Timeline

Peter 22Apr15: ToDo-2 I have copied in stuff from github re. Steve's recent changes to Timeline Quick Play. This is still a Work-In-Progress, but edits/comments welcomed.

• I'm thinking that we could do with a custom TOC as this page has grown somewhat now that the functionality of Timeline has grown.

The Timeline displays a horizontal ruler above the tracks measuring time from zero (the start of the track). Depending on zooming the ruler may span minutes of audio or give a "close up" view of a few seconds or fractions of a second. The Timeline is not merely an indicator of audio position but can also be used to effect Quick-Play

Symbols displayed on the Timeline ruler

• The selected region: (when present) is shown as a shaded region on the ruler. Pressing Play or Record on Transport Toolbar plays or records from the left edge of this region.
  • Underneath the shaded region, the playback region is shown by thin left-pointing and right-pointing arrowheads connected by a line. This region will be played whenever the Play button is clicked.

• The editing cursor: (always present when there is no selected region) is shown as a black vertical line. When "Quick-Play" is not active, the playback start position cursor is attached to it . Pressing Play or Record plays from this cursor position.

• The playback cursor: (when playing or paused during play) is shown as a green triangle.

• The record cursor: (when recording or paused during record) is shown as a red triangle.

• Quick-Play region: A region in the Timeline that plays immediately when dragged with the mouse, even if audio is already playing elsewhere. It is shown by thick left-pointing and right-pointing arrowheads connected by a line. Quick-Play never modifies the position of the editing cursor or region in the waveform. To start "Quick-Play" of a region (even if the track is already playing or paused from playing), hover over the Timeline until the mouse cursor changes to a hand, then drag in either direction and release. Playback will continue to the end of the Quick-Play region.
  • To make the dragged Quick-Play region loop (play repeatedly until stopped), press and hold SHIFT, drag in the Timeline then release the drag. Loop play will be indicated by the Play button in Transport Toolbar changing to Loop Play File:Loop.png.
    Gale 18Aug14: On Mac, neither CTRL or COMMAND perform the Quick-Play Cut Preview. Not clear yet if this will be fixed for 2.0.6.
    James 18Aug14: Unlikely to be fixed for 2.0.6. If the Cut-Preview feature of ruler is not mentioned here it is IMHO P4 not having it for Mac. So I commented the explanation out. Can be restored easily later.
  • If you just want to play from a particular point to the end of the project, click in the Timeline at the point from which you want playback to start or restart. The Quick-Play cursor is then shown only by a left-pointing arrowhead. Playback will continue to the end of the project.
  • As with standard playback, you can press SPACE or click the Stop button to stop Quick-Play before the end of the region or project is reached.

• Play Region Lock: The position of the editing cursor or playback region (or the current position of the Quick-Play region or Quick-Play cursor) can be locked in the Timeline for use in all further standard playback. To do this, choose Edit > Play Region > Lock.
  • When "Locked", the region or cursor position displays in red in the Timeline. A locked region or cursor is always used for standard playback (including Play-at-Speed) irrespective if the editing cursor or region in the waveform is at a different position.
  • The locked region can be expanded or contracted by dragging either red arrowhead, then the next standard playback will use that new region. If you drag a new region in the Timeline then release, that new region will Quick-Play and will then be used for all further standard playback. Similarly if you click in the Timeline, the project Quick-Plays from there, and all further standard playback starts from there.
  • To unlock the region or cursor position, so that all further playback respects the editing cursor or region in the waveform, choose Edit > Play Region > Unlock.

Play Region Lock or Unlock may be performed even when the track is playing or paused from playing.

The Timeline is not active for Quick-Play whenever Audacity is recording.

The Timeline in use

Peter 22Apr15: ToDo-2 should we be thinking of replacing these images with expanded ones showing waveform (mono) and the white line.

Standard playback shows: The editing cursor (the black vertical bar) The playback start position cursor (the left-pointing gray triangle with short gray vertical bar to left) When Quick-Play is not active (see below) the editing cursor and the playback start position cursor are always at the same point on the Timeline, and together are called the standard cursor The playback cursor (the green triangle) - playback will continue until stopped.

Recording with no selection present shows: The editing cursor and the playback start position cursor (as above) The recording cursor (the red triangle) - recording will continue until stopped.

After clicking in the Timeline to initiate "Quick-Play": The editing cursor position is unchanged The playback start position cursor moves to the point clicked The green playback cursor shows the current playback position.

After clicking and dragging in the Timeline to initiate "Quick-Play" of a region: The editing cursor position is unchanged The green playback cursor shows the current playback position The "Quick-Play" region is indicated by the thick horizontal gray bar with arrowheads on each end.

