[Q] timecode for dropping frame?

27 Dec 2009

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I would like to add some more information I asked in quicktime-apl mailing list.

The issue was the the timecode returned by [[qtMovie attributeForKey:QTMovieCurrentTimeAttribute] QTTimeValue]; or currentTime returns somewhat weird timecode for dropping frame video files.
However, the FCP and the QuickTime player ( not X ) displays the timecode correctly for dropping frame video clips.

This is the pattern I found :

Left : timecode from QuickTime API, which is not right.
Right : timecode overlay imposed by FCP, which is correct (QuickTime Player also shows this timecode. )

Time from QT : 33 sec 28                                  Overlay :      33 sec 28
                           34 sec 00 ( jump 1 frame)                             33 sec 29 (continue)
                           34 sec 01                                                         34 sec 00
                           34 sec 02                                                         34 sec 01

Time from QT :          59sec 29                                 Overlay : 59;28
                        1 min 00 sec 00                                                   59;29
                        1 min 00 sec 01                                               1:00;02 ( jumping 2 frames) ( This is correct. At every 1 min, timecodes for 2 frames are dropped. )

                         1 min 06 sec 28                                               1:06;29
                         1 min 07 sec 00  (jump 1 frame )                  1:07;00

                         1 min 39 sec 28                                               1:39;28
                         1 min 40 sec 00  (jump 1 frame )                  1:39;29
                         1 min 40 sec 01  				                 1:40;00

                        1 min 59sec 29                                                 1:59;28
                        2 min 00 sec 00                                                1:59;29
                        2 min 00 sec 01                                                2:00;02 ( jumping 2 frames)
                        2 min 00 sec 02                                                2:00;03

                        2 min 13 sec 28                                                2:13;29
                        2 min 14 sec 00 (jump 1 frame)                     2:14;00

For me to let my program display the correct timecode, I should either have unmodified timecode to have it increased by 2 frame at every 1 min, or QuickTime API should detect that the clip is DF one and return correct time code. However, it drops 1 frame at every 33rd or 34th frame ( I'm not sure it is always so. )
So, is there any way to retrieve correct timecode?

Thank you.
JongAm Park _______________________________________________
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