Overview: Frame timing and interlacing

Frame timing and interlacing determine how picture samples become motion on a playback timeline.

Motion depends on when a picture is shown and which instant it represents. Frame rate, field structure and cadence describe the source; frame-rate conversion and interpolation describe changes made for presentation. Keeping those layers distinct helps explain uneven motion even when every picture is decoded successfully.

• Frame rates
  Frame-rate descriptions express the frequency and regularity of pictures along a video's timeline.

• Interlacing and cadence
  Interlacing and cadence describe how fields or repeated pictures carry motion from capture to presentation.

• Frame-rate conversion
  Frame-rate conversion changes the number or timing of pictures presented each second.

• Motion interpolation
  Motion interpolation estimates new pictures between existing video frames to create a smoother presentation.