Bug creating a 1 minute comp in 29.97 DF

[F23d321c]

In the Composition Settings panel when I type 0;01;00;00 in the duration box AE reverts it to 0;00;59;28.

So I end up with a comp with a last frame at 0;00;59;27 instead of desired 0;00;59;29, so 2 frames short for a full minute or my 1800 frames target.  So in the panel I need to type 0;01;00;02 to create a timeline that end at 0;00;59;29.

Same thing goes in my comp timeline panel when I click the timecode in the upper left corner.  If typing 0;01;00;00 it will jump to 0;00;59;28.  The same action in Premiere will bring me to 0;01;00;02, which is the correct behavior.

[Mylenium]

Check the project settings for the time base. This sounds like an issue of the time base being set to 30 FPS rather than actual 29.97.

Mylenium 

[F23d321c]

If you look at my screenshot, I'm using the default HD comp preset at 29.97 DF.  As for the Projet Settings it is at default too.

[Rick Gerard]

The Current Time Indicator will always be placed at the start of a frame. If your comp is 30 seconds and 24 fps, then the CTI will stop at 0:00:29:23. If the 30-second comp is 29.97 fps, then the start of the last frame is 0;00;29;29. If the comp were 120fps, the start of the last frame would be 0:00:29:119.

The last frame has not been played yet, so the time indicator shows the start of the last frame. If you move the time indicator to the end of the last frame, so it is stopped after the composition has played, then the time will be exactly 0;00;30;00 if you use drop frame timecode. Non-Drop timecode uses a colon (:). No frames are actually dropped with DF timecode. Only frame numbers are dropped every few seconds so that the actual hours, minutes, and seconds remain accurate. That nonsense happened with NTSC television (60Hz) added color, and they didn't have enough scale lines for the color information, so they slowed the frame rate from 30 fps to 29.97 to add the color info to the interlaced signal. 29.97 is still the broadcast standard for all NTSC countries. That's any country that has 60Hz power. 

There is no error. There is no bug. The CTI is just stopping one frame before the end of the comp so you can see what is on that frame instead of just looking at black. That's the way all compositing apps work. Editing apps like Premiere Pro show black when you trim a clip to the CTI. That is also standard because when you are editing, you want to see the frame you are cutting off, and in a compositing or animation app, you want to see what is on the last frame to ensure it is good.  I hope that makes sense.

[F23d321c]

It makes total sense.  I know DF drops 2fr every minutes except every 10min, so every hour we loose 108fr or 3.6s.  The thing I dont understand is why AE, when entering a 1 minute  duration in the sequence settings panel, remove 2 frames when it shouldn`t.  It should be 0;00;00;00 to 0;00;59;29 for a full 1800 frames = 60s.  But instead AE drop 2 frames so my last frame is 0;00;59;27 for a total of 1798 frames.  Is it because AE forces me to be on a broacast spec correct path?  In Premiere if I generate a 1 minute offline clip it with be a full 1800 frames long.

[Rick Gerard]

Once again, DF timecode does not drop frames; it only drops frame numbers so that the time in hours, minutes, and seconds stays accurate. You do not lose 3.6 seconds when using DF timecode. If you set the timecode to NDF (non drop frame) the comp would be more than 3 seconds longer than one hour. DF timecode was created so that television stations would run on time. NO FRAMES ARE EVER MISSING. Only frame numbers. 

If the last frame of your comp starts at 0;00;59;29, then the comp is exactly one minute long because the last frame has not been played yet. This is normal behavior for all compositing, animation, and visual effects apps. The last frame is visible. If the CTI were at 0:01:00:00 in a one-minute comp, the composition panel would be blank because the last frame is over, and you could not see anything. If the last frame of the composition started at one minute, then the comp would be one minute and one frame long. 

There is no bug. There is just a problem with your expectations.