H.265 (HEVC) Video Compression – How does it differ from H.264

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Everyone has experienced a situation where they are watching an online video, movie, or sporting event when all of a sudden, the screen freezes or the quality degrades. Whatever you’re watching, this sudden deterioration in quality is really annoying. One of the biggest challenges facing end users and systems integrators is the recording and storing of surveillance video as the security industry adopts 4K, Ultra HD, and other high-resolution imaging formats with high bitrates.H.265 Video Compression is a solution for this.

In order to address these issues, manufacturers have developed systems capable of utilizing compression technologies to reduce the data size while still preserving the detail and quality of the video. Therefore, a new technology called H.265 (also known as HEVC, or High-Efficiency Video Coding) has been developed. This guide will explain what H.265 is and its benefits and more.

What is H.265?

According to estimates, HEVC has been able to reduce bitrates by 50% for better video quality when compared to H.264/AVC, which allows for a significant reduction in the amount of storage and bandwidth required for Ultra HD Blu-ray. This is due to the improvements in coding efficiency that HEVC brings, including its use of quadtree-structured block partitioning, intra-prediction modes, and improved motion compensation. This is due to the fact that H.265 utilizes an improved compression algorithm which more efficiently reduces the data necessary to represent a video, while still providing higher resolution and better clarity than its predecessor.

With all of these advantages and improvements, H.265 enables the streaming and downloading of 4K and 8K videos, which were previously impractical due to H.264’s large file size and high bitrate.

How does H.265 Video Codec Work?

In order to take full advantage of the H.265 codec, it is important to understand the Discrete Cosine Transform (DCT) and how it works with the intra and inter-prediction techniques.

The following is an overview of how the H.265 video codec is encoded.

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The first stage of how H.265 compression process entails predicting each unit and carrying out the required computations. In this step, the encoder loads a frame of video units with 16×16 (macroblocks) display pixels. The encoder predicts a value for each pixel in a macroblock by considering nearby values that may have been encoded previously or in the current frame. This involves searching for similarities between the current unit and its neighboring ones, calculating the difference in values, and quantizing it with a smaller number of bits.

The H.265 codec utilizes an approximate form of DCT to quantize and transform the differences between the prediction and the original picture unit, resulting in a set of coefficients that can be further compressed for transmission or storage. Each of these refers to the weighting value of fundamental patterns. In contrast, the DCT transforms 4×4 and 8×8 pixel block sizes into 32×32 block sizes for inter-prediction. Blocks up to 64×64 pixels can be handled by the H.265 codec for intra-prediction!

Entropy encoding is often used as the final step in a data compression system which takes advantage of the natural uncertainty of data to achieve a much higher level of compression than other schemes.

Below is an overview of the decoding process for the H.265 video codec.

In the process of decoding, entropy decoding allows for the efficient recovery of a series of data elements from an encoded sequence. It involves applying the inverse transform to each frame of the video, inverting the transformations, rescaling the image values, predicting each unit, and then adding it to the output of the inverse transform format, recognizable by us (humans).

By isolating static areas, the overall complexity of video compression can be reduced, thereby lowering bandwidth consumption and allowing for more efficient streaming. This technique is known as “motion estimation.” By using this method, the amount of data that needs to be transmitted is significantly reduced.

Benefits of H.265

H.265 Video Compression has various benefits in addition to lowering the size of the final file, including the following:

  • While H.264 only supports films up to 4K at 60 frames per second, H.265 allows videos up to 8K at 300 frames per second.
  • By requiring fewer bits, H.265 is able to encode and decode video streams at a much faster rate than H.264 codecs, allowing for more efficient video streaming and encoding processes.
  • H.265 relies on an enhanced interframe prediction process that uses multiple reference frames from previously encoded frames to produce higher-quality and more detailed images.
  • H.265 codec offers a major leap forward in compression efficiency by supporting larger macroblocks.
  • H.265 utilizes a new, more advanced compression algorithm that helps reduce errors and noise in the image, allowing for better image quality than H.264.
  • The prediction motion used by H.265 is a more complex algorithm that reduces the redundant data found between frames, leading to a higher compression rate and greater image quality.

What are the justifications for switching to H.265?

Here are some good reasons to switch to H.265 Video Compression right away.

When streaming live, an H.265-compatible encoder consumes half as much bitrate as an AVC encoder. Fewer data is used for the transfer, hence more data is saved. Think about how much data is used to stream a 1080p YouTube video in AVC format, which is 8 Mbps, as opposed to H.265 format, which only uses 4 Mbps. The amount of bandwidth needed to provide a lossless feed with AVC while broadcasting at 1080p HD is excessive. For users of data-restricted gadgets like cellular 4G and subscription services for on-demand content, H.265 is essential.

Users will be able to access the same amount of information with less bandwidth because of H.265 and transfer more video data over their current network. The market for professional security will keep creating and implementing more advanced, high-resolution, high-performance cameras. This impressive technical achievement benefits the professional security industry.

In comparison to H.264, the Coding Tree Units (CTU)-based macroblock-encoding technique used in H.265 provides higher compression levels and improved coding efficiency, allowing for more effective data streaming and storage that makes use of inter-frame predictions.

Consequently, there are many applications where the H.265 format is very effective. Several of these applications are:

  • The H.265 encoding standard is designed to support these different color spaces in order to provide a better viewing experience for viewers such as sRGN, NTSC, SMPTE 170M, sYCC, PAL, generic film, Rec. 601, and more.
  • Advances in video streaming technology have enabled the next generation of HDTV displays and content capture systems to offer seamless video streaming and data sharing.

Final Words

The considerably improved efficiency of H.265 video compression has sped up the standardization process. Since it can make premium content accessible and affordable for distributors and users, it appeals to everyone.

The future of video compression will unavoidably be H.265 even though worldwide demand and playback support are still growing. As TVs, laptops, OTT devices, and other user content devices switch to the future standard, having H.265 devices on hand now helps to future-proof encoding efforts. When everyone starts using HEVC, you’ll be in the lead.

We trust that this article offered you a clear understanding of the basics and process of the H.265 compression method. Understanding this may lead you to decide to implement your future project with H.265, in which case we (Vadzo) will be able to assist you.


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