nguyen van dien - do an iptv 10082011

8/3/2019 Nguyen Van Dien - Do an IPTV 10082011

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n tt nghip i Hc ti: Nghin cu cng ngh truyn hnhqua giao thc Internet (IPTV)

MC LCMC LC.............................................................................................................................I

THUT NG VIT TT.................................................................................................IV

DANH MC HNH V...................................................................................................VIIDANH MC BNG BIU................................................................................................IX

LI M U.......................................................................................................................1

CHNG 1: TNG QUAN IPTV V TNH HNH PHT TRIN IPTV VIT

NAM 3

1.1. Gii thiu IPTV 3

1.1.1. Khi nim IPTV ...................................................................... 3

1.1.2. Mt s c im IPTV ............................................................. 3

1.1.3. S khc bit gia IPTV v Internet TV ...................................... 4

1.2. M hnh cu trc IPTV 6

1.3. Tnh hnh pht trin IPTV Vit Nam 7

1.3.1. Tnh hnh pht trin dch v IPTV ca VNPT ............................. 7

1.3.2. Tnh hnh pht trin dch v IPTV ca FPT .............................. 11

1.3.3. Tnh hnh pht trin IPTV ca VTC ........................................ 12

1.4. Cc dch v cung cp bi IPTV 13

1.4.1. Dch v video IPTV ............................................................... 15

1.4.1.1. Dch v video qung b .................................................................................151.4.1.2. Dch v Video theo yu cu ...........................................................................15

1.4.2. Dch v m thanh IPTV ......................................................... 17

1.4.2.1. Dch v pht thanh qung b .........................................................................171.4.2.2. Dch v m nhc qung b .............................................................................171.4.2.3. Dch v m nhc theo yu cu .......................................................................171.4.2.4. Dch v m nhc tr tin ................................................................................17

1.4.3. Dch v tr chi.................................................................... 17

1.4.4. Dch v thng tin tch hp ..................................................... 18

1.4.4.1. Dch v thoi tch hp ................................................................................... 181.4.4.2. Dch v Internet tch hp ...............................................................................18

1.4.5. Dch v qung co ................................................................ 19

1.4.6. Dch v tng tc ................................................................. 19

1.4.6.1. Ghi hnh ring t (PVR) ................................................................................191.4.6.2. Ghi hnh ring t trn mng (nPVR) .............................................................191.4.6.3. Bnh chn v d on ....................................................................................191.4.6.4. Gio dc trn ti vi ..........................................................................................201.4.6.5. Thng mi trn ti vi .....................................................................................201.4.6.6. Tng tc qua di ng ..................................................................................20

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1.4.6.7. Tin nhn trn ti vi .......................................................................................... 201.4.7. Dch v truyn hnh hi ngh................................................. 21

1.4.8. Dch v gia tng khc ........................................................... 21

1.4.8.1. Tin nhin SMS/MMS .................................................................................... 211.4.8.2. Th in t trn ti vi ......................................................................................211.4.8.3. Chia s truyn thng (an bum nh) ................................................................211.4.8.4. Ghi nht k hnh nh ......................................................................................221.4.8.5. Quan st ton cu ...........................................................................................22

CHNG 2: CNG NGH TRUYN HNH TRN IP 24

2.1. Kin trc h thng IPTV 24

2.2. H thng cung cp dch v IPTV 25

2.3. Mng cung cp dch v Triple Play 262.4. Cc chun nn hnh nh s dng cho IPTV 27

2.4.1. Chun nn MJPEG v Wavelet ................................................ 28

2.4.2. Chun nn MPEG-x v H.26x ................................................. 29

2.4.3. Chun nn MPEG-2 ............................................................... 30

2.4.4. Chun nn MPEG-4: .............................................................. 31

2.4.4.1. Phn phi cc lung d liu ...........................................................................322.4.4.2. H thng .........................................................................................................332.4.4.3. MPEG-4 Audio ..............................................................................................34

2.4.4.4. MPEG-4 Visual ............................................................................................. 342.4.5. Chun nn H.264/MPEG-4 Part 10/AVC ................................. 35

2.5. Giao thc mng 39

2.6. Mng truyn ti dch v IPTV 43

2.6.1. Video Sites .......................................................................... 43

2.6.1.1. Thit b u cui c bit ...............................................................................432.6.1.2. Trung tm ngun hnh nh .............................................................................442.6.1.3. Trung tm chuyn mch hnh nh ..................................................................44

2.6.2. Cc yu cu v dch v Video ................................................ 44

2.6.2.1. Bng tn cao .................................................................................................. 442.6.2.2. Bng tn khng i xng ...............................................................................452.6.2.3. Cht lng dch v .........................................................................................452.6.2.4. Thi gian i knh video qung b .............................................................. 45

2.6.3. Hng pht hnh nh ............................................................ 46

2.6.3.1. Dch v Video lp 3 ................................................................................... 462.6.3.2. Kin trc chuyn tip video ...........................................................................47

2.6.4. Chuyn tip truy nhp Internet ............................................. 49

2.6.4.1. Chuyn tip thoi ...........................................................................................50

2.6.4.2. Kin trc truyn ti bin ................................................................................50

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2.6.5. Cc chc nng DSLAM .......................................................... 51

2.6.6. Cc chc nng cng truy nhp gia nh (HAG) ........................ 52

2.6.6.1. S phn chia lu lng da trn cc cng vt l ...........................................53

2.6.6.2. S phn chia lu lng da trn a ch MAC ..............................................53

CHNG 3: CC YU T NH HNG N CHT LNG IPTV V NG

DNG TRIN KHAI TI VNPT BC NINH 55

3.1. Khi nim QoE v QoS 55

3.2. Cc yu t nh gi cht lng dch v Video 57

3.3. Cc yu t nh hng ti cht lng dch v IPTV 58

3.3.1. Yu t cht lng ngun tn hiu video .................................. 58

3.3.2. Yu t m ha tn hiu .......................................................... 59

3.3.3. Yu t di nhm nh (GOP) .............................................. 603.3.4. Yu t gi tin ....................................................................... 61

3.3.5. Yu t th t gi tin ............................................................. 61

3.3.6. Yu t mt gi..................................................................... 61

3.3.7. Yu t tr ............................................................................ 63

3.3.8. Yu t rung pha ................................................................... 63

3.3.9. Yu t tranh chp vi cc dch v triple-play khc .................. 63

3.3.10. Yu t tham s cu hnh ..................................................... 64

3.3.11. Yu t my ch .................................................................. 64

3.4. Cc phng php o cht lng dch v Video 643.4.1. Phng php o cht lng video nh tnh ........................... 64

3.4.2. Phng php o cht lng video nh lng ......................... 65

3.4.2.1. H thng o cht lng video da trn m hnh tham chiu y .............663.4.2.2. H thng o cht lng videoda trn m hnh khng tham chiu ...............683.4.2.3. H thng o cht lng video da trn m hnh tham chiu rt gn .... ........69

3.4.3. Phng php o gin tip cht lng video ........................... 69

3.4.3.1. H s tr .........................................................................................................703.4.3.2. T l mt gi ...................................................................................................71

3.4.4. Phng php o thi gian chuyn knh ................................. 733.4.5. Phng php nh gi tin cy .......................................... 74

3.4.6. Phng php kim tra bo mt ......................................... 75

3.4.7. Cc im o gim st cht lng ........................................... 77

3.5. Cc yu cu k thut m bo cht lng dch v IPTV 78

3.5.1. Ch tiu cht lng tn hiu video .......................................... 78

3.5.1.1. Cc tham s lp truyn dn ........................................................................... 783.5.2. Ch tiu thi gian tng tc ................................................... 79

3.5.3. Ch tiu ng b gia tn hiu hnh v ting ........................... 80

3.6. ng dng trin khai IPTV ti Vin Thng Bc Ninh 80

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3.6.1. V tr a l ........................................................................... 80

3.6.2. Tnh hnh trin khai IPTV ti VNPT Bc Ninh ........................... 82

3.6.3. Khai thc, qun l thu bao MyTV ......................................... 85

3.6.3.1. Khai bo mi ti khon cho khch hng ........................................................863.6.3.2. Qun l thu bao MyTV ................................................................................90

THUT NG VIT TT

Vit tt Ting Anh Ting Vit

ACM Admission Control Mechanism C ch kim sot truy cp

ATIS

Aliance for Telecommuniction

Industry Standard T chc cng nghip vin thngBRAS Broadband Remote Access Server My ch bng rng truy cp t xa

CA Conditional Access Truy cp c iu kin

CDP Content Delivery Protocols Giao thc phn pht ni dung

CPE Customer Premises Equipment Thit b nh thu bao

DF Delay Factor H s tr

DHCPDynamic Host Configuration

ProtocolGiao thc cu hnh host ng

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DNS Domain Name System H thng tn min

DRM Digital Right Management Qun l quyn s dng s

DSLAMDigital Subscriber Line AccessMultiplexer

Thit b ghp knh ng dy thubao s

DVB Digital Video Broadcasting Qung b truyn hnh s

DVB-HDigital Video Broadcasting -Handheld

Thit b cm tay h tr qung btruyn hnh s

DVR Digital Video Recorder B ghi video s

EPG Electronic Program Guide Hng dn chng trnh in t

ESG Electronic Service Guide Hng dn dch v in t

ETSIEuropean TelecommunicationsSdandards Institute

Vin tiu chun vin thng chuu

FEC Forward Error Correction Hiu chnh li hng i

FTTx Fiber To The (Home, Building...) H cng ngh FTTx

GOP Group of Pictures Nhm nh

HAG Home Access Gateway Cng truy nhp gia nh

HDTV High Definition TeleVision Truyn hnh phn gii cao

HTTP Hypertext Transfer Protocol Giao thc truyn siu vn bn

ICMP Internet Control Message ProtocolGiao thc bn tin iu khininternet

IGMPInternet Group ManagementProtocol

Giao thc qun l nhm Internet

IP Internet Protocol Giao thc internet

IPTV Internet Protocol TeleVision Truyn hnh da trn IP

IPTVCD IPTV Consumer Device Thit b IPTV ca ngi s dngIPTVCM

IPTV Communications Model M hnh thng tin IPTV

ISP Internet Service Provider Nh cung cp dch v Internet

ITU-TInternational TelecommunicatinUnion

T chc vin thng th gii

KoD Karaoke on Demand Karaoke theo yu cu

MoCA Media over Coax Alliance Kt hp truyn thng trn cp ngNguyn Vn DinLp: H09VT3 V


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trc

MOS Mean Opinion Score im kin trung bnh

MPEG Moving Picture Experts Group Nhm chuyn gia hnh nh ng

MPLS Multi Protocol Label Switching Chuyn mch nhn a giao thc

NGN Next Generation Network Mng th h tip theo

PIM Protocol Independent Multicast Giao thc a hng c lp

PPP Point-to-Point Protocol Giao thc im-im

PPPoEPoint-to-Point Protocol overEthernet

Giao thc im-im trn Ethernet

PVR Personal Video Recorder Dch v ghi li ni dung video theonhu cu c nhn

PSNR Peak Signal-to-Noise Ratio T s tn hiu nh trn nhiu

RGRouting Gateway / ResidentialGateway

Cng nh tuyn/Cng thng tr

RTCP Real-Time Control Protocol Giao thc iu khin thi gian thc

RTSP Real Time Streaming Protocol Giao thc lung thi gian thc

QoS Quality of Setvice Cht lng dch v

RTP Real Time Protocol Giao thc thi gian thc

RTSP Real Time Streaming ProtocolGiao thc iu khin lung thigian thc

SD Standard Definition nt tiu chun

SIP Session Initiation Protocol Giao thc khi to phin

SM Sparse Mode Ch tha

SNR Signal Noise Ratio T s tn hiu trn nhiu

STB Set-Top-Box Thit b truyn hnh u cui

TCP Transmission Control Protocol Giao thc iu khin truyn dn

TS Transport Stream Lung truyn ti

UDP User Datagram Protocol Giao thc d liu s dng

VHE Video Head End Ngun Video

VHO Video Headend Office Trung tm ngun video

VoD Video on Demand Dch v xem video theo yu cu

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VoIP Voice over IP Thoi trn giao thc Internet

