digital video recorder eric bowden, matt ricks, irene thompson
TRANSCRIPT
Digital Video RecorderEric Bowden, Matt Ricks, Irene Thompson
Wed., February 29, 2006 Digital Video Recorder 2
Presentation Roadmap
Introduction& MotivationIntroduction& Motivation
Analog Design
Digital Design
What is a DVR?
Why make a DVR?
Implementation Overview
Specifications (Baseline and Extensions)
Initial Tasking
Initial Timeline
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What is a Digital Video Recorder?A video capture unit for live television
signals
Baseline FunctionalityPause Live TV
Never miss part of a show again due to interruptions
Rewind Live TV For up to 15 minutes of the broadcast
Fast Forward Allows the user to skip through selected
portions of the buffered broadcast
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Motivation
Currently available DVRs charge a monthly subscription fee
Non-trivially combines both hardware and software components
Allows us to explore analog signal processing, analog-to-digital conversion, and digital storage
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DVR Implementation
We will develop a PCI 2.2 compliant card (FPGA solution or etching our own PCB) for use in a black box system that sits next to the television source.
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Functional Specification
The baseline device must: Convert an analog, NTSC television
signal (video/audio) into a digital signal
Manipulate live television using pause, play, rewind and fast-forward
Store, at minimum, 15 minutes of live television for recall using the aforementioned techniques
The recalled audio/video data must be converted back into an NTSC composite signal
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Extended Specification
Additional functionality, time permitting Commercial detection and
eradication for recorded broadcasts Increased storage capacity Audio/Video compression User interface via remote control
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Tasking
Matt Ricks: analog-to-digital encoding and decoding, hardware development
Irene Thompson: signal subsystem processing and software development
Eric Bowden: analog and digital integration and the software development for the PCI interface
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Initial TimelineApril 2006 – Final Design Decisions have been
madeMay 2006 – All hardware components that
need to be purchased have been orderedJune 2006 – Implementation of individual parts
for the DVR has begunAugust 2006 – Individual components of the
project are readySeptember 2006 – Integration of individual
parts and debuggingOctober 2006 – Baseline Specifications have
been metDecember 2006 – Some of the extensions
have been put into effect
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Presentation Roadmap
Analog to Digital Video Decoding
Analog Video Signal
PCI Video Capture Card Schematic
Introduction& Motivation
Analog DesignAnalog Design
Digital Design
Introduction& Motivation
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Video Signal Decoding
Tuner (what channel?) 6MHz apart
Audio/Video filter Audio and Video ADC Chrominance/Luminance Horizontal and Vertical Sync Noise Filter Video Amplifier
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Analog Video Signal
30 Frames per second (60 Hz)
525 lines per frame (15 kHz)
Pixel Frequency = 12.5 MHz
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Video Capture PCI Card
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Commercial Detection
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Presentation Roadmap
PCI Microcontroller
PCI-Host Communication
Speed Considerations
Host Application
Digital to Analog Encoding
Introduction& Motivation
Analog DesignAnalog Design
Digital DesignDigital Design
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PCI Microcontroller
There will be a small, simple microcontroller to manage input/output data buffering. This allows major processing to be offloaded to the host computer.
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PCI-Host Communication
The device will periodically unload its digitized signal-buffer onto the PCI bus through standard interrupt methods.
This data will be received on the host computer by a software application that stores the A/V data to disk.
This will necessitate building a kernel module for Windows XP.
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Speed Considerations
In order to prevent frame-loss the device must be able to process incoming data and output it to the host faster then data is coming in.
PCI 2.2 Bus: 66 MHz 3.3 V signaling with a peak transfer rate of 533 Mb/s
Data input bandwidth must be approximately: 300 Mb/s
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Video Signal Detail Diagram
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Host Application
The host software will act as an agent
Its job is to constantly record A/V data to disk and send requested data back to the PCI card
This software will provide the video control user experience
Ideally there would be a GUI to allow for advanced broadcast manipulation
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Data Re-encoding
Data will be passed back to the card, encoded into an analog signal, mixed and then sent as a composite NTSC signal to the Television.
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The End