From 979c13772decbde2dfb05c2a269efef14a759a06 Mon Sep 17 00:00:00 2001
From: Alexandre Prokoudine
Ardour supports three common timecode formats:
LTC,
@@ -16,7 +14,6 @@
translate timecode. e.g create LTC timecode from incoming MTC.
@@ -83,6 +80,7 @@
The MTC generator has no options. Ardour sends full MTC
frames whenever the transport is relocated or changes state (start/stop).
@@ -91,17 +89,20 @@
The level of the LTC generator output signal can be configured
in the Preferences > Transport dialog. By
default it is set to -18 dBFS, which corresponds to 0dBu in an EBU
calibrated system.
The LTC generator has an additional option to keep sending timecode even
when the transport is stopped. This mode is intended to drive analog tape
machines which unspool the tape if no LTC timecode is received.
LTC is sent regardless of Ardour's transport speed. It is accurately
generated even for very slow speeds (<5%) and only limited by the
@@ -111,8 +112,8 @@
for high speeds.
The timecode source can be switched with the button just right of
Ardour's main clock. By default it is set to Edit > Preferences
> Transport.
When Ardour is chasing (synchronizing to) an external timecode
source, the following cases need to be distinguished:
and
In both cases the first option is preferred: clock sync + same FPS setting.
If the frames-per-second do not match, Ardour can either re-calculate
and map the frames, or the configured FPS (Session >
@@ -147,6 +154,7 @@
> Preferences > Transport > Match session video frame rate to
external timecode.
When enabled, the session video frame rate will be changed to match that
of the selected external timecode source. When disabled, the session video
@@ -155,6 +163,7 @@
flash red, and Ardour will convert between the external timecode standard
and the session standard.
29.97 drop-frame timecode is another corner case. While the SMPTE 12M-1999
specifies 29.97df as 30000/1001 frames per second, not all hardware devices
@@ -173,6 +182,7 @@
As described in the
On Clock and Time
@@ -180,30 +190,29 @@
source is not in sample-sync with the audio hardware (and JACK), Ardour
needs to run at varispeed to adjust for the discrepancy.
The checkbox External timecode is sync locked
allows to select the behavior according to the setup. When enabled, it
indicates that the selected external timecode source shares sync (Black
& Burst, Wordclock, etc) with the audio interface.
In other words: if enabled, Ardour will only perform initial
synchronization and keep playing at speed 1.0 instead of vari-speed
adjusting to compensate for drift.
- Note that vari-speed is unavailable when recording in Ardour, and all
- tracking happens at speed 1.0. So in order to record in sync with
- external timecode it must be sample-locked or it will drift over time.
-
MIDI Clock is not a timecode format but tempo-based time. The
absolute reference point is expressed as beats-per-minute and Bar, Beat
and Tick. There is no concept of sample-locking for MIDI clock signals.
Ardour will vari-speed if necessary to chase the incoming signal.
Note that the MIDI Clock source must be connected to the
When Ardour is chasing MTC, the main transport clock will display the
- received Timecode as well as the delta between the incoming signal and
+ received timecode as well as the delta between the incoming signal and
Ardour's transport position.
- When slaved to jack, Ardour's transport will be identical to
- JACK-transport. As opposed to other slaves, Ardour can be used to control
- the JACK transport states (stopped/rolling). No port connections need to
- be made for jack-transport to work.
+ When slaved to jack, Ardour's transport will be identical to JACK Transport.
+ As opposed to other slaves, Ardour can be used to control the JACK transport
+ states (stopped/rolling). No port connections need to be made for
+ JACK Transport to work.
- JACK-transport does not support vari-speed, nor offsets. Ardour does not
+ JACK Transport does not support vari-speed, nor offsets. Ardour does not
chase the timecode but is always in perfect sample-sync with it.
- JACK-transport also includes temp-based-time information in Bar:Beats:Ticks
+ JACK Transport also includes temp-based time information in Bar:Beats:Ticks
and beats-per-minute. However, only one JACK application can provide this
information at a given time. The checkbox
Session > Properties > JACK Time Master
diff --git a/include/transport-bar.html b/include/transport-bar.html
index da7155b..134b395 100644
--- a/include/transport-bar.html
+++ b/include/transport-bar.html
@@ -61,9 +61,9 @@
allows to temporarily scrub through the audio quickly. The slider
decides the playback speed: the further from the center it is set,
the faster the playback will scrub in both directions. The range of
- this acceleration can be set by right
- clicking the control and setting the multiplier, between 1.5
- (± 150%) and 8 (± 800%).
+ this acceleration can be set by right-clicking
+ the control and setting the multiplier, either 1.5 (± 150%) or 2
+ (± 200%).
Ardour Timecode Configuration
MTC Generator
+
LTC Generator
+
Ardour Slave Configuration
+
+
+
Frames-per-second
+
Clock Sync Lock
+
MIDI Clock
+
ardour:MIDI clock in
port.
@@ -271,23 +280,26 @@
JACK Transport
+
VariSpeed
@@ -71,21 +71,22 @@
The VS (for VariSpeed)
button sets a constant playback/record speed. It can be set
in semitones (1 semitone = × 2 1⁄12 ≈
- 105,9%), or cents of semitones, and is armed/disarmed by clicking the
- button. The VS button will blink when VariSpeed
- is enabled. Whether or not this VariSpeed is persistent when
- stopping/restarting transport depends on the Reset
- default speed on stop parameter in the Preferences.
+ 105,9%), cents of semitones, or percentages, and is armed/disarmed
+ by clicking the button. The VS button will blink
+ when VariSpeed is enabled. Whether or not this VariSpeed is persistent
+ when stopping/restarting transport depends on the
+ Reset default speed on stop parameter in the
+ Preferences dialog.
- On the left of the slider is the positional sync button (which might show Internal, - or MTC or several other values), than can be used to control whether or not the - transport position and start is controlled by Ardour, or by an external positional - synchronization source, such as MIDI Time Code (MTC), Linear Time Code (LTC) or JACK - (see Timecode Generators and Slaves). + On the left of the slider is the positional sync button (which might show + Internal, or MTC or several other values), than can be + used to control whether or not the transport position and start is controlled + by Ardour, or by an external positional synchronization source, such as MIDI + Time Code (MTC), Linear Time Code (LTC) or JACK (see + Timecode Generators and Slaves).