I.e.
29.97
FPS non drop timecode is
30
FPS
timecode running 0.1% slower (defined as
1000/1001 pull down rate) and within the 6%
window.
The timecode speed is displayed in the
DISPLAY
mode
CAL
.
1.0000
indicates timecode running at
nominal
speed.
29.97
FPS non drop timecode will be displayed
as
30
FPS running at
0.9990
.
29.97 DF
drop frame timecode is indicated by
LED
30
and LED
DF
with a calibration factor
CAL
0.9990
Timecode faster or slower than 6% or timecode
running reverse is translated into so-called MTC
full messages.
MTC full messages are used to spot a
DAW
or
other MTC controlled software to a specific
location, just like a locater.
In operation mode SOURCE = LTC a video
sync input signal does not influence the LTC
to MTC translation process.
Synchronisation is always referenced to the LTC
I
nput signal, indicated in CAL DISPLAY mode by
"
I
" (
I
1.0000 ).
The
default
timecode standard after powering
up is defined by the non volatile stored settings
made in the generator setup. Detection of a
different timecode standard takes one time 2-3
seconds. A correctly setup default standard
avoids this delay each time after powering up.
MTC and USB input modes
D
igital
A
udio
W
orkstations as well as lighting
and show control software use MTC midi
timecode for synchronisation.
mif4 reads MTC to regenerate synchronised,
stable LTC and MTC timecode.
MTC timecode can be quite unstable and jittery
caused by the latency of computer operating
systems. For this reason, mif4 makes use of
slow and integrating sync algorithms.
If the unit receives an MTC full message, it will
stop and generate a short burst of stationary
LTC timecode.
The unit repeats one LTC frame 8 times.
On the LED display there are DECIMAL POINTS
to separate hours, minutes, seconds and frames
(00
.
00
.
00
.
00
.
).
The rightmost decimal point (to the right of the
frame digits) is used as a LOCKED indicator.
If the unit is in sync and outputs locked timecode,
this LOCKED indicator will light up. In MTC or
USB input modes the LOCKED threshold is <
5ms, in LTC mode < 100µS.
If the incoming midi timecode is jumping or
drifting away so that mif4 is unable to follow the
source, it will display ERROR 01 in MTC mode
or ERROR 02 in USB mode.
In this case a stop and restart of the timecode
synchronisation will be executed.
GEN generator mode
To start the timecode generator manually please
select the generator mode (SOURCE = GEN)
and display mode timecode (DISPLAY = TC).
Now press and hold the left key for about two
seconds until the HOUR digits and the right key
start blinking.
Change the "HOUR" setting with the right key.
Holding down this key for a second will
automatically count up the "HOUR" value.
Press the left key again to navigate to MINUTES.
Change the "MINUTES" value using the right
key.
Press the left key again to navigate to FPS
section. (FPS = Frame Per Second)
Select the timecode standard 24, 25, 30 or 30
drop using the right key.
Press the left key once again to
start
the
timecode generator manually.
If there is an external video sync signal applied
matching
the selected frame rate, the timecode
generator will be started
genlocked
.
So the start of picture (vertical sync) matches the
start of the 80 bit LTC timecode word and MTC
quarter frame F1 0x.
Applied pull down video syncs (i.e. NTSC =
480i59.97) will change 30 FPS timecode frame
rate automatically into pull down 29.97 FPS
timecode frame rate.
CAL display 0.990 informs about pull down
timecode rates.
