What are Frame Rates & FPS?
Frame rate is the frequency at which video frames are captured, encoded, or displayed, usually measured in frames per second. Capture, stream, and display rates need not be identical.
How Frame Rates & FPS work
Frame rate describes temporal sampling, while container timestamps determine when individual pictures are actually presented. Constant-frame-rate media uses a regular cadence; variable-frame-rate media permits unequal intervals even if tools report an average FPS. Display refresh rate and camera shutter duration are related production concerns but are not the same quantity. Frame-rate decisions span capture, editing timelines, encoder time bases, streaming constraints, and final display behavior.
Key facts
- 1Many production rates are rational values rather than exact whole decimals. Rounding a time base or treating a fractional rate as an integer can accumulate synchronization drift.
- 2Container or stream timestamps are authoritative for presentation order and spacing. Dividing a frame count by a reported average rate can misstate variable-rate duration.
- 3Raising FPS increases temporal samples but does not automatically reduce motion blur, which is governed by exposure time. It also does not guarantee that a display shows every frame.
When Frame Rates & FPS matter
Developers choose FPS by weighing motion smoothness, latency, bitrate, compatibility, and production requirements. Converting between mismatched rates can cause judder, duplicate frames, or interpolation artifacts.