El CD-Audio

•
CD-A
•
•
•
•
•
El CD-Audio
2 Canales
2 B por muestra
44,1 ksps
74 minutos
2x2x44100x74x60=
784 MB
El número de datos grabado en la superficie del disco es muy superior. En parte
debido al código de protección contra errores
1
HA(2+8(ABA(A"'+&#&"+
Superficie de datos
HA
ABA
N&35$"(OP(
Paso de pista
Long. de resalte mínima (1 capa) (nm)
Long. de resalte mínima (2 capas) (nm)
(
(
CD
1600
830
-
DVD
740
400
440
(
2
Estructura DVD-A
•
•
Densidad DVD =
(1600/740)(830/400) =
4,5 Densidad CD-A
Capacidad DVD =
4700/780 = 6 Capacidad
CD-A
1 cara, 1 capa (4,7 GB)
1 cara, 2 capas (8,5 GB)
2 cara, 2 capas (17 GB)
•
El código de protección
es menos redundante
3
Contenido DVD-A
Tipo de disco / Contenido
Tipo de reproductor
DVD- Audio sin vídeo DVD- Audio sin vídeo
DVD-Audio
sólo audio
•
•
Audio
DVD-Audio
universal
•
•
•
Audio
DVD-Vídeo
•
No reproducible
Video
•
•
Texto informativo
No reproducible
Elementos de audio para
DVD-Audio y DVD-
Texto informativo
Imágenes fijas
DVD- Video
Menús visuales
Audio, texto, gráficos y
•
Todo el vídeo
•
Todo el vídeo
video
•
Sólo vídeo
4
Opciones en DVDAudio
16, 20 ó 24 bits
44.1
48
88.2
96
176.4
192
Mono (1.0)
Sí
Sí
Sí
Sí
Sí
Sí
Estéreo (2.0)
Sí
Sí
Sí
Sí
Sí
Sí
Cuadrafónico
(4.0)
Envolvente
(5.1)
Sí
Sí
Sí
Sí
No
No
Sí
Sí
Sí
Sí
No
No
5
Duraciones en DVD-A
Resolución
F. muestreo
(kHz)
Canales
Flujo binario
(Mbps)
Duración
(minutos)
16
44.1
2
1.41
422
16
48
2
1.54
388
20
96
4
7.68
78
24
192
4
9.22
65
• Disco de 1 capa, 1 cara
• Sin compresión MLP
• Con compresión MLP (45% de reducción), la
capacidad aumenta un 80 %
6
CD-A vs SACD
CD-A
SACD
Diámetro
120 mm
120 mm
Grosor
1,2 mm
1,2 mm
Caras
Una
Una
Capas
Una
Dos: CD y HD
780 MB
-
780 MB
4.700 MB
16 bit PCM
44,1 ksps
16 bit PCM
44,1 ksps
Código Super Audio
-
DSD 1 bit
2,8224 Msps
Multicanal
-
6 canales
5-20.000 Hz
0-100.000 Hz (DSD)
96 dB
120 dB
Duración de grabación
74 minutos
74 minutos
Extras
Texto CD
Texto, gráficos, vídeo
Capacidad de datos
CD
HD
Código Audio Estándar
Respuesta en frecuencia
Margen dinámico
7
•
Capacidad
CD-A
•
•
•
•
•
2 Canales
2 B por muestra
•
SACD
•
•
6 Canales
•
•
74 minutos
44,1 ksps
74 minutos
2x2x44100x74x60=
784 MB
2,8224 Mb/s/canal
(64 b/muestra a
44,1ksps)
6x2822400x74x60=
¡9.400 MB!
El SACD incluye un método de compresión sin pérdidas (DST: direct stream
transfer) que reduce el número de datos al 50%.
La capacidad necesaria es, por tanto de 4.700 MB
8
DSD en el SACD
Difference between PCM & DSD
PCM
Standard multibit PCM recording requires a decimation filter on the recording side
and an oversampling filter on the playback side .
DSD
Direct Stream Digital eliminates the need for these filters, enabling sound to be recorded
directly in the 1-bit signal format.
9
“ventaja” del SACD
10kHz square wave
input
10kHz square wave
input
44.1kHz/16-bit
output
Direct Stream
Digital output
The above diagram demonstrates the high fidelity of DSD recording.
