Setting the basic track and sample properties

The track and sample Inspectors let you set properties, select filter effects, create sprite actions, and control layout parameters. Each track and sample has a corresponding Inspector. Most of the following basic properties are available for video tracks and other visible tracks such as sprites, 3D, text, and SWF files. For information about properties not described in this section, see the appropriate section for the track type later in this chapter or in GoLive Help.

To set the basic track and sample properties:

After you add or select a track, set the following properties in the Basic tab of the track's Inspector:

Title

Enter a name for the track.

Start Time and Duration

Enter a beginning time and the length of time you want the track to run.

Scale Sample Time

Select this option to proportionally change the duration of tracks containing samples (sprites, text, chapter, HREF, and filters) when you change the duration in the track Inspector (or if you Shift-drag the track bar's end). Deselect this option to lengthen only the last sample to the end of the track bar. This also works for the folder track, which contains other tracks.

Note: If you have a sprite track with a lot of samples (for example, frame actions) that need to occur at specific times in the movie, and you then change the duration of the sprite track by selecting the Scale Sample Time option, all the samples (keyframes) would move as well. This is not a recommended process because this could drastically change the timing of the sprite samples.

Position

Enter a pixel value to position the selected track horizontally and vertically. For example, you can place two tracks next to each other by using different positions for each track.

Size

Enter a pixel value to set vertical and horizontal dimensions of the selected track. Whenever you adjust dimensions, QuickTime uses a scaling factor to scale the track's size.

Normalize Track/ Set Track Dimension

Click the normalize track/set track dimension icon  to display a menu that lists the Normalize Track and Set Track Dimension commands. If you changed the dimensions of the selected track, you can use Normalize Track to reset the track back to its original size and return the track to its original position. Or, you can use Set Track Dimension to change the track's original size and position to the current dimensions and position.

Constrain Proportion

Resizes the video track proportionally. For example, when you edit the value in the width text box, the height is adjusted to maintain the original aspect ratio of the track, and vice-versa.

Mode

From the Mode menu, select how you want a video track to overlay other tracks in the movie:

• Dither Copy (default mode) overlays the image on a track directly below it and applies dithering for a more refined look. There is no interaction between a track in Dither Copy mode and tracks below it.
• Copy is the same as Dither Copy, with one exception: Copy lacks the dithering capability, which makes it less suitable for display on systems in 256-color mode. However, the Copy option may provide better performance in low memory situations.
• Blend makes the track translucent so you can see partially through it to the track below. You can set the degree and color of the transparency by clicking the color field next to the Mode menu to display the Color palette. Drag a color from the preview pane of the Color palette to the Mode color field. The lighter the color, the less translucent the track is; the darker the color, the more translucent it is.
• Transparent lets you define a transparent color for any visual track. Click the color field and drag a color from the preview pane of the Color palette to the color field.

Note: The Mode menu is not available for movie tracks, and the Type menu on the Basic tab is only available for movie tracks. (See Using movie tracks.)

The next four modes determine how alpha channel content appears. An alpha channel defines how an image is combined with a background image already present at the location where the image appears. By defining an alpha channel, you specify which part of a visible image is left out (the proper term is "masked") to make a background image appear in that area.

• Straight alpha means that the color components of each pixel are combined with the background pixel at the same location based on the value contained in the alpha channel.
• Premul white alpha supports images created on a white background with a premultiplied alpha channel.
• Premul black alpha supports images created on a black background with a premultiplied alpha channel.
• Straight alpha blend is a combination of straight alpha and blend, so the masked areas are transparent and the nontransparent areas are translucent. As with the Blend mode, you can use the Color palette to edit the degree of translucency.
• Composition (Dither Copy) is similar to Copy and Dither Copy, but more appropriate for video tracks created from animated GIF files.

Note: The Basic tab in the Color Track Inspector also contains a Color field below the Mode menu where you can select a fill color for the color track. (See Using color tracks.)