Specifications

Pro Tools Reference Guide372
Sample Rate Conversion
Options
When importing AAF or OMF tracks into
Pro Tools, these settings let you convert the sam-
ple rate of the session’s audio files. For example,
you can convert from 48 kHz to 44.1 kHz, or from
44.1 kHz to 48 kHz. Avid HDX, HD Native, and
Pro Tools|HD systems support sample rates higher
than 48 kHz (88.2 kHz, 96 kHz, 176.4 kHz, and
192 kHz). These settings also enable you to con-
vert to compensate for the 0.1% speed change (pull
up or pull down) between 24 fps film and 29.97 fps
NTSC video, or the 4% speed change (pull up or
pull down) between 24 fps film and 25 fps PAL
video.
Source Sample Rate
This setting lets you specify the sample rate of the
audio material you are working with in Pro Tools,
independent of the project sample rate settings.
For example, you may receive a project originated
on Media Composer at 44.1 kHz. If you want to
work at 48 kHz in Pro Tools, you should set the
Source Audio Sample Rate setting to 44,100 and
the Destination Audio Sample Rate to 48,000.
These settings can also be used to correct for pull
up or pull down problems. For example, you may
receive an AAF or OMF transfer from a Film
Composer that contains audio media at “film
speed” when played back at 48 kHz. You may
want to convert all the audio files and edits to play
back at NTSC video speed and 48 kHz.
In this case, set the Source Audio Sample Rate set-
ting to 47,952 and the Destination Audio Sample
Rate to 48,000. These settings tell Pro Tools that
you want to fit 47,952 of the original “film speed”
samples into 48,000 of the new “video speed” sam-
ples. With these settings, you sample-rate-convert
the material to NTSC video speed.
You can set the Source Audio Sample Rate either
by selecting one of the predefined sample rates
from the pop-up menu, or by typing a value into
the text box.
Destination Sample Rate
This setting determines the target session’s audio
sample rate setting, as shown in the Session Setup
window, and the sample rate of all audio files in
the target session. Available settings include
Pro Tools standard sample rates of 44.1 kHz or
48 kHz. Avid HDX, HD Native, and
Pro Tools|HD systems support sample rates higher
than 48 kHz (88.2 kHz, 96 kHz, 176.4 kHz, and
192 kHz).
If this setting differs from the Source Audio Sam-
ple Rate setting, audio is sample-rate converted
digitally to the Destination Audio Sample Rate.
Sample Rate Conversion Options
See “Speed Correction for Film, NTSC Video,
and PAL Video” on page 1164 for information
about converting between different speeds and
sample rates.