This section explores video as in video monitors and video standards.
See also my blog posts on Videos (usually online videos as opposed to about video). Feel free to modify the URLs as needed.
Important monitor features include:
There are several settings that can be adjusted on the monitor, including the following:
| Bits per Pixel | Colors per Pixel | Comments |
|---|---|---|
| 0 | 2^0 = 1 | Your monitor is off. |
| 1 | 2^1 = 2 | "Monochrome". Sufficient for black and white line art or halftones. |
| 2 | 2^2 = 4 | Sufficient for most grayscale images. |
| 3 | 2^3 = 8 | |
| 4 | 2^4 = 16 | |
| 5 | 2^5 = 32 | |
| 6 | 2^6 = 64 | |
| 7 | 2^7 = 128 | |
| 8 | 2^8 = 256 | Used in VGA. Also sufficient for most grayscale images. |
| 16 | 2^16 = 65,536 | "High Color" |
| 24 | 2^24 = 16,777,216 | "True Color". Actually stored as 32 bpp, but only 8 bits are unused. |
Monitors can be calibrated with stethoscope like devices. These calibrators then adjust either the video card or, better yet, the voltage on the electron guns of the monitors.
Resolution is one of the most important settings but it is usually adjusted through the operating system. Adjusting the resolution sets the grid of pixels shown on the monitor, usually either 640x480, 800x600, 1024x768, or 1600x1200. However to be readable, the grid must be sized to the monitor's screen size or viewable size . A value of 72 or 96 dpi is usually considered comfortable.
The following table shows the screen/viewable size you will need for displaying different resolutions:
| Monitor |
% of Users (ca 1999) (ca 2004) |
Horizontal (4 units) x Vertical (3 units) Diagonal (5 units) Area (HxV) |
|||
|---|---|---|---|---|---|
| pixels |
inches @ 72 dpi |
inches @ 96 dpi |
twips @ 15 twips/px |
||
|
4x3 5 12 |
0.06x0.04 0.07 0.17 |
0.04x0.03 0.05 0.12 |
60x45 75 180 |
||
| VGA |
14 1 |
640x480 800 307,200 |
8.9x6.7 11.1 4,267 |
6.7x5.0 8.3 3200 |
9,600x7,200 12,000 4,608,000 |
| SVGA |
55 35 |
800x600 1,000 480,000 |
11.1x8.3 13.9 6,667 |
8.3x6.3 10.4 5,000 |
12,000x9,000 15,000 7,200,000 |
| XGA |
25 50+10 beyond |
1,024x768 1,280 786,432 |
14.2x10.7 17.8 10,923 |
10.7x8.0 13.3 8,192 |
15,360x11,520 19,200 11,796,480 |
|
1,152x864 1,440 995,328 |
16.0x12.0 20.0 13,824 |
12.0x9.0 15.0 10,368 |
17,280x12,960 21,600 14,929,920 |
||
|
1,200x900 1,500 1,080,000 |
16.7x12.5 20.8 15,000 |
12.5x9.4 15.6 11,250 |
18,000x13,500 22,500 16,200,000 |
||
| SXGA | 3 |
1,280x960 1600 1,228,800 |
17.8x13.3 22.2 17,067 |
13.3x10.0 16.7 12,800 |
19,200x14,400 24,000 18,432,000 |
| SXGA+ |
1,400x1,050 1,750 1,470,000 |
19.4x14.6 24.3 20,417 |
14.6x10.9 18.2 15,313 |
21,000x15,750 26,250 22,050,000 |
|
|
Ultra XGA UGA |
1,600x1,200 2,000 1,920,000 |
22.2x16.7 27.8 26,667 |
16.7x12.5 20.8 20,000 |
24,000x18,000 30,000 28,800,000 |
|
|
1,920x1,440 2,400 2,764,800 |
26.7x20.0 33.3 38,400 |
20.0x15.0 25.0 28,800 |
28,800x21,600 36,000 41,472,000 |
||
| Unknown |
3 4 |
||||
This drawing is 1200x900 pixels and it has a number of other smaller sizes on it too. Each square in the grid is 20x20 pixels.
A video card (aka video adapter or graphics processor) is a controller card that controls communication between the CPU and the monitor. If you play computer games or do anything graphic intensive, then a good video card is very important. See also http://www.gamespot.com/gshw a guide for gaming hardware.
Video card are designed to be programmatically accessed via at least one API (Application Programming Interfaces). An API is a set of objects, libraries, routines, sub-routines, protocols, and tools that programmers will use in their applications. There are three major video card APIs.
A video card fits into an expansion slot. Here are the slots used in chronological order and ordered by increasing power.
It often utilizes its own RAM, i.e. RAM independent of the RAM used by the computer for processing. The type of RAM on a video card is typically DRAM, SGRAM, VRAM, WRAM, or RDRAM.
Images from the computer are represented as bit maps in a portion of video memory called the frame buffer. The more resolution, color depth, or more frames per second desired, then the greater the need for a video card with increasingly more memory.
As of 2003, the usual minimum is 16 MB, with an upper limit of 64 MB.
