OpenH264是一个编解码器，支持H.264编码和解码。它适合用在实时应用程序中，比如使用 WebRTC。

Ontop of this we built a recompression layer that can get additional win ontop of CAVLC and other algorithms.

Encoder Features

• Constrained Baseline Profile up to Level 5.2 (4096x2304)
• Arbitrary resolution, not constrained to multiples of 16x16
• Rate control with adaptive quantization, or constant quantization
• Slice options: 1 slice per frame, N slices per frame, N macroblocks per slice, or N bytes per slice
• Multiple threads automatically used for multiple slices
• Temporal scalability up to 4 layers in a dyadic hierarchy
• Spatial simulcast up to 4 resolutions from a single input
• Long Term Reference (LTR) frames
• Memory Management Control Operation (MMCO)
• Reference picture list modification
• Single reference frame for inter prediction
• Multiple reference frames when using LTR and/or 3-4 temporal layers
• Periodic and on-demand Instantaneous Decoder Refresh (IDR) frame insertion
• Dynamic changes to bit rate, frame rate, and resolution
• Annex B byte stream output
• YUV 4:2:0 planar input

Decoder Features

• Constrained Baseline Profile up to Level 5.2 (4096x2304)
• Arbitrary resolution, not constrained to multiples of 16x16
• Single thread for all slices
• Long Term Reference (LTR) frames
• Memory Management Control Operation (MMCO)
• Reference picture list modification
• Multiple reference frames when specified in Sequence Parameter Set (SPS)
• Annex B byte stream input
• YUV 4:2:0 planar output

OS Support

• Windows 64-bit and 32-bit
• Mac OS X 64-bit and 32-bit
• Linux 64-bit and 32-bit
• Android 64-bit and 32-bit
• iOS 64-bit and 32-bit
• Windows Phone 32-bit

Processor Support

• Intel x86 optionally with MMX/SSE (no AVX yet, help is welcome)
• ARMv7 optionally with NEON, AArch64 optionally with NEON
• Any architecture using C/C++ fallback functions

项目主页：http://www.open-open.com/lib/view/home/1440929172340