Selection Toolbar

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.

Gale 10Apr13: ToDo-2 I removed the exact instructions how to change format from the Snap To section as it made no sense to me to have it there and in Selection Formats (it must be in the latter as it will be used as an anchor link). Do you think it would work to arrow the three drop-down arrows in the spinboxes in the image above to make clearer where to change formats (like the image at top of Device Toolbar)?

• Peter 18Apr13: Personally I don't think it worthwhile, it will clutter the image unnecessarily - and you're not going to talk about the LDPBTs in this early section, are you?

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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

Check the box  Snap To to force all mouse clicks and selections made with the mouse to snap to the current Selection Format. The default format is hours, minutes, seconds and milliseconds (seconds accurate to three decimal places, as in the above image).

Even if Snap To is enabled, a track or clip can still be time-shifted to any location, and the Tracks > Align Tracks and Tracks > Align and Move Cursor commands will still align to locations outside the chosen unit of time.

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, clicking in-between 6.500 seconds and 6.501 seconds on the Timeline snaps the cursor to the nearest preceding unit, in this case 6.500 seconds.

To snap to whole seconds, change the format to one where the smallest unit is seconds, for example, hours, minutes and seconds. Clicking at 2.8 seconds will now snap the cursor to 2.0 seconds, and dragging from that cursor point will always snap the selection edge to a whole second. 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).

Some selection formats are based on other units of time such as samples, Audio CD frames or film frames. Snapping to film frames can be useful to maintain video and audio synchronization when editing audio from video files.

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 time values

You can edit the individual time 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 how to use Selection Toolbar with the keyboard.

Selections made by modifying the Selection Toolbar time values with either keyboard or mouse will always snap to the current Selection Format, even if the Snap To checkbox is unchecked.

Selection Formats

To access the context menu listing the time formats, click the triangle to right of any box. You can also select in or right-click over any digit in a box (or use a keyboard equivalent). The following table lists the 16 available 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	Default
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

In the following example we changed the format to samples, which is the most finely detailed format available. All three time selection boxes converted the time units to the new format.

For the technically minded, assuming the selection above was exactly 30 seconds, 1,323,000 samples are shown because the sample rate of 44100 Hz means there are 44100 audio samples per second. Multiplying (44100) by the length in seconds (30) produces 1,323,000.

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.