Comp Sci Abstraction level in programming - multimedia

[shivajikobardan]

Homework Statement

Few questions about data as time capsules-abstraction level in programming-multimedia

Relevant Equations

none

source-: http://ce.sharif.ir/courses/84-85/2/ce342/resources/root/BOOK/Multimedia/215814- Chapter 16.pdf
page number 7

Questions-:

1) What is read access?

2) What is presentation rate?

3) In fast forward, some data units are skipped but the valid life span for each frame is not changed.
what does this highlighted line signify?

4) In the slow forward process, presentation of individual frame occurs twice or several times. Does it really? Aren't they different frames when we do 0.5x? Are they really same frames?

 

[pbuk]

When you read the trivial answers below I hope it will lead you to think harder before asking questions.

1) What is read access?

Accessing a frame by reading it.

2) What is presentation rate?

The rate at which frames are presented.

3) In fast forward, some data units are skipped but the valid life span for each frame is not changed.
what does this highlighted line signify?

It means that each frame (that is displayed) is displayed for 40 ms.

4) In the slow forward process, presentation of individual frame occurs twice or several times. Does it really? Aren't they different frames when we do 0.5x? Are they really same frames?

Where would these different frames come from?

The most recent reference I can see in that chapter is 1995: you should learn from something more up to date.

 

[shivajikobardan]

When you read the trivial answers below I hope it will lead you to think harder before asking questions.Accessing a frame by reading it.The rate at which frames are presented.It means that each frame (that is displayed) is displayed for 40 ms.

how can in fast forward valid life span of frame not changed?

Where would these different frames come from?

The most recent reference I can see in that chapter is 1995: you should learn from something more up to date.

 

[pbuk]

how can in fast forward valid life span of frame not changed?

If you are displaying at normal speed at a frame rate of 25 fps then frames are displayed at an interval of, or have a "valid life span*" of 4 ms. If you are displaying at 2x speed at the same frame rate then frames are still displayed at an interval of 4 ms, but only every alternate frame is displayed.

* Note that the term "valid life span" used in the linked document is not commonly used in this context: I have never seen it anywhere else. Edit: oh except in this thread on Reddit which I assume you posted and then withdrew?

 

[pbuk]

Discussing the linked paper is pointless: it is based on VCR and Laser Disc which were analog technologies that are only of historical interest today.