Sound
-
Upload
maaz-hamed -
Category
Education
-
view
123 -
download
3
Transcript of Sound
![Page 1: Sound](https://reader035.fdocuments.net/reader035/viewer/2022070323/55a25d541a28ab9c2b8b47b4/html5/thumbnails/1.jpg)
![Page 2: Sound](https://reader035.fdocuments.net/reader035/viewer/2022070323/55a25d541a28ab9c2b8b47b4/html5/thumbnails/2.jpg)
![Page 3: Sound](https://reader035.fdocuments.net/reader035/viewer/2022070323/55a25d541a28ab9c2b8b47b4/html5/thumbnails/3.jpg)
![Page 4: Sound](https://reader035.fdocuments.net/reader035/viewer/2022070323/55a25d541a28ab9c2b8b47b4/html5/thumbnails/4.jpg)
![Page 5: Sound](https://reader035.fdocuments.net/reader035/viewer/2022070323/55a25d541a28ab9c2b8b47b4/html5/thumbnails/5.jpg)
![Page 6: Sound](https://reader035.fdocuments.net/reader035/viewer/2022070323/55a25d541a28ab9c2b8b47b4/html5/thumbnails/6.jpg)
![Page 7: Sound](https://reader035.fdocuments.net/reader035/viewer/2022070323/55a25d541a28ab9c2b8b47b4/html5/thumbnails/7.jpg)
![Page 8: Sound](https://reader035.fdocuments.net/reader035/viewer/2022070323/55a25d541a28ab9c2b8b47b4/html5/thumbnails/8.jpg)
![Page 9: Sound](https://reader035.fdocuments.net/reader035/viewer/2022070323/55a25d541a28ab9c2b8b47b4/html5/thumbnails/9.jpg)
![Page 10: Sound](https://reader035.fdocuments.net/reader035/viewer/2022070323/55a25d541a28ab9c2b8b47b4/html5/thumbnails/10.jpg)
![Page 11: Sound](https://reader035.fdocuments.net/reader035/viewer/2022070323/55a25d541a28ab9c2b8b47b4/html5/thumbnails/11.jpg)
![Page 12: Sound](https://reader035.fdocuments.net/reader035/viewer/2022070323/55a25d541a28ab9c2b8b47b4/html5/thumbnails/12.jpg)
![Page 13: Sound](https://reader035.fdocuments.net/reader035/viewer/2022070323/55a25d541a28ab9c2b8b47b4/html5/thumbnails/13.jpg)
![Page 14: Sound](https://reader035.fdocuments.net/reader035/viewer/2022070323/55a25d541a28ab9c2b8b47b4/html5/thumbnails/14.jpg)
![Page 15: Sound](https://reader035.fdocuments.net/reader035/viewer/2022070323/55a25d541a28ab9c2b8b47b4/html5/thumbnails/15.jpg)
![Page 16: Sound](https://reader035.fdocuments.net/reader035/viewer/2022070323/55a25d541a28ab9c2b8b47b4/html5/thumbnails/16.jpg)
![Page 17: Sound](https://reader035.fdocuments.net/reader035/viewer/2022070323/55a25d541a28ab9c2b8b47b4/html5/thumbnails/17.jpg)
) وقانون Samplingعملية أخذ العينات (Nygest
الصوت المسجل بواسطة المايكروفون أو الكاسيت أو التلفون • بحيث يتم Samplingيتم معالجته رقمي ًا في عملية تسمي
أخذ عينات من الموجة التماثلية وتخزينها في صورت بتات عينة في 144.0ويحسب معدلها في الثانية الواحدة ( مث ًال
الثانية).
) Quantizationيتم تقريب قيمة العينة لقرب عدد صحيح (•وقد يسبب التشويش ( وهذه العملية يقوم بها كرت الصوت
الموجود في جهاز الحاسوب).
