Zoom Panel

Below the displayed tracks in the timeline, you will find the zoom panel as seen in figure 2.2. In addition to the scrollbars, these options and their values are another set of tools for positioning the timeline. In order of appearance in the zoom panel as rectangular boxes and either tumbler arrows or a up/down arrow, this next list shows each option along with its tooltip description if available. Then more details are provided in the next paragraphs.

Sample zoom	Duration visible on the timeline
Amplitude	Audio waveform scale
Track audio zoom	Height of audio tracks
Track video zoom	Height of video tracks
(type)	Automation Type
Curve zoom	Automation range minimum and maximum
Selection change	3 boxes with starting point, length, and ending point
Alpha slider	Slider bar to control alpha value for colored assets

Changing the sample zoom changes the amount of time displayed on the timeline so you can see your media as individual frames or as the entire length of your media. To see more frames, use a higher setting. The sample zoom value is not an absolute time reference because it refers to the duration visible on the timeline. It will change as you modify the length of the program window horizontally. You can either use the ↑ and ↓ arrows to change the sample zoom by a power of two, or use the mouse wheel on the tumblers to zoom in and out.

The next option is amplitude and it only affects the audio waveform size. Ctrl-↑ and Ctrl- ↓ are shortcuts used to change the amplitude zoom as an alternative to the down arrow to the right of the numerical size.

The track audio and video zoom affects all tracks of that type and determines the height of each track. If you change the audio track zoom, the amplitude zoom will be changed also so that the audio waveforms are proportionally sized. Shortcuts, Ctrl-Pgup and Ctrl-Pgdown, change the track zoom to the next level simultaneously for all of the audio and video tracks.

Automation type is used for selecting one of the following: Audio Fade, Video Fade, Zoom, Speed, X, or Y (X and Y are for the compositor's Camera and Projector). When an auto line is present on the timeline and is being manipulated, a small square the same color as the line will be shown to the left of the Automation type when the left mouse button (LMB) is pressed. This is just an indicator to make it easy to see what is being worked.

The curve zoom affects the curves for the selected automation type in all the tracks of that type and determines the value range for those curves. Use the tumbler arrows to the left of the numbers for the minimum value and the tumblers to the right for the maximum value, or manually enter the values in the text box. Good default values for audio fade are -40.0 to 6.0 and for video fade are 0.0 to 100.0. The tumbler arrows change curve amplitude, but the only way to curve offset is to use the fit curves button on the curve itself.

The selection start time, selection length, and selection end time display the current selected timeline values. When there is no selection, both the start and end time are the current position of the timeline and the selection length is 0. The alpha slider allows for varying the alpha value when using colors on the tracks as set in your Preferences → Appearance for Autocolor assets. It has no function without that flag set.

There are 3 additional pieces of information in the line immediately below the zoom panel. In the lower left hand corner there could be messages such as "Welcome to CINELERRA-GG" when there is no need to display a red-colored error message or a line that reads "Rendering took H:MM:SS" after a render has just been completed. Or when working with an auto, a small square the color of the last changed auto line, will be present along with its keyframe type, location on the timeline, and its current value. This is simply for easy recognition of what is being worked. The second piece of helpful information is all the way to the right which is a long rectangular box indicating the percentage completion of a render. Finally there is an X with the tooltip of "Cancel operation" used to stop an ongoing render (the cancel operation may seem slow due to the amount of data still in the buffer upon cancellation).