Computers, Software
Cuag ntaub ntawv nyob rau hauv ib tug computer: siv cov piv txwv
Yog hais tias ib tug neeg yog koom nyob rau hauv txoj kev tshawb no ntawm lub computer technology yog tsis dag, tab sis tiag, nws yuav tsum muaj tseeb yuav tsum paub txog dab tsi yog qhov txawv ntaub ntawv ntawm cov ntaub ntawv nyob rau hauv lub computer. Lo lus nug no yog ib tug siv, vim hais tias tsis tsuas yog tus siv ntawm software thiab kev khiav hauj lwm systems, tab sis kuj cov programming yog nyob rau hauv tus raws li cov kev Ahas.
Zaj lus qhia "Kev nthuav qhia ntawm cov ntaub ntawv nyob rau hauv lub computer": cov qauv rau kev
Feem ntau, computer cov khoom rau txoj kev nws perceives cov ntaub ntawv los yog commands, converts lawv mus rau hauv cov ntaub ntawv tawm tswv yim thiab muab rau tus neeg siv lub tiav lawm no sib txawv dog dig los ntawm cov pa tswv yim.
Lub fact tias tag nrho cov ntawm cov uas twb muaj lawm systems raws li nyob rau hauv tsuas yog ob tug cov zajlus kom tswv - "muaj tseeb" thiab "cuav» (muaj tseeb, cuav). Nyob rau hauv ib tug yooj yim kev txiav txim zoo nws yog "yes" los yog "tsis tau."
Nws yog to taub hais tias cov lus computer science tsis to taub yog vim li cas ib tug tshwj xeeb cov system nrog zwj ceeb code yog tsim nyob rau kaj ntug ntawm computer technology, nyob rau hauv uas pom zoo los ntawm cov tsev, thiab tsis kam muab - zero. Uas yog raws nraim li cas nyob rau hauv lub thiaj li hu ua binary sawv cev ntawm cov ntaub ntawv nyob rau hauv ib lub computer. Nyob rau hauv lub ua ke ntawm sawv daws yuav thiab zeros yog determined thiab qhov luaj li cas ntawm cov ntaub ntawv kwv.
Tus me tshaj unit ntawm no hom yog qhov luaj li cas ib tug me ntsis - me ntsis, uas yuav muaj ib tug nqi ntawm tog twg los 0 los yog 1. Txawm li cas los, niaj hnub nruab nrog tej me ntau yog tsis ua hauj lwm, thiab yuav luag txhua txoj kev uas cuag tau cov ntaub ntawv nyob rau hauv lub computer yog txo kom siv xwb yim me me, uas ua ke roos bytes (2 mus rau lub yim hwj chim). Yog li, nyob rau hauv ib byte yuav ua los ntawm tej lub cim encoding ntawm 256 tau. Thiab nws yog ib tug binary code yog lub bedrock ntawm ib yam ntawm cov ntaub ntawv kwv. Nws yuav tsum to taub, yuav ua li cas nws zoo nyob rau hauv xyaum.
Informatics: kev ntawm cov ntaub ntawv nyob rau hauv lub computer. taag-point tooj
Txij li thaum nws tau muas thaum chiv thawj sib tham txog cov xov tooj, peb xav txog yuav ua li cas lub system, khoom rau lawv. Sawv cev ntawm suav ntaub ntawv nyob rau hauv lub computer hnub no yuav tau muab faib mus rau hauv ua tus xov tooj nrog taag thiab floating taw tes. Tus thawj hom yuav kuj yuav ntaus nqi zoo tib yam zauv, uas tom qab tus zauv point yog tsim nyog pes tsawg.
