Frame Rate Conversion

 

There are times in a production when the footage only exists in one format and the user needs to use it in another. A common example of that is a 24p project being handed an establishing shot that was shot on digibeta. In this case, the footage is interlace, 60 fields at 30 frames per second while the project type is progressive and 24 frames per second.

Using the Timewarp effect, part of the FluidMotion™ effects engine, the user can create alternate frame rates and keep the original audio in sync.

 

The Timewarp effect can be used to create all the frame rate conversions needed, but we will use the 60 field interlace to 24p as the example. The table below gives all the values needed to create any frame rate needed. There is also a bin available here that has all of the frame rate conversions as a preset template.

 

The user needs to capture the footage to be converted in its native project type. The example below is for converting 60 field NTSC material to 24p (59.94 fields into 23.976p), a 30i project will be created and the footage to be converted captured. The user will want to use the highest quality possible since the rendered timeline will become their new source master.

 

  1. Create 30i NTSC or 25i project
  2. Capture shot to be converted
  3. Edit onto timeline (V and A)
  4. Apply the Timewarp effect from the effects palette
  5. Select “FluidMotion” from the “render using” menu
  6. From the “formats” menu, select “interlace” as input and “progressive” as “output”
  7. Then open the “speed” graph and enter "125" into value entry box at the bottom of the window
  8. Render

 

 

 

The result will be a progressive clip of the same duration but is now running 125% faster. The reason for this is that when this clip is imported back into a 24p project, it will be slowed down by 25% due to the 1:21 frame relationship. This way, durations remain the same and the original audio remains in sync.

In order to get the clip back into a 24p project, export V only as a QuickTime reference and the audio as a WAVE file.

 

Import these two files back into a 24p project and sync the V only clip with the A only clip using AutoSync and the result is a sync VA clip in a 24 frame progressive format.

When importing the QuickTime file into the 24p project in Media Composer Adrenaline HD and Xpress Pro , the user may see a message indicating that the source is interlace in a progressive project. Click “OK and continue.” For versions 4.6 and earlier, the user can export sequential graphic files as workaround to the QuickTime interlace import issue.

 

Below is a table showing the value and settings for the most popular frame rate conversions:

 

NTSC

 

FROM

TO

 

 

 

SPEED

INPUT

OUPUT

29.97i

24P

124.88

interlace

progressive

29.97i

25p

119.88

interlace

progressive

29.97i

23.976p

125.00

interlace

progressive

29.97i

25i

119.88

interlace

interlace

29.97i

29.97p

100.00

interlace

progressive

 

 

 

 

 

29.97p

24p

124.88

progressive

progressive

29.97p

25p

119.88

progressive

progressive

29.97p

23.976p

125.00

progressive

progressive

29.97p

25i

119.88

progressive

interlace

29.97p

29.97i

100.00

progressive

interlace

 

PAL

 

FROM

TO

 

 

 

SPEED

INPUT

OUTPUT

25i

24p

104.17

interlace

progressive

25i

23.976p

104.27

interlace

progressive

25i

29.97p

83.42

interlace

progressive

25i

29.97i

83.42

interlace

interlace

25i

25p

100.00

interlace

progressive

 

 

 

 

 

25p

24p

104.17

progressive

progressive

25p

23.976p

104.27

progressive

progressive

25p

29.97p

83.42

progressive

progressive

25p

29.97i

83.42

progressive

interlace

25p

25i

100.00

progressive

interlace

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

23.976/24p

 

 

 

FROM

TO

 

 

 

 

 

SPEED

INPUT

OUTUT

24p

25p

96.00

progressive

progressive

24p

29.97p

80.08

progressive

progressive

23.976p

25p

95.90

progressive

progressive

23.976p

29.97p

80.00

progressive

progressive

 

For 30i to 60p (29.97i to 59.94p) use a speed of 50%, INPUT interlace and OUTPUT progressive.

The.abv file contains presets for all the frame rate conversions listed in the above table. These presets will work in both Media Composer Adrenaline HD and Xpress Pro HD. Add bin to project and open as you would any other bin. Download Bin