13
NTSC National Television Systems Committee - US standards setting organization. Also referred to as the 525line,
29.97 FPS video standard for the first US color television system.
PAL
Phase Alternating Line - The 625 line, 25 FPS video standard for one of the first European color television
systems.
PPS
Pulse-Per-Second - A positive or negative going signal that occurs once-per-second.. Also sometimes written
as 1-PPS. The 1-PPS signal derived from the GPS system of satellites "ticks" at the same instant of time
everywhere on earth.
Preset
To set a time code generator to the same time as another time source to cause the generated time code to have
the same time value as that of the source time. Differs slightly from the "Jam" operation in that preset generally
refers to setting the TCG time to a manually entered user "preset" value.
SD
Standard Definition - generally refers to the original analog color television specifications of the US
"NTSC" system of 525 interlaced lines at 29.97 FPS, or the European (EBU) "PAL" equivalent of 625 interlaced
lines at 25 FPS.
SMPTE Society of Motion Picture and Television Engineers - A US standards setting organization. Usually Pronounced
“sim-tea” or “simpt-tea”
TC
Time Code - See “ SMPTE Time Code” in paragraph 1.2.
TCR
Time Code Reader – reads (decodes) SMPTE time code. The TRG-100 incorporates an internal multi-frame-rate
SMPTE time code reader., sometimes referred to in this manual as the “TRG-100 TCR” or just the “TCR”.
TCG
Time Code Generator - generates SMPTE time code. The TRG-100 incorporates a multi-frame-rate internal
SMPTE time code generator, sometimes referred to in this manual as the “TRG-100 TCG” or just the “TCG”.
UB
User Bits - See “SMPTE Time Code” in paragraph 1.2.
5.2 SMPTE Time Code
SMPTE time code is an electronic timing signal that assigns a unique number to identify each individual frame (image) of
video or film. SMPTE time code was initially developed in the 1960’s to facilitate the operation of electronic video tape
editing systems, but has since found numerous other applications.
As an electronic signal, SMPTE time code has a frequency range that allows it to be recorded on an audio recorder or the
audio track of a video recorder.
Sometimes SMPTE time code is referred to as “longitudinal” or “linear” time code because of it originally being recorded
on a continuous path along the length of a video or audio tape, rather than being recorded on slanted "tracks" via a spinning
head as is the method for video recording.
SMPTE Time Code Format
- Instead of numbering video or film frames starting with frame number 1 and then counting
on up into the thousands of frames from there, SMPTE time code numbers each frame in an hours, minutes, seconds, and
frame number format: “HH:MM:SS:FF”. This produces a “digital clock” type of time representation for each frame
number.
So, with SMPTE time code you end up with a unique frame number as well as a time value that goes up to 24 hours. For 30
FPS time code the time code would start at 00:00:00:00 and count on up to 23:59:59:29 after exactly 24 hours of elapsed
time.
SMPTE Time Code Bits
- The SMPTE time code format provides eighty (80) digital bits of information per frame.
"Sync Pattern" Bits -
Sixteen (16) bits are used to assist in locating and properly decoding the other 64 bits of the time
code. These bits are generally called the "sync pattern" or "framing" bits.
Time Bits
- Thirty two (32) of the remaining 64 bits are sub-divided into 8 groups of 4 bits each to encode the hours,
minutes, seconds, and frame number of the actual SMPTE time code time value for a particular video/film frame.