Nws yog ntseeg hais tias cov xov tooj ntawm no hom yuav noj 1, 2, los yog 4 bytes. Lub thiaj li hu ua lub taub hau byte yog lub luag hauj lwm rau lub kos npe rau ntawm tus naj npawb, thaum ib tug zoo kos npe rau sau raws nkaus Ii pes tsawg, thiab tsis zoo - unit. Yog li, piv txwv li, ib tug 2-byte sawv cev ntawm lub ntau yam ntawm qhov tseem ceeb rau zoo naj npawb xov tooj nyob rau hauv lub chav 0 mus txog 16 Ob Hlis 1, uas yog 65535, thiab rau cov zauv negative - -2 15 mus rau 2 15 -1, uas yog sib npaug zos rau ib tug xov tooj ntau yam los ntawm -32768 rau 32767.
Floating-point sawv cev
Tam sim no xav txog ob hom ntawm cov zauv. Qhov tseeb hais tias lub tsev kawm ntawv cov ntaub ntawv kawm qhia rau "Qhia rau ib tug computer" (qib 9) floating-point xov tooj yog tsis suav hais tias. Operations nrog lawv yog heev thiab yog siv, piv txwv li, nyob rau hauv computer ua si. Los ntawm txoj kev, ib tug me ntsis distracted los ntawm lub npe, nws yuav tsum tau hais tias rau niaj hnub graphics phaib ib tug ntawm lub ntsiab ntsuas ntawm kev ua tau zoo yog cov kev ceev ntawm muas yog nrog xws li tus xov tooj.
Ntawm no peb siv lub exponential daim ntawv no, nyob rau hauv uas txoj hauj lwm ntawm tus zauv point yuav raug hloov. Raws li qhov yooj yim mis, uas qhia ib tug sawv cev ntawm tej xov tooj ntawm txais A nram qab no: A = m A * q P , qhov twg m A - yog lub mantissa, q P - yog ib tug Radix, thiab P - thiaj tooj.
Lub mantissa yuav tsum tau raws li qhov yuav tsum tau q -1 ≤ | m A | <1, ces yuav tsum muaj kom zoo binary feem uas muaj lub lej tom qab tus zauv point, uas yog txawv los ntawm xoom, thiab qhov kev txiav txim ntawm - ib tug tag nrho tus naj npawb. Thiab tej normalized decimal tooj yuav ua tau heev yooj yim mus xav txog tej yam nyob rau hauv exponential daim ntawv. Thiab tus naj npawb ntawm no hom muaj ib tug loj ntawm 4 los yog 8 bytes.
Piv txwv li, tus zauv xov tooj 999.999 raws li mis nrog ib tug normalized mantissa yuav zoo li 0,999999 ~ 10 3.
Piav txog kev cov ntawv nyeem cov ntaub ntawv: ib tug me ntsis ntawm keeb kwm
Feem ntau ntawm tag nrho cov neeg ntawm lub computer systems tseem siv lub xeem ntaub ntawv. Thiab saib cov ntseeg cuav thaum ub ntaub ntawv nyob rau hauv lub computer sau raws nkaus Ii mus rau tib binary code hauv paus ntsiab lus.
Txawm li cas los, vim rau qhov tseeb hais tias hnub no peb yuav suav ib tug ntau hom lus nyob rau hauv lub ntiaj teb no, los sawv cev rau hauv cov ntawv nyeem ntaub ntawv siv tshwj xeeb encodings system los yog code ntxhuav. Nrog lub advent ntawm MS-DOS twb xam tau tias yog ib tug yooj yim txheej txheem encoding CP866, thiab kua Mac computers yuav siv nws tus kheej txheem. Thaum ib tug tshwj xeeb ISO 8859-5 encoding twb nkag tau mus rau lub Lavxias teb sab lus. Txawm li cas los, nrog cov kev loj hlob ntawm computer technology tsim nyog yuav ua kom paub tshiab qauv.
ntau yam ntawm encodings
Piv txwv li, nyob rau hauv lub lig 90-ies ntawm lub xyoo pua xeem muaj yog ib tug universal encoding ntawm Unicode, uas muaj peev xwm lis tsis tau tsuas yog ntawv nyeem cov ntaub ntawv, tab sis kuj suab thiab video. Nws peculiarity yog hais tias ib tug tib cim tau tseg ntau tshaj ib tug me ntsis, tiam sis ob.
