HEVC
/ˌeɪtʃiːviːˈsiː/ · noun · codec · High Efficiency Video Coding (H.265)
The video codec behind HEIC. Efficient compression, but patent-encumbered.
In more detail
HEVC, also called H.265, is a video codec designed to roughly halve file size compared with its predecessor at the same quality. HEIC stores still images encoded with it.
Its licensing complexity is a big reason support lagged outside Apple’s ecosystem, making conversion to JPG a frequent necessity.
How HEVC compresses media
HEVC divides an image into blocks, predicts their contents from nearby pixels or video frames, and stores the remaining difference efficiently. Its larger and more flexible block structure improves compression for high-resolution footage compared with H.264.
The extra efficiency costs computation. HEVC can take longer to encode, and smooth playback may depend on hardware decoding. A device can therefore be powerful enough for ordinary video yet struggle with high-resolution HEVC in software.
HEVC compatibility
HEVC is widely used for 4K video, iPhone recording, streaming, Blu-ray, and HEIC photography. Support varies by browser, operating system, device hardware, and installed codec licences, so the same file may play on a phone but fail in a web page or desktop editor.
Transcode to H.264 when reach is more important than size. Expect the converted file to grow at a similar visual quality, and avoid repeated conversion between lossy codecs. For archival work, keep the original HEVC source alongside any compatibility copy.
Key points
- HEVC and H.265 are two names for the same video coding standard.
- It is efficient for high-resolution media but more demanding to encode and decode.
- Playback support depends on the complete device, browser, and licensing environment.