In bilibili watch some videos, the video found its definition There are many election law. Such as 720p, 1080p, 2k, 4k, and I often encountered when watching live Blu-ray, ultra-clear. What do they mean, respectively? To understand this problem, but also for future viewing experience ha ha ha ha (better choices sources Well), find information are summarized as follows:
P What does it mean?
First, 720p, 1080p in the P, I do not want to take it for granted regarded pixels (pixels) mean, P means progressive scan means (progressive). Is a 1080p achieve a resolution of 1920 × 1080 in the progressive scan display format.
The method defines a video has only a few K: number of horizontal pixels has several 1024, there is defined a method for video P is only a few: the number of longitudinal rows of pixels. In the case where a resolution of 2048 × 1080, and 2048 represents the number of pixels in the horizontal direction, 1080 represents the number of pixels in the vertical direction; Similarly, when the resolution is 4096 × 2160, 4096 represents the number of pixels in the horizontal direction, 2160 represents a vertical the number of pixels directions. In the actual digital mastering and digital projection, the need to be adjusted according to the different aspect ratios of the number of pixels of the frame image in the horizontal direction or vertical direction. So close to the 4K image resolution of 8,847,360 pixels number can also be called 4K, such as the common market of 3840 * 2160 also called 4K resolution. 4K resolution is just the standard 2K resolution of 2048 × 1080 pixels four times the number of points, it is 16 times the number of 1K resolution of 1024 × 540 pixels.
Often said standard 720p i.e. 1280 × 720, i.e., the standard 1080p 1920 × 1080.
Why do we sometimes see the video will shrink very clear, very vague enlarge to see it?
The key is to figure out "clarity" and "resolution" of the concept.
We often say how much multiply the number of video, strictly speaking not a resolution, but height / width of the pixel values of the video. Resolution is a measure of the amount of image data a parameter number, usually expressed as PPI (pixel per inch Pixel per inch)
Such that it refers to the video 320X180 pixels in the effective horizontal and vertical, higher ppi value hour window, look clear; the window is enlarged, not so much because the effective pixel fill the window, the effective pixel ppi value decreased to blur. (When the distance between the effective pixel enlarged widening, while the graphics will fill these voids, i.e. pixel interpolation, interpolation is used in accordance with the vertical and horizontal effective pixel "guess" out "dummy pixels", there is no original video information)
Traditionally we say that the resolution refers to the height / width of the pixel values of the image, the resolution in the strict sense refers to the effective ppi pixel values per unit length. The difference here. Height / width value of the image pixel dimensions and does nothing but effective pixel value ppi and size per unit length in relation to, the smaller the size of the larger apparent ppi.
BD when downloading movies, HD respectively, what does it mean?
HD is just a popular name for, HD namely HD High Definition, BD Blu-ray disc that is BlueRay Disk. We see movies or resources generally claim to be BD1280 BD1024
1, in different formats. bd1024 refers 1024X768, it is 4: 3 format. bd1280 refers 1280X720, 16: 9 format.
2, different resolutions. bd1280 higher resolution, the higher the number the greater the resolution.
3, different definition. bd1280 clearer, the larger the number the more clear.
Clarity comparison is 1080P> 720P> BD1280
The first two are all based on the original Blu-ray disc BD conversion of repression, is part of the true high-definition MKV format (really BD), although the name is the last BlueRay Disk (BD) 1280, but it belongs to the false definition (false BD), is generally RMVB format, using the high-pressure mode converted, so a smaller volume.