Ib me ntsis tom qab, muaj lwm yam ntau ntau yam. Rau lub qhov rais-raws li, cov feem ntau siv yog lub encoding CP1251, tab sis rau cov Lavxias teb sab lus thiab yog tseem siv los ntawm Koi-8P - encoding, uas nyob rau hauv lub lig 70 lub, thiab 80 tus tau koom siv txawm nyob rau hauv UNIX-raws li lub nruab.
Tus heev tib yam ntaub ntawv nyob rau hauv ntseeg cuav thaum ub sawv cev ntawm ib tug computer raws li nyob rau hauv lub ASCII rooj, xws li ib lub hauv paus thiab ib ncua feem. Tus thawj muaj xws li cov lis dej num ntawm 0 mus 127, lub thib ob - los ntawm 128 mus 255. Txawm li cas los, cov thawj ntau yam leb 0-32 rho tshaj lub cim uas yuav muab rau hauv lub lag luam ntawm ib tus qauv keyboard thiab cov nuj nqi lag luam (F1-F12).
Graphics: lub ntsiab hom
Raws li rau lub graphics, uas yog dav siv nyob rau hauv hnub no tus cov ntiaj teb no, muaj ib co nuances. Yog hais tias koj saib nyob rau ntawm qhov duab sawv cev ntawm cov ntaub ntawv nyob rau hauv ib lub computer, koj yuav tsum xub them xim rau lub ntsiab hom ntawm cov dluab. Ntawm lawv yog cov ob lub ntsiab hom - vector thiab raster.
Vector graphics raws li nyob rau kev siv ntawm txheej thaum ub nrhiav (kab, voj voog, curves, uas, thiab hais txog. D.), ntawv nyeem thawv thiab nyob ib lub cev nqaij daim tawv. Bitmaps yog raws li nyob rau kev siv ntawm ib lub matrix, txhua lub caij ntawm uas yog hu ua ib tug pixel. Nyob rau hauv tas li ntawd, rau txhua lub caij, koj yuav tau teem lub brightness thiab xim.
vector duab
Niaj hnub no, txoj kev siv cov vector muaj ib tug tsawg cheeb tsam. Lawv yog cov zoo, piv txwv li, thaum tsim kev kos duab thiab kos duab, los yog rau ob-seem los yog peb-dimensional qauv ntawm cov khoom.
Piv txwv ruaj ruaj vector nrhiav yog tawm tswv yim xws li PDF, WMF, PCL. Kev tsiv nrhiav mas siv Macromedia Flash txheem. Tab sis yog hais tias peb tham txog qhov zoo los yog nqa tawm ntau ua hauj lwm tshaj lub tib scale, nws yog zoo dua siv raster tawm tswv yim.
bitmaps
Nrog raster khoom nws yog ntau npaum li cas complicated. Qhov tseeb hais tias qhov kev nthuav qhia ntawm cov ntaub ntawv nyob rau hauv lub computer-based matrix yuav siv cov ntxiv tsis - xim tob (quantitative qhia ntawm palette xim) nyob rau hauv me me, thiab lub matrix loj (tus naj npawb ntawm pixels ib nti, xa mus rau raws li DPI).
Ntawd ces yog lub palette yuav muaj 16 xyoo, 256, 65.536 los yog 16.777.216 xim, thiab cov matrix yuav sib txawv, tab sis feem ntau yog hu ua ib tug daws teeb meem ntawm 800x600 pixels (480 000 pixels). Raws li cov kev ntsuas los mus txiav txim tus naj npawb ntawm cov khoom yuav tsum tau mus cia tus kwv. Rau no peb thawj siv cov mis N = 2 Kuv, nyob rau hauv uas N - yog tus naj npawb ntawm cov xim, thiab kuv - yog ib cov xim tob.
