H.265 also known as HEVC (High-Efficiency Video Coding) - a video compression standard which uses more efficient video encoding tools than previous H.264.
Standard has been developed by ITU-T Video Coding Experts Group (VCEG) and MPEG group. H.265 was published as a standard in 2013. HEVC format supports frames with resolution up to 8K (UHDTV).
There are some new encoding tools in this standard, such as:
- AIF filter
- motion interpolation upt ⅛ pixel
- adaptive prediction errors of coding (APEC)
- adaptive quantization matrices (AQMS)
- more intra prediction modes
and many others.
But the most important change is tree blocks structure (instead of simple macroblocks in H.264) with a maximum block size up to 64x64 pixels.
Comparison with H.264 standard shows bitrate decreasing up to 35%.