Step 6:

But before we do anything with the video, let's think for a moment about something equally important: the sound. Always make sure the sound is turned off in you silent loops. If a sound track is attached to the moving images, the size of the resulting digital video file will increase, often considerably. Even if the soundtrack is silent. To turn off the soundtrack, select the No audio item of the Audio menu.

Step 7:

Ok, back to the video. Let's address the playback speed, technically called "frame rate". Rewind your movie and let it play at its own speed pressing the "play" button.

Step 8:

If your movie has only a few frames (say less than 30), it probably plays very quickly To adjust this, select the Frame Rate... item of the Video menu

Step 9:

Examine the top part of the Video frame rate control dialog. In this case, under Source rate adjustment, the frame rate is set to 29.970 fps (which is one of several TV standard speeds). fps means "frames per second". So a 30 fps movie will need 30 images times its length in seconds. That is a lot of images!

Step 10:

With VirtualDub it is possibe to reduce the fps of a loop to any custom number. As the fps decrease, so does the "fluidity" of movement in the screen. At very low fps, the action becomes an obvious sequence of still images. It is well worth experimenting with different fps settings (and number of frames when rendering the loops).

Many movies are projected at 15 and even 10 fps. Animators often use low fps for work in progress and then render the loop at top-quality speeds. 30 fps is generally tops, except for slow motion, which can take 60 fps and more (and are then played back at a lower fps) . Experiment introducing a different frame rates using the Change to option and watch your loops play at different speeds.