Mewa Film User's Guide/Using the Timeline
What is the Timeline 
While the node graph allows you to arrange and adjust the nodes that comprise your composite, the timeline window provides a visual representation of the timing for each frame of a footage node. The timeline lets the user position footage nodes in time as do some holding and trimming adjustments to footage nodes. The figure below illustrates the correspondence of the footage nodes with the timeline.
This chapter covers how to navigate the timeline window, and how to make adjustments to the timing parameters of each footage node.
Timeline window 
Play bar 
The play bar, at the top of the timeline window, and the play head, provide information about the progress and the working frame. The figure below illustrates the play bar and play head.
The play Bar can be used to control the playback and facilitate the playhead navigation. Clicking with the mouse within the play bar moves the play head to the clicked position. It's also possible to control the playback speed and direction by interactively scrubbin the mouse across the play bar.
Playback range 
The timeline shows a area in gray to represent the playback range. The playback range is set on the player toolbar.
Note that the timeline length grows as footage is dragged to the right.
Clips (or bars) in the timeline show a tool tip if the mouse is left unmovable over a clip. The tool tip gives several information about the specific clip.
First frame at represents the number of the actual start frame of the clip. The frame number in which the bar starts and the timeline frame in which the bar ends.
Hold first frame or Hold last frame holds the first or last frame of the clip for the specified amount of frames. You can think on holding a frame as repeating the first or last frame at the begin or end of the clip.
The Trim In means the number of frames removed from the start and Trim Out specify the number of frames removed from the end of the clip. The values used here are offsets. A value of 5 in Trim In would use the 5th frame in the sequence as the start, ignoring the first four frames. A value of 95 would stop loading frames after the 95th.
Manipulating clips 
As said before, the timeline lets you view and arrange the timing of your footage nodes. Each footage node has an instance in the timeline displayed as horizontal bar.
Adjust clip's start time 
The duration of a clip is determined by the length of the correspondent bar in the timeline. Where the clip starts and ends is represented by the begin and end of the horizontal bar. To adjust the start time of a clip just move the correspondent clip's bar. Timeline bars only move horizontally.
Holding and trimming 
Holding and trimming are techniques to change the clip duration. Trimming consists of cutting frames from the original clip, and holding is used to extend the clip.
Footage bars have 2 handlers, in the form of arrows, at their ends. These handlers are used to adjust the length of the clip. You can trim frames off of the beginning or the end of a clip by adjusting the left or right handler.
To increase the duration of a clip, by holding the last frame, drag the right handle to the right. The clip’s duration extends as you pull the handle to the right or left. Note that the original clip size has a different color than trimmed/hold frames at the bar ends.
If the left handler at the beginning of the bar is dragged to the left the newly extended area of the clip, in a lighter color, represents the duration of the clip that has been expanded by freezing the first frame.