H.265

H.265, also known as MPEG-H Part 2 or High Efficiency Video Coding (HEVC), is a video compression standard, designed as a successor to the widely used H.264 (MPEG-4 Part 10, Advanced Video Coding, or AVC). In comparison to AVC, HEVC offers from 25% to 50% better data compression at the same level of video quality, or substantially improved video quality at the same bit rate. It supports resolutions up to 8192×4320, including 8K UHD, and unlike the primarily 8-bit AVC, HEVC's higher fidelity Main10 profile has been incorporated into nearly all supporting hardware. HEVC is competing with the royalty-free AV1 coding format for standardization by the video standard working group NetVC of the Internet Engineering Task Force (IETF).

While AVC uses the integer discrete cosine transform (DCT) with 4x4 and 8x8 block sizes, HEVC uses integer DCT and DST (discrete sine transform) with varied microblock sizes between 4x4 and 32x32. The High Efficiency Image Format (HEIF) is based on HEVC. As of 2019, HEVC was used by 43% of video developers, and making it the second most widely used video coding format after H.264.

Support by iOS / macOS

 * The first version of iOS to include support for H.265 / HEVC and HEIF was iOS 11.
 * The first version of macOS to include built-in support for H.265 was MacOS High Sierra.