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Answers
- Video
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1.1 |
What
are the advantages of digital video?
Digital
video has many advantages over analague video tape due to its great ease
of use, portability and durability. The most common usage is presentations
which include training, corporate presentations, video kiosks and video
libraries. Advantages of using digital video are :
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- Enhanced
learning as moving pictures with sound are more effective than stills.
- Footage
can be updated or changed with ease.
- Digital
video adds a whole new dimension to presentations as it can be easily
incorporated into computer presentations.
- With network
capabilities, presentations can be distributed easily.
- Since
digital video clips are basically files, they can be integrated into
many databases just like text or numeric fields for useful applications.
For example, video clips of historical/educational/marketing events
or trips can be integrated with more mundane information to provide
a more interesting presentation.
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1.2
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Why
do video tapes deteriorate?
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- Video
tapes lose their magnetic signal with time. The tape itself can grow
brittle and eventually break... EVEN if you never watch them!
In just 5 years of storage, a video tape will have an observable loss
in picture crispness.
- Every
time a tape is played, a small amount of the tape's surface and data
is permanently removed due to physical contact between tape head and
video tape.
- Dirty
tape heads are more abrasive and accelerate the degradation process.
- Tape player
functions such as slow motion, pause and fast forward search can accelerate
tape wear if they are used excessively. For example, if the recorder
is placed in a "pause" mode, the video heads will still be
spinning against the tape at a high speed rate but the tape will be
stationary. If used excessively, the tape can easily become worn.
- Tapes
placed close to electric fields (E.g top of TVs or VCRs) may lose part
of their information.
- When video
tapes are copied, each copy loses a bit of the information from the
original.
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1.3
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So,
how long do video tapes last?
Since environmental conditions are the key to the tape's chemical stability,
the answer is based on storage conditions. Theoretically, if you can keep
tapes at a CONSTANT temperature and relative humidity, GOOD
QUALITY tapes will probably last up to 15 years without significant
degradation. It is important here to note the word "constant"
when speaking of the environmental conditions in which tapes are stored.
Fluctuation in temperature or humidity will cause expansion and contraction
of the tape and a more realistic lifespan is probably 5 to 10 years.
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1.4
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How
do you deal with fungus tapes?
Generally,
when a tape develops fungus, there is already a certain amount of damage
on the tape. Cleaning has to be carried out before any video conversion
can take place, otherwise playback quality will be affected due to tape
head clogging. There may also be possible tape head damage. Depending
on the extent of the fungus attack, video stabilisation and enhancement
will probably be needed to achieve a minimum level of quality. As effort
is high, cost will naturally be higher. Convert the tape ONLY if
the contents are very important and there is no alternative source.
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1.5
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What
is the criteria for selecting tapes for mass conversion for schools?
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- Importance
of tape contents
This is the obvious one. If tape contents relate to school events such
as Speech Day, Graduation ceremonies, Concert Day, Founder's Day &
etc, the decision would probably be to go ahead for the preservation
of the rich school history.
- Frequency
of usage
Tapes subjected to frequent usage have shorter lifespans as tape gets
thinner due to wear and tear caused by contact between tape media and
tape head. Equipment maintenance costs increase due to replacement of
worn-out VCR heads. If heads are not maintained, their abrasive action
(just like sandpaper) will wear out more video tapes. For CDs, there
is no contact between head and media and thus no deterioration in quality
with frequent usage.
- Current
condition of tape
If fungus is present, there is already damage on the tape. Cleaning
has to be done immediately before the fungus spreads or thickens beyond
restoration. Such tapes SHOULD NOT BE USED as fungus is deposited
on tape heads and is then spread to other tapes. In extreme cases, substantial
tape collections can be damaged. In schools, fungus tapes are common
due to a lack of time in maintenance.
- Required
lifespan
A normal video tape will probably last only 3 - 10 years. CDs are more
cost-effective as they can last up to 50 years with no quality loss
in their digital contents.
- Implementation
on network infrastructure
This will need to be considered for the present or future needs as digitised
contents can be easily distributed across the school network or internet,
to enable convenient access by teachers and students.
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1.6 |
How
do I decide whether to have a CD-ROM or VCD when I convert my videos?
Essentially, videos will be converted to the common MPEG1 video format.
The MPEG1 video file in a CD-ROM has the extension name of "MPG"
whereas for a VCD, it is "DAT". The DAT file contains the basic
MPEG1 file along with additional information to enable playback on standalone
devices.
Convert to CD-ROM if you are only playing back on a computer or you
intend to include videos in your presentations/software that only support
"MPG" files.
Convert to VCD if you need to playback on both the computer and standalone
VCD/DVD players.
There are also other considerations related to TV/PC monitors and encoding
bit rates that will complicate this FAQ if elaborated.
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1.7 |
Can I convert my VHS tape to DVD?
YES. However, VHS resolution is low and is equivalent to VCD resolution
of 352x288(PAL) and 352x240(NTSC). In comparison, DVD resolution is double
at 720x576(PAL) and 720x480(NTSC). In simple terms, if you have a better
source than VHS such as Mini-DV, it will be more ideal as the DVD produced
will be of a better quality. If not, VCD is a better choice, bearing in
mind that DVD conversion costs are still high.
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1.8 |
Can
DVD players read CD-R?
Depends on whether these players come with two lasers to enable them to
read both DVD and CD-R media. Even if they do, different CD-R media may
give different results. Check with your manufacturer's manual to confirm.
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1.9 |
Why
is there a wide price difference for VCD conversion?
Depends on the following factors : |
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- Desired
quality
- Format/type
of source tape
- Condition
and age of source tape
- Nature
of video contents
- Video
conversion/encoding equipment used
- Skill
and expertise of the video technician/engineer
- Frills
or no-frills presentation for disc-based output media
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