H.265 (also known as HEVC) is the new video compression standard after H.264. Based on the existing video coding standard H. 264, H.265 keeps some of the original technologies, while improves some relevant techniques. H.265 adopts the advanced techniques to improve the bit-stream, promote the coding quality, and better the relationship between time delay and algorithm complexity, to achieve best possible optimizations.

To make it clear to understand the H.265 and H.264, and make best use of them, I make a detailed comparison.

1. Compression Ratio & Bandwidth Utilization

H.265 has better compression performance and lower bandwidth utilization ratio.

For video services, the ultimate goal of compressing a movie is to reduce the size of the movie file, so as to take up less storage space, as well as drop the network bandwidth consumption in transmission.

Compared with H.264, the greatest strength of H.265 is that it has a higher compression ratio, which can be discerned from its name. H.265 is also called HEVC (High Efficiency Video Coding), and the primary use is to further reduce the design flow rate, in order to lower the cost of storage and transmission. At the same quality of coding, H. 265 can save around 50% of the bit rate, and coding efficiency can be doubled than H. 264. As H.265 provides more different tools to reduce the bit rate. For example, in H. 264, each macroblock is fixed to the size of 16 x16 pixels, but the coding unit of H.265 can be chosen from a minimum of 8 x 8 to the maximum of 64 x 64.

2. Quality

0n the left hand side as the illustration shows above is using traditional H.264 standard, and each macro block is fixed; In H. 264 coding technology, the giant sections of data is completely independent to each other, so coding distortion situations are likely to happen in border areas of the giant block.

It is HEVC video on the right, the size of code unit is determined by the regional information. From the image contrast, we can see the picture quality enhancement and the more delicate character’s skin under H. 265 are much better than H. 264.

Now we know well that how is H.265 superior to H.264.