What is HD video and what does 1080p, 720p mean?
High definition (abbreviated HD) is translated from English as “high definition”, “high definition”. The HD direction is divided into two branches: HDTV (transmission by satellite, terrestrial terrestrial and terrestrial cable) and HDV, high definition video (reproduction of content of physical media such as Blu-ray or HD DVD).
As you know, the DVD format with its resolution 720×576 (PAL) or 720×480 (NTSC) is adopted for standard definition (SD – Standard Definition). HD refers to video with a resolution of at least 1280×720 pixels.
What does 720p, 1080p, 1080i mean?
This input stands for high definition video and indicates how many vertical pixels the frame of this video has. So 720p is high definition video with 720 vertical pixels (1280×720 image resolution). 1080p video is Full HD video, also known as high definition video, with 1080 vertical pixels and an image resolution of 1920 x 1080. The letters after the numbers indicate the recording format of the video frame. p – progressive format, i – interlaced.
Why do they write 720p / 1080p in the title, but in fact offer video materials in incomprehensible resolutions?
There are 720p (1280×720) and 1080p (1920×1080) high definition resolution standards, which are designed for the 16: 9 aspect ratio common to modern digital video equipment. This aspect ratio is due to the fact that it is more efficient to fit the picture of the most common TV / video / movie formats. When digitizing the signal according to the 720p / 1080p high definition video standards, black stripes are pasted to the image, if necessary, from above / below to record on high definition optical media / broadcast on satellite television channels of High Definition.
When re-compressing a video, saving these black multiplicity bars is usually useless, so they are usually cut off and only the usable area of the signal image remains: 1280×544, 1280×536, 1280×688, 1920×800, 1920×860, etc. All of these resolutions are 720p / 1080p in the original aspect ratios conceived by the filmmakers who created the footage.