VSAQ Video Service Audio QualityCht lng m thanh dch vVideo

VSCQ Video Service Control QualityCht lng iu khin dch vVideo

VSMQ Video Service Multimedia QualityCht lng a phng tin dch vVideo

VSPQ Video Service Picture Quality Cht lng nh dch v Video

VSTQ Video Service Transmission Quality Cht lng truyn dch v Video

WDM Wavelength Division Multiplexing Ghp knh theo bc sng quang

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DANH MC HNH V

Hnh 1:IPTV l cng ngh ca tng lai 4

Hnh 2:M hnh chun IPTV 6

Hnh 3:M hnh IPTV thc t 7

Hnh 4:Cu hnh cung cp dch v IPTV ca VASC 8

Hnh 5:Dch v iTV ca FPT 11

Hnh 6:Kin trc chung ca mt h thng IPTV 24

Hnh 7:M hnh kin trc h thng cung cp dch v IPTV 25

Hnh 8:Kin trc mng cung cp dch v Triple Play 27

Hnh 9:Lch s v xu hng pht trin ca cc chun nn 28

Hnh 10:M hnh cc lp h thng MPEG-4 32

Hnh 11:So snh hot ng ca cc chun nn 39

Hnh 12:So snh v yu cu bng thng, lu tr v thi gian ti ca cc chun nn 39

Hnh 13:So snh cc phng thc truyn dn 40

Hnh 14:So snh lu lng s dng gia Unicast v Multicast 42

Hnh 15:Kin trc mng truyn ti dch v IPTV 43

Hnh 16:Kin trc Lp 3 ca mng truyn ti dch v Video 46

Hnh 17:Kin trc chuyn tip video 48

Hnh 18:Cu hnh chuyn tip truy nhp Internet 49

Hnh 19:Cu hnh chuyn tip thoi 50

Hnh 20:Mng truyn ti bin 51

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Hnh 21:DSLAM Bridge-Group 52

Hnh 22:Phn chia lu lng trn cc cng vt l 53

Hnh 23:M tng quan git QoE v QoS 56

Hnh 24:Cc yu t tc ng ti QoE 56

Hnh 25:H thng phn phi dch v video u cui-ti-u cui 59

Hnh 26:Cc loi li lp vt l v giao thc 59

Hnh 27:H thng o cht lng video da trn m hnh tham chiu y 68

Hnh 28:Gim st cht lng video s dng m hnh rt gn 69

Hnh 29:Mng IPTV vi rung pha bng 0 70

Hnh 30:Mng IPTV c rung pha 71

Hnh 31:Tnh cc gi tr MDI ti cc im khc nhau trong mng IPTV 72

Hnh 32:Cu hnh o tr chuyn knh 74

Hnh 33:Kim tra bo mt theo da trn DHCP Option 82 76

Hnh 34:Kim tra ng dng firewall 76

Hnh 35:Cc im o, gim st cht lng trong mng IPTV 77

Hnh 36:Bn hnh chnh tnh Bc Ninh 82

Hnh 37:S trin khai ti MAN-E ti VNPT Bc Ninh 83

Hnh 38:Giao din thm mt khch hng mi 86

Hnh 39:Thm ngi s dng t mt danh sch di dng file 87

Hnh 40:Danh sch khch hng ang ch kim tra lp t dch v IPTV 88

Hnh 41:Giao din kim tra v cp nht tnh trng lp t 88

Hnh 42:Gi mail thng bo cho khch hng v kh nng lp t 89

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Hnh 43:Giao din thc hin ng b d liu 90

Hnh 44:Giao din thay i gi cc s dng 90

Hnh 45:Giao din thay i trng thi s dng dch v 91

Hnh 46:Giao din thay i b gii m 92

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DANH MC BNG BIU

Bng 1:Mc cc thu bao thng cho dch v MyTV 10

Bng 2:Mc cc dch v theo yu cu (PayTV) ca MyTV 11

Bng 3:Cc dch v IPTV 14

Bng 4:Yu cu v bng thng i vi cc chun nn 38

Bng 5:Cc nguyn nhn chnh gy m gi 62

Bng 6:Cc thang ic thang icc php kim tra cht l IPTV 65

Bng 7:Cc ch tiu truyn dn i vi dch v SDTV, VoD m MPEG-2 78

Bng 8:Ch tiu truyn dn i vi dch v SDTV, VoD m MPEG-4 AVC/VC-1 79

Bng 9:Cc ch tiu truyn dn i vi dch v HDTV m MPEG-2 79

Bng 10:Cc ch tiu truyn dn i vi dch v HDTV m MPEG-4 AVC/VC-1 79

Bng 11:Ch tiu thi gian tng tc 80

Bng 12:Ch tiu ng b gia tn hiu hnh v ting 80

Bng 13:M t kt ni mng MAN-E Bc Ninh 84

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LI M U

Ngy nay trc s pht trin mnh m ca khoa hc k thut vi nhng pht

minh quan trng trong mi lnh vc lm cho i sng con ngi c nhng thay ito ln. Trong lnh vc gii tr phi k n cc dch v truyn hnh v tinh, s tng

trng ca dch v truyn hnh cp s v c bit l s ra i ca truyn hnh nt

cao (HDTV) li du n trong truyn hnh. Bn cnh l s pht trin bng n

ca Internet, c bit mng Internet bng thng rng lm thay i c ni dung v k

thut truyn hnh. Truyn hnh giao thc Internet (IPTV) ang l cng ngh truyn

hnh ca tng lai. Vi s hu thun ca vin thng, IPTV d dng cung cp nhiu

hot ng tng tc hn, cung cp s cnh tranh mnh m hn cho cc doanh nghip

kinh doanh dch v truyn hnh. IPTV c c hi ln pht trin nhanh chng khi m

mng bng rng c mt khp mi ni. Rt nhiu nh cung cp dch v vin thng

ln trn th gii ang trin khai dch v IPTV v xem y nh mt c hi mi thu

li nhun t th trng hin c ca h v coi nh mt gii php t bo v trc s

ln sn ca cc dch v truyn hnh cp. Vit Nam hin nay mt s nh cung cp

ang trin khai dch v IPTV trn mng bng rng xDSL. Trong tng lai gn, truyn

hnh HDTV s c ng dng trin khai rng ri trong nc cung cp dch v

truyn hnh cht lng cao cho ngi s dng.Ti Vit Nam, hin nay c rt nhiu nh khai thc dch v vin thng ln ang

cnh tranh nhm cung cp cho ngi s dng cc dch v bng thng rng vi cht

lng cao v gi r. H cng nhn ra xu hng pht trin ca truyn hnh trc

tuyn v video theo yu cu, v ang c nhng bc i mnh m. l cc dch v

MyTV ca VNPT, iTV ca FPT v cc dch v IPTV ti cc a phng ca VTC vi

cc thng hiu khc nhau. Nhm mc ch nng cao cht lng dch v IPTV, n

ny s nghin cu v vn m bo cht lng dch v IPTV trn mng vin thng

c nh. n c xy dng vi b cc nh sau:Chng 1: Tng quan IPTVv tnh hnh pht trin IPTV Vit NamChng 2: Cng ngh tuyn hnh trn IP

Chng 3: Cc yu t nh hng n cht lng IPTV v ng dng trin

khai ti IPTV Bc Ninh

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Do c im cng ngh, thi gian v kin thc cn hn ch nn ti ch dng

li mc nghin cu l thuyt. Trong thi gian thc hin n, tc gi c gng tm

hiu ti liu, v tham kho kin gio vin hng dn. Tuy nhin do kin thc cn

hn ch nn khng trnh khi nhng sai st, rt mong nhn c s gp chn thnhca cc thy c gio v cc bn n c hon thin hn.

Mt ln na xin chn thnh cm n cc thy c gio to iu kin trong qu

trnh thc hin n. c bit, xin cm n s quan tm ca thy gio TS. Trn Thin

Chnh tn tnh hng dn v gip ti c th hon thnh n ny.

H Ni, ngy 10 thng 08 nm 2011

Sinh vin thc hin

Nguyn Vn Din



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n tt nghip i Hc Chng 1: Tng quan IPTV v tnh hnhtrin khai IPTV Vit Nam

CHNG 1: TNG QUAN IPTV V TNH HNH PHT TRIN IPTV

VIT NAM

1.1. Gii thiu IPTV

1.1.1. Khi nim IPTV

IPTV l tn vit tt ca cm t Internet Protocol Television - truyn hnhqua

giao thc Internet, Telco Televison hay truyn hnh bng rng, vi ngha truyn ti

truyn hnh qung b hoc video theo yu cu, chng trnh pht thanh c cht

lng cao trn mng bng rng. Theo quan im ca i tng s dng, vic khai

thc v xem IPTV cng ging nh dch v Ti vi tr tin. ITU-T (ITU-T FG IPTV) chnh thc chp thun nh ngha IPTV nh sau:

IPTV c nh ngha l cc dch v a phng tin nh truyn hnh, video,

audio, vn bn, s liu truyn ti trn cc mng da trn IP c kim sot nhm

cung cp mc cht lng dch v, tnh t ng tc, bo mt v tin cy theo yu

cu.

T quan im ca nh cung cp dch v, IPTV bao hm qu trnh thu thp, x

l, v truyn ti mt cch an ton ni dung video trn h tng mng da trn cng

ngh IP. Tham gia vo qu trnh cung cp dch v IPTV gm nhiu nh cung cpdch v t cc nh cung cp dch v truyn hnh cp, truyn hnh v tinh n cc

cng ty Vin thng ln v cc nh khai thc mng ring nhiu ni trn th gii.

1.1.2. Mt s c im IPTV

H tr truyn hnh tng tc - Cc kh nng hot ng hai chiu ca h thng

IPTV cho php nh cung cp dch v a ra mt s lng ln cc ng dng truyn

hnh tng tc. Cc loi hnh dch v c phn phi qua dch v IPTV c th bao

gm truyn hnh trc tip tiu chun, truyn hnh trung thc cao (HDTV), cctr chi trc tuyn, v kt ni Internet tc cao.

Khng ph thuc thi gian - IPTV khi kt hp vi my thu video s cho php

to chng trnh ni dung khng ph thuc thi gian bng c ch ghi v lu li ni

dung IPTV v sau c th xem li.

Tng tnh c nhn - H thng IPTV t u cui-n-u cui h tr thng tin

hai chiu v cho php cc i tng s dng la chn v thit lp vic xem TV theo

s thch ring nh chng trnh v thi gian xem a thch.

Yu cu v bng thng thp - Thay v phi truyn ti tt c cc knh cho mi



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i tng s dng, cng ngh IPTV cho php cc nh cung cp dch v ch cn phi

pht cc knh m i tng s dng yu cu. Tnh nng hp dn ny cho php nh

khai thc mng tit kim bng thng.

Kh nng truy nhp trn nhiu loi thit b - Vic xem ni dung IPTV khngb gii hn l dng cho cc my thu hnh. Cc khc hng thng s dng my tnh

c nhn v cc thit b di ng truy cp ti cc dch v IPTV.

IPTV thng c xem l cng ngh TriplePlay (d liu, m thanh v hnh

nh). Nhng trong mt mi trng m thch thc nhn ln theo cp s m v cng

ngh phi lin tc c cp nht, b ba dch v ni trn chuyn thnh b t khi

c thm xem truyn hnh Internet qua in thoi di ng (MobileTV).

Hnh 1: IPTV l cng ngh ca tng lai

Kh nng ca IPTV ha hn mang n nhng ni dung k thut s cht lng

cao nh video theo yu cu (Video-on-Demand- VoD), hi tho, truyn hnh tngtc/trc tip, game, gio dc t xa, tin nhn nhanh qua TV, v.v...

1.1.3. S khc bit gia IPTV v Internet TV

Do u dc truyn ti trn mng da trn giao thc IP nn i khi chng ta

hay hiu nhm gia IPTV v Internet TV. Thc t hai loi hnh ny c nhiu im

khc nhau.

H tng mng khc nhau: ng nh tn gi, Internet TV da trn mng

Internet truyn ti ni dung video ti i tng s dng. Ngc li, IPTV sdng cc mng ring bo mt truyn ti ni dung video ti i tng s dng.



