4 menu_title: Transport Tab
8 This tab contains settings that relate to the behavior of the
9 <a href="/controlling-playback/using-the-transport-bar">Transport Bar</a>
10 and <a href="/synchronization/">Synchronization</a>.
13 <img src="/files/a4/a4_preferences_transport.png" alt="preferences
19 <strong>Keep record-enable engaged on stop</strong> leaves the global
20 record-enable engaged after transport is stopped. Does not affect track
21 level record-enable which is never changed on stop.
27 <strong>Play loop is a transport mode</strong> changes the behavior of the
28 loop button, turning it into a toggle. When enabled, the loop button does
29 not start playback but forces playback to always play the loop. Looping
30 stays engaged when the transport is stopped. Playback continues where the
31 transport stopped and continues to loop.
34 When disabled, the loop button starts playing the loop but stop then
35 cancels loop playback.
40 <strong>Stop recording when an xrun occurs</strong> will stop the transport
41 when an xrun occurs during recording, ensuring no audible glitches are
47 <strong>Create markers where xruns occur</strong> will create a new
48 <a href="/working-with-markers/">marker</a> when an xrun occurs during
49 recording at the location of the xrun. This marks where possible xruns
50 might produce audible glitches when stopping on xruns is disabled.
55 <strong>Stop at the end of the session</strong> causes the transport to
56 stop during playback when it reaches the end marker. Behavior during
57 recording is not changed.
62 <strong>Do seamless looping</strong> removes any clicks that might
63 otherwise be audible when the transport moves from the end of the loop
64 range back to the beginning.
69 <strong>Disable per-track record disarm while rolling</strong>, when
70 enabled, will not allow the any track's record-enable to be disarmed
71 during record, preventing accidentally stopping the recording of a take.
76 <strong>12dB gain reduction during fast-forward and fast-rewind</strong>
77 when enabled will reduce the unpleasant increase in perceived volume
78 that occurs when fast-forwarding or rewinding through some kinds of audio.
83 <strong>Sync/Slave</strong>
87 <strong>External timecode source</strong> determines which external
88 source to use when Ardour is using an external
89 <a href="/synchronization/">synchronization</a> source. Depending
90 on the timecode source chosen, additional preference options are
96 <strong>Match session video frame rate to external timecode</strong>
97 controls the value of the video frame rate <em>while chasing</em>
98 an external timecode source.
101 When enabled, the session video frame rate will be changed to match
102 that of the selected external timecode source.
105 When disabled, the session video frame rate will not be changed to
106 match that of the selected external timecode source. Instead, the
107 frame rate indication in the main clock will flash red and Ardour
108 will convert between the external timecode standard and the session
114 <strong>Sync-lock timecode to clock</strong> can disable drift
118 When enabled, Ardour will never varispeed when slaved to external
119 timecode. Sync Lock indicates that the selected external timecode
120 source shares clock-sync (Black & Burst, Wordclock, etc) with
121 the audio interface. This options disables drift compensation.
122 The transport speed is fixed at 1.0. Vari-speed LTC will be ignored
126 When disabled, Ardour will compensate for potential drift regardless
127 if the timecode sources shares clock sync.
132 <strong>Lock to 29.9700 fps instead of 30000/1001</strong>, when
133 enabled, will force Ardour to assume the external timecode source
134 uses 29.97 fps instead of 30000/1001.
135 SMPTE 12M-1999 specifies 29.97 df as 30000/1001. The spec
136 further mentions that drop-frame timecode has an accumulated error
137 of -86 ms over a 24 hour period. Drop-frame timecode would
138 compensate exactly for an NTSC color frame rate of 30 * 0.9990 (i.e.
139 29.970000). That is not the actual rate. However, some vendors use
140 that rate - despite it being against the specs - because the
141 variant of using exactly 29.97 fps has zero timecode drift.
148 <strong>LTC Reader</strong> specifies which incoming port will provide
153 <strong>LTC Generator</strong>
157 <strong>Enable LTC generator</strong>, when enabled Ardour will
158 output an LTC timecode signal on it's <em>LTC-out</em> port.
163 <strong>Send LTC while stopped</strong>, when enabled Ardour will
164 continue to send LTC information even while the transport (playhed) is
170 <strong>LTC generator level:</strong> specifies the peak volume of
171 the generated LTC signal in dbFS. A good value is 0dBu^=-18dbFS in an
172 EBU calibrated system.