Our website comprises more and more videos. To smoothly play them back it is helpful to know some video basics.
Streaming speed is given in Mbps. Mega-Bit per second.
A bit is a yes/no information. For a lamp to turn on or off with a switch one uses 1 bit. Don't confuse b=bit with B= bytes. Bit is the smallest unit of data storage. 8 bits equal a byte -> 8b = 1B
Storage of data is expressed in bytes B. E.g. 1KB. 1MB, 1GB, 1TB. For transporting data over the Internet one typically uses 'bit per second' bps, for example: 10kbps, 5Mbps (b is lower case!).
Since a video consists of 15-30 frames per second, a lot of continuous information has to be received. Depending on the size of the image window, 0.5 to 8 Mbps may be used to produce a good quality picture. (1Mbps = 1,000,000 bits per second). For the size of the image window one uses a number and the letter P.
The number represents the amount of pixels of the vertical side of the image window. A pixel is the smallest unit of an image. You could also use the word picture-dot. The P means progressive. Each picture frame is completely built. Then the next ... etc. In contrast, there are i=interlaced.
TV images (NTSC) have have 60 half-fields (interlaced) instead of 30 frames (progressive). This goes back to the television date of origin. Then, the 50 half-fields caused less screen flickering than 25 full images.
Computer screens - as opposed to TV screens - are working by using the progressive method (P).
Name | image size | Total pixels per frame | -> Streaming minimum / optimum
240P 426x 240 = 0102 Total Millions of Pixels -> 0.3Mbps / 0.5Mbps
360P 640x 360 = 0230 Total Millions of Pixels -> 0.6Mbps / 1.2Mbps
480P 854x 480 = 0410 Total Millions of Pixels -> 1.0Mbps / 1.8Mbps
720P 1280x 720 = 0922 Total Millions of Pixels -> 2.5Mbps / 5.0Mbps
1080P 1920x1080 = 2073 Total Millions of Pixels -> 4.0Mbps / 8.0Mbps