Personal tools

Frame

From DigiWiki

(Difference between revisions)
Jump to: navigation, search
 
(14 intermediate revisions not shown)
Line 1: Line 1:
Videos are made out of frames. In simple terms, each frame is a picture  
Videos are made out of frames. In simple terms, each frame is a picture  
-
Framerate is a property of video that indicates how many frames the video displays per second. It is denoted in FPS (frames per second). Common video framerates are 23.976 (NTSC/Film), 25 (PAL) and 29.97 (NTSC).
+
Framerate is a property of video that indicates how many frames the video displays per second. It is denoted in FPS (frames per second). Common video framerates are 23.976/24 (NTSC/Film), 25 ([[PAL]]) and 29.97 ([[NTSC]]).
Line 13: Line 13:
* B picture (bi-predictive) - references past and future frames. Compression rate of about 50:1
* B picture (bi-predictive) - references past and future frames. Compression rate of about 50:1
 +
 +
 +
==See Also==
 +
 +
* [[Telecine]]
[[Category:Glossary]]
[[Category:Glossary]]

Current revision as of 07:11, 1 August 2007

Videos are made out of frames. In simple terms, each frame is a picture

Framerate is a property of video that indicates how many frames the video displays per second. It is denoted in FPS (frames per second). Common video framerates are 23.976/24 (NTSC/Film), 25 (PAL) and 29.97 (NTSC).


Types of Frames:

There are several different types of video frames when video compression is used.

  • I picture (key frames) - frames that do not reference other frames, and so they contain all the information needed to render the current frame. Usually occur at scene changes. Compression rate of about 7:1
  • P picture (predictive) - references earlier I and P frames, storing differences data. Compression rate of about 20:1
  • B picture (bi-predictive) - references past and future frames. Compression rate of about 50:1


See Also