Bit Depth

Bit depth is maximal number of value digital signal measurement.

Distinguish  audio and video bit depth.

 
Bit-depth audio

Sound (oscillations of air) at each instant has different values.

Intensity of air pressure to ear changed in time.

The stronger the pressure changes, the louder the sound.

We have analog (uninterrupted) signal (air pressure).

Converting analog signal to digital format
Measurements of the value (of the air pressure power) at the each instant stored into memory.
By time the instants are spaced equally.

Bit depth audio is maximal value of the measurement (pressure).

Bit depth may be integer or floating point number.

Integer bit depth consists some number bits (8, 12, 16, 20 ,24, 32, 64).
More number of bits less level (loudness) of noise (more precision of the measurements).

Floating point bit depth has range 0.0 ... 1.0
1.0 is highest level of air pressure.



For different purposes used various bit depths:

Speech, lo-fi music - 8 bit

Hi-Fi, Hi-End CD, DVD-video, downloaded audio - 16 bit

Hi-Fi, Hi-End DVD-audio and video, Blue-Ray, downloaded audio - 24 bit

Studio recording and mixing (music production) - 24 or 32 bit and 32 or 64 bit float

For high precision applications - 64 bit integer or floating point

Bit-depth video

Each pixel (point of monitor or TV screen) has 3 colours.

Each colour has level of brightness 0 to <bit-depth>.