What Are We Trying to Compress? - A Practical Guide to Video and Audio Compression - page 37

3.4.2 Production Company

Independent production companies now produce a lot of their own programs. They don't
have the money available to invest in massive technical infrastructures that the broad-
casters use, but they do use similar equipment to shoot and edit.
Programs are typically delivered on Sony Digital betacam-based systems or on a
format called DVCAM and its derivatives such as DVCPRO. These correspond to the 50-
Mbps and 25-Mbps formats that broadcasters prefer. HDTV variants of these are also
beginning to be used. These formats are slightly compressed. All formats in use sacrifice
some small portion of the picture information, even if it is just recording color data at a
lower resolution than brightness.
The original material might have been shot on film or on video. Today's material is
delivered to broadcasters in a digital format. New technologies such as Material eXchange
Format (MXF) allow media to be delivered in files rather than on tapes, and this allows
transfers to be networked through an information technology (IT) infrastructure.
Any long-term storage of programs must be in a form that is ready to be reprocessed
for new platforms and markets. A production company that has been in business for a
while is likely to have some format-conversion and storage problems similar to those
experienced by the broadcaster due to the continued change in video formats.

3.4.3 Pro-Consumer

This is a category of consumer that buys high-end equipment that is near professional
quality and is almost good enough for production companies and broadcasters to use. The
gap is narrowing, and the difference between pro-consumer and professional equipment
is likely to be in the quality of the imaging optics and the storage capacity. Many of the
physical components in the camera are common to consumer and professional equip-
ment—especially in the case of DV-format cameras.
The imaging chip in professional broadcast-standard equipment produces a higher
resolution and has a greater dynamic range from black to white, resulting in high-quality
images. Sometimes a professional system will use multiple CCD chips rather than a single
chip to get even better quality.
Broadcasters will require lenses with good depth-of-field control and little or no dis-
tortion of the image. The storage capacity of the videotape in a professional system will be
higher than a consumer model in terms of bit rate. A professional format is also likely to
record for less time because the amount of data recorded is larger. The consequence is that
tape-based systems must transport the tape faster to record sufficient data. The same
applies to solid-state storage because the bulk of the stored data is larger.

3.4.4 Amateur

The pricing of digital handycams is reducing to the point where this market is opening up
now. Analog video recorders can still be purchased, but most manufacturers are also