Frame rate, F sampling rate modes, Frame rate f sampling rate modes – Sound Devices 702T User Manual

Page 32

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702T User Guide and Technical Information

30

v. 2.67

Features and specifications are subject to change. Visit www.sounddevices.com for the latest documentation.

Frame Rate

A single time code frame rate is selected in the

TIMECODE:FRAMERATE menu.

The 702T supports all of the common production time code rates, including:

23.976 – used with Sony high definition video cameras

24 – to sync audio to film where no transfer to NTSC video is expected

25 – to sync sound to PAL video

29.97 – to sync sound to NTSC SD video shot in non-drop frame mode and Panasonic high

definition cameras

29.97DF - to sync sound to NTSC video shot in drop frame mode

30 – to sync sound to film where transfer to NTSC SD downconvert is expected

30DF – to sync sound to film for transfer to NTSC video in drop-frame mode 29.97 fps

30+ – Records at 48.048 sampling rate at 30 frames per second but stamps the file at 48kHz, 30

frames per second.

Sound Devices Wave Agent Beta for Mac OS and Windows computers allows users to change the Frame
Per Second Stamp of any file. This is useful when the wrong Frame Rate was selected at the time of re-
cording.

See Wave Agent Beta for more details.

F Sampling Rate Modes

48.048k and 48.048kF

The 48.048kF mode (F stands for fake, faux, Fostex—take your pick) is a specific compatibility mode

for use with the Fostex DV40 software (1.74 and previous), Avid, Final Cut Pro, and other post-

production environments. The 48.048kF mode can aid in obtaining an NTSC 0.1% speed pulldown

without sample rate conversion. In this mode files are recorded at a 48.048 kHz sampling rate but are

stamped at 48 kHz. When played at 48 kHz, they will play back 0.1% slower than real time.

One use for the 48.048kF mode is to force a 0.1% speed reduction (pull down) of audio to match

MOS-telecined film (24 fps-to-NTSC SD) in non-linear edit systems, such as Avid or Final Cut Pro.

Since the file is stamped as a 48 kHz file, the edit system will play it back at 48 kHz and not at 48.048

kHz. This “audio pull down” will match the transferred picture without the need for an intermediate

step through other software or though an analog conversion to create the pull down.

The time code frame rate (actual recording rate) is forced to 30 ND in 48.048kF mode. The front panel

of the unit will show 30 ND during recording. No other frame rate is available in 48.048kF mode.

the file is recorded at 48.048 k, 30 ND

The sound file, however, is stamped with a 29.97 ND frame rate, along the 48 kHz sampling rate. It

will appear as if the file was originally recorded at a 48 kHz sampling rate at a TC rate of 29.97 ND.

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