x265 is an open-source encoder implementation of the H.265 / HEVC (High Efficiency Video Coding) video compression standard; it produces highly compressed video streams that preserve quality at lower bitrates compared to older codecs.

x265 is characterized by three key components:

• HEVC compression tools: advanced prediction, transform, and entropy coding techniques that improve compression efficiency.
• Configurable encoding profiles: tradeoffs between bitrate, quality, and encoding complexity (preset and tune options).
• Hardware & software acceleration: encoding/decoding can be accelerated via dedicated ASICs, GPUs, or optimized CPU code paths.

x265 enables significant bandwidth savings and storage reduction for video delivery and streaming. Decoding/encoding performance matters for deployment choices; Arm-based servers (such as Ampere Altra) and specialized accelerators can influence throughput and cost for large-scale video transcoding pipelines.

• x265 project
• HEVC (H.265) overview: MPEG/ITU
• FFmpeg - multimedia framework supporting x265
• Video transcoding and media workloads on Ampere Altra