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Gii hn a l: i tng s dng Internet khng truy cp c cc mng do

cc nh khai thc vin thng hu v vn hnh v bn thn cc mng ny c gii

hn trong vng a l xc nh. Ngc li, Internet khng b gii hn v mt a l,

qua mng Internet, i tng s dng c th truy cp ti dch v Internet TV t btc v tr no trn th gii.

Quyn s hu ca h tng mng: khi ni dung video c truyn ti trn

Inetrnet, cc gi giao thc IP mang ni dung video c truyn ti c th b mt

hoc tr, khi truyn qua cc mng khc nhau. Kt qu l, nh cung cp dch v

video trn internet khng th m bo mc hi lng ca khc hng khi xem TV

qua internet so vi TV truyn thng, TV cp hay TV qua v tinh. Trn thc t, tn

hiu video qua internet i khi b git trn mn hnh v phn gii hnh nh hon

ton thp. Ni dung TV cung cp n i tng s dng theo kiu best effort.

IPTV c truyn ti trn h tng mng m nh cung cp dch v s hu. Vic s

hu h tng mng cho php cc nh khai thc vin thng thit lp h thng ca

mnh h tr qu trnh truyn ti video cht lng cao t u cui-ti-u cui.

C cu truy cp: thng thng set-top box c s dng truy cp v gii

m ni dung video qua h thng IPTV trong khi , truy cp ti dch v internet TV

hu ht u s dng my tnh c nhn. Loi phn mm s dng trn PC ph thuc

vo ni dung internet TV. V d, on file ni dung video c ti v t internetTV c khi yu cu phi ci t chng trnh chy file dnh ring xem. H thng

qun l bn quyn (DRM) cng yu cu h tr c cu truy nhp ny.

Gi thnh: mt phn ng k ni dung video c truyn ti trn mng

internet l min ph cho mi ngi. Tuy nhin, iu ny s thany i khi s lng

ngy cng tng cc cng ty truyn thng a phng tin bt u a vo cc dch

v min ph da trn internet TV. Cu trc gi thnh p dng cho IPTV tng t

nh m hnh thu bao hng thng c chp nhn bi cc nh cung cp dch v TV

tr tin. Nhiu chuyn gia phn tch cho rng s hi t ca internet TV v IPTV sthnh dch v gii tr ch yu sau ny.

Cc phng php to ni dung: cc nh cung cp internet TV to ra phn ni

dung video c kch thc xc nh v truyn vo cc knh, trong khi , cc nh

cung cp dch v IPTV truyn trn cc knh cc phim v cc chng trnh truyn

hnh thng thng do cc hng phim v hng truyn hnh ln cung cp.

Vi dung lng bng thng ngy cng cao v cc k thut nn tin tin cng

vi nh cu ca cc nh khai thc vin thng mun cung cp cc dch v video ti

ngi s dng ca mnh l nhng yu t thc y th trng IPTV ton cu ngy



17/106


cng pht trin. Vit Nam cng l mt trong nhng th trng IPTV y tim nng

v ha hn mang li nhiu li nhun trong nhng nm sp ti.

1.2. M hnh cu trc IPTV

ITU-T m t m hnh chun dch v IPTV nh trong hnh 1.2. Trong , vai

tr ca bn thnh phn chnh l:

* Nh cung cp ni dung: s hu hoc c cp php bn ni dung hay

quyn s hu ni dung

* Nh cung cp dch v: cung cp dch v IPTV ti ngi s dng. Nh cung

cp dch v da trn QoS trong cc mng ca nh cung cp mng m bo QoE

cc dch v IPTV.

* Nh cung cp mng: cung cp cc dch v mng cho c ngi s dng vnh cung cp dch v. Nh cung cp mng cn cam kt khng ch vi nh cung cp

dch v cn vi c ngi s dng v cc tham s mng.

* Ngi s dng: s dng v tr tin cho cc dch v IPTV.

Hnh 2: M hnh chun IPTV

M hnh hon ton n gin nhng nh ngha n gin ny gip chng ta

phn bit hn na cc dch v IPTV khi xem xt tng vai tr.

Trn thc t, cc mng video IP l nhng h thng kh phc tp c cu

thnh t rt nhiu phn t, l mt trong nhng l do m chng kh thit k v

pht trin. V bn cht cc mng video IP ca cc nh khai thc vin thng l kh

phn b hn so vi cc nh cung cp mng video cp, thng tp trung nhiu chc

nng ti trung tm chnh. Hnh 1.3 minh ha mt cu trc mng IPTV tiu biu trn

thc t. C th thy, trn mng mng thc t, truyn ti dch v IPTV t u

cui-ti-u cui cn c s tham gia ca nhiu phn t mng hng lot cng ngh.Trong cc phn tip theo, chng ta s tp trung vo cc cng ngh s dng trong



18/106


lp h tng dch v IPTV, bao gm cc h thng ngun video IP, cc my ch VoD,

cc phn mm trung gian (middlleware), cc set-top box v phn mm bo

mt/qun l bn quyn l c trng i vi dch v IPTV v mt s giao thc mng

lin quan n qu trnh truyn ti ni dung IPTV.

Hnh 3: M hnh IPTV thc t

1.3. Tnh hnh pht trin IPTV Vit Nam

Xu hng s ha v hi t trong lnh vc vin thng, cng ngh thng tin v

truyn hnh tr thnh mt ln sng lan ta nhiu quc gia trn ton th gii.

Vic IPTV pht trin Vit Nam chnh l mt h qu tt yu ca s lan ta ny.

y cng l hng i c Chnh ph ch trng trong l trnh a Vit Nam tr

thnh quc gia mnh v Truyn thng v Cng ngh thng tin trong thi gian ti.

Trong s pht trin y.1.3.1. Tnh hnh pht trin dch v IPTV ca VNPT

Tp on Bu chnh Vin thng Vit Nam (VNPT) hin l nh cung cp cc

dch v vin thng v Internet ln nht vi th phn rng nht ti Vit Nam, chim

48% th phn thu bao bng rng ti Vit Nam. Mng NGN ca VNPT cho php

trin khai cc dch v a dng vi gi thnh thp, gim thiu thi gian a dch v

mi ra th trng, gim chi ph khai thc mng v dch v ng thi nng cao hiu

qu u t v to ngun doanh thu mi ngoi doanh thu t cc dch v truyn thngnh: thoi, truyn d liu tc cao, dch v a phng tin, hiu sut s dng



19/106


truyn dn rt cao. NGN cho php VNPT tng cng kh nng kim sot, bo mt

thng tin v tin cy trong khi gim thiu c chi ph vn hnh. c xy dng

trn tiu ch m, cc giao thc chun v giao din thn thin, NGN p ng c

hu ht cc nhu cu ca nhiu i tng s dng: doanh nghip, vn phng, kt nigia cc mng my tnh, v.v... NGN thng nht mng hu tuyn truyn thng v

chun truyn ti m thanh, hnh nh, d liu khng dy.

Ngy 28/9/2009 Cng ty VASC thuc tp on VNPT chnh thc cung cp

dch v IPTV vi thng hiu MyTV v Nhng g bn mun. Ch sau 4 thng ra

ra mt tnh n ngy 10/ 3/2010, MyTV c cung cp ti 36 tnh/thnh vi hn

15.000 thu bao. n nay MyTV trin khai 64/64 tnh thnh ca Vit Nam ch

sau hn 1 nm. y l mt thnh cng ln ca VNPT. Dch v MyTV nhn

c s cho n nng nhit t ngi s dng c bit l khu vc min Bc.

Cu hnh cung cp dch v IPTV ca VASC nh trong Hnh 4.

Hnh 4: Cu hnh cung cp dch v IPTV ca VASC



20/106


Cc chng trnh v dch v ang cung cp trn MyTV kh phong ph v

nhiu tnh nng ni tri. Mc tiu ca MyTV l mang li cho ngi s dng cch

thng thc khc bit: Truyn hnh theo yu cu. Cc chng trnh v dch v

l:Truyn hnh (Live TV): Live TV tng t nh dch v truyn hnh truyn

thng. Dch v ny cung cp cho ngi s dng nhng chng trnh truyn hnh

c thu li t h thng truyn hnh mt t, truyn hnh cp, truyn hnh v tinh v

knh truyn hnh ring. Hin nay h thng ca MyTV cung cp 71 knh truyn

hnh. Cc ni dung truyn hnh c pht theo lch trnh v thi gian c nh nh

truyn hnh truyn thng. Nhng vi cng ngh IPTV, ngi s dng khng ch

xem mt cch th ng m c th s dng nhng tnh nng u vit: tm dng, lu

tr, hng dn chng trnh in t, kha chng trnh khng dnh cho tr em.

Phim theo yu cu (VOD): Dch v ny cho php ngi s dng la chn v

xem phim lu li trn server.

Karaoke (KoD): mang n cho ngi s dng danh sch nhng bi ht c

a chung trong nc v quc t. Li bi ht xut hin di dng text trn mn

hnh TV, Karaoke l mt dch v c bit hp dn.

Truyn hnh theo yu cu (TVoD): Dch v ny cho php bn la chn v xem

li cc chng trnh pht trc . Vi dch v Truyn hnh theo yu cu, bnkhng phi ph thuc vo thi gian pht sng ca cc i truyn hnh v khng bao

gi b l bt c mt chng trnh truyn hnh yu thch no.

m nhc (MoD): Dch v ny cho php ngi s dng la chn v nghe, xem

cc clip, video clip ca nhc t th vin ca nh cung cp.

Game theo yu cu (GoD): Dch v cho php chi cc game t danh sch

c nh sn n STB. Ngi dng tr ph cho vic chi game.

Tip th truyn hnh (Tele Marketing): Mang n cho ngi s dng s dng

MyTV cc thng tin v sn phm, dch v la chn v mua sm. Vi mc chgii thiu sn phm, dch v ny gip ngi s dng c th a ra quyt nh mua

sm chnh xc hn cho mnh.

Thng tin cn bit (T - Intormation): Ngi s dng c th s dng tnh nng

ny tra cu cc thng tin cn thit. Nhng thng tin trn h thng MyTV rt a

dng v phong ph.

Tm dng (Time Shift TV): Dch v tm dng l dch v kt hp gia dch v

truyn hnh trc tuyn Live TV v dch v theo yu cu. Vi chc nng dch thi

gian, c th tm dng hoc tua i tua li knh truyn hnh ang pht xem li sau.



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Lu tr (nPVR): Chc nng nPVR ( Personal Video Recorder ) cho php

ngi s dng ghi chng trnh v lu tr chng trong h thng lu tr ca nh vn

hnh v xem li sau vi y chc nng iu khin VCR.

Tr tin theo tng chuyn mc (iPPV): L dch v tr tin theo tng ln xem.iPPV l mt gii php hiu qu bi v i khi bn ch quan tm n mt s chuyn

mc nht nh ch khng mun xem tt c cc knh.

Qung co (Live channel & Advertising): Qung co trn knh trc tuyn l

dch v cho php ngi s dng doanh nghip c nhu cu t qung co trn MyTV

qua nhiu hnh thc: TVC, Panel, Logo, Text...

Sng pht thanh (Broadcast audio channel): L dch v nghe sng pht thanh

theo yu cu. Vi mt danh sch nh sn c trong h thng cc chng trnh pht

thanh c pht trc tip theo chuyn c th nh m nhc, chnh tr, kinh t, x

hi... Bn c th la chn v nghe cc chng trnh pht thanh trong nc, quc t

qua h thng MyTV.

Chia s nh v clip (Media sharing): Tnh nng ny cho php ngi s dng

MyTV c th to, lu tr v qun l cc album nh, clip ca mnh.

Ngoi ra, cc giai on tip theo s c cc dch v tng t nhng vi cht

lng cao (High Definition) v thm mt s dch v gia tng gi tr khc.

Sau y l bng gi cc dch v MyTV:Bng 1: Mc cc thu bao thng cho dch v MyTV



22/106


Bng 2: Mc cc dch v theo yu cu (PayTV) ca MyTV

1.3.2. Tnh hnh pht trin dch v IPTV ca FPT

Dch v IPTV ca FPT cung cp ra th trng vi thng hiu iTV vi slogan:

Mun g xem ny. Dch v iTV kh a dng vi nhiu tin ch gii tr:

Hnh 5: Dch v iTV ca FPT

Truyn hnh: Cc knh truyn hnh trong v ngoi nc c sc, chn lc.

c bit, tnh nng Truyn hnh xem li: cho php xem li chng trnh pht trong vng 48 gi ca 10 knh knh VTV1, VTV2, VTV3, HTV2,

HTV3, HTV7, HTV9, VTC3, HTVC Thun Vit, HTVC Movie bt c

lc no, m khng cn l thuc Lch pht sng ca i.

