Cac chuan nen va truyen thong qua mang internet

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  • 1. I HC QUC GIA H NI TRNG I HC CNG NGHMai Th Lan Oanh CC CHUN NN V NG DNG TRUYN VIDEO TRN MNG INTERNETKHO LUN TT NGHIP I HC H CHNH QUYNgnh : in T - Vin Thng. H NI - 2005Mai Th Lan Oanh Trang i I HC CNG NGH - K46 DB -

2. I HC QUC GIA H NI TRNG I HC CNG NGHMai Th Lan Oanh CC CHUN NN V NG DNG TRUYN VIDEO TRN MNG INTERNETKHO LUN TT NGHIP I HC H CHNH QUYNgnh : in T - Vin Thng.Cn b hng dn: TS. Ng Thi TrCn b ng hng dn: TS. inh Quc Tun H NI - 2005Mai Th Lan Oanh Trang iiI HC CNG NGH - K46 DB - 3. LI CM N Em xin by t lng knh trng v bit n su sc ti thy gio, TS.Ng Thi Tr,ngi thy trc tip dy v hng dn em rt tn tnh, cho em nhng nh hngv kin qu bu v cng ngh truyn hnh. Em cng xin by t lng bit n su scti TS. inh Quc Tun, ngi thy gip em rt nhiu, cho em rt nhiu kinthc b ch trong thi gian em thc tp ti Phng Cng Ngh Thng Tin THVNcng nh trong thi gian em lm lun vn. ng thi, em xin gi li cm n chnthnh ti tt c cc Anh, cc Ch ti Trung Tm Tin Hc v o lng THVN to iu kin v gip em rt tn tnh trong thi gian em thc tp ti trung tm. Em xin chn thnh cm n tt c cc thy c trong Trng i Hc CngNgh- i Hc Quc Gia H Ni nhit tnh ging dy v gip em trong thigian em hc tp ti trng. Con xin gi n B M v gia nh tnh thng yu v lng bit n. B M vgia nh lun l ngun ng vin ca con v l ch da vng chc cho cuc i con.Ti xin cm n cc bn cng lp ng vin v gip ti trong thi gian thc hinlun vn ny.V thi gian c hn , bi lun vn ca em khng trnh khi khim khuyt. Rtmong nhn c s gp ca thy c v cc bn.H Ni 30/5/ 2005Sinh vinMai Th Lan Oanh.Mai Th Lan OanhTrang iii I HC CNG NGH - K46 DB - 4. TM TT NI DUNG Trong k thut truyn hnh, vic nn Video l mt vn qua trng cho victruyn ti cc chng trnh truyn hnh. V n tr thnh vn nng hi khi truynhnh s ra i, vi tn hiu Video sau khi s ho (8 bt) c tc bt bng 216 Mbt/s,khng th truyn trn mt knh truyn hnh thng thng nu khng c nn. Khi, chun nn MPEG-2 vi tc m ho t 4Mbt/s n 30Mbt/s c a ra thc hin nhim v trn. Ngy nay, khi truyn hnh trn mng Internet c pht trin,chun nn Video H.264/MPEG -4 Part 10 c a ra, vi tc m ho 1.5Mbt/s vc kh nng tng tc ti tng i tng , ph hp vi mi trng truyn ti trnmng Internet hin nay. Nghin cu cc chun nn MPEG (MPEG -1, MPEG -2,MPEG -4, MPEG -7) - c gii thiu trong chng 1 v chng 2 v c bit lchun nn H.264/MPEG -4 Part 10 cho ng dng nn Video truyn trn mngInternet- c gii thiu trong chng 3. Chng 3 s ni chi tit cch m ho, giim video v cc u vit ca MPEG -4 Part 10 so vi cc chun nn trc .Mai Th Lan OanhTrang iv I HC CNG NGH - K46 DB - 5. DANH SCH CC CH VIT TTADSL : Asymmetric Digital Subcriber Line.CABAC: Context-based Apdaptive Binary Arithmetic Coding.CAVLC: Context-based Apdaptive Variable Length Codinh.DCT : Discrete Cosine Transform .DVB : DVB TerrestrialDVB-C : DVB CableDVB-S : DVB SatelliteDVB-T : Digital Video BroadcastingES : Elementary Stream.FMO : Flexible Macro-Block Ordery.GOP: Group of Picture.IEC : International Electrotechnical Commission (Part of theISO)ISO : International Standard OrganizationITU : Inernational Telecommunication UnionMB : Macro-Block .MPEG : Moving Picture Expert GroupNTSC : National Television System Committee.PAL: Phase Alternative LineRLC : Run Length CodingRVLC : Reversible Variable Length Codes.SAD: Summation of Absolute DifferenceSI : Switching Intra PictureSIF: Source Intermediate FormatSP : Switching Prediction PictureVLC : Variable Length CodingVO : Video ObjectMai Th Lan OanhTrang v I HC CNG NGH - K46 DB - 6. 1. DANH SCH CC HNHHnh 1: Cu trc dng Bt MPEG Video . 5Hnh 2: Cu trc nh MPEG 7Hnh 3: Nn MPEG . 8Hnh 4: Gii nn MPEG . 9Hnh 5: Qu trnh bin i sang nh dng SIF v kch thc mng cc imnh. ..12Hnh 6: Tnh ton gi tr cho cc im nh trong b lc thp phn 12Hnh 7: Chun nn MPEG -2 . 