The age of 1080p videos is fading and it’s being replaced with 4K videos. We’ve all adjusted to crispier video quality. If you’re researching TVs or screens that output the best display, you’ve certainly seen the '4K’ term being thrown around. However, if you’ve been a long-standing advocate of good video quality, you’ll know that storage is always a plight. 1080p videos do take up a decent amount of space, but 4K videos are extreme.
A single hour of a 4K video totals up to 100+ GB. This ridiculous amount of data has to be compressed, as it is with all other video formats, and the technology that promises great compression efficiency is the HEVC.
High Efficiency Video Coding or H.265 is a complex algorithm that compresses your video and resizes it to smaller units. To understand why HEVC is so great, we’ll need to understand how it differs from the current standard - Advanced Video Coding (AVC)/H.264.
Raw footages can never be streamed or downloaded since their sizes are enormous. Therefore, compression is necessary. The algorithms in compressors use different techniques to compress the video. Intra-frame compression takes a single frame of a video and breaks it down into chunks called macroblocks.
If the frame is of the sky, then the idea is to match all the pixels with the same color instead of each pixel storing data individually. While AVC cuts the frame into 16x16 blocks, HEVC differs in this by deconstructing the frame into 64x64 blocks. The algorithm remembers fewer details thereby decreasing the overall size.
Another technique used is the Inter-frame compression. Predictability plays a key role in this. The algorithm analyses multiple frames and decides what parts of the frames are stationary. So instead of repeating the image continuously, one frame is retained. A more technical explanation talks about the algorithm, which uses the power of the CPU and the graphics card to generate data through the pixel instead of storing them individually.
This has a mathematical context too complicated for a layman, but what we need to remember is that the HEVC has higher predictability models - 35 is the number. In contrast, AVC has 9.
However, problems in hardware acceleration still prevent widespread usage of the HEVC. Since the algorithm draws support from the CPU as well as the Graphics Card, systems with poor functionality perform poorly. HEVC also needs support from players and most players don't possess the codec yet.
These are the major reasons why HEVC hasn't secured a strong foothold yet, but worries aside, improvements in video quality requires excellent compressors and H.265 will soon transit to all workstations.