Selection Toolbar

Peter 9Apr13: ToDo-2 Ready for re-review and merciless editing now that I have added in a section on "Selection Formats"

Selection Toolbar  includes the Project Rate, Snap To and time selection controls. Using the "Start" and "End/Length" boxes, you can precisely place the cursor point or selection region without using a mouse to click or drag in the waveform, and without zooming in first to find the exact spot.

Selection Toolbar (above) is normally at the bottom of the Audacity window, but like any of the Toolbars, it can be moved as desired by dragging the serrated edge on its left side.

Project Rate (Hz)

The sample rate for the project, by default this is set to 44100 Hz. To change the default rate that is used each time Audacity is launched, or each time a new project window is opened, use Quality Preferences.

Changing the project rate in Selection Toolbar immediately changes the sample rate at which new tracks will be recorded or generated in the current project, and at which existing tracks will be played, rendered or exported. If the rate you require is not in the drop-down list, you may type the rate you want directly over the currently selected rate.

Snap To

If checked, selections and mouse clicks snap to the current Selection Format, which is hours, minutes, seconds and milliseconds (hh:mm:ss + milliseconds) by default (as in the above image).

To change the Selection Format to other resolutions such as a frame format or audio samples, open the context menu by clicking the triangle in any of the three boxes to right of Snap To. You can also open the menu by hovering over or selecting in any digit, then right-clicking or using a keyboard equivalent.

Gale 29Mar13: ToDo-1 The below is incorrect. From 1.3.14 onwards, clicks snap to the nearest Snap To point, not the preceding one. At the moment I assume it to be a bug and undesirable change.

For example, six and a half seconds displays as 6.500 seconds. With Snap To checked and the format set to hours, minutes, seconds and milliseconds, you can click to set the cursor at 6.500 seconds or 6.501 seconds on the Timeline, but clicking in-between those two values causes the cursor to snap to the nearest preceding unit, in this case 6.500 seconds.

If you wanted to snap to whole seconds, you would set the format to one where the smallest unit was seconds, for example, hours, minutes and seconds. If you placed the cursor at 2.8 seconds, this would cause the cursor to snap to 2.0 seconds. If a selection was dragged from that cursor point, the dragged edge would snap so that the selection must be in whole seconds. This could be useful for exporting a selection that needed to be exactly a certain number of seconds, without entering precise values in the Selection Toolbar boxes which would be another way of ensuring accuracy.

When Snap To is on you can move the cursor to the preceding or following Snap To point by using keyboard LEFT arrow or RIGHT arrow respectively.

Selection and Audio Position Boxes

• Selection Start: If there is no selection, this shows the cursor position.
• (Selection) End/Length: Click the "End" radio button to show the end point of the selection. If there is no selection, the value is the same as the Selection Start. Clicking the "Length" button shows the length of the selection instead (the value shows as zero if there is no selection).
• Audio Position: Displays the current real time position of playback or recording. Editing the values has no effect.

Editing the Selection Toolbar values

You can edit the individual values in the "Selection Start" and "End/Length" boxes so as to change the cursor position or selection region on the waveform. Using a mouse, click on a digit in one of the boxes then use the mouse wheel or up and down arrow on the keyboard to increment the value, or type the required value. Use left and right arrow to navigate quickly to adjoining digits, and TAB or SHIFT + TAB to navigate to adjoining boxes.

Selection Toolbar is also fully accessible using only the keyboard.

See Audacity Selection for full details of Selection Toolbar features.

Selection Formats

By default, Selection Toolbar enables you to enter values in units of hours, minutes and milliseconds, this is more than accurate enough for most purposes. However if you need for example to make a selection that is accurate to the nearest sample or is defined in CDDA frames or film frames, numerous other Selection Formats are available to represent time. To choose other formats, click on the triangle to right of any box, or select in or right-click over any of the digits in a box. This opens a context menu which lists the formats. Click to select the format required, then all three boxes will show the new format.

The following table lists all the available Selection Formats:

Selection Format	Example	Notes
seconds	005,408 seconds
hh:mm:ss	01 h 30 m 08 s	Hours, minutes, seconds
dd:hh:mm:ss	00 days 01 h 30 m 08 s	Days, hours, minutes, seconds
hh:mm:ss + hundredths	01 h 30 m 08.51 s
hh:mm:ss + milliseconds	01 h 30 m 08.512 s
hh:mm:ss + samples	01 h 30 m 08 s + 22500 samples
samples	238,514,850 samples
hh:mm:ss + film frames (24 fps)	01 h 30 m 08 s + 12 frames
film frames (24 fps)	129,804 frames
hh:mm:ss + NTSC drop frames	01 h 30 m 08 s + 14 frames	American video format
hh:mm:ss + NTSC non-drop frames	01 h 30 m 03 s + 02 frames
NTSC frames	162,092 frames
hh:mm:ss + PAL frames (25 fps)	01 h 30 m 08 s + 12 frames	European video format
PAL frames (25 fps)	135,212 frames
hh:mm:ss + CDDA frames (75 fps)	01 h 30 m 08 s + 37 frames
CDDA frames (75 fps)	405,637 frames	Audio CD frames

Changing the Selection Format does not change the units displayed on the Timeline.
The Timeline is always displayed in hours, minutes, seconds and parts of seconds, varying according to the current zoom level.