--- /dev/null
+---
+layout: default
+title: OSC: Feedback
+---
+
+<p>
+ Feedback from the Ardour to the the control surface is very useful for
+ a number of things. Motor faders need to know where the the track
+ they have been attached to is at before they were assigned otherwise
+ the DAW fader will jump to where the controller fader is. Likewise,
+ the buttons on each strip need to know what their value is so they can
+ light their LED correctly. Transport controls should let you know if
+ they are active too. This is what feedback is all about.
+</p>
+<p>
+ Ardour does feedback by sending the same path back that is used to
+ control the same function. As such any controls that have feedback
+ have a parameter that is the value of the control or it's state
+ (on or off). In the case of OSC paths listed on the main OSC page
+ as having no parameter, if they have feedback, they will also work
+ with a 1 for button press and 0 for button release. This is because
+ many OSC controllers will only use exactly the same path for feedback
+ as for control. For example:
+</p>
+
+<dl class="bindings">
+ <dt><kbd class="osc">/transport_stop</kbd></dt>
+ <dd></dd>
+</dl>
+<p>can be used also in the form:</p>
+
+<dl class="bindings">
+ <dt><kbd class="osc">/transport_stop <em>press</em></kbd></dt>
+ <dd>where <em>press</em> is an int/bool indicating if the button is pressed or not.</dd>
+</dl>
+
+<p>
+ The feedback does not have the same meaning as the control message.
+ Where the button release sent to Ardour will be ignored and has no
+ meaning. Both states have meaning in feedback to the controller.
+ The feedback will be:
+</p>
+
+<dl class="bindings">
+ <dt><kbd class="osc">/transport_stop <em>state</em></kbd></dt>
+ <dd>where <em>state</em> is an int/bool indicating if the transport is stopped or not.</dd>
+</dl>
+<p>
+ With feedback turned on, OSC control commands that try to change a
+ control that does not exist will get feedback that resets that control
+ to off. For example, sending a /strip/recenable to a buss will not work
+ and Ardour will try to turn the controller LED off in that case. Also
+ note that Pan operation may be limited by pan width in some cases.
+ That is with pan width at 100% (or -100%) there is no pan position
+ movement available.
+</p>
+<p>
+ It may come as a surprise, but feedback often generates more network
+ traffic than control itself does. Some things are more obvious like
+ head position or meters. But even a simple button push like transport
+ start sends not only a signal to turn on the play LED, but also one to
+ turn off the stop LED, the Rewind LED, the Fast Forward LED and the
+ Loop LED. That is still minor, think instead of a surface refresh
+ such as happens when the surface is first connected and then most of
+ that happens every time the fader strips are banked. This is why
+ feedback is enabled in sections so that as little feedback as is
+ actually needed is sent. This is also a consideration if the surface
+ is connected via wifi.
+</p>
+<h2>List of OSC feedback messages</h2>
+
+<h3>Feedback only</h3>
+<p>
+ These messages are feedback only. They are sent as status from Ardour
+ and some of them may be enabled separately from other feedback. See:
+ <a href="/using-control-surfaces/controlling-ardour-with-osc/calculating-feedback-and-strip-types-values/">
+ Calculating Feedback and Strip-types Values.</a>
+</p>
+<p class="note">
+ See strip section below for info about ssid and wrapping it into the
+ path. Also /master and /monitor support what the /strip does.
+</p>
+<p>
+ In the case where Gainmode is set to position, the track name will
+ show the dB value while values are changing.
+</p>
+<dl class="bindings">
+ <dt><kbd class="osc">/strip/name <em>ssid</em> <em>track_name</em></kbd></dt>
+ <dd>where <em>track_name</em> is a string representing the name of the track</dd>
+ <dt><kbd class="osc">/session_name <em>session_name</em></kbd></dt>
+ <dd>where <em>session_name</em> is a string representing the name of the session</dd>
+ <dt><kbd class="osc">/strip/meter <em>ssid</em> <em>meter</em></kbd></dt>
+ <dd>where <em>meter</em> is a value repesenting the current audio level.