Phim truyn: Kho phim mi, phong ph, th loi, c cp nht hng

tun

Thiu nhi: Th gii mun mu ca cc thin thn nh tui t phim, hot

hnh n ca nhc, Ting Anh Cho B: Nhng bi hc ting Anh vui nhn, b ch dnh cho cc



23/106


b t 3 n 10 tui.

Ca nhc: Sn khu si ng vi cc album nhc ca cc ca s ni ting, cc

s kin m nhc

Hi Ci lng: Vi cc v tu hi n khch, hp dn ca cc ngi sao hi

Hoi Linh, Kiu Oanh, Thnh Lc, Bo Quc, Thu Nga v cc v ci

lng ni ting ca V Linh, Ti Linh, Thoi M, Minh Vng

Vn ha - Th thao: Ni tng hp cc s kin ni bt bng cc on video

clip sng ng, chn thc

Th gin: Gm nhng clip ngn vi mc ch mang li nhng giy pht

gii tr th v, gip khn gi qun i nhng mt mi hng ngy.

c bo: Tin tc nng hi c cp nht hng gi a ch cn bit: Trang vng cho nhng ngi bn rn nhanh chng tm

thy thng tin a im cn bit nh n u ? Mua g ? Nh hng no gn

nht ?

1.3.3. Tnh hnh pht trin IPTV ca VTC

Thng 04 nm 2009, VTC Digicom phi hp vi mt s Vin thng cc tnh,

thnh ph chnh thc bt u trin khai dch v IPTV. Cho n nay dch v

IPTV ca VTC Digicom cung cp gn 100 knh truyn hnh trong c 30 knhtruyn hnh phn gii cao theo chun HD (High Definition), VTC cn xy dng

thnh cng kho d liu khng l vi hn 3000 b phim c sc c thuyt minh ph

ting Vit, gn 2000 video ca nhc cng mt h thng cc phim ti liu hp dn

khc phc v cho VoD. c bit IPTV ca VTC Digicom s song hnh cng gii

ngoi hng Anh, vi tnh nng xem li cc trn bng , cc chng trnh tng hp

gii ngoi hng Anh.

La chn cng ngh nn hiu qu (MPEG-4) VTC Digicom hin lm ch

h thng c th p ng v nng lc cho 100.000 thu bao cng vi nn truy nhpbng rng ADSL 2+ c tc download 25 Mb/s trong khong cch 1.5 km, bng

thng rng ti 2.2 MHz. Ngoi ra vi xu th Quang ha trn mng li Vin

thng hin nay th cc nh cung cp dch v c mt h tng tt hn hn cung

cp dch v IPTV so vi trc y.

So vi cc nh cung cp dch v IPTV khc nh FPT v VNPT, VTC c th

mnh vt tri v mt ni dung. Ni dung ca dch v IPTV s c ly ch yu t

i truyn hnh KTS VTC y l i truyn hnh cp quc gia, ln th 2 ti Vit

Nam. y l li th rt ln ca VTC trong thi im m vn ni dung cc



24/106


chng trnh ang lm au u cc nh cung cp dch v v chi ph bn quyn

truyn hnh ngy cng t .

Cho n nay VTC l n v ang l n v i u trong vic nghin cu, pht

trin v cung cp dch v truyn hnh s bao gm Truyn hnh k thut s, Truynhnh phn gii cao (VTCHD) v IPTV. nh hng ca VTC l tp trung pht

trin h thng cung cp ni dung truyn hnh s v dch v gi tr gia tng trn nn

vin thng vn l th mnh ca VTC.

Do c im th trng ca tng vng min khc nhau (v phong tc, cch

hng th cuc sng) nn p ng nhu cu ti tng a phng VTC

Digicom s hp tc vi cc n v Vin thng ca VNPT cung cp cc chng trnh

truyn hnh. Ti mi a phng IPTV ca VTC s c mt thng hiu ring to

ra s gn gi, gn b ca ngi dn a phng, gip h d tip cn dch v

(IPTV) hn. Bn cnh vic pht trin IPTV tng tnh thnh cng l p n tt

cho bn ton v s hn ch c ly truyn dn ca mng cp ng Vit Nam hin

nay. Vic cung cp tn hiu trong phm vi gn hn ch ng k nhng hin tng

gin on khi s dng dch v.

Hin VTC ang cung cp dch v IPTV hp tc vi VNPT:

VNPT Hi Phng tn thng hiu VipTV

VNPT Ninh Bnh vi thng hiu HoaLuTV

VNPT Thanh Ha vi thng hiu LamSonTV

VNPT Ngh An vi thng hiu SongLamTV

VNPT Nng vi thng hiu SongHan TV

VNPT Hu vi thng hiu HueTV

VNPT Bnh nh Vi thng hiu TaySonTV

VNPT Khnh Ha vi thng hiu FamilyTV

VNPT Vng Tu vi thng hiu MegaVNN VNPT Bnh Dng vi thng hiu LifeTV

VNPT Lm ng vi thng hiu MimosaTV

VNPT TpHCM vi thng hiu SaigonTV

VNPT k Lk vi thng hiu BazanTV

1.4. Cc dch v cung cp bi IPTV

IPTV khng ch n thun l IP video. Trn thc t, cc nh khai thc vin

thng ang tp trung vo dch v ny to ra s khc bit ca dch v h cung cp



25/106


vi cc dch v m cc nh khai thc mng truyn hnh cp hay v tinh cung cp.

Tt c cc la chn cu trc v cng ngh c s tp trung vo vic phn phi nhiu

loi dch v video theo yu cu v video qung b, nhng vi kinh nghim v cc

dch v thoi v truyn s liu tc cao cho php cc nh khai thc vin thngcung cp cho ngi s dng cc dch v tch hp b sung l mt phn ca gi dch

v IPTV ln.

Cc dch v chnh thng c trin khai trc l dch v video theo yu cu

v video qung b, tuy nhin cc nh khai thc vin thng u c k hoch b xung

cc dch v ny vi cc dch v tr chi, qung co, m thanh, thng tiniu cn

bit l nh ngha v phm vi ca cc dch v ny s lin tc c tin trin theo

thi gian. Bng 3 m t tng quan cc loi dch v IPTV khc nhau hin ang c

d kin v trin khai.

Bng 3: Cc dch v IPTV

Live TV

Digital TV

Premium TV

Pay-per-view

Near video-on-demand

Program guide

Entertainment

Gaming

Gambling

Karaoke

Internet TV

Stored TV

Video on demand

Subscription VoD

Time-dhifting PRV

Network PVR

Commerce

Telecomerce

Targeted/interactive advesting

Communictaion

Residental VoIP portal

SMS/MMS mesaging

Instant messaging

Mobile services portal

Video conferencing

Emergency alert system

ASP

Distance learning

Home automation portal

Converged services

Hospitality



26/106


1.4.1. Dch v video IPTV

Cc dch v IPTV video c th phn thnh hai nhm: pht qung b v pht

theo yu cu.

1.4.1.1. Dch v video qung bV c bn, cc dch v video qung b khng khc g so vi cc dch v video

m cc nh khai thc truyn hnh cp, v tinh, mt t cung cp ngy nay. iu ny

gp phn to thnh tiu chun i vi dch v TV, khng k n cc c ch truyn

ti: lai cp ng/quang, DSL hay FTTxCc knh video qung b bao gm cc

knh truyn hnh quc gia, a phng v cc knh tr tin (nh HBO).

S cc knh qung b khu vc c th thay i theo th trng, cc knh ny

thng h tr cc phin bn theo khu vc ca cc mng gc (ABC, CBS, NBC v

Fox..). Mt s trong cc knh qung b c nh dng trung thc cao (HD), iu

c ngha cc nh khai thc vin thng c th cung cp cho ngi s dng c hai

loi knh qung b tiu chun (SD) v trung thc cao (HD). Mt phn ni dung

qung b c th c lu li trong mng v s dng sau .

Tnh nng TVoD (TV on Demand) cho php cc chng trnh LiveTV c

lu li trn server trong mt khong thi gian no . Ngi s dng sau c th

la chn xem li cc chng trnh m mnh b l.

Thi gian lu tr cc chng trnh c th t thay i linh ng theo nhu cuthc t. H thng s h tr c 2 cch thc l lu tr theo thi gian v lu tr theo

chng trnh c chn no .

Thng tin v cc (nu c) i vi dch v c hin th ng n ngi

s dng a ra quyt nh la chn.

H tr cc tnh nng c bn ca thit b ghi hnh VCR, l tm dng, chy

tip, chuyn nhanh v pha trc, chuyn nhanh v pha sau. Tnh nng chuyn

nhanh v pha trc, chuyn nhanh v pha sau cn t c tc 2X, 4X, 8X,

16X, 32X v 64X.Mobile TV l hng pht trin tng lai m bo cung cp knh truyn hnh,

VoD v cc dch v ca h thng IPTV n cc ngi s dng ca mng di ng.

Gii php hon chnh h thng IPTV c th kt ni, trin khai cung cp

dch v Mobile-TV. Vic tnh cc c th tch hp vi h thng Billing c lp

c cc phng thc tnh cc linh ng v hiu qu.

1.4.1.2. Dch v Video theo yu cu

Cc dch v video lu tr c nhiu dng v l nn tng phn bit vi cc

ni dung video khc c truyn ti qua cc mng IP. Ni dung video lu tr p



27/106


ng c nhiu cc s thch khc nhau ca ngi xem. Ty theo v tr lu tr,

ngi s dng c th tn dng c cc u im ca ni dung video lu ti thit b

ngi s dng hoc mng iu khin mt cc linh hot khi s dng dch v nh:

tua nhanh, tua ngc, tm dng.. nh khi h s dng VCDs/DVDs. Ni dung videolu tr l ng lc chnh thc y s pht trin phn mm lp dch v trong cc

mng IPTV cng nh cc ty chn ca set-top box. Cc ty chn ni dung video

lu tr bao gm:

VoD lu tr cc b: Ni dung c xem l ph bin rng ri s c pht

qung b ti CPE qua mng IP v lu cc b ngi s dng c th xem

theo yu cu. Cc ni dung ny thng gn vi qu trnh xc thc quyn s

dng khi xem i vi tng thu bao.

VoD lu trn mng: VoD lu trn mng dnh cho cc ni dung c coi l

khng ph bin cho nhiu thu bao ti cng thi im. Ngi s dng c

th yu cu xem ni dung ngay lp tc v/hoc sau khi yu cu. Ni dung

c th xem ngay c truyn ti di dng unicast trn mng IP, trong khi

ni sung xem sau yu cu c tp hp theo nhm cc thu bao v c th

truyn ti dng broadcast hay narrowcast da trn th t tng ng i

vi cc thu bao khc. iu ny s cho php nh cung cp dch v s dng

ti u cc ti nguyn mng mt cch linh hot. VoD thu bao: VoD thu bao l bin th ca hai dch v trn, cho php

khc hng quyn xem mt s ni dung c c cho php trc

trong mt hong thi gian xc nh, tn dng u im ca c hai ni dung

vdeo lu trn mng v cc b.

Ghi li ni dung video theo yu cu c nhn (PVR): cho php ngi dng

quyn ghi li cc chng trnh qung b/theo yu cu xem li sau .

Cc quyn xem ni dung thay i ty theo vic s dng mt ln, nhiu ln

hay khng gii hn ni dung v phn mm qun l bn quyn (DRM) l

yu t quan trng trong cc trng hp ny kim sot qu trnh chia s

ni dung gia cc thit b trong nh thu bao.

Ghi li ni dung video v lu trn mng (PVR): tng t nh dch v PVR,

s khc nhau ch yu l v tr lu ni dung, trong trng hp ny l trn

mng, thay v s dng thit b ca ngi s dng. Dch v ny cho php cc

thu bao vi set-top box n gin tn dng c cc u im ca cc dch

v video lu tr v cho php cc nh cung cp dch v tp hp cc ni dunglu tr trong mng mt cch ti u nh gim chi ph so vi vic thu



28/106


bao phi s dng set-top box phc tp. Dch v ny cng cung cp mt

cch tt nht cho thu bao kh nng linh hot trong vic la chn chng

trnh v mng c kh nng lu nhiu ni dung hn soa vi set-top box ca

ngi s dng.

