Computers & Technology → Multimedia
- Author Mark Wong
- Published December 15, 2019
- Word count 1,332
Why HEVC better than H.264？
The HEVC codec offers more and better improvements than the h.264 codec, H.264 codec was first developed in 2003, it’s been a while. HEVC offers many new features, but the following benefits are of interest to consumers.
Compared to the h.264 codec, HEVC offers significant improvements in compression. In fact, HEVC compresses video twice as efficiently as h.264. With HEVC, video of the same visual quality occupies only half the space.Alternatively, video with the same file size and bit rate can render better quality.
To better understand the advantages of HEVC, we need to understand some of the concepts of h.264 /AVC.
When you watch a Blu-ray disc, a YouTube video, or a movie from iTunes, it isn’t identical to the original raw video that comes out of the editing room. In order to fit that movie on a Blu-ray disc—or make it small enough to comfortably download from the web—the movie has to be compressed.
Advanced Video Coding, also known as AVC or H.264, is the best standard for video compression in widespread use, and there are a few different methods it uses to try to reduce the file size of your video.
For example, in any given frame, it can look for areas that are mostly the same color. Take this still frame of me and picture—much of the sky is the same color blue, so the compression algorithm can split the image up in to chunks—called “macroblocks”—and say “hey, instead of remembering the color of each pixel, we can just say that all of these chunks along the top are the same color blue.” That’s a lot more efficient than storing the color of each individual pixel, which lowers the file size of the final frame. In video, this is called intra-frame compression—compressing the data of an individual frame.
AVC also uses inter-frame compression, which looks at multiple frames and notes which parts of the frame are changing—and which aren’t. Take this shot from Captain America: Civil War. The background doesn’t change much—most of the difference between frames is in Iron Man’s face and body. So, the compression algorithm can split the frame up into those same macroblock chunks and say “you know what? These chunks don’t change for 100 frames, so let’s just display them again instead of storing the entire image 100 times.” This can reduce file size dramatically.
These are just two over-simplified examples of the methods AVC/H.264 uses, but you get the idea. It’s all about making the video file more efficient without compromising quality. (Of course, any video will lose quality if you compress it too much, but the smarter these techniques are, the more you can compress a video before getting to that point.)
HEVC/H.265 Compresses Videos More Efficiently, Perfect for 4K Video
High Efficiency Video Coding, also known as HEVC or H.265, is the next step in this evolution. It builds off a lot of the techniques used in AVC/H.264 to make video compression even more efficient.
For example, when AVC looks at multiple frames for changes—like the Captain America example above—those macroblock “chunks” can be a few different shapes and sizes, up to a maximum of 16 pixels by 16 pixels. With HEVC, those chunks can be up to 64×64 in size—much larger than 16×16, which means the algorithm can remember fewer chunks, thus decreasing the size of the overall video.
Improved interframe motion prediction
A major factor in video compression is the predicted motion (or lack thereof) between frames. The smart video codec can save space by referencing the pixel while it’s still (solid state background image) instead of reproducing it. With improved motion prediction, HEVC can provide smaller file sizes and higher compression quality.
Improved interframe prediction
Video compression actually benefits from analyzing the “movement” within a single frame, so that the single frame video can be compressed more effectively. This can be achieved by describing the pixel layout using a mathematical function rather than the actual pixel value.This feature takes up less space than pixel data, reducing the file size. However, codecs must support sufficiently advanced mathematical functions for the technology to really work.The interframe prediction function of HEVC is more detailed than that of h.264, which supports motion prediction in 33 directions, while the latter only supports 9 directions.
HEVC can encode and decode the partial unit and fragment layer of the frame independently. This means that the decoding process can be split across multiple parallel processing threads, taking advantage of more efficient decoding opportunities on existing standard multicore processors. With the increasing resolution of video, this efficiency improvement requires decoding video at a viewable speed on low-end hardware.
Maximum higher frame size
The world is becoming increasingly “HD”, and HEVC supports this. Using HEVC, video can be encoded up to 8K UHD or 8192×4320 pixels. Currently, only a few cameras can produce 8K video, and very few monitors can display this resolution.But just as HD is today’s standard, we can expect 4K, or even 8K, to eventually make similar breakthroughs.
HEVC main IPTV program head end system, based on this as the core derived a variety of streaming media applications, such as Netfli, video conference, online teaching system, web celebrity live and so on….
Here is a brief summary about the HEVC hardware and software encoder of the author’s personal choice for your reference:
Explain the importance of encoder in IPTV solution, the core of streaming video and audio encoders is to provide high quality and stable live streaming, then send it to the streaming service for distribution, and finally the client accesses the streaming server to watch the program. Because it is a very important source in the whole scheme, it is necessary to analyze the streaming media video and audio encoders.
1.Hardware video encoders use independent SOC chips to encode and push video and audio signals, the ENC5 Ultra HD h 264 h 265 hardware video encoder encoding algorithm is used to transmit it to the network in the form of network packets. Since it only focuses on one thing, it is stable and has very low power consumption,It can provide 100ms low latency live streaming.As for video and audio quality, it mainly focuses on encoder main chip provider, please check Chip algorithm evaluation. (I recommend ENC5 hevc compression,As shown in figure 3.1)
2.The software encoder adopts the combination of video and audio acquisition card and computer, video and audio signals are encoded and pushed by computer software. 10 years ago, our client would build such a system, but now it is basically on the verge of obsoletion. The advantage of this system is that video has good quality with low code rate and flexible extension function, but running on high code rate or H 265 coding algorithm requires a lot of computer configuration requirements, and it is very unstable to use Windows operating system at the same time,It cannot provide low latency live streaming.(As shown in figure 3.2)
Why Do I Need a Hardware Encoder?
The answer is simply that it really depends on what you’re looking to achieve. The average video streamer using a live streaming service can often get away with using software encoding. However, for professional applications, hardware encoders are turnkey devices dedicated solely to the fast, efficient and reliable encoding of video streams. Hardware encoders have far superior processing power, use high-quality video inputs like SDI and HDMI, and will allow users to stream higher quality video at lower bandwidth rates with lower latency. Example use cases of HEVC encoders by industry include:
Broadcast – for backhaul, live remote interviews, return feeds and remote production
Enterprise – for internet streaming of your all-hands meetings, remote contribution as well as IPTV and digital signage
House of Worship – for online streaming and multi-site delivery
Defense – for mission critical Intelligence, Surveillance and Reconnaissance (ISR) applications
Mr.Wong Mark (Technical Consultant)
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