1. GOVERNMENT ENGINEERING COLLEG GODHRA BRANCH :ELECTRONICS & COMMUUNICATION  SUBJECT:AUDIO VIDEO SYSTEM  TOPIC:CD,DVD & MP3 SYSTEM  CLASS:5 th SEM E.C

2. PREPARED BY  130600111027  DOSHI KRIMA G.  130600111028  LAKHARIA DHWANI H.  130600111029  MEHRA MALKIT KAUR J.  GUIDED BY:-  PROF.KRISHNKANT SHUKLA

3. Compact Disk (CD) Basics Uses Digital Technology to store data in binary values of Zero and One Uses “Pits” and “Lands” to signify binary values CD’s Read at a Constant Linear Velocity (CLV) Capable of Storing Large Amounts of Data (up to 700MB) Uses Error Correction for reliable data retrieval even if the CD becomes lightly scratched.

4. Types Of Compact Disks CD Audio – The first type of CD that was available. This allows for the storage of digital audio. These are playable in all current CD drives and car audio systems including DVD players. CD-ROM – Computer Data is stored on these units such as games, applications, and other files. Only readable on computers. CD-R – Allows users to write data once to a recordable Compact Disk. Can not be re-written and can be read in all current players depending on wither the disk holds Audio or Data. CD-RW – Users Can Write and Re-Write these special disks. However because of the disk format, they cannot be read in Audio CD players or DVD players.

5. CD Basic Technology Principles This diagram shows the side view of a common CD. Printed Label : The image on the top of the CD, more of a “secondary” protection device than anything else. Protective Lacquer: This protects the CD from scratches and helps reflect the CD player’s laser. Aluminum Layer: This is the reflective layer that primarily bounces the CD player’s laser back. Polycarbonate: Known industry wide as a very durable substance, Polycarbonate is a clear covering designed to protect the pits and lands in the CD surface.

6. CD Audio: How Does It Work? Sound is Sampled at 40,000 Times per Second or Higher Each Sample Must be Represented by at least a 16-bit number Therefore, with 40,000 samples per second, and 16-bits per sample, that’s over 640,000 bits per second! Therefore a 1 minute long music clip would take over 38,400,000 bits (+/- 38MB) for storage!

7. Error Correction, Why Bother? Error correction is an imperative part of CD technology, you cannot take good enough care of a CD to prevent errors. Sony and Phillips knew this, so they instituted the basics of Error Correction Technology. Errors can be caused by: Manufacturing defects (Rare) Scratches (Very Common) Error Correction Types: CIRC – (Cross Interleaved Read-Solomon Code) encoder EFM Modulation – (Eight to Fourteen)

8. DVD SYSTEM If CD is so great…why change it? Space limitations plagued CD’s to a life only in the music market, Video producers could not fit full length movies on a CD. The goal of DVD was to create a “vastly increased capacity, with the ability to feature an entire movie in high- quality digital video on a single side of a disc.” They also wanted...Brighter colors, sharper pictures, and outstanding audio quality The goal was a 4.7 gigabyte capacity with the ability to hold hours of full motion video and sound

9. Obviously they did it…but how?  DVD uses Smaller pit and land dimensions, therefore the laser must me exponentially more accurate than with CD’s.  More closely-spaced tracks, called "track pitch"  A shorter-wavelength laser

10. Single Side, Single Layer DVD  Accounts for most DVD’s  4.7 GB of data capacity  "7 times" the data capacity of today’s music CDs and CD-ROMs

11. Single Side, Dual Layer DVD  8.5 GB on one side  additional 3.8 GB on the second layer  more than "13 times" the capacity of today’s music CDs and CD-ROMs

12. Dual Side, Single Layer DVD  9.4 GB (4.7 on each side)  provides a little more capacity  Flipping the disc or having a DVD Player capable of two-sided playback is required

13. Dual Side, Dual Layer DVD  Maximum capacity of 17GB (8.5GB on each side)  Flipping the disc or having a DVD Player capable of two-sided playback is required

14. The future of DVD DVD Video will become the leading format for the movie industry DVD-ROMs will become the mainstream for computer applications DVD will become the leading format for video game systems Recordable DVD will eventually be available to consumers Software projects containing a large amount of multimedia will take advantage of DVD’s high storage capacity DVD Audio will compete with the currently experimental Super Audio CD (SACD) technology.

15. History Of MP3 19852004 1989 19901997 1999 Started in the mid 1980’s at Fraunhofer Institute in Germany where they began developing a high quality, low bit-rate audio format 1989 they were granted a permit for the MP3 compression format Fraunhofer developed the first MP3 player in the early 1990’s

16. What is MP3? MP3 files can be compressed at different rates, higher ratio of 10:1 is equal to about 1 MB for each minute of an MP3 song Fraunhofer has a license on MP3 that if anyone else wants to develop further technology they have to ask them first before making it

17. How Do MP3’s Work? Variety of compression levels, the higher the k-bit the better quality of sound Legal to rip MP3 tracks from CD for only personal use Ripper copies the song’s file from hard disk Encoder gets the music into the MP3 format (compression) so you can listen to it on your player

18. The 2 Main Tools The encoder,the key tool used with MP3s. This gets it into the right format The ripper gets music from somewhere else (ex. CD to MP3)and downloads it into your data.

19. The Process of Compression The encoding tools-rippers and encoders! 1. Encoder analyzes incoming signal determining the “spectral energy”, and breaks it down into a mathematical patterns, and compares it with psychoacoustic models stored in the encoder itself 2.Encoder can then discard most of the data. The person encoding can specify how many bits can be alloted to storing each second of music. More discarded the worse the music!

20. How is compression possible? The size is reduced so the higher frequency is taken out Irrelevant data is removed from the audio bit stream Increase the bit rate for better quality

21. The iPod iPod memory/price. Also available in mini for much less $! iPods are a big part of music culture these days. You can go anywhere with them!

22. Advantages of MP3 players to CD players Ƙ Takes up less file space than the CD format WAV/AIFF Ƙ You can access legal downloads and get them onto your mp3 player faster, and more music! Ƙ Has no moving parts, so it won’t wear out like a CD player will

23. Next Generation of the Music Business? Millions of songs are shared everyday by millions of users MP3 technology is constantly advancing With shareware people can trade music with others and people will not buy as many CDs from the store Dell MP3 player Less CD buying

24. Side By Side Comparison:

25. THANK YOU