16Hnh 8: Gii m phn cp theo SNR 17Hnh 9: Gii m phn cp theo khng gian 18Hnh 10: S t hp khung hnh trong MPEG -4 .. . 22Hnh 11: Cu trc ca b m ho v gii m Video MPEG -4.. 23Hnh 12: Profile v Level trong MPEG -4 . 25Hnh 13: Phm vi ca MPEG -7 28Hnh 14: Truyn hnh trc tuyn trn mng32Hnh 15: Cu trc ca b m ho Video H264 36Hnh 16: Cc phn m ho ring ca Profile trong H264.. 37Hnh 17: S m ho Video ca H264/MPEG Part 10 39Hnh 18: Cc mode trong MPEG-4.. 42Hnh 19: Phn chia Macro-Block cho b chuyn ng . 43Hnh 20: B chuyn ng nhiu Frame ngoi Vector chuyn ng, cc tham stham chiu nh () cng c truyn i.. 45Hnh 21: nh ni suy B (d on hai chiu) 46Hnh 22: chuyn i s dng nh SP 49Hnh 13: S khi ca CABAC 55Hnh 24: Tc dng ca b lc tch khi i vi nh c nn nhiu .. 56Hnh 25: S gii m Video H264/MPEG -4 Part 10 57Hnh 26: V d v M ho chiu di bin i ngc . 59 2. DANH SCH CC BNG BIUBng 1: Tnh cht cc nh dng nh SIF c bn: ....................................................13Bng 2: Tham s theo tiu chun MPEG -1: .............................................................15Bng 3 :Bng thng s chnh Profiles v Levels ca tn hiu chun MPEG -2.......20Mai Th Lan Oanh Trang vi I HC CNG NGH- K46 DB - 7. MC LCLI CM N...........................................................................................................................iiiTM TT NI DUNG.............................................................................................................ivDANH SCH CC CH VIT TT ....................................................................................... v1. DANH SCH CC HNH................................................................................................vi2. DANH SCH CC BNG BIU ........................................................................................viLI M U ............................................................................................................................ 1Chng I: KHI QUT V NN TN HIU VIDEO ........................................... 3V CHUN NN MPEG.......................................................................................................... 3 1.1. Mc ch nn Video ........................................................................................................ 3 1.2. Chun nn MPEG............................................................................................................ 41.2.1. Khi qut v nn MPEG........................................................................................... 41.2.2. Cu trc dng bit MPEG video ............................................................................... 51.2.3. Cc loi nh trong chun MPEG :........................................................................... 71.2.4. Nguyn l nn MPEG ............................................................................................... 81.2.5. Nguyn l gii nn MPEG ........................................................................................ 9ChngII:CC CHUN NN MPEG....................................................... 11 2.1 Chun nn MPEG-1 ....................................................................................................... 112.1.1 Gii thiu khi qut................................................................................................. 112.1.2 nh dng trung gian SIF (Source Intermediate Format). .................................... 112.1.3 Cu trc dng bt v cc tham s ca MPEG-1..................................................... 14 2.2 Chun nn MPEG-2 ....................................................................................................... 162.2.1 Gii thiu v MPEG-2 ............................................................................................. 162.2.2 M ho v gii m video ........................................................................................ 