Factors related to the quality of video and audio data Part 2
resolution
This is also an item dedicated to video.
Resolution is a numerical value that represents the density of pixels in an image. We use the unit “dpi (dots per inch)” or “ppi (pixels per inch)”. The “image” in digital is expressed by “a collection of very small colored dots (pixels).” The higher the resolution value, the higher the density of this point and the finer and more natural the image will be.
There is also a concept similar to this, which is the concept of resolution using pixels (dots, pixels). Uses pixels [pixel], dots [dot], or pixels as the unit. It is often written as “1920 x 1080 pixels” or “2 million pixels”, and in the case of this video, there are “1920 horizontal and 1080 vertical color points (pixels), and the total number of points is 2,073,600 ( approximately). It means “2 million pieces)”. (* Pixel = dot = pixel)
For resolutions that use “dpi”, it represents the density of pixels per 1 inch (= 0.0254 meters) of a straight line.
For resolutions that use “pixels”, it represents the total number of pixels used in the video.
The exact definition of resolution is the first. However, the latter is also widely recognized. Be careful not to get confused.
▲ Source: Wikipedia “Resolution”
Screen resolution / ratio
In the field of displays, there is also “screen resolution”. This is represented by pixels. Because it uses pixels, it represents the total number of pixels on the screen. You can also express the “screen aspect ratio (screen aspect ratio)” by multiplying it by something like “1920 x 1080 pixels”. If it is “1920 x 1080 pixels”, the aspect ratio of the screen is “16: 9”.
If the aspect ratio of the image and the aspect ratio of the screen do not match, black bands may appear at the top and bottom or left and right when the image is fully displayed (enlarged display), or the image may be to stretch.
Some screen aspect ratios have special names. The following are pixel counts, screen aspect ratios, and commonly used screen names. (* Since most pixel ratios are square, screen aspect ratio = screen aspect ratio)
Known as Horizontal x Vertical Ratio
(horizontal: vertical) Number of pixels
VGA 640 × 480 4: 3 307,200
SVGA 800 × 600 4: 3 480,000
XGA 1024 × 768 4: 3 786,432
SXGA 1280 × 1024 5: 4 1,310,720
WSXGA + 1680 × 1050 16:10 1,764,000
FHD (Full HD) 1920 × 1080 16: 9 2,073,600
WUXGA 1920 × 1200 16:10 2,304,000
Wikipedia: screen resolution that
By the way, continuing from last time, there is too much basic knowledge and it seems frustrating, but please do your best. Knowing this and not knowing it will make a big difference in your video and audio conversion and playback work. Remember it little by little as it is a necessary knowledge to be able to play and convert optimally while maintaining quality without waste.
