Adobe 12040118 - After Effects Standard Tutorial page 236

Time-remapping distorts time for a range of frames within a layer.
When you apply time-remapping to a layer containing audio and video, the audio and video remain synchronized. You can remap audio files to
gradually decrease or increase the pitch, play audio backward, or create a warbled or scratchy sound. Still-image layers cannot be time-remapped.
You can remap time in either the Layer panel or the Graph Editor. Remapping video in one panel displays the results in both. Each provides a
different view of the layer duration:
The Layer panel provides a visual reference of the frames you change, as well as the frame number. The panel displays the current-time
indicator and a remap-time marker, which you move to select the frame you want to play at the current time.
Layer panel for time remapping
A. Current-time indicator B. Time-remap value C. Remap-time marker D. Navigator bar
The Graph Editor provides a view of the changes you specify over time by marking your changes with keyframes and a graph like the one
displayed for other layer properties.
Time-remapping graph
A. No change B. Fast motion C. Freeze frame D. Backward motion
When remapping time in the Graph Editor, use the values represented in the Time Remap graph to determine and control which frame of the
movie plays at which point in time. Each Time Remap keyframe has a time value associated with it that corresponds to a specific frame in the
layer; this value is represented vertically on the Time Remap value graph. When you enable time remapping for a layer, After Effects adds a Time
Remap keyframe at the start and end points of the layer. These initial Time Remap keyframes have vertical time values equal to their horizontal
position on the timeline.