Selecting The Generator Drop Frame Mode (29.97 And 59.94 Fps Video Standards Only); Conversion Between Drop Frame And Non Drop Frame Counting Modes - evertz HD9010TM Instruction Manual

3.4.7. Selecting the Generator Drop Frame Mode (29.97 and 59.94 FPS video standards only)

In the 29.97 and 59.94 frames per second video standards, the time code frame rate of approximately
29.97 frames per second causes an error between real time and 'video time'. To overcome this
problem, the drop frame mode was created. This mode compensates for the approximate 86 seconds
per day error by dropping the first two frame counts (0, 1) at the start of each minute, except minutes 0,
10, 20, 30, 40, and 50. A drop frame flag bit is set in the code when the drop frame format is used.
When the HD9010TM is operating in the 29.97 and 59.94 frames per second video standards, the
generator may be programmed to count in either the drop frame or non-drop frame mode.
GEN DROP FRAME
Drop frame: off
Drop frame: on
Drop frame: convert
Drop frame: jamming
Not applicable
The AUX LTC output will normally output nominal 24 FPS time code that is
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concurrent with the nominal 30 FPS timecode on the main LTC. When the main
LTC output is in the Drop Frame counting mode, the AUX LTC output will be muted
as there is no 24 FPS equivalent.

3.4.7.1. Conversion Between Drop Frame and Non Drop Frame Counting Modes

In certain circumstances, it may be necessary to convert from the Non Drop Frame counting mode to
the Drop Frame counting mode. For example, material that originated in a 1080p/23.98 format will
have a 24 frame per second time code, which by definition is non drop frame time code. If that material
is subsequently converted to a 1080i/59.94 format the recommended procedure for conversion of the
time code (according to SMPTE 12M) will result in a 30 frame per second non drop frame time code
where the hours, minutes and seconds are aligned with the 24 frame per second code.
broadcast delivery specifications require Drop Frame time code. Because of the 'dropped frame counts'
in Drop Frame time code, the time code count will diverge from Non Drop Frame time code, The Drop
Frame and Non Drop Frame time codes will only be co-incident at one frame count which shall be
called the "Sync Point'.
OPERATION
HD9010TM High Definition Time Code Master Manual
The GEN DROP FRAME menu item is used to the desired drop frame
mode for the generator.
Select Drop frame off to configure the generator in the non-drop frame
or 'full frame' mode.
Select Drop frame on to configure the generator in the drop frame
mode.
Select Drop frame convert to configure the HD9010 to operate in a
special Drop Frame conversion Mode. This mode is available in
firmware version 2.0 build 138 or later. See section 3.4.7.1 for more
information on using the Drop Frame Conversion Mode.
When the HD9010TM is in the continuous Jam Sync mode, the
generator drop frame mode is the same as the incoming time code
data. The Drop Frame sub-menu shows Drop frame jamming.
When the HD9010TM is operating in the 24, 25 or 50 frames per
second video standards, the Drop Frame sub-menu shows Not
applicable.
Revision 2.4.1
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