Answers.Body: <p>I know this is a very old Q, but it should be pointed out that a 'negative timecode' makes no sense. The SMPTE frame before 00:00:00:00 is 23:59:59:29. The namespace for drop frame (and non-drop) codes is already well-defined -- no need to postulate negative values. If there are systems or programs that use this notation, they should be rethought.</p>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2014-06-08T16:14:50.403Z
Answers.LastActivityDate: 2014-06-08T16:14:50.403Z
Answers.UserDisplayName: Jim Mack
Answers.Body: <p>Taking into account that</p>
  
  <ul>
  <li>frame dropping works on a 10min-regular basis</li>
  <li>project offsetting by a multiple of 10min should keep frame dropping at the same positions</li>
  </ul>
  
  <p>I guess the correct way of doing this is on a <strong>regular</strong> basis.</p>
  
Answers.ContentLicense: CC BY-SA 2.5
Answers.CreationDate: 2011-03-28T11:10:06.507Z
Answers.LastActivityDate: 2011-03-28T11:10:06.507Z
Answers.UserDisplayName: moala
Body: <p>How are negative timecodes handled with drop-frame:</p>
  
  <ul>
  <li>Is the frame before <code>-00:00:59:29</code> labelled <code>-00:00:01:02</code> (symmetric), or</li>
  <li>Is the frame after <code>-00:01:00:01</code> labelled <code>-00:00:59:28</code> (regular)?</li>
  </ul>
  
  <p>Thanks.</p>
  
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2015-07-21T06:19:50.130Z
Comments.Text: Negative timecodes are not mentioned in SMPTE-12, the relevant standard, so I presume that as with timecodes > 24 hours the behaviour is implementation defined. FFMPEG's timecode flags allow for negative timecodes, you could check their implementation: https://www.ffmpeg.org/doxygen/2.7/timecode_8h_source.html
Comments.UserDisplayName: jsj
Tags: <sync><timecode>
Title: Negative SMPTE timecode drop-frame handling?
UserDisplayName: moala
ThreadText: # Negative SMPTE timecode drop-frame handling?
  
  (Asked by: username_0 on 2011-03-21)
  
  How are negative timecodes handled with drop-frame:
  
  * Is the frame before `-00:00:59:29` labelled `-00:00:01:02` (symmetric), or
  * Is the frame after `-00:01:00:01` labelled `-00:00:59:28` (regular)?
  
  Thanks.
  
  **Tags:** sync, timecode
  
  > **Comments:**
  > **username_1**: Negative timecodes are not mentioned in SMPTE-12, the relevant standard, so I presume that as with timecodes > 24 hours the behaviour is implementation defined. FFMPEG's timecode flags allow for negative timecodes, you could check their implementation: https://www.ffmpeg.org/doxygen/2.7/timecode_8h_source.html  
  
  ---
  
  ## 2 answers
  
  ### Answer by username_2 on 2014-06-08. Score: 2
  
  I know this is a very old Q, but it should be pointed out that a 'negative timecode' makes no sense. The SMPTE frame before 00:00:00:00 is 23:59:59:29. The namespace for drop frame (and non-drop) codes is already well-defined -- no need to postulate negative values. If there are systems or programs that use this notation, they should be rethought.
  
  
  ---
  
  ### Answer by username_0 on 2011-03-28. Score: 1
  
  Taking into account that
  
  * frame dropping works on a 10min-regular basis
  * project offsetting by a multiple of 10min should keep frame dropping at the same positions
  
  I guess the correct way of doing this is on a **regular** basis.
  
  
  ---
  
  