Ces xam tus nqi ntawm cov ntaub ntawv. Piv txwv li, los xam qhov luaj li cas ntawm cov ntaub ntawv duab uas muaj 65.536 xim thiab ib tug matrix ntawm 1024x768 pixels. Cov tshuaj no yog raws li nram no:
- I = teev 2 65536, uas yog 16 me me;
- lub xov tooj ntawm pixels 1024 * 768 = 786 432;
- nco muaj peev xwm yog 16 me me * 786 432 = 12 582 912 bytes, uas sib raug rau 1.2 Mb.
Ntau hom suab: lub ntsiab kev coj ntawm synthesis
Kev nthuav qhia ntawm cov ntaub ntawv nyob rau hauv ib lub computer, hu ua suab, kev kawm mus rau tib cov qauv uas tau piav saum toj no. Tab sis, raws li rau lwm yam daim ntawv ntawm cov ntaub ntawv khoom los sawv cev rau lub suab, ib yam nkaus thiab, siv lawv ntxiv nta.
Tu siab, high-zoo suab tu tub tu kiv thiab nyob rau hauv computer technology nyob rau hauv lub heev kawg. Txawm li cas los, yog hais tias tus playback tau fared ntau tsis zoo, lub synthesis ntawm real-sounding suab paj nruas ntsuas suab tsis yooj yim sua. Yog li ntawd, ib co ntaub ntawv tuam txhab uas muag tau ua tswvcuab lawv tus kheej cov qauv. Niaj hnub no, feem ntau lug siv, qhov FM synthesis thiab lub rooj-yoj txoj kev.
Nyob rau hauv thawj rooj plaub no nws txhais tau tias tej yam ntuj tso suab, uas yog tas mus li, yuav decomposed rau hauv ib tug tej yam ib theem zuj zus (ib theem zuj zus ntawm) qhov nyuaj harmonics siv ib tug piv txwv txoj kev thiab tsim kev nthuav qhia ntawm cov ntaub ntawv nyob rau hauv lub computer nco raws li cov kev cai. Mus ua si siv qhov rov qab tus txheej txheem, tab sis nyob rau hauv cov ntaub ntawv no, lub inevitable tsis ntawm ib co ntawm cov yam uas yuav tshwm sim rau qhov zoo.
Thaum lub rooj-yoj synthesis yog lam xav hais tias muaj yog ib tug pre-tsim rooj nrog cov piv txwv ntawm lub suab ntawm nyob seev. Tej piv txwv yog hu ua kuaj. Nyob rau tib lub sij hawm mus ua si qhov pab MIDI (suab paj nruas Ntsuas Cov Interface) yog siv feem ntau txaus rau perceive los ntawm cov code hom kev ntsuas, suab, ntev, suab siv thiab muaj zog ntawm kev hloov, ib puag ncig chaw thiab lwm yam ntxwv. Tsaug rau qhov no zoo ntawm lub suab ze txaus ze rau tej yam ntuj tso.
niaj hnub tawm tswv
Whereas yav tas los lub hauv paus rau standard WAV tau npaum li cas (nyob rau hauv qhov tseeb, lub heev suab thiab yog nyob rau hauv daim ntawv ntawm ib tug yoj), thaum lub sij hawm nws tau los ua heev tsis yooj yim, yog hais tias tsuas vim hais tias ntawm qhov tseeb hais tias xws ntaub ntawv nyob dhau ntau qhov chaw nyob rau hauv lub cia xov xwm.
Thaum lub sij hawm, technologies rau hlob hom ntawv no. Raws li, hloov thiab tswv yim rau lawv tus kheej. Qhov zoo tshaj plaws-paub hnub no yuav hu ua MP3, OGG, WMA, FLAC thiab ntau lwm tus neeg.
Txawm li cas los, kom txog rau thaum tam sim no lub ntsiab tsis muaj yam suab siv cov ntaub ntawv tseem zauv zaus (44.1 kHz yog txheem, txawm hais tias qhov tseem ceeb yuav tsum muaj nyob saum toj no thiab hauv qab no), thiab tus naj npawb ntawm teeb liab ntau ntau (16 me me, 32 khoom). Nyob rau hauv hauv paus ntsiab lus, xws li ib tug digitizing yuav muab txhais raws li ib tug sawv cev ntawm cov ntaub ntawv nyob rau hauv lub acoustic hom computer raws li nyob rau hauv lub analog thawj lub teeb liab (nyob rau hauv qhov xwm ntawm yam suab yog Ameslikas analog).