Video Standards define the allowable resolution and colors for a computer/monitor. The monitor must be able to receive the standard and the video card on the computer must be able to transmit the standard. Some of these were actual standards via VESA (Video Electronics Standards Association), but some of them are de facto standards.
| Standard | H x W, D | Color Depth |
Aspect Ratio |
|---|---|---|---|
|
MDA (Monochrome Display Adapter) ca 1970s |
80 characters x 25 lines | 2^1 = 2 | NA |
|
HGC (Hercules Graphics Card) ca 1980s |
80 characters x 25 lines 720 x 350 (348), ~ 800 |
2^1 = 2 2^1 = 2 |
NA 2.06 |
|
CGA (Color Graphics Adapter) ca 1981 |
40 characters x 25 lines 80 characters x 25 lines 160 x 200, ~356 320 x 200, ~ 377 640 x 200, ~ 670 |
2^4 = 16 2^4 = 16 2^4 = 16 4 out of 2^4 = 16 2^1 = 2 |
NA 0.80 1.60 3.20 |
|
EGA (Enhanced Graphics Adapter) ca 1984 |
320 x 200, ~ 377 640 x 200, ~ 670 640 x 350, ~ 729 |
16 out of 2^6 = 64 16 out of 2^6 = 64 16 out of 2^6 = 64 |
1.60 3.20 1.83 |
|
PGC, PGA (Professional Grapics Controller/Adapter/Arra6) ca 1984 |
640 x 480, 800 | 2^8 = 256 | 1.33 |
|
VGA (Video Graphics Array) Aka IBM 8514. ca 1985 |
320 x 200, ~ 377 320 x 200, ~ 377 640 x 350, ~729 640 x 480, 800 |
2^8 = 256 2^4 = 16 2^4 = 16 2^4 = 16 |
1.60 1.83 1.33 |
|
QVGA (Quarter VGA). Often shown as portrait, esp. for mobile phones. |
320 x 240, 400 | 1.33 | |
| 1/8 VGA | 240 x 160, ~288 | 1.50 | |
|
QQVGA (Quarter QVGA). |
160 x 120, 200 | 1.33 | |
|
SVGA (Super VGA) - ca 1989. VESA insted of IBM like the preceding. Any color depth became possible after SVGA |
800 x 600, 1000 1024 x 768, 1280 1280 x 1024, ~1639 |
2^4 = 16 2^8 = 256 2^16 = 65,536 |
1.33 1.33 1.33 1.25 |
|
XGA or XVGA (eXtended Graphics Array) ca 1990 |
640 x 480, 800 800 x 600, 1000 1024 x 768, 1280 |
2^16 = 65,536 2^16 = 65,536 2^8 = 256 |
1.33 1.33 1.33 |
| XGA-2 | 1024 x 768, 1280 | 2^16 = 65,536 | 1.33 |
|
SXGA (Super XGA) |
1280 x 960, 1600 1280 x 1024, ~1639 |
2^24 = 16,777,216 2^24 = 16,777,216 |
1.33 1.25 |
| SXGA+ | 1400 x 1050, 1750 | 2^24 = 16,777,216 | 1.33 |
|
UGA or UXGA (Ultra Graphics Array or Ultra XGA) ca 1992 |
1600 x 1200, 2000 | 2^24 = 16,777,216 | 1.33 |
|
WSXGA (Wide SXGA) |
1440 x 900, ~1698 1680 x 1440, ~2212 |
1.60 |
IBM is working on Roentgen LCD displays (aka AMLCD or Active Matrix Liquid Crystal Display) that can display paper sharp quality.
TeleVision. A mechanical version of the TV was invented by German Paul Gottlieb Nipkow in 1884. In the 1920s the MTV was further developed by John Logie Baird for Britain and Charles Francis Jenkins for the US. German Karl Braun invented the CRT (Cathode Ray Tube), i.e. the electronic TV in 1897. The CRT was further developed by Russian Dr. Vladimir Kosma Zworykin in 1929. Philo T. Farnsworth was the first to transmit TV signals in 1927.
Here are the various monitor technologies:
Video signals are either composite or component.
These standards are generally incompatible with the RGB video signals used by computer monitors.
The HDTV (High Definition TeleVision) should merge the worlds of television and computers. HDTV uses digital instead of analog data. The HDTV screen is wider than regular TV, i.e. it has an aspect ratio of 16 wide by 9 high instead of 4 wide by 3 high. HDTV has a high resolution:
Depending on screen size this can look like 35 mm film. The data can also be compressed for transmission and decompressed for viewing. This should help merge the television with the computer. Currently computer displays use RGB standards which are incompatible with the standards for TV. The FCC plans to have HDTV phase in by 2006.
The aspect ratio of HDTV is also known as wide screen or letter box. This makes sense in a theater because it is much easier to increase the number of seats horizontally than vertically. Theaters are also the place to see wide broad landscapes. Thus movies should be wide screen.
What is my personal preference? I like the 4x3 aspect ratio simply because the math is cleaner.
4x3 | 3/4 = 0.75 | 4/3 = 1.333... | diagonal = 516x9 | 9/16 = 0.5625 | 16/9 = 1.777... | diagonal = 18.35755975...The film format refers to the capture size of the original film. Common film formats include:
Video is encoded into digital format via a codec program. Encoding also frequently also compressed as either lossy or lossless. A codec produces the essence (digital video and audio itself) plus some metadata (synching, titles & subtitles, length of file, etc.). The codec file is encapsulated/stored/wrapped in a video file format. Some file formats store only one kind of codec while others take more. Some "super" file formats (ASF, Ogg, and Quicktime) store a wide variety of video or audio codecs.
Some video codecs:
Some video file formats
.asf. Advanced Systems Format or Advanced Streaming Format. Stores a wide variety of audio or video codecs..wmv. Windows Media Video. Lossy or lossless. A WMV file is almost always additionally enclosed in an ASF, and thus it can have a .asf extension, but only WMV files lacking metadata can have a .wmv extension.Links that lead to off-site pages about video.
Page Modified: (Hand noted: 2008-03-29 16:10:18Z) (Auto noted: 2008-03-29 15:46:57Z)