science

Video recorder scheduling code

Video recorder scheduling code is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Video recorder scheduling code rather than just read about it. In short: VCR Plus+, G-Code, VideoPlus+ and ShowView are different names for the same scheduling system for programming VCRs and digital video recorders. These names are all registered trademarks of Macrovision, whose corporate predecessor, Gemstar, developed these algorithms for use in integrated endecs.

Key takeaways

Video recorder scheduling code belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Video recorder scheduling code to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Video recorder scheduling code from memory before moving on to harder problems.

Reference excerpt

VCR Plus+, G-Code, VideoPlus+ and ShowView are different names for the same scheduling system for programming VCRs and digital video recorders. These names are all registered trademarks of Macrovision, whose corporate predecessor, Gemstar, developed these algorithms for use in integrated endecs. This system was actively used for two decades, introduced in the late 1980s, and the last publication of а PlusCode was in 2010.

History

Before the advent of on-screen displays, the only interface available for programming a home video recorder was a small VFD, LED or LCD panel and a small number of buttons. Correctly setting up a recording for a specific program was therefore a somewhat complex operation for many people. G-Code, VideoPlus+ and ShowView were intended to help remove this difficulty.

Concept The central concept of the system is a unique number, a PlusCode, assigned to each programme, and published in television listings in newspapers and magazines (such as TV Guide). To record a programme, the code number is taken from the newspaper and input into the video recorder, which would then record on the correct channel at the correct time. The code could also be entered into a dedicated remote control device that would then control the VCR. The number is generated by an algorithm from the date, time and channel of the programme; as a result, it does not rely on an over-the-air channel to serve as a conduit to ensure the recording is properly timed. This means it will not compensate for a disrupted schedule due to live sporting events or bulletins for breaking news events, however many video recorders with these systems also incorporate Programme Delivery Control (PDC) and use that to alter times if possible.

Branding

The system has been licensed to television and VCR manufacturers in about 40 countries, but is branded under different names depending on the country. It is known as VCR Plus+, VCR Plus+ Silver and VCR Plus+ Gold in the United States and Canada; G-Code in Japan, China, New Zealand and Australia; VideoPlus+ in Ireland, the United Kingdom, and Japan; and ShowView in the rest of Europe as well as in South Africa. The system is branded as VideoPlus+/ShowView in Europe due to an existing trademark registration for "VCR" by Philips in that continent, and as G-Code (the "G" standing for the system's developer, Gemstar) in Japan because VCR is not a common abbreviation there ("VTR," for videotape recorder, is used instead). Japan initially used the name VideoPlus+ and later changed to G-Code, an example of this is the Victor (JVC) HR-880. Because television programming schedules are different, the coding has to be adjusted in each of the regions and recording equipment is not interchangeable.

Algorithms The algorithms used to encode and decode the television guide values from and to their time representations were published in 1992, but only for codes with six or fewer digits. Source code for seven and eight digit codes was written in C and Perl and posted anonymously in 2003.

See also TrueCookPlus, a similar system for microwave oven cooking

References

External links VideoPlus+ & ShowView Description of the algorithm Improved software: generates and decodes VCR Plus+ codes up to 8 digits in length VideoPlus/VCR+ Codec & Trivia The Straight Dope: How do the TV program codes for VCR Plus+ work?

Illustrations

Video recorder scheduling code illustration

Worked examples

Example 1 — a first encounter with Video recorder scheduling code

Start with the simplest possible case. Write down what Video recorder scheduling code claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Video recorder scheduling code before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Video recorder scheduling code ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Video recorder scheduling code

In research: Video recorder scheduling code appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Video recorder scheduling code in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Video recorder scheduling code is common in secondary-school and first-year university syllabi. It links to neighbouring topics Consumer electronics, TV Guide, so understanding it makes those chapters shorter.
In everyday life: Look for Video recorder scheduling code outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Video recorder scheduling code in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Video recorder scheduling code means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Video recorder scheduling code out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Video recorder scheduling code in simple terms?

Why does Video recorder scheduling code matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Video recorder scheduling code?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Video recorder scheduling code.