The 10kHz square wave frequency (top line in the diagram) includes
high-frequency components which clearly exceed the audio range. With the
16-bit PCM system, these are converted into 10kHz sine waves (left
diagram). However, with the 1-bit DSD system, the reproduced sound wave
is nearly identical to the original sound wave (right diagram).
Una onda cuadrada y una sinusoide de 10 kHz suenan igual para el oído humano
Son las no-linealidades de los amplificadores las que producen la diferencia.
10
Estructura SACD
Hybrid Disc Construction
Hybrid Disc Signal Heading
11
SACD Disc Types
Single Layer Disc
Formatos SACD
Dual Layer Disc
Hybrid Layer Disc
12
El SACD híbrido
Hybrid Disc Content
12 cm
CD LAYER
PCM Stereo
HIGH DENSITY LAYER
Enrichment:
• Lyrics
• Graphics
• Video
DSD Multi-Channel
DSD Stereo
13
Reproductor SACD
To find out how much more there is to hear, visit a Sony SACD retailer.
Call 1-800-222-SONY or visit
www.sony.com
Sony Electronics Inc. 1 Sony Drive, Park Ridge NJ 07656 http://www.sony.com
© 1999 Sony Electronics Inc. All rights reserved. Reproduction in whole or in part without written permission is prohibited. Sony, DSD, Direct Stream Digital,
Dual Discrete, Super Audio CD, the DSD logo and the Super Audio CD logo are trademarks of Sony. Direct Stream Transfer is a trademark of Philips.
14
onstruction.
neral Impedance
r positions the active
+
-
-
Level [d
signal path, we chose
design goals: flat amplitude response, maximum
-50
-100
high-frequency extension, low noise, optimum
Voltage for the analog stage is provided by a
20
+
100
1k
Frequency [Hz]
10k
100k
discrete left and right power supply secondaries,
Sony's filter design achieves
phase characteristics and suitability with
located directly on the audio circuit board.
Electrónica
flat response to 50,000 Hz.
rcuit Board Layout.
Separate left and right 3-layer bus bars help
ng such meticulous attention to the
minimize power supply impedance.
To optimize
op amps and other active circuit elements
outare
of the
signal path.
grounding, the audio output terminals
con-
The GIC filter is followed by a discrete
nected to the audio circuit board using a thick
component buffer amp, for optimum coupling
e signal path, to
on, design and execution of each
ony was equally careful in the physical
e original sound.
ent of circuits in the chassis.
circuit board—which includes the DSP
, RF processing LSI and system control
The GIC low-pass filter takes transistors,
downstream
audio equipment.
to a preamplifier.
The GIC circuit of the Sony SCD-1
and
copper plate.
SCD-777ES take all these factors into account.
oned directly underneath the fixed
lter
Frequency response is flat to 50,000 Hz (some
r example, it required a hole in the cir-
two and a half times the response of a CD player).
ve assembly. This was a design chal-
d to accommodate a support post. But
guration reduces signal runs from the
ups, reducing exposure
to possible
ce.
+
circuit board itself follows Sony's
nimum" design, with key components
ass through
concentrated as possible. To accomelements
goal, Sony designed the printed circuit
Above 50,000 Hz, response begins to roll off
slowly. The result is smooth, open, non-fatiguing
sound with exceptional definition and dynamics.
SCD-1 Internal structure
4 layers. And then applied surface-mount
Fig. 12 Characteristics of Low-Pass Filter Used in SCD-1
small-scale
on both
sides of the
Signals dochips
not pass
through
anya active
elements
a result,
phenomenal
amount of
ating the main
+ circuit board and placing
he mechanism leaves ample space in
- circuits that need
is for the two
g out." The power supply and the audio
ard.
0 10
Level [dB]
ts comfortably on a single, small board.
Analog circuit with GIC low-pass filter.
-50
-100
20
100
SCD-1 Main circuit board (top)
1k
Frequency [Hz]
10k
100k
audio circuit board includes so many
nts that determine sound quality, Sony
attention to its layout and construc-
is a double-sided glass epoxy board
s bar and symmetrical left/right layout.
Sony's filter design achieves
flat response to 50,000 Hz.
l LSIs, including VC24, S-TACT and
takes transistors,
ve
circuit
elements
mponents.
And they're
all concentrated
ulse D/A Converter, are all surface-
15