VIDEO PHONE SYSTEM

ECES488 VIDEO PHONE SYSTEM (AUDIO UNIT) Yaqiang Wang & Hongwen Lu 4/27/00

VIDEO PHONE SYSTEM

Yaqiang Wang

Hongwen Lu


Block Diagram of Video Phone System (Top Level)

Camera LCD

VideoProcessor

FlashMemory

Video controller

Clockand

timing

Maincontroller

Audio and Video DataI/O port (Modem)

Audioprocessor

Flashmemory

Audio controller

Speaker Microphone

Audio processor

Phonesub-system

Videosub-system

Audiosub-system

Video I/O Audio I/O

Main controlsub-system


Video Phone System (Feasibility Study)

Video unit:• Digital video processor:

DSP56651 (Motorola, $15 each);16-bit DSP, 70 MIPS

• Video controller: MC68HC16S2 (Motorola, $8 each).

• Flash memory: HY29F040 (Hyundai, 4MB module, $12 each).

• Digital camera: Loitech 961121 (Logitech, $30 each).

• Liquid crystal display: TX26D80VC1CAA (Hitachi, 10.4” TFT, $100 each).

Telephone:• Regular phone unit:

$8 each.


Video Phone System (Feasibility Study)

Audio unit:• Digital audio processor:

CS4912 (Cirrus Logic, $7 each); 16-bit DSP, RAM for program and data.

• Audio controller:

CS4281 (Cirrus Logic, $4 each).

• Flash memory: HY29F040 (Hyundai, 4MB module, $12 each).

Main controller and other components:• Main controller:

MC68HC16Z2 (Motorola, $10 each).

• Modem: WINCOMM56 (Jaton Corp. 56K, $15 each).


Video Phone System (Cost and Competition)

• COST:A) Audio processor and controller = $ 11B) Video processor and controller = $ 23C) Memory(4 MB audio, 4MB video) = $ 24D) Telephone = $ 8E) Digital camera = $ 30F) Modem = $ 15G) LCD display = $ 100H) Main microcontroller = $ 10I) Design cost (assuming 100,000 sold) = $ 27Total: Total: = $ 250 = $ 250

• MSRP:Price:Price: (40% gross profit margin) = $ 350= $ 350

• Competition:Standalone: (record motion pictures) >$1,000TV-based: (need TV) around $800PC-based: (need PC, slow) around $100



Camera LCD

VideoProcessor

FlashMemory

Video controller

Clockand

timing

Maincontroller


Audioprocessor

Flashmemory

Audio controller

Speaker Microphone

Audio processor

Phonesub-system

Videosub-system

Audiosub-system

Video I/O Audio I/O



Filter A/D Analysis Quantizer Coder

ModemChannelDecoder ModemQuantizer-1

Synthesis D/A Filter

The Elements of a Speech Coding System

Storage


Pre-emphasis

Pitch detector

LPCanalysis

LPCquantizerand coder

Coder

CoderWindow Correlation computation

Widow length

LPC filterorder

Multi-plexor

Coded gain

Coded LPC

coeff’sDigitalchannel

Coded pitch and voicing

Frame interval

Block Diagram of a LPC Coder

Frame interval


Pulse generator

Demulti-plexor

Noise generator

Gain

Block Diagram of LPC Decoder

Linear predictor

De-emphasis

LPC coeff

Excitation model


Waveform of Input Signal

1000 1500 2000 2500-25000

-20000

-15000

-10000

-5000

0

5000

10000

15000

V

oice

sig

nal a

mpl

itude

Counting of points


1000 1500 2000 2500-25000

-20000

-15000

-10000

-5000

0

5000

10000

15000

Voic

e s

ignal A

mplit

ude

Counting of points

Waveform of Output Signal

Input file size: 336KB; compressed file size 7KB; compression ratio is 48:1. Decompressed file size: 336KB.



Camera LCD

VideoProcessor

FlashMemory

Video controller

Clockand

timing

Maincontroller


Audioprocessor

Flashmemory

Audio controller

Speaker Microphone

Audio processor

Phonesub-system

Videosub-system

Audiosub-system

Video I/O Audio I/O



State Diagram of Audio Unit (top level)

Standby(Idle)Reset

Phonecomm

Respondtosystembutton

Respondtoline

pick

up hangup

ring

=4

hangup

button

Stop


State Diagram of Audio Unit (Respondtosystembutton subsystem)

Standby(Idle)Reset

Handlerew

Handlehearann

Handlerecann

Handleplaymsg

Handleplay

Handlefwd

Handledeletemsg

playbuttonfwdbuttonrewbutton

hearannbuttonrecannbuttonplaymsgbutton

deletemsgbutton

stopbutton


State Diagram of Audio Unit (Respondtoline subsystem)

Standby(Idle)Reset

InitcommPlayannoncement

Recordmessage

Checkcode Respondtoremotebutton

ring=

4 hangup

rem

oteb

utton

han

gup

hangup

passwd=‘1’

passwd=‘0’

hangup

Remotecontrol

Respondtoline


Symbol of Audio Unit Controller


Gate Level of Audio Unit Controller


Simulation Result for Audio Unit (Phonecomm and Respondtosystembutton subsystems)

State sreg

Phone

Handle_play

Handle_fwdHandle_rew

Idle 0000

0001

0111

1000

1001


Simulation Result for Audio Unit (Respondtoline subsystem)

State sreg

Recmsg

Check_codeRespondtocmds

0010

0011

0100

0101

0110

Initcomm

Playann


Conclusions

• Cost/performance reduction approaches:

Hardware/software co-design;

Off-the-shelf components (small quantity);

In-house design and fabrication of chips (large quantity).

• Competing with existing products:

Aiming at GSTN (analog phone line) market;

Cheaper than existing standalone units;

More convenient than TV-based or PC-based units.

VIDEO PHONE SYSTEM

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