162.2.3 Profiles v Levels .................................................................................................... 182.2.4 MPEG -2 vi pht sng v sn xut chng trnh .................................................. 21 2.3 Chun nn MPEG-4 ...................................................................................................... 212.3.1 Khi qut v MPEG-4 ............................................................................................ 212.3.2 Cng ngh m ho v gii m video trong MPEG-4 .............................................. 222.3.3 Cc Profiles v Levels trong chun MPEG-4 ......................................................... 24 2.4 Tiu chun MPEG-7....................................................................................................... 262.4.1 Gii thiu v chun MPEG-7 .................................................................................. 262.4.2 i tng (Objectives) v cch miu t d liu ca MPEG -7............................... 272.4.3 Phm vi ng dng ca tiu chun MPEG-7............................................................ 28ChngIII: CHUN NN VIDEO MPEG-4 V NG DNG TRONG TRUYN HNHTRN MNG INTERNET. ..................................................................................................... 29 3.1 Gii thiu tng quan v truyn hnh trn Internet .................................................... 29 3.2. La chn H.264/ MPEG -4 part 10 cho truyn hnh trn mng Internet....................... 333.2.1 Gii thiu chung v H.264 /MPEG-4 part 10 ......................................................... 333.2.2 Tnh k tha ca chun nn H.264/MPEG- 4 part 10............................................. 35 3.3. Tiu chun H.264/MPEG - 4 Part 10 ............................................................................ 353.3.1. Lp tru tng mng NAL (Network Abstaction Layer)........................................ 353.3.2. Cc Profile v cc Level......................................................................................... 363.3.3. K thut m ho video............................................................................................ 39Mai Th Lan Oanh Trang viiI HC CNG NGH- K46 DB - 8. 3.3.3.2. Cc nh v b chuyn ng dng trong H264/MPEG Part 10....................... 40 3.3.3.3. Xc nh Vector chuyn ng (Motion Estimation) ....................................... 49 3.3.3.4. Nn video......................................................................................................... 51 3.3.3.5. B lc tch khi............................................................................................... 553.3.4. K thut gii m video............................................................................................ 57 3.3.4.1. B chuyn ng .............................................................................................. 57 3.3.4.2. Khi phc li (Error Resiliency) .................................................................... 573.3.5 So snh hiu qu m ho ca H264/MPEG Part 10 vi cc tiu chun trc ...................................................................................................................................... 59KT LUN .............................................................................................................................. 61TI LIU THAM KHO ........................................................................................................ 