Keith Jack's Blog

Peek inside a Blu-ray player, HDTV, IPTV or cable set-top box, digital sign, or media player and you’ll see a large chip that some people call a “Media Processor”. So what is that Media Processor and what does it do?

Simply put, the Media Processor is the heart and soul of the box, executing whatever function the box designer wishes. Program it one way and add a Blu-ray drive, and you have a Blu-ray player. Program it another way and you have an IPTV set-top box. Program it another way and you have digital signage.

In addition to being able to run a variety of programs, the Media Processor offers a variety of audio/video inputs and outputs, and provides a variety of ways to connect to other things (such as memory, hard drives, tuners, Ethernet, etc.).

The inside of a Media Processor typically has these features:

- Host CPU
- Security Processor
- Transport Demultiplexer
- Video Decoder and Processing
- Audio Decoder and Processing
- Perhipheral I/O

The Host CPU is used to run the application, such as Blu-ray software, IPTV software, etc.

The Security Processor is used to control Digital Rights Management (DRM) and Conditional Access (CA) decrpytion. Conditional Access decrpytion is the unscrambling of content coming into the home via IPTV, Satellite, Cable, etc. DRM are the rules of how content is copy protected once the content is inside the home. For example, content coming into the home is decrypted for viewing (CA). But if it is recorded onto a hard drive for PVR purposes, it is again encrypted using another scheme (DRM), and information added to indicate if a copy may be made or not, etc.

Compressed audio/video bitstreams may be input from a variety of sources, such as tuner, Ethernet connection, hard drive, Blu-ray Disc, flash card, etc. These are then separated into separate compressed audio and video streams by the Transport Demultiplexer.

The Video Decoder decompresses the video, usually supporting a wide variety of compressed video formats. The uncompressed video may then be processed in various ways, such as deinterlacing, scaling, and adjusting the brightness, contrast, hue, saturation, sharpness, gamma, chromaticity, etc. There are usually four types of video outputs: HDMI, analog component (YPbPr), s-video, and composite video.

The Audio Decoder decompresses the audio, usually supporting a wide variety of compressed audio formats. There are usually three types of audio outputs: HDMI, I2S (to drive external audio DACs), and SPDIF.

So there you have it! Now every time you watch TV or a Blu-ray movie, you’ll be thinking about that little Media Processor working hard so you can sit back and relax…