1.4.2. Dch v m thanh IPTV

Nu ch c dch v IPTV audio th chc chn khng kch thch cc thu baochuyn nh cung cp dch v v cng khng nh cung cp dch v u t mtlng ln tin vo h tng mng phn phi dch v IPTV. Tuy nhin, khi kt hpvi cc ty chn khc n s nng cao tnh hp dn ca gi dch v tng th.

1.4.2.1. Dch v pht thanh qung b

Dch v ny cho php ngi s dng d tm bt k i pht no trn th giiv nghe qua li ra m thanh ca TV hay h thng loa km theo.

1.4.2.2. Dch v m nhc qung b

Theo quan im dch v m thanh, dch v ny rt ging qung b video c

bn, ngha l ngi dng c th s dng nhiu knh m nhc khc nhau. Dch v

ny kh ph bin v c cung cp bi nhiu nh cung cp dch v cp/MSO.

Dch v m nhc ny thng i km vi thng tin ha v ni dung nhc hin th

trn TV ca ngi s dng. Hng dn chng trnh chn knh cng tng t nh

i vi cc knh video.1.4.2.3. Dch v m nhc theo yu cu

Tng t nh VoD, quyn yu cu v nghe tng t nh i vi cc dch v

VoD. Mi quan h gia cc nh cung cp ni dung v phng tin l yu t quan

trng nh i vi dch v VoD m bo c c th vin ln cc file nhc.

1.4.2.4. Dch v m nhc tr tin

Cho php thu bao lu tr v sp xp theo s thch ca mnh.

Dch v m nhc theo yu cu s c truyn ti qua mng IP theo cch

tng t nh cc dch v VoD s dng cc c cu qung b hay n hng, theo

thi gian v mc tng ng vi cc thu bao khc.

1.4.3. Dch v tr chi

Chi game (mt ngi hay nhiu ngi cng lc) trn truyn hnh l dch v

ring bit m cc nh khai thc vin thng ang xc tin tch hp vo cc gi dch

v IPTV. S c nhiu loi ch tri cho nhiu loi i tng khc nhau cng nh

cng nh cc tr chi cho 1 ngi v nhiu ngi chi cng lc. Ngi s dng c

th la chn ngi chi cng cng nh ln k hoch thi gian chi vi ngi khc.



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1.4.4. Dch v thng tin tch hp

Dch v thng tin IPTV tch hp l lnh vc trong cc nh khai thc vin

thng c u th hn so vi cc nh cung cp a dch v/truyn hnh cp. Cc dch

v thng tin tch hp s tn dng cc li th v ti nguyn ca cc nh nh cung cpdch v vin thng khi cung cp cc dch v thoi v truy cp Internet tc cao.

Cc v d v dch v thoi v Internet tch hp c m t nh sau:

1.4.4.1. Dch v thoi tch hp

Dch v thoi tch hp cho php cc thu bao s dng TV ca h m rng cc

chc nng dch v thoi di ng v c nh. V d:

Dch v thng bo cuc gi n (Incoming Call Notification Service): Hin

th biu tng trn TV, thng bo cho thu bao c cuc gi thai/vdieo n.Ngoi ra cn h tr cc chc nng hin th s thu bao v ghi li cuc gi.

Dch v thng bo bn tin (Message Notification Service): Hin th biu

tng trn TV, thng bo cho thu bao c li nhn (voice mail) trong hp

th km theo dch v thoi c nh v/hoc di ng.

Dch v thit lp kt ni (Connection Establishment Service): cho php

thu bao gi thoi/video t TV ca h.

Dch v hi ngh thoi/video (Voice/Video Conferencing Service): cho

php thu bao tham gia v/hoc khi to hi ngh thoi/video. Dch v danh b (Directory Service): Cung cp cho thu bao danh b in

thoi in t c th truy cp qua TV.

1.4.4.2. Dch v Internet tch hp

Cc dch v Internet tch hp s cho php s dng TV s dng cc ng

dng Internet trc y phi s dng bng my tnh c nhn. Cc dch v ny

khng nhm thay th cc ng dng Internet da trn PC m chng cung cp cc

bin php thun tin hn truy cp thng tin trong nhng khu vc khc nhau trong

nh thu bao hay cc thi im khc nhau.

Duyt web bng TV (TV web browsing): cho php thu bao xem cc trang

web trn TV ca h.

Nhn tin bng TV (TV Instant Messaging): cho php thu bao thng tin qua

IM trong khi ng thi s dng cc dch v video/audio hay gaming khc.

TV Email: cho php thu bao s dng cc ng dng ngi s dng trn TV

c, gi v nhn th in t.

Telecommerce Service: tng t nh cc dch v e-commerce, cc dch v



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ny c thit k cho php thu bao s dng TV ca mnh tm kim

v t mua hng.

1.4.5. Dch v qung co

H tr cc qung co qung b truyn thng v xen vo cng vi qung b

cc b ti cc im khc nhau trong mng IPTV. Kh nng tng quan gia cc

set-top box v cc mc u tin dch v cho php nh cung cp dch v a ra cc

dch v qung co c hng i tng.

Vic tch hp cc dch v qung co hng vo i tng s dng vi cc

dch v mua bn t xa cho php nh cung cp dch v c th gip ngi s dng

ca mnh thc hin c nhng tha thun mua bn theo yu cu. Vi bn cht hai

chiu ca mng thng tin v cc dch v kt hp, cc thu bao c th cung cp kin nh gi ca mnh i vi qung co trn IPTV lm cho dch v qung co

ny st vi i tng hn, ph hp hn.

1.4.6. Dch v tng tc

1.4.6.1. Ghi hnh ring t (PVR)

Trong trng hp ny, thu bao c th thu li cc chng trnh vo th mc

ca mnh, cc thu bao s tr tin thng qua ti khon. i vi ni dung c m

ho, kho gii m s c download t trn h thng ti thi im xem ni dung.

Chc nng ny thu bao c th chia s nhng hnh nh ca h cho bn b v

nhng ngi thn ca h.

1.4.6.2. Ghi hnh ring t trn mng (nPVR)

nPVR l mt thnh phn mng ghi v pht li ni dung ca cc knh truyn

hnh. C th khng nht thit ghi li tt c cc knh truyn hnh, nPVR s gii hn

trc ch nhng chng trnh c chn, nhng chng trnh ny c th c ghi

li vi mc ch iu khin lu tr d liu.

EPG s c nhim v xc nh xem knh no m nPVR c th cung cp. Datrn list ny, cc thu bao c th lu li cc chng trnh m h chn trong th

vin nPVR hoc thng qua EPG chng hn nh mt biu tng hay mt icon.

Trong lc xem nhng chng trnh do nPVR cung cp, thu bao c th tu thch s

dng nhng cc chc nng iu khin nh Play, Pause, FF, RW. Nh cung cp dch

v s thit lp cc quy tc ghi cho mi knh TV ring, chng hn thi gian lu tr

cho knh c ghi.

1.4.6.3. Bnh chn v d on

Cung cp tnh nng bnh chn trc tip v dch v tr chi d on cho ngi



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xem qua TV. Vic d on, bnh chn c kt hp th hin trc tip trn cc

chng trnh truyn hnh.

Cho php to cc kch bn bnh chn hoc d on d dng v linh ng theo

nhiu tiu ch khc nhau. Chc nng bnh chn c th thc hin ng thi trong khivn ang xem chng trnh TV.

H tr m thanh, hnh nh minh ha cho cc mc a ra. Thao tc bnh

chn, d on cn c h tr thun tin thng qua Remote Control.

1.4.6.4. Gio dc trn ti vi

Cung cp tt c cc dch v hc tp, o to theo cc ni dung v theo tng

la tui. H thng h tr kh nng qun l ni dung cc chng trnh hc tp, o

to. Giao din h thng m bo thn thin, EPG hin th d dng thun tin cho

ngi s dng.

H thng cho php pht trin, tch hp thm cc dch v learning mi vo h

thng IPTV hin ti theo yu cu. C gii php hon chnh cho cc nh cung cp

third-party tch hp vo h thng cung cp dch v.

1.4.6.5. Thng mi trn ti vi

Thng mi qua TV l cc dch v tng tc cho php ngi s dng trao i,

mua bn v u gi nhng sn phm c gii thiu trn TV hoc nhng chng

trnh qung co. thu bao c th ng k, thc hin cc dch v ny h thng cnh tr cc phng thc t hng, thanh ton, giao hng n tn tay ngi dng.

H thng c s ng b, nht qun t server, middleware, EPG n STB

cung cp dch v n ngi s dng. H tr gii thiu, qung b cc thng tin sn

phm trn cc knh Live TV, VoD .. mt cch linh ng v hiu qu. C gii php

tch hp vi h thng thanh ton qua ngn hng, gii php m bo an ton tr tin

trc tuyn.

1.4.6.6. Tng tc qua di ng

Dch v ny cho php thu bao c th xem v tng tc hnh nh thng quacc thit b cm tay nh trn mn hnh TV. Ngoi ra cn c th cho php thu bao

t thit b cm tay ca mnh iu khin mi qu trnh tng tc ca STB i vi h

thng qua thit b cm tay ca mnh.

V d, khi thu bao ang bn i cng tc nhng mun thu mt chng trnh

m h thch xem ti mt thi im no vo b nh trn STB ca mnh ti nh.

H c th iu khin t thit b cm tay ca h trn thit b cm tay.

1.4.6.7. Tin nhn trn ti vi

Chc nng ny cho php ngi xem TV c th chat trc vi nhau thng qua



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h thng IPTV. Ngoi chat trc tip vi nhau, ngi s dng c th chat vi cc

ngi dng ca h thng khc nh Yahoo, MSN, cc tin nhn SMS ..

H thng c th qun l thng tin c nhn ca cc thnh vin (Profile). Qun

l danh sch bn b nh thm, xa, sa thng tin, c ch thng bo ti ngidng khi c message mi n. Qun l thng tin Offline Message.

Ngoi ra cc tnh nng khc s pht trin nh h tr voice chat v video

(webcam), STB h tr bn phm khng dy, font ch Unicode v tch hp b g

ting Vit.

1.4.7. Dch v truyn hnh hi ngh

Hi tho truyn hnh cho php nhiu thu bao tham gia i thoi trc tuyn

thng qua truyn hnh. Gii php ny cho php t chc cc cuc hp, cc bui hitho, o to trc tuyn t xa, ngi dng c th tham gia t bt c v tr a l no

min l c kt ni h thng IPTV.

H thng h tr vic thay i cc thng s v cht lng hnh nh, chun nn,

cho ph hp vi bng thng ca mng li.

1.4.8. Dch v gia tng khc

1.4.8.1. Tin nhin SMS/MMS

Chc nng ny cho php ngi dng TV c th gi nhn tin nhn SMS, MMS

n cc mng di ng. Cho php gi nhn tin nhn trc tip gia ngi s dng ca

h thng IPTV v ngi s dng ca mng mobile.

H thng c giao din nhp tin nhn d dng, STB s h tr bn phm khng

dy trong tng lai. C ch cnh bo ngi dng khi c SMS mi n.

1.4.8.2. Th in t trn ti vi

Chc nng ny ging nh mt trnh email-client. Ngi dng c th gi, nhn,

c trc tip email thng qua mn hnh giao din trn mn hnh TV. Tuy nhin hin

ti cc STB cu hnh thp c hn ch l khng th gi c file nh km, cn phttrin kh nng tch hp thit b u vo (USB chng hn..) upload ni dung.

Chc nng ny h tr y chun SMTP, POP3 thng dng. H tr cc tnh

nng email-client c bn nh: CC, BCC, HTML mail, chn ch k (signature), sp

xp message theo cc tiu ch khc nhau... Cho php cu hnh, to nhiu ti khon

email kt ni gi nhn email n cc mail-server khc nhau. Qun l thng tin

Address Book.

