<li><strong>Sound propagation through the air</strong>: since it is a mechanical perturbation in a fluid, sound travels at comparatively slow <a href="http://en.wikipedia.org/wiki/Speed_of_sound" title="http://en.wikipedia.org/wiki/Speed_of_sound">speed</a> of about 340 m/s. Some interesting consequences:
<ul>
<li>Your acoustic guitar or piano has a latency of about 1-2 ms, due to the propagation of the sound between your instrument and your ear . </li>
-<li>At a large concert venue if you are far away from the stage the sound will travel faster through the path “singer → mic → nearest loudspeaker → your ear” than through the “singer → air → your ear” one, so you'll hear the real sound as an echo of the amplified one. </li>
+<li>At a large concert venue if you are far away from the stage the sound will travel faster through the path "singer → mic → nearest loudspeaker → your ear" than through the "singer → air → your ear" one, so you'll hear the real sound as an echo of the amplified one. </li>
</ul>
</li>
<li><strong>Digital-to-Analog and Analog-to-Digital conversion</strong>: electric signals travel quite fast, so their propagation time is negligible in this context, but the conversions between the analog and digital domain take a comparatively long time to perform, so their contribution to the total latency may be considerable. Fast converters are, for instance, one of the factors that distinguishes a quality audio interface from a cheap one, along with other features like low noise, low distortion, etc.</li>
<h2>Ardour Timecode Configuration</h2>
<p>
-Each Ardour session has a specific timecode frames-per-second setting which is configured in <code>session→properties→timecode</code>.
+Each Ardour session has a specific timecode frames-per-second setting which is configured in <code>session > properties > timecode</code>.
</p>
</p>
<p>
-The relevant settings for timecode generator can be found in the Preferences dialog: “MIDI Preferences” (for MTC, MClk) and “Transport Preferences” respectively.
+The relevant settings for timecode generator can be found in the Preferences dialog: "MIDI Preferences" (for MTC, MClk) and "Transport Preferences" respectively.
</p>
<p>
</p>
<p>
-In <code>session→properties</code> it is possible to define an offset between Ardour's internal time and the timecode sent. Currently only the LTC generator honors this offset.
+In <code>session > properties</code> it is possible to define an offset between Ardour's internal time and the timecode sent. Currently only the LTC generator honors this offset.
</p>
<h3>LTC generator</h3>
<p>
-The volume of the LTC signal can be conigured in in the <code>Preferences→Transport</code> dialog. By default it is set to -18dBFS which corresponds to 0dBu in an EBU calibrated system.
+The volume of the LTC signal can be conigured in in the <code>Preferences > Transport</code> dialog. By default it is set to -18dBFS which corresponds to 0dBu in an EBU calibrated system.
</p>
<p>
<h2>Ardour Slave Configuration</h2>
<p>
-Switching the timecode-source can be done via the button just right of Ardour's main clock. By default it is set to <code>Internal</code> in which case ardour will ignore any external timecode. The button allows to toggle between Internal and the configured timecode source which is chosen in <code>Edit→Preferences→Transport</code>.
+Switching the timecode-source can be done via the button just right of Ardour's main clock. By default it is set to <code>Internal</code> in which case ardour will ignore any external timecode. The button allows to toggle between Internal and the configured timecode source which is chosen in <code>Edit > Preferences > Transport</code>.
</p>
<p>
<h3>Frames-per-second</h3>
<p>
-If the frames-per-second don't match, ardour can either re-calculate (map) the frames or the configured FPS (<code>session→properties</code>) can be changed automatically while the Slave is active. The behavior is configured with the checkbox in <code>Edit→Preferences→Transport</code> labeled <code>Match session video frame rate to external timecode</code>: <strong>When enabled</strong> the session video frame rate will be changed to match that of the selected external timecode source. <strong>When disabled</strong> the session video frame rate will not be changed to match that of the selected external timecode source. Instead the frame rate indication in the main clock will flash red and Ardour will convert between the external timecode standard and the session standard.
+If the frames-per-second don't match, ardour can either re-calculate (map) the frames or the configured FPS (<code>session > properties</code>) can be changed automatically while the Slave is active. The behavior is configured with the checkbox in <code>Edit > Preferences > Transport</code> labeled <code>Match session video frame rate to external timecode</code>: <strong>When enabled</strong> the session video frame rate will be changed to match that of the selected external timecode source. <strong>When disabled</strong> the session video frame rate will not be changed to match that of the selected external timecode source. Instead the frame rate indication in the main clock will flash red and Ardour will convert between the external timecode standard and the session standard.
</p>
<p>
</p>
<p>
-A global offset between incoming timecode and ardour's transport can be configured in <code>Session→Properties</code>.
+A global offset between incoming timecode and ardour's transport can be configured in <code>Session > Properties</code>.
</p>
<p>
</p>
<p>
-A global offset between incoming timecode and ardour's transport can be configured in <code>Session→Properties</code>.
+A global offset between incoming timecode and ardour's transport can be configured in <code>Session > Properties</code>.
</p>
</p>
<p>
-JACK-transport also includes temp-based-time information ie. Bar:Beats:Ticks and beats-per-minute. However, only one JACK application can provide this information at a given time. The checkbox <code>JACK Time Master</code> in the <code>Session→Properties</code> dialog allows to configure ardour to act as translator from timecode to BBT information.
+JACK-transport also includes temp-based-time information ie. Bar:Beats:Ticks and beats-per-minute. However, only one JACK application can provide this information at a given time. The checkbox <code>JACK Time Master</code> in the <code>Session > Properties</code> dialog allows to configure ardour to act as translator from timecode to BBT information.
