A question about video's FPS (am i right?)

[MRAR]

hi

Assumed that i have a 800mb video file(avi,mkv,...) with 25 FPS(Frame Per Second) and 90 minutes duration

i want to know 1 second contains how many size and to do that:

• 90m X 60 = 5400s
  800mb X 1024 = 819,200 kb
  So: 819,200 / 5400 = 151.703Kb

it means 1 second require about 152 kb .

First Thing is ,Is my calculations correct? And Second is:

if it is correct could somebody explain to me:

how 1second contains 25[fps] when every frame size is only about 6kb(152/25=6.08)?

i think i am wrong and i know some of video formats has their own Compression methods but is there any image with 6kb size with almost 720p quality exist?

Thanks in Advanced.

[Jean-Baptiste Kempf]

This is mostly right.

A decent 720p stream is 6Mbps, or 240kbits per image, or 30kBytes per image.

Sacrificing the quality to reach 6kB is not that hard.