Comments on: What is drop-frame Timecode? http://www.philiphodgetts.com/2009/10/what-is-drop-frame-timecode/ Philip Hodgetts Thu, 09 Feb 2012 22:12:37 +0000 hourly 1 http://wordpress.org/?v=3.2.1 By: James Gardiner http://www.philiphodgetts.com/2009/10/what-is-drop-frame-timecode/#comment-55015 James Gardiner Tue, 27 Oct 2009 20:02:43 +0000 http://www.philiphodgetts.com/?p=542#comment-55015 I know the why and how, but really, non-integer frames rates should have been killed. There is no reason to have kept them. The "issues" stated could have been dealt with by the new tech. I feel it was more of the vendors weaving black bullshit trying to fool the purchasers. "We support more standards" - (Most you should never use...) Non- integer frames rates is a crime. In the end it just costing us all more time and money. James I know the why and how, but really, non-integer frames rates should have been killed.
There is no reason to have kept them. The “issues” stated could have been dealt with by the new tech.

I feel it was more of the vendors weaving black bullshit trying to fool the purchasers. “We support more standards” – (Most you should never use…)

Non- integer frames rates is a crime. In the end it just costing us all more time and money.

James

]]> By: Philip http://www.philiphodgetts.com/2009/10/what-is-drop-frame-timecode/#comment-54686 Philip Wed, 21 Oct 2009 21:51:10 +0000 http://www.philiphodgetts.com/?p=542#comment-54686 I've known the "why" and the rest of the description for more than 15 years and it wasn't that helpful. That's why I had to draw it for myself (mentally first then a real image). The explanation is readily available (Wikipedia et al) and was completely unhelpful in visualizing what's going on. Perhaps the explanation and the visual together will make it clearer to others. I’ve known the “why” and the rest of the description for more than 15 years and it wasn’t that helpful. That’s why I had to draw it for myself (mentally first then a real image). The explanation is readily available (Wikipedia et al) and was completely unhelpful in visualizing what’s going on. Perhaps the explanation and the visual together will make it clearer to others.

]]> By: Dennis Degan http://www.philiphodgetts.com/2009/10/what-is-drop-frame-timecode/#comment-54683 Dennis Degan Wed, 21 Oct 2009 21:31:28 +0000 http://www.philiphodgetts.com/?p=542#comment-54683 Phillip, your diagram doesn't explain WHY there is a need for Drop Frame Time Code. Here's my explanation: The difference in the total number of frames between 29.97fps NTSC video and exact 30fps video is approximately 108 frames per hour. IOW, there are 108 FEWER frames of video at 29.97fps than there are in 30fps video. In order to make 29.97fps NTSC video time code run at accurate clock time (where an hour of video displays exactly one hour of DF TC), those 108 frame numbers must be skipped so that the clock time (as represented by time code) will 'catch up' to actual clock time and be accurate at the end of the hour. It was decided (I think SMPTE made this the standard) to skip 2 frames every minute except on the tens-of-minutes. There are of course 60 minutes per hour. If you skipped 2 frames for each minute, that would be 120 skipped numbers, which is too many skipped frame numbers. By NOT skipping frame numbers on the tens-of-minutes, there would be 6 occasions when numbers would NOT be skipped each hour. Since each skipping occurrence skips 2 frames, that means 12 frames would NOT be skipped on those special instances. The result is 120 minus 12, which is of course 108; the exact number of frames that must be skipped each hour. Phillip, your diagram doesn’t explain WHY there is a need for Drop Frame Time Code. Here’s my explanation:
The difference in the total number of frames between 29.97fps NTSC video and exact 30fps video is approximately 108 frames per hour. IOW, there are 108 FEWER frames of video at 29.97fps than there are in 30fps video. In order to make 29.97fps NTSC video time code run at accurate clock time (where an hour of video displays exactly one hour of DF TC), those 108 frame numbers must be skipped so that the clock time (as represented by time code) will ‘catch up’ to actual clock time and be accurate at the end of the hour.
It was decided (I think SMPTE made this the standard) to skip 2 frames every minute except on the tens-of-minutes. There are of course 60 minutes per hour. If you skipped 2 frames for each minute, that would be 120 skipped numbers, which is too many skipped frame numbers. By NOT skipping frame numbers on the tens-of-minutes, there would be 6 occasions when numbers would NOT be skipped each hour. Since each skipping occurrence skips 2 frames, that means 12 frames would NOT be skipped on those special instances. The result is 120 minus 12, which is of course 108; the exact number of frames that must be skipped each hour.

]]> By: Philip http://www.philiphodgetts.com/2009/10/what-is-drop-frame-timecode/#comment-54676 Philip Wed, 21 Oct 2009 16:09:42 +0000 http://www.philiphodgetts.com/?p=542#comment-54676 Well, you can never, ever work in interger frame rates and display on a video monitor, so shooting those frame rates is not recommended or desirable. That's not particularly important unless you deliver a 60 second TVC, or any show for broadcast. Broadcast (or other places where real, exact run time is important) will reject something that is the wrong run time. Philip Well, you can never, ever work in interger frame rates and display on a video monitor, so shooting those frame rates is not recommended or desirable. That’s not particularly important unless you deliver a 60 second TVC, or any show for broadcast. Broadcast (or other places where real, exact run time is important) will reject something that is the wrong run time.

Philip

]]> By: Chris Gilbert http://www.philiphodgetts.com/2009/10/what-is-drop-frame-timecode/#comment-54675 Chris Gilbert Wed, 21 Oct 2009 15:56:14 +0000 http://www.philiphodgetts.com/?p=542#comment-54675 With the multitude of frame rates available with current generation cameras why is drop frame timecode used anymore? Where material is being made for web purposes there is no need to stick with archaic NTSC framerate with odd fractions per second. Shoot at 24, 25, 30 or even 60 frames a second and all your cuts will be exactly the length you think they are! With the multitude of frame rates available with current generation cameras why is drop frame timecode used anymore?
Where material is being made for web purposes there is no need to stick with archaic NTSC framerate with odd fractions per second. Shoot at 24, 25, 30 or even 60 frames a second and all your cuts will be exactly the length you think they are!

]]> By: Michael Horton http://www.philiphodgetts.com/2009/10/what-is-drop-frame-timecode/#comment-54662 Michael Horton Wed, 21 Oct 2009 07:28:11 +0000 http://www.philiphodgetts.com/?p=542#comment-54662 Ah. Cool. Now I get it. :) Ah. Cool. Now I get it.

:)

]]> By: Philip http://www.philiphodgetts.com/2009/10/what-is-drop-frame-timecode/#comment-54655 Philip Wed, 21 Oct 2009 02:50:07 +0000 http://www.philiphodgetts.com/?p=542#comment-54655 There, fixed now. I put in a smaller image that fits the theme and linked to the full size version. Philip There, fixed now. I put in a smaller image that fits the theme and linked to the full size version.

Philip

]]> By: Philip http://www.philiphodgetts.com/2009/10/what-is-drop-frame-timecode/#comment-54654 Philip Wed, 21 Oct 2009 02:38:53 +0000 http://www.philiphodgetts.com/?p=542#comment-54654 Could be, that's the first time I've tried to put in an image that big. Philip Could be, that’s the first time I’ve tried to put in an image that big.

Philip

]]> By: Michael Horton http://www.philiphodgetts.com/2009/10/what-is-drop-frame-timecode/#comment-54653 Michael Horton Wed, 21 Oct 2009 02:32:40 +0000 http://www.philiphodgetts.com/?p=542#comment-54653 Is it me or is the illustration kind of cut off? Is it me or is the illustration kind of cut off?

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