+ (the exact math used is determined by the feedback bits set)</dd>
+ <dt><kbd class="osc">/strip/signal <em>ssid</em> <em>signal</em></kbd></dt>
+ <dd>where <em>signal</em> is a float indicating the instantaneous
+ audio level is -40dB or higher.</dd>
+ <dt><kbd class="osc">/position/smpte <em>time</em></kbd></dt>
+ <dd>where <em>time</em> is a string with the current play head time. Seconds as per smpte.</dd>
+ <dt><kbd class="osc">/position/bbt <em>beat</em></kbd></dt>
+ <dd>where <em>beat</em> is a string with the current play head bar/beat.</dd>
+ <dt><kbd class="osc">/position/time <em>time</em></kbd></dt>
+ <dd>where <em>time</em> is a string with the current play head time. Seconds are in milliseconds</dd>
+ <dt><kbd class="osc">/position/samples <em>samples</em></kbd></dt>
+ <dd>where <em>samples</em> is a string with the current play head position in samples.</dd>
+ <dt><kbd class="osc">/heartbeat <em>LED</em></kbd></dt>
+ <dd>where <em>LED</em> is a float that cycles 1/0 at 1 second intervals.</dd>
+ <dt><kbd class="osc">/record_tally <em>state</em></kbd></dt>
+ <dd>Some record enable is true or "ready to record". For a "Recording" sign at studio door.</dd>
+</dl>
+
+<h3>Transport Control</h3>
+<dl class="bindings">
+ <dt><kbd class="osc">/transport_stop <em>state</em></kbd></dt>
+ <dd><em>state</em> is true when transport is stopped</dd>
+ <dt><kbd class="osc">/transport_play <em>state</em></kbd></dt>
+ <dd><em>state</em> is true when transport speed is 1.0</dd>
+ <dt><kbd class="osc">/ffwd <em>state</em></kbd></dt>
+ <dd><em>state</em> is true when transport is moving forward but not at speed 1.0</dd>
+ <dt><kbd class="osc">/rewind <em>state</em></kbd></dt>
+ <dd><em>state</em> is true when transport speed is less than 0.0</dd>
+ <dt><kbd class="osc">/loop_toggle <em>state</em></kbd></dt>
+ <dd><em>state</em> is true when loop mode is true</dd>
+ <dt><kbd class="osc">/cancel_all_solos <em>state</em></kbd></dt>
+ <dd>Where <em>state</em> true indicates there are active solos that can be canceled.</dd>
+</dl>
+
+<h3>Recording control</h3>
+<dl class="bindings">
+ <!--dt><kbd class="osc">/toggle_punch_in</kbd></dt>
+ <dd></dd>
+ <dt><kbd class="osc">/toggle_punch_out</kbd></dt>
+ <dd></dd-->
+ <dt><kbd class="osc">/rec_enable_toggle <em>state</em></kbd></dt>
+ <dd>Master record enabled.</dd>
+</dl>
+
+<h3>Master and monitor strips</h3>
+<p>
+ Master and monitor strips are similar to track strips but do not use
+ the SSID. Rather they use their name as part of the path:
+</p>
+<dl class="bindings">
+ <dt><kbd class="osc">/master/gain <em>dB</em></kbd></dt>
+ <dd>where <em>dB</em> is a float ranging from -193 to +6 representing the actual gain of master in dB</dd>
+ <dt><kbd class="osc">/master/fader <em>position</em></kbd></dt>
+ <dd>where <em>position</em> is an int ranging from 0 to 1023 representing the fader control position</dd>
+ <dt><kbd class="osc">/master/trimdB <em>dB</em></kbd></dt>
+ <dd>where <em>dB</em> is a float ranging from -20 to +20 representing the actual trim for master in dB</dd>
+ <dt><kbd class="osc">/master/pan_stereo_position <em>position</em></kbd></dt>
+ <dd>where <em>position</em> is a float ranging from 0 to 1 representing the actual pan position for master</dd>
+ <dt><kbd class="osc">/master/mute <em>yn</em></kbd></dt>
+ <dd>where <em>yn</em> is a bool/int representing the actual mute state of the Master strip</dd>
+ <dt><kbd class="osc">/monitor/gain <em>dB</em></kbd></dt>
+ <dd>where <em>dB</em> is a float ranging from -193 to 6 representing the actual gain of monitor in dB</dd>
+ <dt><kbd class="osc">/monitor/fader <em>position</em></kbd></dt>
+ <dd>where <em>position</em> is an int ranging from 0 to 1023 representing the fader control position</dd>
+</dl>
+
+<h3>Track specific operations</h3>
+<p>
+ For each of the following, <em>ssid</em> is the surface strip ID for the track
+</p>
+<p class="note">
+ Some Surfaces (many Android applets) are not able to deal with more
+ than one parameter in a command. However, the two parameter commands
+ below can also be sent as /strip/command/ssid param. Feedback can be
+ set to match this with the /set_surface/feedback <em>state</em>
+ command. See <a
+ href="/using-control-surfaces/controlling-ardour-with-osc/calculating-feedback-and-strip-types-values/">
+ Calculating Feedback and Strip-types Values.</a>
+</p>
+
+<dl class="bindings">
+ <dt><kbd class="osc">/bank_up <em>LED</em></kbd></dt>
+ <dd>where <em>LED</em> is a bool that indicates another bank_up operation is possible.</dd>
+ <dt><kbd class="osc">/bank_down <em>LED</em></kbd></dt>
+ <dd>where <em>LED</em> is a bool that indicates another bank_down operation is possible.</dd>
