Media processor
A media processor, mostly used as an image / video processor, is a microprocessor-based system-on-a-chip which is designed to deal with digital streaming data in real-time (e.g. display refresh) rates. These devices can also be considered a class of digital signal processors (DSPs).
Unlike graphics processing units (GPUs), which are used for computer displays, media processors are targeted at digital televisions and set-top boxes.
The streaming digital media classes include:
uncompressed video
compressed digital video - e.g. MPEG-1, MPEG-2, MPEG-4
digital audio- e.g. PCM, AAC
Such SOCs are composed of:
a microprocessor optimized to deal with these media datatypes
a memory interface
streaming media interfaces
specialized functional units to help deal with the various digital media codecs
The microprocessor might have these optimizations:
vector processing or SIMD functional units to efficiently deal with these media datatypes
DSP-like features
Previous to media processors, these streaming media datatypes were processed using fixed-function, hardwired ASICs, which could not be updated in the field. This was a big disadvantage when any of the media standards were changed. Since media processors are software programmed devices, the
processing done on them could be updated with new software releases. This allowed new generations of systems to be created without hardware redesign. For set-top boxes this even allows for the possibility of in-the-field upgrade by downloading of new software through cable or satellite networks.