<p>
Every Region has a fade-in and fade-out. By default, the region fade
is very short, and serves to de-click the transitions at the start and
- end of the region. By adjusting the regions fade length, a more
+ end of the region. By adjusting the regions fade length, a more
gradual transition can be accomplished.
</p>
<h2>Region Fades</h2>
<p>
- <dfn>Region fades</dfn> are possible at the beginning and end of
+ <dfn>Region fades</dfn> are possible at the beginning and end of
all audio regions. In object mode, a grip appears at the top left and
top right of an audio region when the cursor hovers over it. Placing
the cursor over the top of the grip displays the region fade cursor
- tip. Click and drag the grip left or right in the timeline to
- adjust the length of the fade.
+ tip. Clicking and dragging the grip left or right in the timeline adjusts the
+ length of the fade.
</p>
<h2>Crossfades</h2>
<p>
- <dfn>Crossfades</dfn> refer to the behavior when you want to make
- a smooth transition (mix) from one audio region to another on the same
- track. Historically, this was done by splicing 2 pieces of analog
+ <dfn>Crossfades</dfn> refer to the behavior of two audio regions transitionning
+ smoothly (mixing) from one to another on the same
+ track. Historically, this was done by splicing two pieces of analog
tape together, and this concept was carried forward into digital
editing. Each track is a sequence of sound files (regions). If
two regions are butted against each other, there needs to be a method
to splice them smoothly together. The crossfade allows one region
- to fade smoothly out, while the next region fades smoothly in, like 2
+ to fade smoothly out, while the next region fades smoothly in, like two
pieces of tape that have been cut at and angle, and overlapped.
</p>
<p>
But Ardour uses a more refined "layered" editing model, and
therefore it is possible for multiple regions to be stacked on a single
location with arbitrary overlaps between different layers. For
- this reason, crossfades must be implemented differently. We can't
- assume that a crossfade is an entitry that exists between 2 regions;
+ this reason, crossfades must be implemented differently. It can't be
+ assumed that a crossfade is an entitry that exists between two regions;
instead each region must have its own associated crossfades at each
end, and the topmost region must always crossfade down to the
underlying region(s), if any.
the region(s) beneath it.
</p>
<p>
- It is important to understand that region fades <em>are</em> crossfades. When one region has
- another region or multiple regions beneath its fade area, then you will
- hear the topmost region fade-out be mirrored as a fade-in on the
- underlying region(s). The grip for the topmost region will allow
+ It is important to understand that region fades <em>are</em> crossfades.
+ When one region has another region or multiple regions beneath its fade area,
+ then what will be heard is the topmost region fade-out mirrored as a fade-in
+ on the underlying region(s). The grip for the topmost region will allow
changing the length and type of the crossfade into the underlying
- region(s). In this way you can create a complicated series of
- crossfades, and then layer another region atop the others, and fade
- into a complicated series.
+ region(s). In this way complicated series of crossfades can be created, and
+ then another region layered atop the others, and faded into a complicated
+ series.
</p>
<p>
If a region doesn't have any region(s) under it, then the region is
- crossfaded to silence; for convenience we call this a "fade"
+ crossfaded to silence; for convenience this is called a "fade"
rather than a crossfade.
</p>
<h2>Fade Shapes</h2>
+<figure class=right>
+ <img src="/images/crossfade_menu.png">
+ <figcaption class=center>The fade shape context menu.</figcaption>
+</figure>
+
<p>
To activate/deactivate or change the shape of a region's fadein or
- fade-out, hover the cursor over the regionfade grip till the cursor tip
- indicates region fade editing and context-click to bring up a context
- menu. In the context menu there is a list of options for the
- regionfade. <kbd class="menu">Activate/Deactivate</kbd> enables and
+ fade-out, the cursor has to be hovered over the regionfade grip until the
+ cursor tip indicates region fade editing, then <kbd class="mouse">right</kbd>
+ clicked to bring up a context menu. In the context menu is a list of options
+ for the regionfade. <kbd class="menu">Activate/Deactivate</kbd> enables and
disables the regionfade.
