Digital Signal Processing in Home Entertainment - Signal Processing Systems - page 249

output interfaces. DVRs may also include additional interfaces, including USB and
Ethernet ports, so they can play media from external devices or for adding external
peripherals, such as an external hard disk drive.

4.4 Digital Video Processing

Comparing Figs. 2 and 4 , we see that the digital video processing pipeline for
personal camcorders is not that much different from the digital camera pipeline.
After video capture using a CCD, video processing algorithms take the raw censor
data, color correct them, and translate them in real-time to a compressed digital
video bit stream. Alternatively, one can use any PC-based video capture card to
capture and translate any analog video signal to digital. Regardless of the input,
PC-based video editing tools allow us to apply a variety of post-processing imaging
algorithms to the videos and create custom videos in a variety of formats. User
videos can be stored either on DVDs or NAS-based media libraries. In addition,
many users upload their videos into social networking sites, where videos are
automatically transcoded to formats suitable for video streaming over the Internet,
such as Adobe's Flash video or H.264. Modern video servers allow for the seamless
integration of video with Internet content, allowing users to search within video
clips using either metadata or by automatically extracting data from the associated
audio and video data.

4.5 Digital Video Playback and Display

Every video eventually needs to be displayed on a screen, and modern High-
definition monitors or TVs were never more sophisticated than now. Starting from
their input ports, they need to interface with a variety of analog and digital ports;
from the traditional RF input to DVI or HDMI. Sophisticated deinterlacing, motion
compensation, and scaling algorithms are able to take any input, at any resolution,
and convert it to the TV's native resolution. For example, more recently, 100/120 Hz
HDTVs need to apply advanced motion estimation and interpolation techniques to
interpolate traditional 50/60 Hz video sequences to their higher frame rate. LED-
based LCD displays use also advanced algorithms to adjust the LED backlight
according to the input video for the best possible dynamic contrast.
In summary, digital signal processing is involved in every aspect of the capture,
post-processing, and playback of photos, music, and videos, but that's only the
beginning. In the next section we will examine how our digital media can be shared
anywhere in our home, using existing coding and communication technologies.