introduction to video

1. The video format we will be using this term is Digital Video, what is the other older format that was used recently.

The older format that was recently used is analog.

2. Describe the difference between the two formats.

The difference between the two formats is:

- analog signals are of varying wavelengths

- digital signals are transmitted only at precise points selected at intervals on the curve.

3. What are some advantages of digital video.

Some advantages of digital video is..... you can edit parts of the video, instead of starting from scratch.

4. What is meant by frame rate in video.

In video, frame rate is the number of images being shown per second.

5. Do all applications use the same frame rate, explain your answer.

Not all applications use the same frame rate. This is because.... there are more frames per second in movies on television, and the usual frame rate to perceive smooth motion is 10 frames per second.

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

Resolution is "the amount of information in each frame". It is measured/ represented by the number of individual picture elements [pixels].

7. What is the colour system called RGB.

The colour system RGB is "red, green and blue".

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

Secam - used for broadcasting.

Pal - cameras and decks are used.

Ntsc - a format to record video on VHS.

The main differences between them are the countries that use those formats.

9. Which standard do we use in Australia?

We use PAL.

10. For what type of video camera would you need to have a Video Capture Card in your computer to download video?


An analog video camera would need to have a Video Capture Card in your computer.

11. Why don't we need a video capture card for the video we will be doing at school.

We will be using digital video cameras?

12. What is an IEEE 1394 port.

An IEEE 1394 port is the most common form of connection for the camera to communicate with your computer.

13. Why do digital video cameras use video compression.

Digital video cameras use video compression because.....when your video is digitized it will be compressed.

14. Describe what a codec is.

A codec is the compression and decompression of video.


15. What is meant by generation loss, where does it happen?

Generation loss - "incremental reduction in image and/or sound quality due to repeated copying of analog video or audio information". It does not occur when copying digital video, unless it is repeatedly compressed and decompressed.

image file types.

GIF files:

gif files are used for.....storing drawings that have lots of same-colour pixels. these files are bitmapped images

JPEG files:

jpeg files use a complex technique that compresses images, such as, photos. the colour of every pixel is different.

Animated GIF files:

an animated gif file, is a series of gif files all bonded together. the file of the size is determined by the sum of all the files that create the series.

MPEG files:

an mpeg file uses an algorithm. it tries to eliminate repetition between frames to compress video information.

Shockwave files:

a vector-based images/animations. a shockwave file specifies the coordinates of shapes as well as the colour of each shape. these files can be very small and allow animation and sound to be produced.



What is a vector-based image?

Vector based images contain well-defined elements such as shapes and curves of various colours. each element is defined mathematically on the computer.

What is a bitmap-based image?

Bitmap-based images do not rely on mathematical formulas to define elements. each image is mapped out on a grid. A bitmap-based image is like a mosaic of pixels.

animation at last.

this is now my animation.

animation.

im now gonna upload my animation.....


hopefully it works.



umm... i just tried uploading it.... and it didnt move...

i'll try it again at home then.

post 5..

hmmm....
T__T i have a headache....... the screen might be a bit too bright...

well anyway, lets start off.....

[What frame rate were you aiming for?]

ummm... i think i was aiming for around ..... 15-20 frames per second...?


[What difficulties did you encounter?]

ummm.... some difficulties i encountered are...:
- in the beginning i couldnt think of what to do....
- once i finished all my frames, and imported it into gimp, gimp always froze when i tried to save it. i think the size of my images were a bit too big == , and i had too many frames... [about 188 or something]
- even if i deleted some of the frames to make it look better and so that the animation size would be smaller, gimp still froze when i tried saving it.
- i had to compress the frames to make it smaller
and yeahh...

ughhhh... this headache is getting worse by the minute......
i'm glad i finished my animation already ~~
hmmm.. all i have to do now... is to upload my animation to here....
i hope everyone enjoys it
[ forces a smile =] ]