And there are two ways to tackle it, you can either:
1) maintain the duration (= modify the number of frames) which has the effect that the footage will play at the same speed in the new 25 fps frame rate. This process is slower, takes more processing time,
or
2) reduce the duration (= maintain the same number of frames) which has the effect of speeding-up the footage in the new 25fps frame rate. This process is faster since no new frames are created.
Below are a few examples using different Software. As a general rule, use the best settings possible and the best codec/export settings, knowing that highest quality equals longer render times. Run tests.
1) Maintain duration (plays at same speed)
Compressor:
Use Apple Settings QT ProRes with pass through audio as a starting point.
Go to Inspector, Encoder, Video Format Select Frame Rate 25, make sure AR is correct. Verify your media source, check your Geometry tab, set Frame Size 1920x1080 and Pixel Aspect Square if necessary (Open Preview Window and look at the results) Something is set wrong in the AR or Geometry if you are getting a squeezed or stretched image.
Go to Frame Control. turn Controls ON, select Rate Conversion: Best (You might see ghosting with the other settings, test on a short clip.)
After Effects:
import your footage, right-click / New comp from selection.
Go to: Composition / Settings, change Frame Rate to 25. Click OK.
In the Composition window, enable Frame Blending, set Layer / Frame Blending to Pixel Motion.
Optional: add Force Motion Blur to taste.
FCPX:
Import your footage.
File / New Project, set Frame Rate at 25
Drag your footage into the Project Timeline
Select the clip, Go to the Inspector /Video /Rate Conform, Select Frame Sampling = Optical Flow (best.)
2) Reduce duration (plays faster)
Cinema Tools
This one is probably the easiest of the bunch, but USE THIS ON A DUPLICATE FILE as it will modify the QT and not create a new one -- no rendering needed. Open Clip, click Conform, Select Conform to 25, Click Conform.
Compressor:
Use Apple Settings QT ProRes with pass through audio as a starting point.
Go to Inspector, Encoder, Video Format Select Frame Rate 25, make sure AR is correct. Verify your media source, check you Geometry tab, set Frame Size 1920x1080 and Pixel Aspect Square if necessary (Open Preview Window and look at the results) Something is set wrong in the AR or Geometry if you are getting a squeezed or stretched image.
Go to Frame Control. Click so Source Frames play at... Select 23.976 @ 25.
After Effects:
import your footage, right-click / interpret footage / Main
conform frame rate to 25, click OK, Export.
FCPX:
Import your footage.
File / New Project, set Frame Rate at 25
Drag your footage into the Project Timeline
Select the clip, Go to the Speed button, select Automatic Speed.