Kev nthuav qhia video
Yog hais tias lub suab teeb meem tau solved sai sai txaus, lub video txhua yam yog tsis yog li ntawd tus. Qhov teeb meem yog hais tias cov clip, ib tug yeeb yam los yog ib tug yees duab kev ua si yog ib tug ua ke ntawm video thiab audio. Nws yuav zoo li uas zoo li cas yuav ua tau yooj yim tshaj rau muab tsiv duab cov khoom uas ib tug scale? Raws li nws muab tawm, qhov no yog ib tug teeb meem tiag tiag.
Txhua yam uas tseem ceeb yog hais tias los ntawm ib tug kev taw tes ntawm view, chiv kom nco ntsoov thawj ncej ntawm txhua scene, hu ua ib tug tseem ceeb, thiab xwb ces khaws cia cov sib txawv (txawv ntas). Thiab yog dab tsi ntau heev, digitized los yog tsim yeeb yaj duab tau xws li ib tug loj uas cia lawv nyob rau hauv koj lub computer los yog tshem tau xov xwm yog tsuas tsis yooj yim sua.
Qhov teeb meem yog solved thaum nyob AVI hom uas nruab nrab yog ib tug tej yam universal thawv, muaj raws ntawm ib tug txheej ntawm blocks uas tej zaum yuav muab cia rau hauv ib tug arbitrary ntaub ntawv, yog li txawm compressed nyob rau hauv ntau txoj kev. Yog li, txawm cov ntaub ntawv ntawm tib hom ntawv AVI rau txhua lwm yam yuav txawv muaj nuj nqis.
Thiab hnub no koj yuav tau raws li ib tug ntau ntawm lwm yam nrov video tawm tswv yim, tab sis rau tag nrho cov ntawm lawv siv lawv tus kheej tsis thiab parameter qhov tseem ceeb, Hmoob cov uas yog tus naj npawb ntawm cov thav ntawv ib ob.
Codecs thiab decoders
Kev nthuav qhia ntawm cov ntaub ntawv nyob rau hauv lub computer raws li lub hom phiaj yog tsis yooj yim sua xav txog tej yam tsis muaj kev siv ntawm codecs thiab decoders siv nyob rau hauv lub compression thiab decompression ntawm thawj zaug cov ntsiab lus thaum lub sij hawm playback. Lawv heev lub npe qhia tias ib txhia encode (Hlob) lub teeb liab, lub thib ob - nyob rau tsis tooj - yog Unpacked.
Nws yog lawv uas yog lub luag hauj lwm rau tus txheem ntawm lub ntim ntawm kev loj, raws li zoo raws li txiav txim seb tus loj ntawm lub kawg cov ntaub ntawv. Nyob rau hauv tas li ntawd, qhov tseem ceeb luag hauj lwm ua si los ntawm cov kev daws teeb meem parameter, raws li qhia rau raster graphics. Tab sis hnub no peb yuav txawm tau raws li UltraHD (4 k).
xaus
Yog hais tias ib co twg sum txog cov saum toj no, tej zaum nws yuav tsum tau muab sau tsuas yog hais tias cov niaj hnub lub computer systems chiv ua hauj lwm heev dua lwm yam rau lub xaav ntawm ib binary code (lwm tus lawv cia li tsis to taub). Thiab nws siv yog raws li tsis tsuas muab cov ntaub ntawv, tab sis kuj tag nrho paub programming lus niaj hnub no. Yog li, chiv, to taub yuav ua li cas nws tag nrho tej hauj lwm, nws yog tsim nyog los muab lub essence ntawm txoj kev siv ntawm sequences ntawm sawv daws yuav thiab zeros.
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