I am trying to predict video file size given:
- camera fps.
- number of horizontal pixels.
- number of vertical pixels.
- bit depth.
- time duration of the video.
using the following formula
file_size = horizontal_px * vertical_px * bit_depth * fps * duration_s
For a specific video in my phone (mp4 format) a video of 13s occupies 23.72Mb of memory. However considering the characteristic value of each of the given parameters and the formula provided, that should be 2313Mb instead, almost a two orders of magnitude difference.
- camera fps: 30 fps.
- number of horizontal pixels: 1920.
- number of vertical pixels: 1080.
- bit depth (unspecified, assume it to be 24 bits).
- time duration: 13s.
I imagine that part of it may amount to the compression algorithms to reduce raw video size, but I wouldn't expect it to be able to reduce ~99% of the original size. What am I missing?