In the OnTheAir Video and OnTheAir Video Express playlists, you sometimes can see warning icons in front of some clips:
These warning icons are shown when the frames per seconds (fps) of a video file uses a fraction of the fps of video format used in the playback settings.
In the example above, you can see that :
- There is a warning in front of the first 2 clips because it means that we will have to duplicate or drop frames every now and then, irregularly. This can be seen on the output video signal and this is why we have to warn about this.
- But there is no warning in front of the last 3 because they either use the same fps as the output, OR it is an entire multiple/divider. For example a 720p29.97 will not show any warning when used in a 720p59.94 output because what we'll do is simply duplicate every frame. Be aware though that it takes a bit more CPU to decompress those files, but for the viewers there is no difference and it looks like playing out in 720p29.97.
A few things to note:
- We do not “interpolate” the frames when there is a difference between the fps of a clip and the fps of the output. We only drop or duplicate frames in order to maintain AVSync.
- It is independent of the size of the frame. Remember that OnTheAir Video with the "Smart Resize and Graphics" option enabled has a much better resize quality than OnTheAir Video Express or OnTheAir Video with the option disabled.