H.265 is a video compression standard designed to substantially improve coding efficiency when compared to its precedent, the Advanced Video Coding (AVC), or H.264. An increasing growth of video streaming on the Internet over popular websites such as Netflix and YouTube, and with 4K cameras gaining new ground in the market, a considerable amount of storage and bandwidth is required. HEVC promises a 50% storage reduction as its algorithm uses efficient coding by encoding video at the lowest possible bit rate while maintaining a high image quality level.
Compression Ratio & Bandwidth Utilization
The ultimate goal of compressing a movie is to reduce the size of the movie file, so that it can take up less storage space, reduce the network bandwidth consumption in transmission and increase streaming speed.
Compared with H. 264, H. 265 has a higher H.265 compression ratio which is primarily used to further reduce the design flow rate, in order to lower the cost of storage and transmission.
In other words, at the same quality of coding, H.265 provides more powerful tools like CTU to save around 50% of the bit rate, and the coding efficiency can be doubled than H. 264. For example, in H. 264, each macroblock is fixed to the size of 16 x 16 pixels, but the coding unit of H.265 can be widely chosen from a minimum of 8 x 8 to the maximum of 64 x 64.