<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>

CC BY-SA 3.0
2014-06-08T16:14:50.403Z
2014-06-08T16:14:50.403Z
Jim Mack
<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>

CC BY-SA 2.5
2011-03-28T11:10:06.507Z
2011-03-28T11:10:06.507Z
moala
<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>

CC BY-SA 3.0
2015-07-21T06:19:50.130Z
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
jsj
<sync><timecode>
Negative SMPTE timecode drop-frame handling?
moala
# 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  

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## 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.


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### 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.


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