</p>
</p>
<p>
-<strong>Session→Properties→Timecode</strong>
+<code>Session > Properties > Timecode</code>
</p>
<p>
-<strong>Edit→Preferences→Transport</strong>
+<code>Edit > Preferences > Transport</code>
</p>
<p>
-<strong>Edit→Preferences→MIDI</strong>
+<code>Edit > Preferences > MIDI</code>
</p>
<h3>Timecode Settings</h3>
<ul>
-<li>“<strong>Timecode frames-per-second</strong>” – configure Timecode frames-per-second (23.976, 24, 24.975, 25, 29.97, 29.97 drop, 30, 30 drop, 59.94, 60). Note that all fractional framerates are actually fps*(1000.0/1001.0).</li>
-<li>
“<strong>Pull up/down</strong>” – video-pullup modes change the effective samplerate of Ardour to allows for changing a film soundtrack from one frame rate to another. see <a href="http://en.wikipedia.org/wiki/Telecine" title="http://en.wikipedia.org/wiki/Telecine">Telecine</a></li>
-<li>“<strong>Slave Timecode offset</strong>” – The specified offset is added to the received timecode (MTC or LTC).</li>
-<li>“<strong>Timecode Generator offset</strong>” – Specify an offset which is added to the generated timecode (so far only LTC).</li>
-<li>“<strong>JACK Time Master</strong>” – provide Bar|Beat|Tick and other information to JACK</li>
+<li>"<strong>Timecode frames-per-second</strong>" – configure Timecode frames-per-second (23.976, 24, 24.975, 25, 29.97, 29.97 drop, 30, 30 drop, 59.94, 60). Note that all fractional framerates are actually fps*(1000.0/1001.0).</li>
+<li>
"<strong>Pull up/down</strong>" – video-pullup modes change the effective samplerate of Ardour to allows for changing a film soundtrack from one frame rate to another. see <a href="http://en.wikipedia.org/wiki/Telecine" title="http://en.wikipedia.org/wiki/Telecine">Telecine</a></li>
+<li>"<strong>Slave Timecode offset</strong>" – The specified offset is added to the received timecode (MTC or LTC).</li>
+<li>"<strong>Timecode Generator offset</strong>" – Specify an offset which is added to the generated timecode (so far only LTC).</li>
+<li>"<strong>JACK Time Master</strong>" – provide Bar|Beat|Tick and other information to JACK</li>
</ul>
<h3>Transport Preferences</h3>
<ul>
-<li>“<strong>External timecode source</strong>” – select timecode source: JACK, LTC, MTC, MClk</li>
-<li>“<strong>Match session video frame rate to external timecode</strong>” – This option controls the value of the video frame rate <em>while chasing</em> an external timecode source. <strong>When enabled</strong> the session video frame rate will be changed to match that of the selected external timecode source. <strong>When disabled</strong> the session video frame rate will not be changed to match that of the selected external timecode source. Instead the frame rate indication in the main clock will flash red and Ardour will convert between the external timecode standard and the session standard.</li>
-<li>“<strong>External timecode is sync locked</strong>” – <strong>When enabled</strong> indicates that the selected external timecode source shares sync (Black &amp; Burst, Wordclock, etc) with the audio interface.</li>
-<li>
“<strong>Lock to 29.9700 fps instead of 30000/1001</strong>” – <strong>When enabled</strong> the external timecode source is assumed to use 29.97 fps instead of 30000/1001. SMPTE 12M-1999 specifies 29.97df as 30000/1001. The <acronym title="specification">spec</acronym> further mentions that drop-frame timecode has an accumulated error of -86ms over a 24-hour period. Drop-frame timecode would compensate exactly for a NTSC color frame rate of 30 * 0.9990 (ie 29.970000). That is not the actual rate. However, some vendors use that rate - despite it being against the specs - because the variant of using exactly 29.97 fps has zero timecode drift.</li>
+<li>"<strong>External timecode source</strong>" – select timecode source: JACK, LTC, MTC, MClk</li>
+<li>"<strong>Match session video frame rate to external timecode</strong>" – This option controls the value of the video frame rate <em>while chasing</em> an external timecode source. <strong>When enabled</strong> the session video frame rate will be changed to match that of the selected external timecode source. <strong>When disabled</strong> the session video frame rate will not be changed to match that of the selected external timecode source. Instead the frame rate indication in the main clock will flash red and Ardour will convert between the external timecode standard and the session standard.</li>
+<li>"<strong>External timecode is sync locked</strong>" – <strong>When enabled</strong> indicates that the selected external timecode source shares sync (Black &amp; Burst, Wordclock, etc) with the audio interface.</li>
+<li>
"<strong>Lock to 29.9700 fps instead of 30000/1001</strong>" – <strong>When enabled</strong> the external timecode source is assumed to use 29.97 fps instead of 30000/1001. SMPTE 12M-1999 specifies 29.97df as 30000/1001. The <acronym title="specification">spec</acronym> further mentions that drop-frame timecode has an accumulated error of -86ms over a 24-hour period. Drop-frame timecode would compensate exactly for a NTSC color frame rate of 30 * 0.9990 (ie 29.970000). That is not the actual rate. However, some vendors use that rate - despite it being against the specs - because the variant of using exactly 29.97 fps has zero timecode drift.</li>
</ul>
<h3>MIDI Preferences</h3>
<ul>
-<li>“<strong>Send MIDI Timecode</strong>” – enable MTC generator</li>
-<li>“<strong>Send MIDI Clock</strong>” – enable MIDI Clock generator</li>
+<li>"<strong>Send MIDI Timecode</strong>" – enable MTC generator</li>
+<li>"<strong>Send MIDI Clock</strong>" – enable MIDI Clock generator</li>
</ul>
projects / ardour-manual / commitdiff