Qtzتقريب العينة إلي المستوي القل أو العلي يسمي •level
![Page 18: Sound](https://reader035.fdocuments.net/reader035/viewer/2022070323/55a25d541a28ab9c2b8b47b4/html5/thumbnails/18.jpg)
تقريب العينات لقرب عدد صحيح.•
تقلل منه بزيادة عدد Qtz error يمثل ب errorيحدث • وكلما زاد حجم الملف. Levelsال
![Page 19: Sound](https://reader035.fdocuments.net/reader035/viewer/2022070323/55a25d541a28ab9c2b8b47b4/html5/thumbnails/19.jpg)
عمل كرت الصوت
111111 110001Sampling Quantization Coding 1100111
![Page 20: Sound](https://reader035.fdocuments.net/reader035/viewer/2022070323/55a25d541a28ab9c2b8b47b4/html5/thumbnails/20.jpg)
Nygestقانون
ينص علي أن: Nygest قانون •
FS >= 2 Fm) يجب أن يكون ضعف تردد الاشارة FSأي أن تردد أخذ العينات (•
)Distortion) وإل سوف يحدث ضياع للصوت(FMالصوتية (
نحسب عدد مستويات التقريب ( مث ًال Codingقبل عملية ال • )m=16 : ونحسب طول الكود حسب القانون
•]2**n = m] bit كلما زاد طول الكود بالتالي سيزيد حجم mكلما زاد عدد المستويات •
الملف.
![Page 21: Sound](https://reader035.fdocuments.net/reader035/viewer/2022070323/55a25d541a28ab9c2b8b47b4/html5/thumbnails/21.jpg)
مثال
•An audio signal has 10khz bandwidth, modulated using 16000, 32 PCM , calculate
the file size of 100 seconds recording ?
خطوات الحل:
المعطيات:Fm = 10 khz = 1000 Hz
Fs = 16000 samples
T= 100 seconds
n = m**2- أحسب طول الكود حسب القانون: 1
![Page 22: Sound](https://reader035.fdocuments.net/reader035/viewer/2022070323/55a25d541a28ab9c2b8b47b4/html5/thumbnails/22.jpg)
•2**n = 32 , n= 5 bits) العينة الواحد تحتاج لخمسة بتات(
- أحسب العدد الكلي للعينات حسب القانون: 2
TNS = Fs x t
= 16000 x 100 = 1600,000 samples
- أحسب حجم الملف حسب القانون: 3
Files Size = TNS x n
= 1600,000 x 5 = 8000000 bit / 10000
8000 KB
![Page 23: Sound](https://reader035.fdocuments.net/reader035/viewer/2022070323/55a25d541a28ab9c2b8b47b4/html5/thumbnails/23.jpg)
![Page 24: Sound](https://reader035.fdocuments.net/reader035/viewer/2022070323/55a25d541a28ab9c2b8b47b4/html5/thumbnails/24.jpg)
![Page 25: Sound](https://reader035.fdocuments.net/reader035/viewer/2022070323/55a25d541a28ab9c2b8b47b4/html5/thumbnails/25.jpg)
![Page 26: Sound](https://reader035.fdocuments.net/reader035/viewer/2022070323/55a25d541a28ab9c2b8b47b4/html5/thumbnails/26.jpg)
![Page 27: Sound](https://reader035.fdocuments.net/reader035/viewer/2022070323/55a25d541a28ab9c2b8b47b4/html5/thumbnails/27.jpg)
![Page 28: Sound](https://reader035.fdocuments.net/reader035/viewer/2022070323/55a25d541a28ab9c2b8b47b4/html5/thumbnails/28.jpg)
![Page 29: Sound](https://reader035.fdocuments.net/reader035/viewer/2022070323/55a25d541a28ab9c2b8b47b4/html5/thumbnails/29.jpg)
![Page 30: Sound](https://reader035.fdocuments.net/reader035/viewer/2022070323/55a25d541a28ab9c2b8b47b4/html5/thumbnails/30.jpg)
![Page 31: Sound](https://reader035.fdocuments.net/reader035/viewer/2022070323/55a25d541a28ab9c2b8b47b4/html5/thumbnails/31.jpg)
![Page 32: Sound](https://reader035.fdocuments.net/reader035/viewer/2022070323/55a25d541a28ab9c2b8b47b4/html5/thumbnails/32.jpg)
![Page 33: Sound](https://reader035.fdocuments.net/reader035/viewer/2022070323/55a25d541a28ab9c2b8b47b4/html5/thumbnails/33.jpg)
![Page 34: Sound](https://reader035.fdocuments.net/reader035/viewer/2022070323/55a25d541a28ab9c2b8b47b4/html5/thumbnails/34.jpg)
![Page 35: Sound](https://reader035.fdocuments.net/reader035/viewer/2022070323/55a25d541a28ab9c2b8b47b4/html5/thumbnails/35.jpg)
![Page 36: Sound](https://reader035.fdocuments.net/reader035/viewer/2022070323/55a25d541a28ab9c2b8b47b4/html5/thumbnails/36.jpg)
![Page 37: Sound](https://reader035.fdocuments.net/reader035/viewer/2022070323/55a25d541a28ab9c2b8b47b4/html5/thumbnails/37.jpg)