Why cuts never drift in Video by Zaweba

Odd frame rates have tripped up editing software for years. A rate like 29.97 frames per second cannot be written exactly as a short decimal, and a program that stores clip positions as rounded numbers can slowly drift, so that after an hour a cut lands a frame away from where you put it, or sound creeps out of step with picture. Video by Zaweba is built to avoid that from the ground up.

Whole ticks, not rounded seconds

Every clip position on the timeline is stored as a whole number of ticks, small fixed units of time chosen so that each supported frame rate fits into them exactly. Because the numbers are whole, there is no rounding to pile up. A cut placed on a frame stays on that frame, however long the programme and however many edits you make around it.

The supported rates are 23.976, 24, 25, 29.97, 30, 48, 50, 59.94, 60 and 120 frames per second. That covers film-style rates, the European and American television families and the high rates used for smooth motion and slow motion.

Why it matters in practice

Drift is the kind of fault you do not notice until late. Lips move a fraction before the words. A cut you made on a hand clap is now one frame off. A music edit that was tight sounds slightly loose. With positions stored exactly, those problems do not creep in from the timeline itself, and you can trust that what you set is what you get on export.

It also makes moving between rates safer. Mixing 25 and 50 frame footage, or 23.976 and 59.94, still lands every clip on a real frame boundary of the timeline.

Drop-frame timecode

Timelines at 29.97 and 59.94 show drop-frame timecode. Those rates run very slightly slower than 30 and 60, so a counter that simply counted frames would fall behind the clock, by several seconds over an hour. Drop-frame timecode skips certain frame numbers on a fixed pattern so the displayed time keeps step with real time. No pictures are dropped; only labels are skipped.

That matters most for broadcast in regions that use these rates, where programme lengths are measured to the second against the clock. The timecode on your timeline agrees with the clock on the wall, which is what a running order expects.

Choosing a rate

Set the project rate to match your main footage or the delivery you are making, before you cut much. In regions that use 25 and 50, those are the natural choices. In regions that use 29.97 and 59.94, follow them. For a cinematic look, 23.976 or 24 is the usual pick, and 120 suits material meant to be slowed down.

When footage arrives at a rate that does not match, it can still go on the timeline, but motion may look less smooth. Shooting at the project's rate in the first place gives the cleanest result.

Something you rarely think about

The time base is one of those foundations that only shows itself when it is wrong. In Video by Zaweba it sits under every other tool, from trimming to the sound mixer to captions, keeping them all in step without your having to think about it.