### The Timeline

The timeline allows you to control what frame in a sequence or movie is displayed.
It can be toggled on and off by using the F3 hotkey.
The slider allows you to easily jump around the video sequence being displayed. When in EDL mode (see EDL), the timeline will also display each movie sequence as a video segment. The current video segment will be highlited.
When displaying sequences, the cache for the sequence is displayed as a green bar below the timeline.

#### Timecode / Frame Display

The button refers to the current frame being displayed. Clicking on it will toggle between displaying the timeline and frame information as either frames, time or timecode.

#### Playback Controls

The playback controls function very similarly to those in your VCR or Stereo. They allow you to, from left to right: go to the beginning of the movie, play the movie backwards, go back a single frame, pause the playback, go forwards one frame, play the movie forwards and go to the end of the movie.
Unlike your VCR, there is no fast-forward or rewinding controls. That functionality can be obtained by changing the frame rate and then playing the movie.
If you play a sequence of images, playback will not be smooth at first. mrViewer will first try to cache all the images in memory before playback. The images cached are displayed with a green line below the sequence frames. If you run out of memory or you start swapping, you might not be able to play back the sequence smoothly.
Smooth reverse playback of movie files is largely dependant on the codec used in the movie file and movies without audio or with audio turned off work much better.
In addition to the play controls, mrViewer supports scrubbing (or moving quickly from one frame to the next in any direction). This is now a mode like selection. The default mode is scrubbing. With the
LMB
and dragging left/right you can now scrub.
In addition to that, you can move quickly between annotations (text or the arrow, circle, rectangle and freehand drawings) with
SHIFT + Left/Right Arrow
keys by default.

#### Playback Speed (FPS)

The FPS (Frames per Second) control allows you to adjust the speed of playback. This allows you to play the sequence in slow motion or at several times its normal speed.

#### Audio Control (Volume)

The audio control can be used to switch between different audio tracks by clicking on the A button. In addition, the audio volume can be controlled with the slider next to it (or with SHIFT + MouseWheel).

#### Timeline Limits

Finally, the S and E inputs allow you to change the start and end of the timeline. This has no effect on changing the actual length of the movie or image sequence, and is only provided for playback looping and display purposes.