AV video output interface type

Reprinted please indicate the source and the author contact: http://blog.csdn.net/mimepp
Contact information: Yu Tao <yut616 at Sohu dot com>

The video output interface type is a note.

Type

Name	Chinese name	Connector	Description	Features
Composite	AVCompound video	Yellow/white/red	The meaning of the combination is to transmit analog signals of brightness and color signals in the same channel. The yellow line is a video line, White/Red: left/right audio channels.	A video is transmitted online. The brightness and color are mixed. Corresponding TV "AV video 1/2" Three formats are available: pal, NTSC, and SECAM.
S-video	S Terminal	Four-core wire, two grounded wires, two separately transmit brightness and color (Y and C)	Separated video	Only videos can be input and output. The brightness and color are separated for better performance than composite.
Component (YUV)	Chromatic Aberration	Green/blue/red	Green indicates the Brightness Signal, y Blue and red (PB and Pr) are color difference Signals	Color signal C is decomposed into color difference Cr and CB Ypbpr: line-by-line scanning color difference output YCbCr The chromatic aberration interface is a analog interface that allows you to transmit video signals in formats such as 480i/480 P/576 P/720 p/1080i/1080p without transmitting audio signals. The effect is better than S-video. Corresponding TV "Hd/DVD" mode. Y Brightness Signal, which only contains black and white image information R-Y signal (u), is the difference between the red signal and the Brightness Signal B-Y signal (v) is the difference between blue signal and Brightness Signal G is a green signal, which generally accounts for 59% of the color signal, this is not conducive to data compression, and green signal can be obtained through the R-Y, B-Y matrix calculation, so do not use green color. From y/R-Y/B-Y can obtain RGB three primary color signal to imaging.
RGB	Primary colors	RCA or scart (Europe)	Primary color output	RGB signal is better than chromatic aberration Signal The connector is an RCA plug, or scart for Europe to transmit RGB Signals
DVI	Digital Visual Interface	Square port, 24-pin	Digital Visual Interface	Digital signals are transmitted without digital-analog conversion. Therefore, the image quality is very high. DVI interfaces are available in two ways: DVI-Digital (DVI-D) and DVI-integrated (DVI-I ), The DVI-D only supports digital signals, while the DVI-I not only supports digital signals, but also supports analog signals, that is, the DVI-I is more compatible. The DVI-I plug-in has 24 Digital Plug-In + 5 analog plug-in Jack (that is next to the four pinholes and a cross flower ). The DVI-D plug-in has only 24 Digital Plug-In jacks (the four pinholes and a cross flower are not simulated ).
Scart	Consortium of Radio and Television Receiver Manufacturers	Square port, 21 needles	Syndicat des Constructeurs D 'appareils radior é cepteurs et t é l é viseurs Standard video interfaces for France and other European countries	Scart is just a connector that can be set to transmit signals such as composite/S-Video/RGB. Scart is usually used to transmit RGB signals. Because the three primary colors are transmitted separately, the color is superior to that of S-video. Scart currently only has the standard for transmitting the 480i/576i signal.
Spdif	Sony and Philips digital audio interfaces	Coaxial or optical fiber	Sony/Philips digital interconnect format	Used only for digital audio output
HDMI	High Definition Multimedia Interface	19-pin flat trapezoid Joint	High Definition Multimedia Interface	Added copyright protection HDCP It can not only transmit high-definition digital video signals, but also transmit high-quality audio signals at the same time. Provides up to 5 Gbps data transmission bandwidth, which can transmit non-compressed audio signals and high-resolution video signals. Corresponding TV "HDMI" Mode

Terms:
Brightness: luminance, y indicates brightness,
U and V indicate the color information. UV is not short for any text.
YUV: The color TV uses YUV space to solve the compatibility problem between the color TV and the black and white TV with the Brightness Signal y, so that the black and white TV can also receive the color TV signal.
Interline scan: interlaced scanning

The conversion formula between YUV and RGB is as follows (the RGB value ranges from 0 to 255 ):

Y = 0.299r + 0.587G + 0.114b
U =-0.147r-0.289G + 0.436b ---- U = 0.493 (B-Y)
V = 0.615r-0.515g-0.100b ---- V = 0.877 (R-Y)

R = Y + 1.14 V
G = Y-0.39u- 0.58 V
B = Y + 2.03u

YUV sampling (conversion ):
There are multiple sampling methods, commonly used in yuv411 and yuv420 formats. The former is used in NTSC and the latter is used in palss.
Yuv411 extracts the Y component for each pixel, while the UV component samples every four pixels horizontally. That is to say, in four pixels, there are four y, one U, and one v.
Yuv420 does not mean that the V component sampling is 0. Compared with yuv411, it increases the color difference sampling frequency by one time in the horizontal direction, and reduces the color difference sampling by half at the U/V interval in the vertical direction, that is to say, U/V is two samples.

RGB format:
Rgb24: a pixel is represented by 24 bits, and R/G/B is represented by 8 bits. The value range is 0-255, which is true color.
Rgb32: 32 bits represent a pixel, R/G/B are represented by 8 bits, and the remaining 8 bits are used as alpha channels or are not used. The alpha channel is mainly capable of translucent effect. Therefore, rgb24 and rgb32 are consistent.
Rgb565: 16 bits represent a pixel, 5 R, 6g, 5 B, so the r range is 0-31, and the G range is 0-63, the value range of B is 0-31, and the color is not expressive.
Rgb1/rgb4/rgb8: 2, 16, and 256 colors. Each bit is not a real color value, but an index. It is an index of a palette after the bitmapinfoheader data structure. This palette defines a series of colors.