+ <dt><kbd class="osc">/strip/name <em>ssid</em> <em>track_name</em></kbd></dt>
+ <dd>where <em>track_name</em> is a string representing the name of the track
+ (note there is no coresponding command to set the track name)</dd>
+ <dt><kbd class="osc">/strip/mute <em>ssid</em> <em>mute_st</em></kbd></dt>
+ <dd>where <em>mute_st</em> is a bool/int representing the actual mute state of the track</dd>
+ <dt><kbd class="osc">/strip/solo <em>ssid</em> <em>solo_st</em></kbd></dt>
+ <dd>where <em>solo_st</em> is a bool/int representing the actual solo state of the track</dd>
+ <dt><kbd class="osc">/strip/monitor_input <em>ssid</em> <em>monitor_st</em></kbd></dt>
+ <dd>where <em>monitor_st</em> is a bool/int. True/1 meaning the track is force to monitor input</dd>
+ <dt><kbd class="osc">/strip/monitor_disk <em>ssid</em> <em>monitor_st</em></kbd></dt>
+ <dd>where <em>monitor_st</em> is a bool/int. True/1 meaning the track is force to monitor disk,
+ where both disk and input are false/0, auto monitoring is used.</dd>
+ <dt><kbd class="osc">/strip/recenable <em>ssid</em> <em>rec_st</em></kbd></dt>
+ <dd>where <em>rec_st</em> is a bool/int representing the actual rec state of the track</dd>
+ <dt><kbd class="osc">/strip/record_safe <em>ssid</em> <em>rec_st</em></kbd></dt>
+ <dd>where <em>rec_st</em> is a bool/int representing the actual record safe state of the track</dd>
+ <dt><kbd class="osc">/strip/gain <em>ssid</em> <em>gain</em></kbd></dt>
+ <dd>where <em>gain</em> is a float ranging from -193 to 6 representing the actual gain of the track in dB.</dd>
+ <dt><kbd class="osc">/strip/fader <em>ssid</em> <em>position</em></kbd></dt>
+ <dd>where <em>position</em> is an float ranging from 0 to 1 representing the actual fader position of the track.</dd>
+ <dt><kbd class="osc">/strip/trimdB <em>ssid</em> <em>trim_db</em></kbd></dt>
+ <dd>where <em>trim_db</em> is a float ranging from -20 to 20 representing the actual trim of the track in dB.</dd>
+ <dt><kbd class="osc">/strip/pan_stereo_position <em>ssid</em> <em>position</em></kbd></dt>
+ <dd>where <em>position</em> is a float ranging from 0 to 1 representing the actual pan position of the track</dd>
+</dl>
+<h3>Selection Operations</h3>
+<p>
+ Selection feedback is the same as for strips, only the path changes
+ from <em>/strip</em> to <em>/select</em> and there is no <em>ssid</em>.
+ there are some extra feedback and commands that will be listed here.
+</p>
+<dl class="bindings">
+ <dt><kbd class="osc">/select/n_inputs <em>number</em></kbd></dt>
+ <dd>where <em>number</em> number of inputs for this strip</dd>
+ <dt><kbd class="osc">/select/n_outputs <em>number</em></kbd></dt>
+ <dd>where <em>number</em> number of outputs for this strip</dd>
+ <dt><kbd class="osc">/select/comment <em>text</em></kbd></dt>
+ <dd>where <em>text</em> is the strip comment</dd>
+ <dt><kbd class="osc">/select/solo_iso <em>state</em></kbd></dt>
+ <dd>where <em>state</em> is a bool/int representing the Actual solo isolate state of the track</dd>
+ <dt><kbd class="osc">/select/solo_safe <em>state</em></kbd></dt>
+ <dd>where <em>state</em> is a bool/int representing the actual solo safe/lock state of the track</dd>
+ <dt><kbd class="osc">/select/polarity <em>invert</em></kbd></dt>
+ <dd>where <em>invert</em> is a bool/int representing the actual polarity of the track</dd>
+ <dt><kbd class="osc">/select/pan_stereo_width <em>width</em></kbd></dt>
+ <dd>where <em>width</em> is a float ranging from 0 to 1 representing the actual pan width of the track</dd>
+ <dt><kbd class="osc">/select/send_gain", <em>sendid</em> <em>send_gain</em></kbd></dt>
+ <dd>where <em>sendid</em> = nth_send, <em>send_gain</em>is a float
+ ranging from -193 to +6 representing the actual gain in dB for the send</dd>
+ <dt><kbd class="osc">/select/send_fader", <em>sendid</em> <em>send_gain</em></kbd></dt>
+ <dd>where <em>sendid</em> = nth_send, <em>send_gain</em>is a float
+ ranging from 0 to 1 representing the actual position for the send as a fader</dd>
+ <dt><kbd class="osc">/select/send_name <em>sendid</em> <em>send_name</em></kbd></dt>
+ <dd>where <em>send_name</em> is a string representing the name of the buss
+ this send goes to.</dd>
+</dl>
+<h3>Menu actions</h3>
+<p>
+ Every single menu item in Ardour's GUI is accessible via OSC. However,
+ there is no provision for returning the state of anything set this way.
+ This is not a bad thing as most menu items either do not have an on/off
+ state or that state is quite visible. Binding that affect other parameters
+ that OSC does track will show on those OSC controls. Examples of this
+ might be track record enable for tracks 1 to 32, play or stop.
+</p>
projects / ardour-manual-diverged / blobdiff