Digital Signal Processing Reference
In-Depth Information
in practice than a detailed understanding of the video and audio coding
which will be discussed later.
Luminance
sampling frequency
13.5 MHz
5.75 MHz
8/10 Bit
Y
A A
D
A A
D
A A
D
Y
R
G
B
8/10 Bit
Cb
270 Mbit/s
ITUBT.R 601
„CCIR601“
Cb
8/10 Bit
Cr
Cr
2.75 MHz
6.75 MHz
Chrominance
sampling frequency
Right
16 Bit
A
D
up to 768 kbit/s
15 ... 20 kHz
bandwidth
32/44.1/48 kHz
Sampling frequency
= approx.
1.5 Mbit/s
16 Bit
Left
A
D
up to 768 kbit/s
15 ... 20 kHz
bandwidth
32/44.1/48 kHz
Sampling frequency
Fig. 3.2.
Video and audio data signals
All the same, the description of the data signal structure will begin with
the uncompressed video and audio signals. An SDTV (Standard Definition
Television) signal without data reduction has a data rate of 270 Mbit/s and
a digital stereo audio signal in CD quality has a data rate of about 1.5
Mbit/s (Fig. 3.2.).
The video signals are compressed to about 1 Mbit/s in MPEG-1 and to
about 2 - 7 Mbit/s in MPEG-2. The video data rate can be constant or vari-
able (statistical multiplex). The audio signals have a data rate of about 100
- 400 kbit/s (mostly 192 kbit/s) after compression (to be discussed in a
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