Digital Signal Processing Reference
In-Depth Information
recovery when frame data is corrupted or missing; to better
interface with network stacks; there is a Network Abstraction
Layer (NAL) syntax defined to allow H.264 to be used in many
network environments; and packetization is supported, with
minimal header overhead. Two sets of high-level parameters are
defined as the Sequence Parameter Set (SPS) and the Picture
Parameter Set (PPS); these more advanced features are not dis-
cussed further in this text.
15.3 Digital Cinema Applications
Digital cinema is the use of digital compression technology in
the motion picture industry, including areas such as: filming or
recording; storage and distribution; and playing or projecting in
movie theaters using digital representation and compression.
Digital cinema can be much higher resolution than that for home
entertainment systems, and therefore demands correspondingly
higher storage requirements when distributing and archiving
a full-length movie.
Movies can be made with 1080p (1920
1080) pixel resolu-
tion. The next frame size is known as 2K for the vertical resolu-
tion, using 2048
1080. 4K increases
the resolution to
4096
2160 pixels per frame. The latest professional cameras can
record at 8K or 8196
4320 pixels per frame, in 3-D form.
High-end movie cameras also sample much faster
typically
120 fps. The production video can then be fairly easily converted
to 24, 48, or 60 fps. For high speed or motion applications, the
video could be left in 120 frames per second.
Theater projector and playback equipment costs are a key
factor in the adoption of digital cinema. Traditional film projec-
tors may cost ~$50,000, and can last for 30 years or more. A
digital-cinema system costs in the order of $150,000 or more, and
since it's mostly computer-based electronic equipment, is more
difficult and expensive to repair. It is also likely to have a shorter
lifetime, and perhaps be obsolete within five years. The benefit, of
course, is the screen resolution, quality and technical advance-
ments such as 3-D enabled by digital cinema technology.
To encourage adoption, some of the theater costs may be
subsidized by the film producers and distributors, as digital
cinema allows for the electronic distribution of films and more
extensive anti-piracy measures, which save the industry money.
Still, there is little doubt that the digital technology adoption
trend is contributing to higher prices for the movie theater
customer.
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