INTRO TO MULTIMEDIA. MAT 103

Alejandra Jarabo
Multimedia Arts & Technologies Division. Santa Barbara City College
Digital video general topics

 

 

  
Computer formats. Digital video.

Standard Definition video (SD).

The pixel resolution of full screen DIGITAL VIDEO is 640 X 480 pixels.

It has a 4:3 aspect ratio, and its pixels are square.
(this is the default, computer pixels are by default square)

Half screen is 320 X 240 pixels (used on web-video).

 Notice that 640 X 480
is also the screen resolution of a 13" monitor
 
 

DV is the most popular tape format for Digital Video (DV and mini DV tapes).
This format has a slightly bigger pixel resolution of 720 X 480 pixels or 720 X 486 pixels.

DV is both a tape and a Codec for digital video.
A computer video file has to be compressed, since one frame after the other at 30 frames a second will make enormous files.
Computer video files are compressed using a video codec.

Besides DV, there are other known codecs like, MPEG 2 (the video format for DVD's) or MPEG 4/Sorenson/ H.264 (good codecs to compress video for the web, since they produce small file sizes).

All of the codecs above have their qualities and drawbacks.
The tradeoff between compression power, speed, and fidelity (including artifacts) is usually considered the most important figure of technical merit.

 

 A codec is a device or computer program capable of encoding and/or decoding a digital data stream or signal. The word codec is a portmanteau (word used to mean a blend of two or more words) of 'compressor-decompressor' or, most accurately,
'coder-decoder'.
   
DV screen size

Youtube uses
480 X 360
as a standard resolution for
web-video
   
 

High Definition video

HD is a general term for video that has a higher resolution than 720X486.

There are 2 main HD formats:

1280 X 720 pixels (known as 720p)
1920 X 1080 pixels (known as 1080p)

Both sizes have a 16:9 aspect ratio, commonly referred to as wide screen.

 Outside the computer, you need a monitor or television capable of displaying HDTV signals in order to
view the full resolution of HD video.
 
  Video Platforms  
     
 

Quicktime is a digital technology and file format, developed by Apple Computer Co.
It allows for the production of video and multimedia, viewable with the Quicktime player.

Quicktime supports a large number of codecs for video (it is NOT a codec itself, it is a multimedia platform)
     
  Windows Media Video (WMV) is a compressed video file format for several proprietary codecs developed by Microsoft.
The original codec, known as WMV, was originally designed for Internet streaming applications, as a competitor to RealVideo.