frameDuration

Returns the lengthof a frame for this AVItem, in seconds. This is the reciprocal of frameRate. When set, the reciprocal is automatically set as a new frameR

setValueAtTime()

Sets the value of a keyframe at the specified time. Creates a new keyframe for the named property, if one does not currently exist for the specified time, a

audioActiveAtTime()

Returns true if this layer’s audio will be active at the specified time.For this method to return true, audioEnabled must be true, no other layer with audio

setValuesAtTimes()

Sets values for a set of keyframes at specified of times. Creates a new keyframe for the named property, if one does not currently exist for a specified tim