63Mai Th Lan OanhTrangviiiI HC CNG NGH- K46 DB - 9. LI M UTruyn hnh Vit Nam tri qua nhiu giai on pht trin, t truyn hnh entrng, truyn hnh mu v hin nay truyn hnh s ang pht trin mnh m trn tt cmi lnh vc: truyn hnh cp, truyn hnh s mt t DVB-T, truyn hnh s qua vtinh. Khi Internet pht trin mnh v tr thnh h thng c quy m ton cu, tr nnph cp rt nhanh trong mi lnh vc, bng vic kt ni cc chng trnh hnh vi hthng vin thng Internet, mt cng ngh truyn hnh mi ra i l truyn hnhInternet.Thc t hin nay, c rt nhiu hng Vit Nam v trn th gii ang cung cpdch v truyn hnh trc tuyn (Online Television), khn gi ch cn truy cp vo ach Web- Site ca nh cung cp dch v l c th xem trc tip cc chng trnh truynhnh theo thi thc real-time(cn gi l phng thc Dowload and Play)hay c th tiFile cc chng trnh truyn hnh v my tnh c nhn (gi l phng thc DowloadStream-File).Ni v k thut truyn hnh th c rt nhiu k thut nh: k thut ghi hnh, kthut dng hnh, cc k thut nn Video, k thut truyn ti... trong khun kh bi lunvn ny, em xin c tm hiu k thut nn Video. Vn nn Video trong truynhnh khng phi l mt vn mi m. Vi mi cng ngh truyn hnh mi ra i, sc mt cng ngh nn Video ph hp. Nn Video t nhng nm 1950 c thc hinbng cng ngh tng t vi t s nn thp. Ngy nay cng ngh nn t c hiuqu cao hn nh chuyn i tn hiu Video t tng t sang s. Vi ti Cc chunnn v ng dng truyn Video trn mng Internet, mc ch ca bi kho lun ca eml tm hiu mt s cc chun nn MPEG ng dng nn video c s dng, cbit l chun nn H264/MPEG Part 10 . Ni dung ca bi gm 3 chng:Chng 1: L do phi nn tn hiu Video v nn MPEG (Moving PictureExpert Group) l nhm chuyn gia v hnh nh, vi nhim v xy dng tiu chun chotn hiu Audio v Video s. Trong vic nn video, MPEG t c mt t s nntt hn so vi cc chun nn trc nh JPEG, M-JPEG, DVChng 2: Gii thiu khi qut v cc chun nn m nhm MPEG xy dng nn video v lu tr. Trong , MPEG -1 vi mc ch l m ho Video v mthanh km theo trong cc mi trng lu tr nh a CD-ROM, a quang... vi tc bt l 1.5 Mbit/s; MPEG -2 c k tha cc tiu chun ca MPEG -1 v mc chnhm h tr vic truyn Video s tc bt trong khong 4 30 Mbt/s; sau khitruyn hnh Internet ra i th chun nn tng ng l MPEG -4 vi nhim v nhmMai Th Lan OanhTrang 1I HC CNG NGH - K46 DB - 10. pht trin cc chun x l, m ho v hin th nh ng, audio v cc t hp cachng. Cn MPEG -7 l mt chun dng m t ni dung Multimedia, ch khngphi l mt chun dng nn v m ho audio hay nh ng nh cc chun trc . Chng 3: l ni dung chnh ca bi kho lun. Em nghin cu v tm hiuk thut m ho Video/ nh ng s dng chun nn H.264/MPEG -4 Part 10 ngdng cho truyn hnh trn mng Internet . H264/MPEG Part 10 c nhiu u vit trongvic nn Video so vi chun MPEG-2 rt thnh cng trong vic nn video trongtruyn hnh k thut s ra i trc . Phn cui l phn kt lun, l phn tng kt li nhng g m em lm ctrong bi kho lun ny. ng thi, Em cng nu ln mt vi nhn nh ca mnh vhng pht trin tip theo ca ti.Mai Th Lan OanhTrang 2I HC CNG NGH - K46 DB - 11. Chng 1: Khi qut v nn tn hiu Video v chun nn MPEGChng I: KHI QUT V NN TN HIU VIDEOV CHUN NN MPEG1.1. Mc ch nn VideoTn hiu video sau khi c s ho 8 bit c tc 216 Mb/s. c th truyntrong mt knh truyn hnh thng thng, tn hiu video s cn phi c nn trongkhi vn phi m bo cht lng hnh nh.Nn video trong nhng nm 1950 c thc hin bng cng ngh tng t vit s nn thp. Ngy nay cng ngh nn t c nhng thnh tu cao hn bngvic chuyn i tn hiu video t tng t sang s. Cng ngh nn s (DigitalCompressed) i hi nng lc tnh ton nhanh. Song ngy nay vi s pht trin cacng ngh thng tin, iu ny khng cn tr ngi.Nh chng ta bit tn hiu video c di ph t 0 6 MHz, tuy nhin trong nhiutrng hp nng lng ph ch yu tp trung min tn s thp v ch c rt t thngtin cha ng min tn s cao.i vi tn hiu video s, s lng bit c s dng truyn ti thng tin ivi mi min tn s khc nhau, c ngha l: min tn s thp, ni cha ng nhiuthng tin, c s dng s lng bt ln hn v min tn s cao, ni cha ng tthng tin, c s dng s lng bt t hn. Tng s bt cn thit truyn ti thngtin v hnh nh s gim mt cch ng k v dng d liu c nn m cht lnghnh nh vn m bo. Thc cht ca k thut nn video s l loi b i cc thngtin d tha. Cc thng tin d tha trong nn video s thng l:+ d tha khng gian gia cc pixel;+ d tha thi gian do cc nh lin tip nhau;+ d tha do cc thnh phn mu biu din tng pixel c tng quancao;+ d tha thng k do cc k hiu xut hin trong dng bt vi xc sut xuthin khng...