manual/include/transport-clocks.html

<figure>
  <img src="/images/new_main_clocks.png" alt="The transport clocks in Ardour">
  <figcaption>
    The transport clocks in Ardour
  </figcaption>
</figure>

<p>
  <dfn>Clocks</dfn> in Ardour are used to display time values 
  precisely. In many cases, they are also one way to edit (change) time 
  values.
</p>
<p>
  In the transport bar of the editor window there are two clocks by 
  default, that display the current position of the playhead and 
  additional information related to transport control and the timeline. 
  These are called the <dfn>transport clocks</dfn>; the left one is the 
  <dfn>primary transport clock</dfn> (always showing the playhead 
  position) and the right one is the <dfn>secondary transport 
  clock</dfn>.
</p>
<p>
  Having two transport clocks allows seeing the playhead position in 
  two different time units without having to change any settings. For 
  example, one can see the playhead position in both timecode units and 
  BBT time. The secondary transport clock can nevertheless be hidden in 
  the <a 
  href="@@preferences#preferences-appearance-toolbar">Preferences</a>, 
  at <kbd class="menu">Appearance &gt; Toolbar &gt; Display Secondary 
  Clock</kbd>.
</p>
<p>
  All the clocks in Ardour share the same powerful way of editing time. 
  Refer to <a href="@@editing-clocks">Editing Clocks</a> to learn how. 
  Editing the time in the transport clocks will reposition the playhead 
  in the same way that various other editing operations will.
</p>

<p>
  The transport clocks have special attributes due to their function:
</p>

<h2>Information panel</h2>
<p>
	Under each clock is an information panel, that offers information about the current <a href="@@editing-clocks#clock-modes">clock mode</a>:
</p>
<table class="dl">
	<thead>
		<tr>
			<th>Mode</th>
			<th>Information</th>
		</tr>
	</thead>
	<tbody>
	  <tr>
		  <th>Timecode / Minutes:Second / Seconds</th>
		  <td>Source of Timecode (<samp>INT</samp> means that Ardour is its own timecode source)</td>
	  </tr>
	  <tr>
		  <th>Bars:Beats</th>
		  <td>Current tempo and current time signature. Clicking one of this button allows changing the value.</td>
	  </tr> 
	  <tr>
		  <th>Samples</th>
		  <td>Sample rate (<samp>SR</samp>) and pull-up/down, as defined in the <a href="@@session-properties#properties-timecode">session properties</a>.</td>
	  </tr>
  </tbody>
</table>

<h2>Time origin</h2>
<p>
	In the <kbd class="mouse">Right</kbd>-click menu, it is possible to 
	change the time origin, i.e. the zero-point in time, amongst :
</p>

<table class="dl">
  <tr>
	  <th><dfn>Display absolute time</dfn></th>
	  <td>The zero point is the absolute start of the timeline (ignoring the session start and any timecode offsets).</td>
  </tr>
  <tr>
	  <th><dfn>Display delta to edit cursor</dfn></th>
	  <td>The zero point is the Edit Point as chosen from the <a href="@@edit-point-control">Edit Point selector</a>, e.g. a selected marker.</td>
  </tr> 
  <tr>
	  <th><dfn>Display delta to origin marker</dfn></th>
	  <td>The zero point is the <em>start</em> marker of the session.</td>
  </tr>
</table>

<ul>
  <li>
	  The transport clock may display a positive or negative value 
	  depending on the temporal order of the chosen zero value and the 
	  playhead.
  </li>
  <li>
	  The clocks will use a different color when in <em>delta to 
	  edit</em> or <em>delta to origin</em> mode to avoid confusion. 
  </li>
  <li>
	  Also, when in the two later modes, the value of the clock can not
	  be edited.
  </li>
</p>