H264 and H265 are by far one of the most commonly used video formats that have been around for years. Predominantly, confusion arises while figuring out their differences, and which format should be used in the first place.
That is why in this article we are going to dive deep into the differences between H264 vs H265 and which one is better to use based on your requirements.
Also Read: What is VSync? And When Should You Use It?
What is H264 or AVC Codec?
When it comes to the current coding standard, the H.264 or AVC (Advanced Video Coding) is the most commonly used one. In fact, the H.264 video codec has paved the pathway for High-Definition video, while using a substantially lower bitrate.
Fact: A video in H.264 occupies almost half the size compared to any video in H.263, MPEG-2, or MPEG-4.
Salient Features of H.264 (Advanced Video Coding)
The H.264 video codec features several advantages over its predecessor H.263. Some of the most prominent ones include:
- H.264 videos can be saved in a much smaller file size
- Users can expect better video quality at lower data rates
- Significantly shrinks the storage capacity without reduced quality
- Comes with variable block size segmentation
- Predictability between multiple images
- H.264 can support up to 8K UHD resolution
- H.264 is mostly used for Blu-ray discs video encoding
- The latest iteration, Version 26 was released back in June 2019
What Exactly is H265 or HEVC Codec?
The H.265 video codec is also known as HEVC (High-Efficiency Video Coding) or commonly ‘high-efficiency video codec.’ The popularity of H.265 video codec increased with the advent of 4K video streaming.
Not to mention, with 8K just around the corner, it is very important to develop a new standard of video encoding with utmost efficiency. This is where the HEVC codec comes in to save the day since it reduces the overall file size up to 50% as compared to H.264.
Advantages of H265 or High-Efficiency Video Coding
With H.265 video codec you can always expect several advantages over its predecessor H.264 video compression standard. Some of the most prominent ones include:
1. The H.265 video codec drastically increases the overall coding efficiency, as compared to its previous iteration. This facilitates a higher image quality with the smallest possible video file size.
2. With a similar image quality, H.265 can deliver a highly efficient codec ensuring the system needs to process substantially lesser data.
3. H.265 only uses half of the bit rate as compared to H.264.
4. There are huge practical implications while using H.265 video codec including a reduced bandwidth as well as storage requirements. Furthermore, it also reduces infrastructure costs while ensuring the affordability of high-resolution surveillance systems.
5. The HEVC video codec uses GPU accelerated decoding ensuring the system can ensure the required performance while using very minimal or no additional cost.
6. With H.265 files, there is no requirement for decoding until there is a need for playback.
Underlying Difference Between H264 and H265
In Layman’s terms, videos can be best defined as the succession of a large number of images. For the most part, movies are often recorded at 24 frames per second. So, if the video codec needs to reduce the overall video size, it needs to compare two consecutive frames.
This would assist in better identifying which parts of the frame are the same and which are different. For similar parts, the same information can be used while cutting down the file size. Apart from saving space, it also helps to help to keep to retain new information within the video.
So, here are some of the technicalities that differentiate H.265 (HEVC) from H.264 (AVC):
1. Coding Tree Units: With H.265, the CTU (Coding Tree Units) allows the original pixels from previous frames to be further divided into various segments. Based on each scene, these divisions can be made in different sizes. For instance, in H.265 the block sizes range from 4 x 4 to 64 x 64, while with H.264 it can only up to 16 x 16.
2. Better Segmentation Algorithm: As stated earlier, the H.265 codec compares two consecutive frames and tries to use the shared information between them. This ensures that without making substantial changes to the information, it can be used on multiple frames.
3. Superior Movement Tracking: Even with different frames, the algorithm is able to track down the movement, caused by a slight change in the position. With improved movement tracking, the same information can be used multiple times for different parts of the screen.
Should You be Using H265 over H264?
At the end of the article, the underlying question arises, which video codec is actually better? The answer can be subjective and mostly depend upon the use case. So, prior to deciding which video codec to use, start with your streaming device.
For instance, if you want to watch your content at 1080p or higher resolution, H.265 is not ideal for you, due to its lack of support for HD content. On the contrary, if you plan to watch videos on Netflix or YouTube or any other streaming service then your choice comes down to which codec would consume less data.
The Bottom Line
For the most part, the underlying difference between H.264 and H.265 codecs comes down to their video compression efficiency. H.265 is proven to be more efficient while offering better allocation of bandwidth and resources as compared to H.264.
Not to mention, in turn, ends up putting less strain on servers and storage, which results in an overall reduced cost. With H.264 being used at large, now is the best time than ever to actually transition to H.265 video codec.