1.4.8.3. Chia s truyn thng (an bum nh)

Chc nng ny cho php ngi s dng thng qua h thng IPTV c th to,



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lu tr v qun l cc album nh ca mnh.

H thng album cho php qun l theo cc category khc nhau. H tr giao

din thn thin, EPG hin th d dng thun tin. Chc nng tm kim thng tin nh,

to cc th mc c nhn (Private).1.4.8.4. Ghi nht k hnh nh

Dch v ny cho php ngi s dng IPTV c th to ring cho mnh mt blog

c kh nng lu tr cc clip video. Ngi dng c th son tho, thm mi cc

mc, bi vit d dng.

H thng h tr qun l thng tin c nhn ca cc thnh vin (Profile), cho

php phn quyn cc thnh vin khc nhau. Ngi s dng c th qun l danh

sch bn b nh thm, xa, sa thng tin.

1.4.8.5. Quan st ton cu

Dch v ny ng dng cho theo di giao thng, gim st an ninh v gim st

h gia nh t xa. Vi loi hnh dch v ny, h thng IPTV c th ng dng cho

tp ngi s dng nhm ln nh cc cng ty, doanh nghip.

H thng h tr gii php hon chnh cho php tch hp cung cp dch v trn

h thng IPTV trin khai. Cung cp cc thit b tch hp i km (camera,

remote,..) pha ngi s dng h tr cho vic monitoring.

Kt lun chng 1Cng ngh truyn hnh s to ra nhng ci tin v c bn so vi cc dch v

truyn hnh tng t. S xut hin truyn hnh s mang li nhng li ch r rt v

cht lng hnh nh, m thanh v kh nng truy cp ti nhiu dch v gii tr mi.

IPTV l phng php mi truyn ti ni dung truyn hnh s trn mng v

c xem l mt phn ca dch v triple-play thng c cc nh khai thc Vin

thng trn th gii cung cp. Thut ng IPTV m t h thng c th truyn ti cc

chng trnh truyn hnh trc tip, phim v cc loi ni dung video tng tc khc

trn mng da trn IP. Cc thnh phn cu to nn mng IPTV ny gm cc h

thng nh nh cc qu x l video, bo mt mng truyn ti. Cu trc h tng mng

IPTV t u cui-ti-u cui c th bao gm tt c hay mt s cc thnh phn sau:

Trung tm s liu IPTV chu trch nhim x l v chun b ni dung

truyn ti qua mng bng rng.

Mng phn phi IPTV bao gm nhiu phn t v cng ngh truyn ti ni

dung IPTV t trung tm s liu ti cc i tng s dng.

Thit b set-top box c lp t ti nh cc thu bao cung cp kt ni giaTV v mng truy nhp da trn IP.



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Mng trong nh ca ngi s dng cho php phn phi s liu, thoi v

video gia cc thit b khc nhau.



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n tt nghip i Hc Chng 2: Cng ngh truyn hnh trn IP

CHNG 2: CNG NGH TRUYN HNH TRN IP

2.1. Kin trc h thng IPTV

Hnh 6: Kin trc chung ca mt h thng IPTV

Kin trc IPTV gm cc khi chc nng sau:

* Ngun ni dung: Ngun d liu, c chc nng thu nhn cc ni dung d liu

nh phim nh t cc nh sn xut v cc ngun khc. Sau , cc ni dung ny

c m ha v lu tr trong c s d liu phc v cho dch v video theo yu

cu (VoD).* Nt dch v IPTV: Cc node dch v IPTV, c chc nng nhn cc lung d

liu hnh nh di cc nh dng khc nhau. Cc lung d liu ny s c nh

dng v ng gi li truyn i vi cht lng dch v (QoS) m bo. i vi

vic qun l dch v, cc node dch v ny s trao i trc tip vi thit b u cui

ngi s dng (CPE), cn i vi cc thu bao cc node dch v ny trao i vi

dch v IPTV.

* Mng phn phi din rng:Mng phn b vng rng hnh thnh nn vic

phn b kh nng, dung lng v cht lng ca dch v. Mng ny cng gm ccchc nng khc nh truyn a hng, vic ny rt cn thit cho vic phn b cc

lung d liu IPTV t cc node dch v n ngi s dng mt cch tin cy v

ng thi gian. Ngoi ra, mng li v mng truy nhp gm c mng ng trc

quang v b ghp knh truy nhp ng dy thu bao s (DSLAMs).

* Kt ni ngi s dng:Kt ni truy nhp ngi s dng, i hi s dng

cc cng ngh DSL tc cao nh ADSL2+ v VDSL, thng tin c truyn n

ngi s dng qua ng in thoi.

* Thit b u cui ngi s dng (CPE): Thit b u cui ngi s dng



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cung cp chc nng kt cui mng bng rng (B-NT). Thit b ny c th cung cp

cc chc nng nh cng nh hng, set-top box, internet.

* Khch th IPTV: L khi chc nng c nhim v kt cui lu lng IPTV

ti u cui ngi s dng. Thit b ny, v d nh set-top box, thc hin chc nng

x l nh thit lp kt ni v QoS i vi cc node dch v, gii m cc lung tn

hiu hnh nh, chuyn i knh, hin th iu khin v cc kt ni n cc ng dng

ngi s dng nh truyn hnh s tiu chun (SDTV) hoc truyn hnh s nt

cao (HDTV).

2.2. H thng cung cp dch v IPTV

H thng cung cp dch v IPTV s bao gm cc thnh phn v th hin nh

trong hnh 7.

Middleware

H thng phn phini dung

VoD servers

Mng truy nhp

Qun l mng& Tnh cc

Thu bao

STB

Thu bao

STB

Ngun tn hiu(s, analog)

Headend

Encoder

DRM IP multicast stream

IP multicast/unicast stream

Hnh 7: M hnh kin trc h thng cung cp dch v IPTV

H thng cung cp ngun d liu: Thu, nhn v x l cc d liu chng trnh

t cc ngun khc nhau nh v tinh, truyn hnh mt t v cc ngun khc chuyn sang h thng Headen.

H thng u cui (Headend): Thu, iu ch v gii m ni dung hnh nh v

m thanh t cc ngun khc nhau v s dng cc thit b m ha chuyn i ni

dung ny thnh cc lung IP multicast khun dng m ha mong mun.

H thng trung gian (Middleware): c vai tr gn kt mt s thnh phn logc

thnh mt h thng phn mm IPTV/video hon chnh hn. H thng Middleware

cung cp giao din ngi s dng cho c dch v bng rng v theo yu cu. H

thng ny cng c s dng nh phn mm lin kt tch hp cc sn phm t



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cc nh cung cp khc nhau thnh mt mc ng dng.Middleware cung cp kh

nng qun l thu bao, ni dung v bo co hon chnh cng vi cc chc nng

qun l chng trnh in t (EPG) v thit b u cui ngi s dng (STB), ng

thi vn duy tr tnh m cho vic tch hp cc dch v trong tng lai.

H thng phn phi ni dung: Bao gm cc cm my ch truyn hnh theo yu

cu (VoD) v cc h thng qun l VoD tng ng, cho php lu tr cc ni dung

c m ha v thit lp cc chnh sch phn phi ni dung mt cch mm do.

H thng ny cng cho php nh khai thc m rng mt cch kinh t, ph hp vi

ti v yu cu dch v ca cc thu bao.

H thng qun l bn quyn s (DRM): Gip nh khai thc bo v ni dung

ca mnh, nh trn cc tn hiu truyn hnh hay m ha ni dung VoD, khi truyn i

trn mng Internet v tch hp vi tnh nng an ninh ti STB pha thu bao.Mng truy nhp: H tng mng IP bng rng truyn dch v t nh cung

cp n khch hng

Thit b u cui ngi s dng (STB): Thit b u cui pha ngi s dng

cho php thu, gii m v hin th ni dung trn mn hnh TV. STB cng c th h

tr HDTV, c kh nng kt ni vi cc thit b lu tr bn ngoi, video phone, truy

nhp web ...

H thng qun l mng v tnh cc.

2.3. Mng cung cp dch v Triple Play

Hin nay, vi vic s dng cc cng ngh mng truy nhp v chuyn mch gi

da trn giao thc IP, cc cng ty vin thng c th gim chi ph u t ng thi

a ra c nhiu loi dch v mi. Cc nh cung cp ng truyn ang n lc

chuyn i t knh sang gi theo nh hng cng ngh chin lc ca h

tng kh nng to ra dch v v cung cp vi gi thnh thp v to ra c mt cu

trc mng IP linh hot. S pht trin ca cc sn phm mi l cha kha cho s

chuyn i ny, c th nh cc chuyn mch mm dng cho cc dch v thoi, cch thng Headend s cung cp truyn hnh IP, cc h thng mch vng bng

rng cho php hp nht thoi, s liu v truyn hnh trn mt h tng mng truy

nhp duy nht. Vi s tc ng ca cc cng ngh gi, cc nh cung cp dch v c

th duy tr kh nng cnh tranh bng cch cung cp cc dch v "Triple-Play" vi

thoi - s liu - truyn hnh trn cc ng truyn DSL.



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NxGEGE

COT

RTRT

RTRT

RT

Router

Class 5

PSTN

Internet

Central Office

Video HeadendCO

CO

CODSL

Access Network Back bone/Metro/Interoffice

Hnh 8: Kin trc mng cung cp dch v Triple Play

Trong kin trc mch vng ni ht cung cp dch v Triple Play, mt h thng

mch vng mang cc lu lng thoi, s liu v truyn hnh t cc RT (RemoteTerminal) s dng cc ng dy in thoi tiu chun vi giao din DSL. Cc RT

c kt ni n u cui trm trung tm (COT) thng qua mng truy nhp. Khch

hng c kt ni trc tip trn cc i cp ng n trm trung tm (CO) c th

nhn c tt c cc dch v nh nhau trc tip t COT. COT cung cp cc truy

nhp n mng chuyn mch cng cng (PSTN) thng qua h thng chuyn mch

truyn thng hoc chuyn mch mm (dng cho VoIP), cung cp truy nhp Internet

thng qua thit b nh tuyn v cung cp truy nhp n cc dch v truyn hnh

thng qua kt ni n Video Headend.Gii php ny s dng cng ngh IP tiu chun. V mt k thut, cch tip cn

ny loi b s phc tp ca mng. V mt kinh t, gii php ny gim ng k chi

ph xy dng v vn hnh mng.

Xt v kha cnh lu lng, khch hng kt ni vo mng ti u xa (RT) hay

trung tm (CO) qua cc giao tip truyn thng nh cc ng analog/POTS, E1 hay

DSL. Mi lu lng khng phi l IP s c chuyn i thnh cc gi ti RT, v

d thoi analog c chuyn thnh VoIP. RT c kt ni n CO qua cc lin kt

Ethernet hoc POTS theo mi cu hnh mng nh ring, string, star, v.v... ph hp

vi cu hnh mng ca nh cung cp. Lu lng IP i t RT n COT ti CO. COT

kt ni vi cc thit b chuyn mch Class 5 v kt ni n thit b nh tuyn truy

nhp Internet, chuyn mch mm v n cc Video Headends.

2.4. Cc chun nn hnh nh s dng cho IPTV

Cng vi s pht trin mnh m ca my tnh v s ra i ca internet, th

vic tm ra mt phng php nn nh nhm gim bt khng gian lu tr thng tin

v truyn thng trn mng l yu cu cp thit. Cc k thut nn Video u c gng



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gim lng thng tin cn thit cho mt chui cc bc nh, m khng lm gim cht

lng nh. Mc ch ca nn video l gim bt s bt khi lu tr v truyn bng

cch loi b lng thng tin d tha trong tng frame v dng k thut m ho

ti thiu ho lng thng tin quan trng cn lu gi. Vi mt thit b lu hnh k

thut s thng thng, nh sau khi c s ho s c nn li. Qu trnh nn s x

l cc d liu trong nh a hnh nh vo mt khng gian hp hn nh trong

thit b nh k thut s hoc qua ng dy in thoi, ... Vi th trng lu hnh

k thut s hin nay, cc chun nn ph bin l Motion JPEG (MJPEG), Wavelet,

H.261/ H.263/ H.263+/ H.263++ v MPGE-1/ MPGE-2/ MPGE-4. Nhn chung, c

hai nhm tiu chun ch yu: nhm mt gm nh dng nn MJPEG v Wavelet; v

nhm hai gm cc nh dng chun cn li. Cc thut ton m ha ca hai nhm l

tng t nhau nhng mc ch ca chng li khc nhau. H.26x series c phttrin cho in thoi truyn hnh trong khi MPEG series c pht trin chnh cho

vic qung b hnh nh cht lng cao.

