H.264/MPEG-4 AVC - Hardware-based Encoding and Decoding

Hardware-based Encoding and Decoding

See also: List of cameras with onboard video stream encoding

Because H.264 encoding and decoding requires significant computing power in specific types of arithmetic operations, software implementations that run on general-purpose CPUs are typically less power efficient. However, the latest quad-core general-purpose x86 CPUs have sufficient computation power to perform real-time SD and HD encoding. Compression efficiency depends on video algorithmic implementations, not on whether hardware or software implementation is used. Therefore, the difference between hardware and software based implementation is more on power-efficiency, flexibility and cost. To improve the power efficiency and reduce hardware form-factor, special-purpose hardware may be employed, either for the complete encoding or decoding process, or for acceleration assistance within a CPU-controlled environment.

CPU based solutions are known to be much more flexible, particularly when encoding must be done concurrently in multiple formats, multiple bit rates and resolutions (multi-screen video), and possibly with additional features on container format support, advanced integrated advertising features, etc. CPU based software solution generally makes it much easier to load balance multiple concurrent encoding sessions within the same CPU.

The 2nd generation Intel Core i processors i3/i5/i7 (code named "Sandy Bridge") introduced at the January 2011 CES (Consumer Electronics Show) offer an on-chip hardware full HD H.264 encoder. The Intel marketing name for the on-chip H.264 encoder feature is "Intel® Quick Sync Video".

A hardware H.264 encoder can be an ASIC or an FPGA. An FPGA is a general programmable chip. To use an FPGA as a hardware encoder, an H.264 encoder design is required to customize the chip for the application. A full HD H.264 encoder could run on a single low cost FPGA chip by 2009 (High profile, level 4.1, 1080p, 30fps).

ASIC encoders with H.264 encoder functionality are available from many different semiconductor companies, but the core design used in the ASIC is typically licensed from one of a few companies such as Chips&Media, On2 (formerly Hantro, acquired by Google), Imagination. Some companies have both FPGA and ASIC product offerings.

Texas Instruments manufactures a line of ARM + DSP cores that perform DSP H264 BP encoding 1080p at 30fps. This permits flexibility with respect to codecs (which are implemented as highly optimized DSP code) while being more efficient than software on a generic CPU.