This helps to understand the basis of the benefits that H.265 can offer over H.264. And although in most cases it does not provide 50% savings in channel bandwidth, the result is close to this figure. When setting q=24 in the quantizer, we get a file size of 57% of the one created in H.264, when setting q=30 – 59%, and q=40 gives 47%. Of course, when setting q=40, the final file is far from perfect, but it allows you to save bandwidth by more than half.
Performance and picture quality
The next question that interested the researchers was productivity. It is known that compared to H.264, H.265 requires more horsepower for encoding and decoding. However, the developers promise to strengthen the role of parallel computing in encoding and decoding in order to speed up these processes. The implication is that OpenCL support will become real sooner or later, meaning that offerings like AMD's HAS could score extra points from x265 support this year.
The researchers were currently limited in processor choice, but MultiCoreWare spokesman Tom Vaughan assured them that the development team was actively working on multithreading. The research team decided to test the capabilities of the test decoder using Sandy Bridge-E, Ivy Bridge and Haswell. The researchers experimented with several different levels of parallelization, but ultimately decided on the number of physical cores in the system (6, 4, and 4). The hyper-threading feature was enabled, but setting the parallelization to 12/8 threads only slightly speeded up the encoding process.
Parallelization showed good performance results. Sandy Bridge-E with its six cores is ahead of the four-core Ivy Bridge. The Ivy Bridge is also inferior to the Haswell model due to its support for the latest AVX2 and better performance characteristics. If you compare encoding time with x264, even with the slowest settings, encoding with x265 takes much longer. For example, a file that the Ivy Bridge 3770K encoded in H.264 in 129 seconds took 247 seconds to encode in H.265. However, do not forget that we are talking about the very, very first test version.
No less interesting for the researchers was the issue of quality. How different will the quality of a video file encoded in H.265 be from the original uncompressed video? To study issues related to quality, the researchers decided to select a fragment of a basketball game. The file, recorded at 50 frames per second, was full of moments showing fast movements, which very often lead to processor freezes or "jerky" images. Agree, if this “disease” is also characteristic of H.265, then its ability to create relatively small video files will be offset by poor quality.
Elmedia Player for Mac supports h.264 and h.265 codecs.
So, here are screenshots of the original uncompressed YUV video, as well as a video encoded in H.265 with q=24, and a video encoded with H.264 with q=24.
As we can see, the difference here is minimal. The wooden floor under the jumping player is a little less blurry in the H.264 version, but the quality of the H.265 version is phenomenal, despite the file size being about half the size. What about installations with lower quality? Here are screenshots of video encoded in H.265 and H.264 with q=30. The first is a screenshot of a video compressed in H.265.
When setting the quantizer q=30 (file sizes are 6.39 MB and 10.87 MB, respectively), the quality of streaming video using the H.265 codec turned out to be better than that of a stream encoded in H.264. Of course, the group of researchers who conducted these experiments is not going to take the results obtained into absolutes - as always, encoding parameters that require tuning are of great importance. However, after more than a year of waiting, the “genie” called H.265 has finally come out of the bottle, and it is already clear that the new compression standard will be able to live up to the expectations placed on it.
In the meantime, encoding/decoding support will be available in many products very soon. Modern processors are more than ready to decode H.265 with the appropriate software. OpenCL support is expected in the next iterations. And hardware support from GPU manufacturers such as AMD, Intel and Nvidia is a matter of the near future. It may not appear in the upcoming models that are about to hit the market, but it will definitely appear in the near future. These three companies have already included support for additional video sources in their products, as noted in the H.265 presentation, as video becomes commonplace in all devices.
In the long term, H.265 will likely replace H.264 as the premier solution for advanced video processing. However, everything will also depend on how much more battery-draining the process of processing H.265 video will be compared to H.264. We will only be able to find out about this when full-fledged hardware appears to work with this standard, but so far the assumptions are very optimistic. The parallel H.265 encoding model should undoubtedly perform well against the backdrop of multi-core devices of the future.
Starting last year, users began to regularly encounter a new video format called HEVC. In this material we will tell you what the HEVC format is, why it is better than old video encoding formats, than watching files in HEVC format, and how to return to old formats if you have an iPhone.
The abbreviation HEVC stands for High Efficiency Video Coding, which can be translated into Russian as highly efficient video coding. This is a format created to compress video with a resolution of up to 8K (UHDTV, 8192x4320 pixels). Another name for the format is H.265, so HEVC and H.265 are the same thing.
The HEVC format was developed as a replacement for the aging H.264/MPEG-4 AVC format. Work on the new standard began back in 2004, when the VCEG (Video Coding Experts Group) began searching for new technologies that could form the basis of the new standard. Then this project was given the temporary names H.265 and H.NGVC (Next-generation Video Coding). The main requirements for the standard being developed were: reducing the video bitrate, maintaining the current picture quality, and also maintaining the current requirements for computing power.
Development has continued since 2012, when this format was officially approved. But after its release, the format did not gain much popularity; it was used in IP cameras, television broadcasting and other specialized areas. The HEVC format became known to ordinary users at the end of 2017, when iOS 11 was released.
Why HEVC is better than older formats
With the release of the macOS High Sierra and iOS 11 operating systems, Apple began to actively introduce new formats for videos and photos. So, for photographs it is now used, which we have already talked about, and for videos the HEVC format.
The transition to the HEVC format took place for two reasons. Firstly, this format provides higher quality images. And secondly, such video takes up less memory space and requires less network bandwidth when transmitted over the Internet. Simply put, HEVC video provides a significant increase in image quality while maintaining the same file size and bit rate. According to Apple, using the HEVC format can save up to 40 percent of memory.
Frame breakdown into blocks in H.264 (top) and HEVC (bottom).
In order to achieve this improvement in video compression levels, several new approaches have been applied. One such approach is to increase the block size into which the encoded file is split. When encoding video in H.264 format, such a block size is 16 by 16 pixels (256 total), while when using HEVC, such a block size can be 64 by 64 pixels (4096 total). This block increase shows especially good results on high-resolution videos, which is very useful, because the HEVC format supports video with a resolution of up to 8192x4320 pixels.
How to go back to old video formats
As already mentioned, in new versions of iOS and in new iPhone models, the HEVC format is used by default. If the settings are not changed, the camera will save video in HEVC format and photos in HEIF format. But, if necessary, the user can return to using old formats. To do this, you need to go to the iPhone settings and open the “Camera” section.
And enable the “Most Compatible” option.
After enabling this option, iPhone will stop using HEIF/HEVC and revert to older video formats. But such a return will lead not only to increased memory consumption, but also to a limitation on the frame rate. For example, with the HEVC format, the iPhone X camera can shoot FullHD video at 240 frames per second, but after reverting to older formats, this feature becomes unavailable.
How to watch HEVC
When faced with video files in HEVC format, users wonder how to watch such content. Currently, all Apple devices running iOS 11 and Macs running High Sierra handle HEVC playback without any problems. For example, on an iPhone or iPad, such files can be played using the standard Video application or using the VLC Media Player application.
On mobile devices with the Android operating system, you can play HEVC files using MX Player and software decoding (if the device's performance is sufficient).
As for desktop computers running Windows, here, as always, everything is much simpler. You can use programs such as Media Player Classic, Media Player Classic BE, KMPlayer, VLC or GOM Player.
