Koodh macluumaadka audio

geedi socod kasta oo si dhab ah loo rogi karaa qaab digital. Sayidka, habaynteeda macluumaadka audio dhinaca combiyuutarka waxaa lagu fuliyaa sida soo socota:

- gariirka hawada duubay qalabka xasaasi ah,

- toogasho diinta ka galay koronto, kuna waari dhexdeeda inta jeer (Ilodanimada) waa sida beddelay;

- hadda keentay waa la waraystay, i.e. jiro ay sampling (oo mararka qaar ay sheegayaan in uu haystaa habaynteeda warbixin maqal ah binary).

The keentay analog electronic socodka audio asalka ah si fiican, sare inta jeer ee shaybaarka ee sampling ah oo qoto dheer sireed.

In si kale loo dhigo, habaynteeda macluumaadka audio - waa hab caan ah oo diinta signal badan analog galay digital ah, loogu talagalay processing dheeraad ah si ay qalab ku haboon. Ha ka fikiro si aynu tallaabooyinka iyo qaababka digitizing dhawaaqa.

Discretization jir waqtiga - aasaas u ah digitizing. Sida laga soo xigtay Aragtida Kotel'nikova, ee signalka analogga korontada la digital kartaa adigoo akhriya tallaabo gaar ah oo taxane ah oo joogto ah ee qiimaha ay Ilodanimada inayan. Inta jeer ee akhrinta sida waa in ay ugu yaraan laba jeer inta jeer xadka of signal ugu weyn ee. Haddii loo baahdo, digitizing analoogga "source code" in inta jeer ee hawlgalka of 0-20 sampling Khz waa in la fuliyaa aan ka yarayn 40 kun. Times per labaad (40 Khz). Sanbal loola jeedaa tirada cabirka halkii il labaad analog signal (sampling, inta jeer sampling ah). Iyada oo sii kordhaya saamiga kordhay tayo leh ma aha oo kaliya, laakiin sidoo kale mugga webigu ku data keentay.

Sidoo kale, macluumaad koodh audio in la sameeyo waxaa laga yaabaa in siyaabo kale. Sida, tusaale ahaan, by digitizing quantizer ku nonuniform, mararka qaarkood loo yaqaan logardam ah. Marka la isticmaalayo kala duwan Ilodanimada dhan keeneysa la qaybsan yahay qaybo la qiimaha sare iyo hoose. Deji macluumaad dheeraad ah audio dhacdaa by codsanaya xaddi badan oo heer quantization meelaha qiimaha yar Ilodanimada (iyo qeybsanaan ku xigeenka). Ogow, si kastaba ha ahaatee, in tirada guud ee heerarka weli la mid ah sida in habka quantization joogga (PCM).

hab gebi ahaan kala duwan waxaa lagu fuliyaa hab habaynteeda kale. Waxaa lagu magacaabaa "Pulse kala Code isbedbeddelka» (DPCM). Iyada oo hab noocan oo kale ah aan la hoos geliyey wax quantization ee Ilodanimada inayan ee signalka toos ah iyo qiimaha qaraabo. Sidaas darteed suurtagal ah si loo gaaro yareynta mugga degan xogta, tan iyo farsamo la shaqeeya saadaasha xiga oo ka mid ah baarka signal asalka ah.

Macluumaadka koodh iyo processing audio tilmaamay in warqad this baahan yahay fulinta qaab beddelidda "analog-to-digital". Nidaamkan waxaa la sameeyaa iyadoo la isticmaalayo ADC ah (analog-to-digital Converter). Iyada oo howlgalkan, qalab kasta oo wajahaya milkiilaha computer maalin qalabaysan kaarka codka ah (haddii ay taasi ku jira nidaam dambe - ka webigu ku digital helo signal analog ah).

hawlaha ADC waa sida soo socota:

- bandwidth inta jeer kooban. Isticmaalka filtarrada, qaybaha signal waa ka go'een, inta jeer ee taas - in ka badan nus inta jeer sampling (oo sabab u tilmaamay hore).

- Selection of qiimaha Ilodanimada dura caadiga ah. The keentay signal analog waxaa wakiil isku xigxiga oo ka mid ah jajabka hal adag ee kala duwan (discretization).

- tiro Bedelida helay gelinno qiyamkooda dhow ka go'an go'an (quantization).

- U beddelaan qiimaha kasta quantized tirada shuruud ka mid ah heerarka quantization (qiimaha kasta - oo ay tirada serial). Kani waa heerka ugu dambeeya ee digitization.