Hnh 9: Lch s v xu hng pht trin ca cc chun nn

2.4.1. Chun nn MJPEG v Wavelet

Tnh cht chung ca cc nh s l tng quan gia cc pixel cnh nhau ln,

iu ny dn ti d tha thng tin biu din nh. Vic d tha thng tin dn ti

vic m ho khng ti u. Do vy, ta cn tm phng n biu din nh vi tng

quan nh nht, gim thiu d tha thng tin ca nh. C 2 kiu d tha thng

tin nh sau:

* D tha trong min khng gian: l tng quan gia khng gian pixel ca



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nh (cc pixel ln cn ca nh c gi tr gn ging nhau, tr nhng pixel gip

ng bin nh).

* D tha trong min tn s: l tng quan gia nhng di mu hoc cc di

ph khc nhau.

* Trng tm ca cc nghin cu v nn nh l gim bt mt s bit biu din

nh bng vic loi b d tha trong min khng gian v min tn s cng nhiu

cng tt. Cc chun nn MJPEG v Wavelet u tun theo nguyn tc tm ra cc

phn t d tha min khng gian (mi Frame nn t ng). Trong khi , c trng

ca cc chun nn thuc nhm 2 l loi b d tha c min khng gian v min

tn s ca nh.

* MJPEG l nh dng nn nh lu i nht v c dng ph bin. Khi

dng chun nn MJPEG, nh c phn chia thnh cc khi vung nh, mi khivung c kch thc 8 x 8 pixel v biu din mc xm ca 64 im nh. M ho

bin i cosin ri rc DCT (Discrete Cosin Tranform) trong chun nn ny khai

thc s tng ng gia cc pixel trong mi khi, ly ra cc biu din nh vi

tng quan nh. Chui biu din s b rt ngn, tu theo mc nn ca h thng hin

hnh vi qui trnh rt ngn chui biu din. V vy, hnh nh sau khi gii nn

thng c nhiu sai lch so vi nh gc.

chun nn Wavelet, thay v m ho theo tng khi 8 x 8, vic thc hin trn

ton b b mt nh, mt lot cc b phn lc khu chuyn i s phn tch cc dkin v tng im nh v cho ra mt tp cc h s. Do chun Wavelet c tc dng

vi ton b b mt nh, nn cc sai lch nh gii nn s khc vi MJPEG. Hiu

ng ghp mnh khng xy n vi nh c quan st, nhng phn gii hnh nh

gim cng nh mt vi vt m s xut hin.

Cc nh dng Wavelet v MJPEG u gy ra hin tng mt thng tin nh

gii nn. S d tha kh nng lu nh mt ngi cm th khi dng chun nn

Wavelet t hn MJPEG 30%.

2.4.2. Chun nn MPEG-x v H.26x

MPEG khng phi l mt cng c nn n l, u im ca nh nn dng

MPEG l ch MPEG c mt tp hp cc cng c m ha chun, chng c th kt

hp vi nhau mt cch linh ng phc v cho mt lot cc ng dng khc nhau.

Nguyn l chung ca nn tn hiu video l loi b s d tha v khng gian v s

d tha v thi gian, c thc hin trc ht nh s dng tnh cht gia cc nh

lin tip. Chng ta dng tnh cht ny to ra cc bc nh mi nh vo thng tin

t nhng bc nh gi trc . Do vy pha b m ha ta ch cn gi li nhng



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nh c s thay i so vi nh trc, sau ta dng phng php nn v khng gian

trong nhng bc nh sai khc ny. Ni mt cch c th, nguyn l chung ca cc

chun nn l phng on trc chuyn ng ca cc frame b m ha. Mi frame

ti mt thi im nht nh s c nhiu kh nng ging vi cc frame ng ngay

trc v sau . Cc b m ha s tin hnh qut ln lt nhng phn nh trong

mi frame (marco blocks) v pht hin ra marco block no khng thay i t frame

ny ti frame khc. Pha bn thu, tc b gii m lu tr sn nhng thng tin

khng thay i t frame ny ti frame khc, chng c dng in thm vo v

tr trng trong nh c khi phc.

Tuy nhin, do s tng ng gia cc frame l rt ln, nn s pht hin ra cc

sai lch l rt kh. Do vy nh khi phc kh t c nh nh gc. iu ny ng

ngha vi vic cht lng nh cng tng t nh khi dng chun Wavelet vMJPEG, nhng dung lng knh truyn v khng gian lu tr ca cc chun nn

H.26x v MPEG-x l nh hn (v d nh khng gian lu tr ca chun H.263 nh

hn Motion JPEG t 3 ti 5 ln). S khc bit gia cc chun nn ny (nh H.26x

v MPEG-x) ch yu nm khu tin on cc frame mi v cch thc tnh ton

sai lch gia cc frame hin ti v frame phng on. Chun nn H.26x (gm cc

th h H.261, H.262 v H.263, ...), thng c tc m ho tn hiu thp hn

MPEG-x (khong 1,5 Mbps vi phn gii hnh 352 x 288) do dng ch yu trong

vin thng. Trong khi , chun MPEG-2 dng cho th trng gii tr c phngii hnh cao hn, v mang li cht lng hnh nh tt (cao hn 1,5 Mbps vi

phn gii 352x288 hoc 6 Mbps cho phn gii hon chnh).

2.4.3. Chun nn MPEG-2

MPEG-2, ra i nm 1994, l tn ca mt nhm cc tiu chun m ha cho tn

hiu m thanh v hnh nh s, c chp thun bi MPEG (Moving Picture Expert

Group) v c cng b trong tiu chun quc t ISO/IEC 13818. MPEG-2 thng

c s dng m ha m thanh v hnh nh cho cc tn hiu broadcast bao gmtruyn hnh v tinh qung b trc tip v truyn hnh cp. MPEG-2 vi mt s sa

i cng l khun dng c s dng bi cc phim DVD thng mi tiu chun.

MPEG-2 bao gm cc phn chnh sau:

* MPEG-2 Systems part (part 1) xc nh hai khun dng ring bit. Lung

truyn ti (Transport Stream) c thit k mang m v hnh nh s qua cc

phng tin khng c tin cy lm. MPEG-2 Transport Stream thng c s

dng trong cc ng dng bng rng, nh ATSC v DVB. MPEG-2 Systems cng

xc nh cc lung chng trnh (Program Stream), mt khun dng c thit k



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cho cc phng tin c tin cy chp nhn c nh a. MPEG-2 Program

Stream c s dng trong cc tiu chun DVD v SVCD. MPEG-2 System c

bit n chnh thc l ISO/IEC 13818-1 v ITU-T Rec.H222.0

* MPEG-2 Video part (part 2) tng t nh MPEG-1, nhng cng h tr cho

video xen k (interlaced video, khun dng c s dng cho cc h thng truyn

hnh qung b tng t). MPEG-2 video khng ti u cho cc tc bt thp (


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lin quan v b sung thm cc tnh nng mi nh h tr VRML cho 3D, cc file bao

gm cc vt th c nh hng (gm audio, video v VRML).

MPEG-4 thc s l mt dng nn nh mang tnh t ph ca cng ngh nn

hnh ng i, th hin r nt nhng tiu chun sau:

* p dng nhng tiu chun c tnh m cao vi s h tr c lc t ngnh

cng nghip an ninh v cng nghip my tnh.

* Kh nng truyn theo dng v mng li.

* Ti thiu ha dung lng knh truyn v khng gian lu tr trong khi vn

gi c tnh trung thc ca nh.

Nhng chun nn MPEG-4 c profile dng n gin chim lnh a phn th

trng. MPEG-4 c pht trin v hon thin tr thnh nh dng nn hnh tin

tin, hon ho, vi tiu ch tp trung pht trin nhng nhn t gip tng cng chtlng hnh nh, cng nh phc v c lc cho cc thit b gim st c cc frame

dng ch nht. Mi bit stream hin th trong nh dng nn MPEG-4 cung cp mt

m t mang tnh phn tng v hnh nh hin th. Tng lp d liu c a vo

lung bit bi nhng mt m c bit gi l mt m khi ngun.

2.4.4.1. Phn phi cc lung d liu

Hnh 10: M hnh cc lp h thng MPEG-4

Vic phn phi mt cch ng b cc lung thng tin t ngun n ch c

xc nh di dng lp ng b (Sync Layer) v mt lp phn phi (Delivery

Layer) gm hai lp c ghp li l DMIF Layer v TransMux Layer.

DMIF Layer c iu khin bi giao din DMIF (Delivery Multimedia

Intergration Framework), l giao din gia ng dng v truyn ti. Mt ng dng

n l c th chy trn cc lp truyn ti khc nhau khi c h tr DMIF.MPEG-4 DMIF h tr cc chc nng sau:



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* L mt giao din ng dng trong sut

* iu khin vic thit lp cc knh FlexMux

* S dng cc mng ng nht gia cc peer tng tc vi nhau: IP, ATM, di

ng, PSTN, ISDN bng hp

* H tr mng di ng, c pht trin cng vi ITU-T

* UserCommands vi bn tin xc nhn

* Qun l thng tin MPEG-4 Sync Layer

Lp TransMux cung cp cc dch v truyn ti ph hp vi cc yu cu v

QoS. Ch giao din i vi lp ny c xc nh bi MPEG-4 trong khi cc sp

xp c th ca cc gi d liu v iu khin bo hiu cn c tin hnh cng vi

cc phn chnh c tc dng qua cc giao thc truyn ti tng ng. Bt k giao thc

truyn ti tn ti thch hp no nh (RTP)/UDP/IP, (AAL5)/ATM hoc lungtruyn ti ca MPEG-2 qua mt lp kt ni thch hp no c th tr thnh mt v d

TransMux c trng. S la chn ny chuyn ti ngi s dng cui/nh cung cp

dch v v cho php MPEG-4 c s dng trong mt di ca mi trng vn hnh.

S dng cng c ghp knh FlexMux l la chn, lp ny c th b trng nu

lp TransMux di cung cp ton b cc chc nng yu cu. Tuy nhin, lp ng

b (Sync Layer) th lun phi tn ti. Chc nng ca lp ny nh sau:

* Nhn dng cc khi truy nhp, truyn ti timestamps v thng tin tham chiu

nhp v nhn dng d liu mt* La chn d liu chn vo t cc lung s cp khc thnh lung FlexMux.

* Truyn thng tin iu khin

* Ch r QoS yu cu i vi mi lung s cp v lung FlexMux

* Chuyn cc yu cu QoS thnh cc ti nguyn mng thc t

* Kt hp cc lung s cp vi cc i tng trung gian

* Truyn i cc sp xp ca cc lung s cp ti knh FlexMux v TransMux

2.4.4.2. H thng

MPEG-4 c xc nh l cng c ca cc thut ton nn tin tin i vi cc

d liu hnh nh v m thanh. Cc lung d liu (Elementary Streams, ES) l kt

qu t qu trnh m ha c truyn i v lu tr ring bit.

Mi quan h gia cc thnh phn hnh nh v m thanh c m t thnh hai

mc chnh:

* BIFS (Binary Format for Scenes) m t s sp xp v khng gian v thi

gian ca cc i tng. Ngi xem c th c kh nng tng tc vi cc i tng,

v d sp xp li chng trn mn nh hoc thay i quan im v cch xem trongmi trng 3D.



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* Ti lp thp hn, Object Descriptors (ODs) xc nh quan h gia

Elementary Streams thch hp vi tng i tng (v d lung m thanh v hnh

nh ca mt ngi trong mt cuc hi ngh truyn hnh). ODs cng cung cp thm

cc thng tin nh nhu cu URL truy nhp Elementary Stream, cc c tnh ca

b gii m, vt s hu tr tu, ...

