Final Concepts Flashcards
Frame rate
Indicates how speed is counted; measured in frames per second
ex. 29.97 df
can associate with time signature
Non-drop frame
The standard way to count time code; 0-29 and back to 0
Drop frame
Method of counting time code that drops time code reference numbers (not actual frames) at specific intervals
What frames does drop frame timing drop?
Drops 2 frames every minute except on the tens minutes
Ex. no frames dropped on minute 0, 10, 20, 20, etc.
How are frames counted in time code?
Frames begin at 0 and go to 29
No frame 30, just like we count from 59 seconds to 0 when the minute goes up
There is no frame 29.97, so 29.97 frame rate is counted like 30 fps but slowed down 0.1%
2-pop
One frame sine wave tone used to sync with the number 2 of a film countdown (the visual 2 is only 1 frame long); added during postproduction
head pop
Placed exactly 2 seconds BEFORE the FFOA- ensures correct sync between sound and picture
tail pop
Placed exactly 2 seconds AFTER the LFOA- ensures correct sync between sound and video is maintained throughout the whole reel
Release print
film shipped to the theater; sound and picture are married together with head and tail pops
Blackburst generator
(similar to a word clock generator) dictates the accuracy of video playback system (aka VIDEO REFERENCE/ VID REF)
Common speeds: 60 Hz, 59.94 Hz, 50 Hz
LTC
linear timecode; When the SMPTE timecode is encoded as an audio signal and recorded on a dedicated audio track (TC track)
TC used to have one machine “chase” (or follow) another machine’s timecode
The connection port is often XLR or BNC
NTSC
National Television Systems Committee; First TV broadcast made in 1939; Resolution is 525 lines horizontal displayed at 30 times a second using 2:1 interleave (i)
24fps; Based on 60Hz AC system
PAL
European version of NTSC; Based on 50Hz AC system; PAL is 25fps; Standard resolution is 325 interlaced 25 times a second; PAL is considered to handle color better than NTSC
Pulldown
Change in playback speed applied to sound element of a project when it needs to be converted to a format running at a different speed; usually associated with transferring film sound to a video medium due to the different speed references
What are the pulldown references for film?
30 fps 60 Hz
What are the pulldown references for NTSC video?
29.97 fps 59.94 Hz
What is the speed difference from film to NTSC?
0.1%
If sound is recorded at a 30fps @ 60Hz using a sampling rate of 48kHz, what happens to the sampling rate to have it play back accurately when referencing 29.97fps @ 59.94Hz?
It gets slowed down by 0.1%
ex. 48,000 Hz * .001 = 48 Hz
48,000 Hz - 48 Hz = 47,952 Hz
What can we do DURING RECORDING so that your END result is a sampling rate of 48kHz?
Sound record ON LOCATION can be 48,000 Hz * 1.01% (.1% FASTER than our pull-down) = 48.048 Hz
After your film is transferred to video, and you slow down your sound 0.1%, you have a sampling rate of 48,000Hz at a speed of 29.97 fps @ 59.94 Hz
Pulldown
Opposite of an audio pull-down; when the sound element (operating at NTSC video speed) needs to be relayed or tied to an element running at FILM speed; commonly, going from a TC rate of 29.97 to a TC 30 fps
What is multichannel audio?
any amount of channels more than mono; stereo, 5.1, 7.1.2, etc
What is surround?
extension of multi channel audio that includes some form of audio that is emitted from B the listener
Discrete surround
uses independent channels to feed each speaker, like sending multitrack outputs to dedicated speaker; for 5.1 system, there are 6 discrete channels; usual speaker assignments include L, R, C, Ls, Rs, and LFE
What are the main discrete formats and what kind of compression formats do they use?
Dolby Digital, Digital Theatre systems, Sony Dynamic Digital Sound; all use Lossy audio data compression and have different bit rates