</p>
<p>
The different types of fades are:
</p>
<table class="dl">
- <tr><th><kbd class="menu">Linear</kbd></th><td>A simple linear coefficient decrease, and its
-mathematical inverse. A Linear fade starts attentuating quickly
-and then cuts off even more abruptly at lower levels. When used
-as a crossfade, the signals are each -6dB attenuated at the midpoint.
-This is the correct crossfade to use with highly-correlated signals for
-a smooth transition.</td></tr>
- <tr><th><kbd class="menu">Constant Power</kbd></th><td>The constant power curve starts fading
-slowly and then cuts off abruptly. When used as a crossfade
-between 2 audio regions, the signals are symetrically attenuated, and
-they each reach -3dB at the midpoint. This is the correct crossfade to
-use when you want to splice audio in the general ( uncorrelated ) case.</td></tr>
- <tr><th><kbd class="menu">Symmetric</kbd></th><td>The Symmetric fade starts slowly, then
-attenuates significantly before transitioning to a slower fade-out near
-the end of the fade. When used as a crossfade, the Symmetric
-curve is not mathematically correct like the Equal Power or Linear
-curves, but it provides a slower fade-out at low volumes. This is
-sometimes useful when editing 2 entire music works together so that the
-transition is more gradual.</td></tr>
- <tr><th><kbd class="menu">Fast</kbd></th><td>The Fast curve is a linear decibel fade; It sounds
-like a perfectly smooth fader or knob moved to silence. This shape is
-excellent as a general-purpose fade-in. When used as a
-crossfade, the inverse fade curve maintains constant power but is
-therefore non-symmetric; so its use is limited to those cases where the
-user finds it appropriate.</td></tr>
- <tr><th><kbd class="menu">Slow</kbd></th><td>The Slow curve is a modified linear decibel fade.
-The initial curve starts more gradually so that it has a less
-abrupt transition near unity. After that, it sounds like a
-perfectly smooth fader or knob moved to silence. This shape is excellent as
-a general-purpose fade-out. When used as a crossfade, the
-inverse fade curve maintains constant power but is therefore
-non-symmetric; so its use is limited to those cases where the user
-finds it appropriate.</td></tr>
+ <tr><th><kbd class="menu">Linear</kbd></th><td>A simple linear coefficient
+ decrease, and its mathematical inverse. A Linear fade starts attentuating
+ quickly and then cuts off even more abruptly at lower levels. When used as a
+ crossfade, the signals are each -6dB attenuated at the midpoint. This is the
+ correct crossfade to use with highly-correlated signals for a smooth
+ transition.</td></tr>
+ <tr><th><kbd class="menu">Constant power</kbd></th><td>The constant power
+ curve starts fading slowly and then cuts off abruptly. When used as a
+ crossfade between 2 audio regions, the signals are symetrically attenuated,
+ and they each reach -3dB at the midpoint. This is the correct crossfade to
+ use when splicing audio in the general ( uncorrelated ) case.</td></tr>
+ <tr><th><kbd class="menu">Symmetric</kbd></th><td>The Symmetric fade starts
+ slowly, then attenuates significantly before transitioning to a slower
+ fade-out near the end of the fade. When used as a crossfade, the Symmetric
+ curve is not mathematically correct like the Equal Power or Linear curves,
+ but it provides a slower fade-out at low volumes. This is sometimes useful
+ when editing 2 entire music works together so that the transition is more
+ gradual.</td></tr>
+ <tr><th><kbd class="menu">Slow</kbd></th><td>The Slow curve is a modified
+ linear decibel fade. The initial curve starts more gradually so that it has
+ a less abrupt transition near unity. After that, it sounds like a perfectly
+ smooth fader or knob moved to silence. This shape is excellent as a
+ general-purpose fade-out. When used as a crossfade, the inverse fade curve
+ maintains constant power but is therefore non-symmetric; so its use is
+ limited to those cases where the user finds it appropriate.</td></tr>
+ <tr><th><kbd class="menu">Fast</kbd></th><td>The Fast curve is a linear
+ decibel fade; It sounds like a perfectly smooth fader or knob moved to
+ silence. This shape is excellent as a general-purpose fade-in. When used as
+ a crossfade, the inverse fade curve maintains constant power but is
+ therefore non-symmetric; so its use is limited to those cases where the
+ user finds it appropriate.</td></tr>
</table>
<p>
- Although these fade shapes serve specific purposes, you might find that
- any of the shapes is usable in your situation. The final decision
- is mostly an artistic choice.
