Digital Signal Processing Reference
In-Depth Information
IR
Receiver
Front Panel
Control
Digital
Video
TV Tuners
Digital Media
Processor
USB
Analog
Video
Ethernet
Audio
Codec
Security
SDRAM
HDD
Fig. 5
Block diagram of a typical DVR
traditional “time shifting” feature of a VCR. Hard disk drive-based recordings
allowed numerous other features, including random access to recordings, instant
replay, and commercial skip. More recently DVRs became complete entertainment
centers with access to the Internet for remote access and Internet-based video
streaming. In addition, USB-based ports allow users to connect personal media for
instant access to their personal photos, music, and videos. Like modern Blu-ray
players, DVRs integrate advanced digital media processors that allow for enhanced
video processing and control.
Figure
5
shows the simplified block diagram of a typical DVR. At the core of the
DVR is a digital media processor that can perform multiple operations, including:
Interfaces with all the DVR peripherals, such as the IR controller and the hard
disk drive,
For digital video, it extracts a Program Stream from the input Transport Stream
and either stores it in the HDD or decodes it and passes it to the output,
For analog video, it passes it through to the output or compresses it and stores it
in the HDD,
Performs all DVR controls, communicates with the service provider to update
the TV Guide, maintains the recording schedules, and performs all playback trick
modes (such as, pause, fast forward, reverse play, and skip), and
Performs multiple digital video and image-related operations, such as scaling and
deinterlacing.
In addition to the media processor, a DVR includes at least one TV tuner, Infrared
(IR) and/or RF interfaces for the remote control, a front panel control, security-
related controls, such as Smart Card or CableCard interfaces, and audio and video
