# Video

Exploring video, as in monitors, video standards, video cards, etc.

TAGS: Computers, Design, Free Gratis, Free Libre, Open Source, Software, Standards, TECH, TV, Videos

See also my blog posts on Videos (usually online videos as opposed to about video). Feel free to modify the URLs as needed.

## Monitors

Important monitor features include:

• screen size (inches). A monitor is usually measured along the diagonal.
• viewable size (inches). Usually somewhat smaller than the screen size.
• resolution (pixels horizontal x vertical). The grid of pixels (dots) composing the image.
• dot pitch (millimeters). The size of the holes through which the photons come through. The usual range is from 0.21 to 0.28 mm, with the smaller dot pitch increasing pixel density.
• pixel density (pixels per inch or cm). The pixels along a physical length. Pixel density increases with resolution and decreases with screen size. If we assume square pixels and that the screen size and viewable size are the same, then using the Pythagorean theorem the formula for pixel density is:
PixelDensity = (DiagonalPixels / DiagonalLength) PixelDensity = sqrt(WidthPixels^2 + HeightPixels^2) / DiagonalLength
• refresh rate (Hz). How many times a second that the image on the display is refreshed. Some people can detect an annoying flicker if the refresh rate isn't high enough. This ranges from 60 to 90 Hz.
• aspect ratio. For an image, picture, video, etc., the ratio of the longer side (usually the horizontal side in videos) to the shorter side. This is frequently expressed as "longer:shorter" or the result of the division of longer by shorter. EG: The analog TV is Width:Height = W:H = 4:3 = 1.333...:1, or W/H = 4/3 = 1.333... (but often denoted as 1.33). See also my spreadsheet on Display Resolution [https://docs.google.com/spreadsheet/ccc?key=0Anl6QqLgOdR9dGp0ZkpFdHdmWHdkVDR4WFRCUThRZlE&usp=sharing].

There are several settings that can be adjusted on the monitor, including the following:

• contrast (aka gamma)
• color temperature (Kelvins). Specifies the color of white.
• brightness (aka white luminance) (candelas/m^2 or footlamberts). Specifies the brightness of white.
• black level. Specifies the dimness of black.
• color depth (bits per pixel or colors per pixel). Specifies how many colors in an image or screen.
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.

## Video Cards

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.

### APIs for Video Card

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.

• Direct3D. Aka D3D. D3D is actually part of Microsoft's DirectX API suite for sound and controls as well as graphics. D3D is generalized and works with most games and video cards.
• Glide. The Glide API by 3dfx and their line of Voodoo video cards. Some games such as Unreal Tournament are optimized for Glide. Please note that Nvidia has since acquired 3dfx.
• OpenGL. This API is particularly suited for FPS (First Person Shooter) games such as Quake III, Baldur's Gate, and Half-Life. The OpenGL drivers work particularly well for the GeoForce video cards by Nvidia.

### The Physical Video Card

A video card fits into an expansion slot. Here are the slots used in chronological order and ordered by increasing power.

• 16 bit ISA (Industry Standard Architecture, aka AT Bus).
• 32 bit EISA (Enhanced ISA).
• 32/64 bit PCI (Peripheral Component Interface).
• 32 bit AGP (Accelerated Graphics Port).

### Video RAM

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

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
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
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
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
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.

• QXGA (Quad XGA) with a resolution of 2048 x 1536 (2560 diagonal), 1.33, 123 dpi, 20.8 inch diagonal, and a cost of roughly $6,000 (as of 2003-01). • 2560 x 2048 (~3278 diagonal), 1.25, 200 dpi, 16.3 inch diagonal. • QUXGA has a resolution of 3200 x 2400 (4000 diagonal), 1.33,$20,000.
• The display code named "Bertha" has a resolution of 3840 x 2400 (~4528 diagonal), 1.60,, 204 dpi.
• Monochrome versions can reach 375 dpi.

## Television Standards

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:

• CRT (Cathode Ray Tubes) screens are the most common which fires electrons through a vacuum tube so the electrons can hit and light up phosphors on the inside of the screen. The electrons are lead by electro magnets so they scan a frame line by line.
• LCD (Liquid Crystal Display) screens are back lit with highly efficient LED (Light Emitting Diodes) and the luminance of each pixel is controlled by blocking the back light.
• Active matrix LCD screens have a TFT (Thin Film Transistor) screen where transistors at each pixel control the luminance of the pixel.
• Passive matrix LCD screens have a screen where conductors at each pixel control the luminance of the pixel.
• Gas plasma screens use ionized plasma to generate light at each pixel. The whole image can be flashed at the same time instead of line scanned.

Video signals are either composite or component.