+ Although these fade shapes serve specific purposes, any of the shapes is
+ usable in any situation, so the final decision is mostly an artistic choice.
</p>
<p>
amount of effort to shorten the fade is much easier than messing with a
crossfade editor dialog.
</p>
-
<table class="dl">
<tr><th>Systems using JACK 1, versions 0.124 or later</th>
- <td>On these systems, simply start JACK with the <code>-X alsa_midi</code>
+ <td>On these systems, JACK must be started with the <code>-X alsa_midi</code>
server argument. To support legacy control applications, the <code>-X
seq</code> argument to the ALSA backend of JACK can also be used to get the
exact same results.</td></tr>
<tr><th>All others</th>
- <td>Use a2jmidid to act as a bridge between ALSA MIDI and JACK. Do not use
- the <code>-X seq</code> or <code>-X raw</code> arguments—the timing and
+ <td>Using a2jmidid acts as a bridge between ALSA MIDI and JACK. The <code>-X seq</code>
+ or <code>-X raw</code> arguments should <em>not</em> be used—the timing and
performance of these options is unacceptable.</td></tr>
</table>
<p>
First it must be ensured that there is no ALSA sequencer support enabled in
- JACK. To check that, open QJackCtl's <kbd class="menu">Setup</kbd> window.
- Set <kbd class="menu">Settings > MIDI Driver</kbd> to <kbd
- class="input">none</kbd>. Then uncheck the <kbd class="optoff">Misc >
- Enable ALSA Sequencer support</kbd> option. Now restart the jack server
+ JACK. To check that, one must open QJackCtl's <kbd class="menu">Setup</kbd> window
+ and set <kbd class="menu">Settings > MIDI Driver</kbd> to <kbd
+ class="input">none</kbd>, then uncheck the <kbd class="optoff">Misc >
+ Enable ALSA Sequencer support</kbd> option. The jack server must then be restarted
before going on.
</p>
-<h3>Check for a2jmidid availability</h3>
+<h3>Checking for a2jmidid availability</h3>
<p>
- Next, check whether a2jmidid is already installed. After starting the JACK
- server, go to the command line and type:
+ Next, it must be checked whether a2jmidid is already installed. This is done
+ by starting the JACK server, then going to the command line and typing:
</p>
<kbd class="cmd lin">a2jmidid -e</kbd>
<p>
- If a2jmidid does not exist, install it with the software manager of the
- Linux distribution in use and try again.
+ If a2jmidid does not exist, it must be installed with the software manager of the
+ Linux distribution in use until this command responds.
</p>
-<h2>Check available MIDI ports</h2>
+<h2>Checking available MIDI ports</h2>
<p>
If JACK is correctly configured for MIDI, then the MIDI ports should appear
</p>
<ul>
- <li>If a newer version of JACK 1 is in use, just make sure the <code>-X
+ <li>If a newer version of JACK 1 is in use, by just making sure the <code>-X
alsa_midi</code> or <code>-X seq</code> options are enabled for whatever
technique is being used to start JACK.</li>
- <li>For other versions of JACK, add <code>a2jmidid -e &</code> as an
+ <li>For other versions of JACK, by adding <code>a2jmidid -e &</code> as an
"after start-up" script in the <kbd class="menu">Setup > Options</kbd> tab
of QJackCtl, so that it is started automatically whenever JACK is
started.</li>
</ul>
-
projects / ardour-manual / commitdiff
