SMPTE Timecode & Pilotone Procedures for Processing Video Dailies at Colorlab

This document describes our operational requirements for processing audio with SMPTE time code or pilotone in video dailies, and is aimed at producers, cinematographers, and sound recordists preparing product for transfer.

The solution is for the technical staff in pre-production to determine the best techniques to use in consideration of the requirements of production and post, and the capabilities of the transfer and post facilities. Too often, this is left to the whims of the production staff at the shoot, resulting in later complications. Default procedures often cause problems.

To simplify the film-audio-video marriage, we have established operational capabilities versatile enough to only minimally limit the production phase. Sound and sync can be recorded on unmodified Nagras, with time code or pilot sync, provided certain requirements are met, and the essential information regarding frame rates and sync frequencies are noted on the materials delivered for transfer.

It is assumed in this discussion that all cameras, pilot sources, and time code generators are crystal controlled and/or properly interlocked where necessary, and have been checked for truly accurate frame rates and frequencies. Do not make assumptions, especially if you are having sync problems. Have these things verified by a competent engineer who understands your equipment and your needs.

The processes and techniques described herein, while not in any way proprietary to Colorlab, may not be available at other facilities, due to equipment differences, custom modifications, etc. Do not assume they represent any kind of universal standard and are available everywhere. What they do represent is our effort to adapt our facility to your needs, with minimum complication, expense, and hassle to you.

FILM FRAME RATE AND PILOT/TIME CODE FREQUENCIES

This chart defines the sync frequency requirements for the three common camera speeds. Crossing values on the chart will result in sync slippage of one frame in 32 seconds. For instance, 29.97 fps camera with a 60 hz. Nagra crystal. This is one of the most common errors. Correction will require another generation of dubbing audio thru special equipment. Rodel Audio in Washington, DC can provide this service.

Note: drop frame and non-drop frame time code do not mean 29.97 and 30 hz respectively. Either type of time code is valid at either speed for the purposes of holding sync-- only the frame rate(frequency)matters, and this must match the camera according to the above table. DF and NDF refer only to the counting sequences of the time numbers, and if time code is used in production, it could be of the same type as will be used in the final on-line(DF or NDF). Your transfer will have the same type of time code as on the 1/4" tapes from the field.

Some primitive stand-alone time code generators give no choice in this matter, they run at 29.97 fps when in the drop-frame mode, and 30 fps when in the non-drop. Others run only at 29.97. the Coherent Smart-Slate will run either type of code at either rate. Generators integral to video equiptment always run at 29.97. Time code can be used as a substitute for pilotone, if mag transfers for conventional film sound editing are desired.

NAGRA RECORDERS--TIME CODE

Nagra IV-S-ST(time code), or modified or unmodified IV-SL(FM pilot)stereo Nagras may be used with our transfer system.

In the first case, the IV-S/TC is used in the normal manner, with or without a Smart Slate.

An unmodified IV-SL can record time code either on an audio track or on the FM center track in lieu of the crystal pilot. To record on an audio channel, it is best to bypass the input stages of the machine by feeding the code into the EXT N.R.S. connector on the left side of the case. This will allow the filter switch and mic inputs to be used normally -- the mono switch will allow the two mics to be mixed on one channel.

To record code on channel 2, feed it to pin 6(hot) and 7(ground), and jumper pins 3&5 to maintain audio channel one continuity. Set the NORMAL-NRS switch to NRS. (To record code 1 and audio on two, feed code to pin 5(hot_and 6(ground), and jumper pins 2&6). Adjust the code generator output level for 8 on the modulometer for the corresponding channel.

To record on the FM center track, the time code is fed into pin 4(hot)and 1(ground)of the PILOT connector. Pins 4 and 5 of the CUE connector must be jumpered together to enable the FM record circuit in absence of pilot. Set the generator output level for 40% on the GROOVE DEPTH scale of the modulometer with the meter switch in PILOT PLAYBACK.

Time code is generally less forgiving than pilotone of recorder calibration problems, dirty heads, and cheap or bad tape...don' t skimp!

NAGRA RECORDERS-- PILOTONE

Ordinary neopilot tapes recorded on a IV-L, 4.2L, or IS may be post-striped with time code at extra cost, and dealt with as any other time code recording. This process precludes subsequent transfer on normal mono equipment, so if mag transfers are desired in addition to the video dailies, this must be done before striping, or if after, at Rodel Audio or similar facility.

SLATING

Head, mid, and tail slates are possible, as with any film work. The only rule is to provide 5 seconds of audio preroll when using pilotone, and 10 seconds with interrupted time code. If interrupted time code is used, keep it sequentially ascending, and try not to cross over midnight, or duplicate numbers on any given sound roll. Smart slates, and digital beepers are useful, but not strictly necessary. Keep in mind that if they are going to replace chalk slates, take logs, etc...THEY MUST BE IN FOCUS. If using regular sticks with time code, write the hours, minutes, and approximate seconds on the sound or camera reports. If using pilotone, make sure the slate is marked up, and the audio voice slated unambiguously. Remember, transfer time is far more expensive than Steenbeck time, and lots of time can be eaten up searching out poorly slated material. Roll numbers can be in the hours or user bits of the time code, if desired, but when using hour numbers, keep in mind the potential confusion of going over 24 rolls in a project.

REPORTS

In order to expedite your transfer, we need several pieces of information for each job, with special emphasis on any exceptions or changes in mid-stream. Failure to provide any of these items can result in delays while we contact someone who can provide the missing information. Below is a summary of the information required.

(If IV-SL w/TC, code on FM?, audio 1?, or audio 2?)

4. Roll numbers

5. Transfer wild sound, where?

6. Info on window dubs-tape format, time code on audio, adr or none, split audio mixed, etc