After clicking and dragging in the waveform: Instead of the editing cursor, a shaded region shows the time range of the selected audio. No audio plays, but the potential playback region is indicated by the thin horizontal gray bar with arrowheads on each end. The potential playback region is identical to the selection region in the waveform.

After locking a Play Region The thick horizontal red bar with arrowheads on each end show the region that will always be played, irrespective if the editing cursor or region in the waveform is at a different position.

After locking a Play Region cursor position The left-pointing red arrowhead shows the point from which the project will always be played, irrespective if the editing cursor or region in the waveform is at a different position.

For other methods of navigating to playback points or areas, see Playing and Recording.

Using Timeline Quick-Play

Timeline Quick-Play provides a quick and convenient means to either initiate playback from any point within the current project or to playback a region of audio.

As you hover the mouse pointer over the Timeline a white vertical line is drawn through the waveform(s) below to aid you making a precise Quick-Play location.

File:TQP white line.png

Peter 23Apr15: ToDo-2 The little double-headed arrow you get when hovering on the Timeline does not get captured with the screen grab. I don't know how that occurs :-/

Timeline Quick-Play is disabled during recording for safety reasons.

Clicking on the Timeline

• Left Click: Play from the time position of the mouse pointer when clicked.
• Shift + Left Click
  • within a selected region: Loop play the selected region, starting from the position of the mouse pointer.
  • not in a selected region: Loop play the project, starting from the position of the mouse pointer.
• Right Click: Opens the Timeline Quick-Play menu.

Click and drag

• Left Click and drag: Creates a temporary play region. Playback begins when the left mouse button is released.
• Shift + Left Click and drag: Creates a temporary play region. Playback begins when the left mouse button is released. Playback of the temporary play region repeats (loops) until the play region is changed or playback is stopped (for example by pressing the spacebar).
• CTRL + Left Click and drag: This is similar to the "Cut Preview". A temporary "Quick-Play region" is created, though in this case playback starts a few seconds before the start of the region, then skips over the "Quick-Play region" and plays a few after the defines region. The duration of playback before / after the "Quick-Play region" is set in Edit > Preferences > Playback > Cut preview.

Adjusting the Quick-Play region

While Timeline Quick-Play is playing, the Quick-Play region may be adjusted by clicking and dragging one or other end of the Quick-Play region. Playback then restarts from the (new) start of the Quick-Play region. If the Shift key is held down while adjusting the Quick-Play region, loop-playback will restart from the (new) start of the Quick-Play region.

The selection

By default, the audio selection (if one exists) is not affected. This default behaviour may be changed by selecting the "Enable dragging selection" right-click menu option. When dragging the selection is enabled, the Quick-Play region will also create or adjust the selection. The selection persists after Quick-Play has stopped. To revert to the default behaviour, select "Disable dragging selection" in the right-click menu.

Note that dragging the selection cannot be enabled if the play region is locked.

Locked Play Region

Audacity allows the play region to be locked. While a play region is locked, Timeline Quick-Play will temporarily over-ride the lock allowing Quick-Play to be used and will immediately restore the lock when the left mouse button is released. It is assumed that if the play region is locked that the user wants the play region to be locked, therefore Timeline Quick-Play only acts in its "temporary" mode and selection dragging is disabled. To enable dragging the selection, the play region may be conveniently unlocked via the right-click menu.

Right Click menu

Right click on the Timeline gives access to options that are convenient when using Timeline Quick-Play, via a short popup menu.

Disable/Enable Quick-Play: This facilitates turning the Timeline Quick-Play functionality on or off (some users may fing the white cursor line on the waveform distracting when navigating over the Timeline). The default setting is "on".

Enable dragging selection: When disabled (default), left click and drag on the end of the play region adjusts the play region only. The current selection is unaffected. When enabled, left click and drag on the end of the play region adjusts both the play region and the selection together. This is particularly useful when finding the right place for a seamless loop.

Disable Timeline Tooltips: Timeline tooltips are visible when hovering over the Timeline. They are useful for indicating whether Timeline Quick- Play is available. For experienced users the tooltips can get in the way. This option allows the user to turn off the Timeline tooltips when not needed. These tooltips are enabled by default.

Do not scroll while playing: This option is primarily aimed at users that are making loops and addresses the inconvenience of this option previously only being available in Edit > Preferences > Tracks > Update display while playing

Lock Play Region: The current position of the Quick-Play region can be locked in the Timeline for use in all further standard playback.

Steve: The concepts of "locking the play region" and "Quick-Play" conflict (hence bug 912). The default behaviour provides a workable compromise in most situations, but in some situations it is necessary to be able to turn the play region lock on or off. In particular, the idea of dragging the selection along with the play region makes no logical sense when the play region is locked. "Play Region > Lock" and "Enable dragging selection" are therefore mutually exclusive.