The Compact Disc Story. Kees A. Schouhamer Immink Turing Machines Inc Rotterdam

Transcription

1 The Compact Disc Story Kees A. Schouhamer Immink Rotterdam

2 Early History Making and listening to music has always been a fundamental human need. Vermeer: The Music Lesson (1662

3 Early recording devices Being able to record sounds was always a dream of inventors. Although musical boxes and barrel organs allowed people to hear music without anyone having to play, the sound was very limited.

4 From Cylinder to CD in a Century 1877 Edison cylinder 1887 Berliner disk 1910 Electronic amplification 1950 LP 1958 Stereo LP 1982 Compact Disc

5 Edison s Studio 1900

6 Discs The first phonographs had one disadvantage - the recordings could not be duplicated. In 1894, Emile Berliner modified the phonograph to use a disc rather than a cylinder.

7 Advantages of digital audio Alec Reeves (1936) Quality depends on conversion steps ONLY Quality independent of transmission media Compatibility with different media and traffic (video, audio, and data) Low cost New features can easily be embedded.

8 Sigsaly, 1943 The first digital speech transmission

9 History of Optical Media 1958 Videodisc, Greg 1965 Digital videodisc, Russell (Battelle) 1969 Videodisc, Compaan (Philips) Development Digital Audio Disc Cooperation Philips & Sony 1982 Introduction Compact Disc, Japan

10 Compact Disc

11 Optical Read-out

12 Early optical recording (1965)

13 Strategic Sony/Philips Alliance Philips Optics Mechanics Servos Sony Digital audio systems Coding

14 Shopping List, Dec Philips SONY Sampling rate , Resolution 14 bit 16 bit Playing time 60 min. 60 min. Disc diameter 11.5 cm 10 cm EC Code?? Channel code M3?

15 Disc Diameter (Philips)

16 Playing Time Sony: 150 min. on a 30 cm disc Philips: 60 min. on an 11.5 cm disc Von Karajan suggested 74 minutes to accommodate Furtwängler's Beethoven s 9th Symphony.

17 Final Technical Decisions March/June 1980 Sampling rate: 44.1 khz (Sony) Resolution: 16 bits (Sony) Error Correction: CIRC (Sony) Disc diameter: 120 mm (Sony) Playing Time: 74 min. 33 sec. (Sony) Channel code: EFM (Philips)

18 Cross Interleaved Reed-Solomon (RS) Code (CIRC) CIRC uses two short RS codes, namely (32, 28, 5) and (28, 24, 5) RS codes using an interleaver. Rate ¾. Interleaving memory: 16 kbit.

19 CIRC characteristics High random error correctability. Burst errors of up to 3,500 bits (2.4mm). Interpolation of error bursts of up to 12,000 bits (8.5 mm) provides concealment of missing samples. Simple decoder strategy possible with reasonably-sized RAM.

20 Eight-to-Fourteen Modulation (EFM) EFM is a dc-free run length limited code, where minimum and maximum run length is 3 and 11. Low frequencies are suppressed.

21 Pits and lands

22 Pits and lands

23 Philips First Decoding Circuitry

24 Philips First ECC Integrated Circuit Area of 45 mm 2 contains about gates. Error Correction IC, n- channel MOS silicongate.

25 First portable CD player, Sony 1984

26 Impact New life for a dying music industry Big Bang digital audio and video revolution Low-cost and reliable data distribution: CD- ROM, CD-R New optical media: DVD, Blu-Ray

27 Recording Basics I Spot diameter: d = λ / 2NA, λ : laser wavelength, NA : Numerical aperture. Storage Capacity: Capacity ~ 1/d 2.

28 Recording Basics II Focus depth ~ D x NA 2 Disc tilt tolerance ~ D x NA 3. D NA For given tilt tolerance: halving the disc thickness, D, allows an NA increase of 2 1/3, and a storage capacity increase of 2 2/3 = 1.6.

29 From CD, DVD to Blu-Ray

30 The Success Story in Numbers 1982: Introduction CD Audio 1985: CD-ROM 1992: CD-R(ecordable) 1993: Video CD 1995: DVD (4.7Gbyte) 2006: BluRay Disc (25 Gbyte) 2008: discs sold