Bitrate
The quantity of data used per second of video, which largely determines its quality within a given codec.
Formula / rule
File size = bitrate × duration
Measured in
Mbps
In depth
Higher bitrates preserve more detail, particularly in complex motion where compression struggles — foliage, water, rain. Variable bitrate allocates data where it is needed and constant bitrate does not, which matters for predictable file sizes. Comparing bitrates across different codecs is meaningless, since efficiency differs enormously.
Examples in practice
Footage of falling snow holds together at 400 Mbps and breaks into blocks at 50 Mbps.