2.4.4.3. MPEG-4 Audio

MPEG-4 Audio to iu kin thun li cho mt lng ln cc ng dng t cc

bi din thuyt n gin n cc hnh nh a knh cht lng cao, v t cc m

thanh t nhin n cc m thanh tng hp. c bit, MPEG-4 h tr cc biu din

hiu sut cao ca cc i tng hnh nh bao gm:

* Cc tn hiu hnh nh thng thng: H tr cho vic m ha hnh nh thng

thng t cht lng thp n cao c cung cp bi k thut m ha bin i. Vichc nng ny, mt di rng cc bt v bng tn c bao ph. Bt u ti tc bt

6 kbit/s v bng tn di 4kHz v m rng ti hnh nh cht lng qung b t n

ti a knh. Cht lng cao c th t c vi tr thp. M ha hnh nh tham

s (Parametric Audio Coding) cho php m thanh vi tc thp.

* Cc tn hiu thoi: M ha thoi c tin hnh s dng tc t 2kbit/s ti

24 kbit/s s dng cng c m ha thoi. Tc bt thp hn, v d 1,2 kbit/s, cng

c th khi m ha tc thay i c cho php. Khi s dng cng c HVXC, tc

v cng c th c thay i di s iu khin ca ngi s dng trongkhi pht li. Nu cng c CELP c s dng, vic thay i tc pht li c th

t c bng cch s dng v thm vo cc cng c vic x l c hiu qu.

2.4.4.4. MPEG-4 Visual

MPEG-4 Visual tiu chun cho php m ha lai ghp cc hnh nh t nhin

(cn c vo pixel) v cc cnh nhn to (ly ra t my tnh). Di y l tng quan

v cc cng c v thut ton ca chun hnh nh MPEG-4.

* Cc nh dng c h tr bi MPEG-4 Visual:

+ Tc bt: t 5kbit/s n ln hn 1 Gbit/s

+ Cc nh dng: pht trin khng ngng cng nh cc hnh nh kt hp

cht ch vi nhau

+ Gii php: in hnh t sub-QCIF ti gii php Studio (4k x 4k pixels)

* Hiu qu nn:

+ i vi ton b cc tc bt c nh a ch, thut ton ny rt hiu

qu. Thut ton ny bao gm vic kt hp m ha vi cht lng c iu chnh

gia kh nng chp nhn i vi tc nn cao vi near lossless+ Nn hiu qu i vi mng li 2-D v 3-D



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+ Truyn hnh truy nhp ngu nhin cho php cc chc nng nh tm dng,

chuyn i nhanh ca cc chng trnh truyn hnh c lu tr

* Cc chc nng Content-Based

+ M ha ni dung hnh nh v video cho php tch bit vic gii m v ti

thit li cc i tng video c nh dng ring.

+ Truy nhp ngu nhin cc ni dung cc video cho php cc chc nng

nh tm dng, chyn i nhanh cc chng trnh truyn hnh c lu tr.

+ Nhn m rng ni dung cc chng trnh truyn hnh cho php cc chc

nng nh lm thay i cc text nhn to hay t nhin, b cc, hnh nh v chng

trnh truyn hnh bao ph ni dung truyn hnh c thay i.

* Tnh linh ng cao v text, hnh nh v video

+ Tnh linh ng v a dng ca b m ha cho php m ha cc lung btphc tp khc nhau i vi mt tex, hnh nh hoc video.

+ Tnh linh ng v a dng ca b gii m cc lung bt vn bn, hnh nh

hoc video c gii m bi b gii m ti cc mc phc tp khc nhau. Nhn

chung cht lng khi phc li lin quan n phc tp ca b gii m c s

dng.

+ Tnh linh ng v khng gian cho php b gii m gii m mt tp hp

ca ton b lung bt c pht ra bi b m ha khi phc li v hin th cc

tex, hnh nh v video.+ Tnh linh ng v thi gian cho php b gii m gii m mt tp hp ca

ton b lung bt c pht ra bi b m ha khi phc li v hin th video.

+ Tnh linh ng v cht lng cho php mt lung bt c phn tch

thnh mt s cc lp lung bt c tc bt khc nhau v d nh s kt hp ca mt

tp hp cc lp vn c th c gii m thnh mt tn hiu c ngha. Phn tch

lung bt c th xy ra trong qu trnh truyn hoc gii m. Nhn chung cht lng

khi phc li lin quan n s lng lp c s dng gii m v khi phc.

2.4.5. Chun nn H.264/MPEG-4 Part 10/AVC

H.264 l tiu chun nn hnh nh, c bit n nh MPEG-4 Part 10 hoc

AVC (Advanced Video Coding). Phin bn u tin ca H.264/AVC c hon

thin vo thng 5/2003. H.264/AVC to ra mt tiu chun c kh nng cung cp

cht lng hnh nh tt ti tc bt thp hn cc tiu chun trc nh MPEG-

2, H.263, hoc MPEG-4 m khng cn tng phc tp v cu trc. Hn na tiu

chun ny c p dng cho cc ng dng trn cc h thng v mng a chng loi,

gm tc bt cao v thp, lu tr DVD, qung b, hnh nh vi phn gii thp



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v cao, cc mng gi RTP/IP, v cc h thng in thoi a phng tin ITU-T.

H.264 c t tn theo dng tiu chun H.26x ca ITU-T, trong khi AVC

theo pha ISO/IEC MPEG. Mc ch ca H.264 l to ra mt chun c kh nng

cung cp cht lng video cao tc bit thp hn hn (bng mt na hoc thp

hn na) so vi yu cu ca cc chun trc (MPEG-2, H.263 hay MPEG-2 Part

2) m khng lm tng nhiu s phc tp trong thit trin khai. Mt mc tiu khc

l cho php tiu chun c p dng cho nhiu kiu ng dng (cho c tc bit

thp v cao, v c phn gii video thp v cao) v c th lm vic tt trn nhiu

kiu mng v h thng (qung b, lu tr DVD, mng gi RTP/IP, cc h thng

in thoi a phng tin ca ITU-T).

JVT gn y hon thin vic pht trin mt s m rng so vi chun ban

u, c bit n vi tn gi M rng phm vi trung thc (Fidelity RangeExtensions, FRExt). Cc m rng ny h tr m ha video trung thc cao bng cch

tng chnh xc ly mu (bao gm m ha 10 bit v 12 bit) v thng tin mu sc

phn gii cao (bao gm cc cu trc ly mu YUV 4:2:2 v YUV 4:4:4). Nhiu

c im khc cng c thm vo trong cc m rng FRExt nh chuyn i thch

ng gia cc khi 4x4 v 8x8, cc ma trn trng s lng t ha da trn cm bin

ca cc b m ha c th, h tr thm nhiu khng gian mu sc, ...

Mt s tnh nng mi ca H.264/MPEG-4 Part 10 cho php chun ny nn cc

tn hiu video hiu qu hn so vi cc chun c v v linh hot hn cho cc ngdng trong cc mi trng mng. Mt s cc tnh nng quan trng l:

* B chuyn ng a hnh s dng cc hnh nh c m ha trc lm

tham chiu theo cch linh hot hn cc chun c, cho php ln ti 32 hnh nh tham

chiu c s dng (cc chun c ch s dng 1, hoc 2 vi trng hp B picture).

Tnh nng c bit ny cho php ci thin tc bit v cht lng trong hu ht cc

trng hp.

* B chuyn ng block c kch thc bin i vi kch thc block rng n

16x16 v nh n 4x4, cho php phn mnh chnh xc cc vng chuyn ng.

* Cu trc cp macroblock, cho php cc macroblock kch thc 16x16 (so

vi 16x8 MPEG-2).

* chnh xc b chuyn ng ln n 1/4 pixel, cho php th hin chnh xc

cc dch chuyn ca vng chuyn ng.

* nh s khung, cho php to ra cc chui con (iu chnh v thi gian bng

cch gp mt nh gia cc nh khc), pht hin v giu cc hnh b mt (xy ra do

mt gi trn mng hoc li knh).* m th t hnh, cho php gi cc hnh v cc gi tr mu theo trt t trong



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cc hnh c gii m tch bit vi thng tin nh thi (cho php thng tin nh thi

c chuyn i v iu khin c lp bi h thng m khng nh hng n ni

dung hnh nh c gii m).

Cc k thut ny, cng vi nhiu k thut khc, lm cho H.264 hot ng tt

hn so vi cc tiu chun trc, trong nhiu trng hp v mi trng ng dng

khc nhau. H.264 thng lm vic tt hn rt nhiu so vi MPEG-2, cho cht lng

tt hn tc bt ch bng mt na hoc thp hn so vi yu cu ca MPEG-2.

H.264 cung cp cc profile sau:

* Baseline profile (BP): Dng cho cc ng dng chi ph thp i hi t ti

nguyn hn, ch yu dng cho cc ng dung hi ngh truyn hnh v di ng.

* Main Profile (MP): Dng cho cc ng dng qung b v lu tr.

Extended profile (XP): C kh nng nn kh cao, gim thiu kh nng mt d liu.* High Profile (HiP): Dng cho cc ng dng qung b v lu tr a, c

bit cho cc ng dng truyn hnh yu cu nt cao (HD-DVD, Bluray disc).

* High 10 Profile (Hi10P): c xy dng bn trn ca HiP, h tr 10 bit

trn mt mu ca chnh xc ca hnh nh c gii m.

* High 4:2:2 Profile (Hi422P): dng cho cc ng dng chuyn nghip s dng

video qut xen k, c xy dng bn trn ca Hi10P, h tr khun dng ly mu

sc 4:2:2 trong khi s dng 10 bit trn mt mu ca chnh xc ca hnh nh

c gii m.* High 4:4:4 Profile (Hi444P): c xy dng bn trn ca Hi422P, h tr ly

mu sc 4:4:4, ln n 12 bit trn mt mu.

MPEG tch hp y cc h tr ca H.264/AVC vo cc h thng tiu

chun ca mnh (MPEG-2 v MPEG-4) v cc tp tin a phng tin theo tiu

chun ISO.

ITU-T a H.264/AVC vo b tiu chun H.32x cho h thng in thoi a

phng tin. Da trn cc tiu chun ITU-T, H.264/AVC c s dng rng ri

cho ng dng hi ngh truyn hnh, v c ng dng trong cc sn phm ca

cc cng ty chim u th trn th trng (nh Polycom v Tendberg). iu quan

trng hn c l tt c cc sn phm hi ngh truyn hnh mi u h tr

H.264/AVC.

H.264 cng c s dng trong nhiu loi dch v Video-on-Demand trn

Internet cung cp phim v cc show din truyn hnh trc tip n my tnh v

my thu hnh v c kh nng s thay th chun m ha H.262/MPEG-2 hin ti

ang s dng trong cc h thng truyn hnh s qung b mt t v v tinh.Yu cu v bng thng ca cc chun nn:



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* So snh hot ng ca chun nn khc nhau nh trong th di y:

* C th thy c t th so snh trn, k thut m ha H.264 rt hiu

qu di bng thng thp. Cht lng video ca chun H.264 ti bng thng 1,5

Mbps tt hn so vi chun MPEG-2 bng thng 3 Mbps. S dng chun nn

H.264 c th tit kim c hn mt na bng thng.

Cc li ch ca H.264/AVC:

* Hiu qu nn gp i, tc nn bng mt na so vi chun MPEG-2 yu

cu i vi hnh nh cht lng cao v gim c c dung lng lu tr cn

thit.

* Cho php nhiu ni dung hn c truyn i trn h thng c sn vi tc

bt thp hn.

* Chi ph truyn dn thp hn do thi gian truyn gim mt na.* Chi ph trin khai thp hn vi cng ngh H.264/AVC xy dng trn nn

tng tiu chun, phn cng x l khng c quyn.

* Kt hp hp vi mt lp thch ng mng (Network Adaptation Layer)

cung cp mt cch linh hot kh nng truyn ti qua mng chuyn mch gi v

lung bt, cho php nng cp mt cch d dng cc gii php phn phi da trn

MPEG-2.

* S dng mt thit lp chung v cng ngh gia mobile v IPTV : lung

TCP/UDP + H.264/AVC.

Bng 4: Yu cu v bng thng i vi cc chun nn

nt tiu chun nt cao ng dngMPEG-1 Ln n 1,5 Mbps - Video on Internet, MP3MPEG-2 4 - 5 Mbps 18 - 20 Mbps Digital TV, DVDMPEG-4 Part

10; H.2642 - 4 Mbps 8 - 10 Mbps Multi video


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