It provides best-in-class performance, compression, and features.
Performance-wise, x264 can encode 4 or more 1080p streams in realtime on a single consumer-level computer.
Quality-wise, x264 has the world's most advanced psychovisual optimizations and has won many awards, .
Feature-wise, x264 supports features necessary for many different applications, such as television broadcast, Blu-ray, low-latency video applications, and web video.
x264 forms the core of many web video services, such as Youtube, Facebook, Vimeo, and Hulu. It is also used in television broadcast by companies such as Avail Media.
* 8x8 and 4x4 adaptive spatial transform
* Adaptive B-frame placement
* B-frames as references / arbitrary frame order
* CAVLC/CABAC entropy coding
* Custom quantization matrices
* Intra: all macroblock types (16x16, 8x8, 4x4, and PCM with all predictions)
* Inter P: all partitions (from 16x16 down to 4x4)
* Inter B: partitions from 16x16 down to 8x8 (including skip/direct)
* Interlacing (MBAFF)
* Multiple reference frames
* Ratecontrol: constant quantizer, constant quality, single or multipass ABR, optional VBV
* Scenecut detection
* Spatial and temporal direct mode in B-frames, adaptive mode selection
* Parallel encoding on multiple CPUs
* Predictive lossless mode
* Psy optimizations for detail retention (adaptive quantization, psy-RD, psy-trellis)
* Zones for arbitrarily adjusting bitrate distribution