Introduction to video

1.    What are some advantages of digital video

The advantages of digital video are:

• There is a reduced sensitivity to noise and interference.
• Digital equipment efficiently and economically perform tasks that are difficult or impossible to perform using analog technology.
• The application has many techniques for efficient retention of essential information such as compression.

2.    What is meant by frame rate in video

The frame-rate says how many images of a movie are displayed every second a movie is played.

The higher frame rate a movie has the smoother objects move in the movie.

3.    Are all videos/movies the same frame rate, explain your answer

No. Compare a movie with low framerate with a movie with higher framerate. The movie with high frame has more frames for the same number of seconds film. The movie with higher framerate will also be stored in a larger file.  

4.    What is meant by resolution, how is it measured.

Resolution is the term used to describe the number of dots, or pixels, used to display an image. Higher resolutions mean that more pixels are used to create the image, resulting in a cleaner image. The display, or resolution on a monitor, is composed of thousands of pixels or dots.Resolution is measured in picture elements, or "pixels" for short.

5.    What is the colour system called RGB

RGB (red, green, and blue) refers to a system for representing the colors to be used on a computer display. 

6.    Explain the video standards PAL, NTSC, and SECAM, what are the main differences between them.

PAL: Stands for Phase Alternating Line, is the analogue video format.The name "Phase Alternating Line" describes the way that part of the colour information on the video signal is reversed in phase with each line, which automatically corrects phase errors in the transmission of the signal.

NTSC: The National Television Standards Committee. The NTSC format consists of 29.97 interlaced frames of video a second, each consisting of 480 lines of vertical resolution out of a total of 525 (the rest are used for sync, vertical retrace, and other data such as captioning)

SECAM: (Sequentiel Couleur avec Mémoire, French for "sequential color with memory") is an analog television system, using frequency modulation to encode chrominance information. It is so named because it uses memory to store lines of colour information, in order to eliminate the colour artifacts found on systems using the NTSC standard.

7.    Which standard do we use in Australia?

PAL

8.    What is an IEEE 1394 port

A very fast external bus standard that supports data transfer rates of up to 400Mbps (in 1394a) and 800Mbps (in 1394b). A single 1394 prort can be used to connect up 63 external devices.

9.    Why do digital video cameras use video compression

It uses video compression because of storage space and also in order to email, a file needs to be small.

10. Describe what a codec is.

Codec is a short name for coder-decoder, the software that takes a raw data file and turns it into a compressed file. Because compressed files only contain some of the data found in the original file, the codec is the necessary “translator” that decides what data makes it in to the compressed version and what data gets discarded.

11. What is meant by “generation loss”, where does it happen?

Generation loss refers to the loss of quality and potential increase of file size between subsequent copies of data. Anything that reduces the quality of the represenation when copying, and would cause further reduction in quality oin making a copy, can be considered a form of generation loss.