• Composite is the older format, it composites the complete visual waveform including the chromatic (color or C information), the luminance (brightness or Y information), and control signals. Most composite video standards that use RCA/Phono plugs. Here are the major composite TV signal formats:
• NTSC. National Television Systems Committee, the default in the North America, Japan, and north and west parts of South America. NTSC has interlaced frames of 720 pixels per line, 525 lines per frame (640x480 usable), and a refresh frequency of 60 Hz (effectively 30 frames per second).
• PAL. Phase Alternate Line, the default in Europe, half of Africa, the Mid-East, the south and west parts of South America, Asia, and Oceania. PAL has interlaced frames of 625 lines per frame and a power frequency of 50 Hz (effectively 25 frames per second)
• SECAM, Sequential Couleur Avec Memoire (Sequential Color with Memory), the default for France, half of Africa, Madagascar, Russia and its like. SECAMs basic tech specs have become just like PAL.
• Component, the newer component format, transmits the chromatic, color, and control portions separately, resulting in less loss of picture quality. Hi8 and S-VHS are component video systems that use S-Video or Y-C plugs.

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:

• 1920 pixels per line, 1080 lines used out of 1125 lines per screen. This is 1080i (interlaced), that is actually either 1080i60 (NTSC areas) or 1080i50 (PAL areas).
• 1280 pixels per line, 720 lines per screen. This is 720p (progressive), that is either 720p60 (NTSC areas) or 720p50 (PAL areas).

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.

• If the majority of your TV watching is for movies, then you should have a letter box monitor. You will only have black bands on the left and right sides when you watch non-letter box shows.
• If the majority of your TV watching is regular TV, then wide screen should not be your default monitor: go for the regular 4x3 monitor. You will only have black bands on the top and bottom when you watch letter box shows.

What is my personal preference? I like the 4x3 aspect ratio simply because the math is cleaner. Compare:

 4x3  | 3/4  = 0.75   |  4/3 = 1.333... | diagonal = 5
16x9  | 9/16 = 0.5625 | 16/9 = 1.777... | diagonal = 18.35755975...


## Film Format

The film format refers to the capture size of the original film. Common film formats include:

• 8mm
• Hi8
• VHS
• VHS-c
• S-VHS
• S-VHS-c
• Mini DV
• Digital8
• Super8
• Pixelvision
• Kidcam

## Digital Video

Digital videos consists of content (video, audio, subtitles, and other metadata), wrapped in a container. The content is often encoded/decoded as well as compressed/decompressed via a codec. For a matrix of content and containers, see Comparison of container format [W].

Some containers: 3GP, 3G2, Advanced Systems Format (asf, asx, wm, wma, wmv), Audio Video Interleave (avi), DivX, EVO, Flash Video (f4v, flv), Matroska (mkf, mk3d, mka, mks, free!), MCF, MP4, MPEG (mpg), Material Exchange Format (MXF), Ogg (by xiph.org), Quicktime (mov, qt), RMVB, VOB+IFO, WebM.

Some video content: MPEG-1, MPEG-2, MPEG-4 (A)SP, H.264/MPEG-4 Part 10/Advanced Video Coding (AVC)/Blu-ray, VC-1/WMV, RealVideo (rv, rm), Theora, VP8, MVC.

Some audio content: aif (aiff), MP1, MP2, MP3, WMA, RealAudio (ra), Vorbis, MIDI (mid, rmi), MPEG Audio (mpga), Musepack, AAC (m4a), AC-3, DTS, PCM, APE, FLAC, ALAC, WavPack, MLP/Dolby TrueHD, DTS-HD, CD Audio (cda), wav.

Some video codecs:

• Lossless: FFv1, Huffyuv, Lagarith, YULS, x264.
• MPEG-4 Part 2: DivX, Xvid (free!), FFmpeg MPEG-4, 3ivx.
• H.264/MPEG-4 Part 10/Advanced Video Coding (AVC)/Blu-ray: x264, Nero Digital, QuickTime H.264, DivX.
• Microsoft: WMV, MS MPEG_4v3.
• On2: VP6, VP7, VP8, libthora.
• Other: DNxHD, Sorensen 3, Sorensen Spark, RealVideo, Cinepak, Indeo.

Some other metadata: MP3 Audio Playlist (m3u), RealText (rt), RealPix (rp).

Some conversion/transcoding tools: HandBrake, Freemake Video Converter, SUPER, Format Factory

Some media players: Windows Media Player (Windows), QuickTime (Macs), VLC (cross platform, transcodes!, free!).

FYI: The ITU-T handles the H.264 standard. The ISO/IEC handles the MPEG-4 Part 10 standard. Both are synced for the Advanced Video Coding (AVC) standard that is famously used in Blu-ray discs, Vimeo, YouTube, Flash, Silverlight, iTunes, and HDTV.

## Miscellany

• WinAmp, iTunes, Yahoo Music Engine, foobar2000, Windows Media Player, Musicmatch, Quintessential, J. River, jetAudio, XMPlay, MediaMonkey, Media Player Classic, Sonique, wxMusik, Real Player, XMMS, Noatun, Juk, Amarok, Music Player Daemon, Rhythmbox and many other players.