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IanB · 20th August 2008, 12:24

Note! ShowSMPTE(23.976) is an Avisynth special. There is no definition (at least that I can find) about how to do the drop count for the NTSC Film rate. I just implemented a progression average approach so that 86313.686 frames in 1 hour counts as 86400, like for 29.97 107892.108 frames in 1 hour counts as 108000. The drop pattern occurs such that the error is never more than 0.5 count i.e. when the error is 0.5 count I jump a 1 count so the error then become -0.5 count. SMTPE(29.97) dictates that you jump 2 counts at the start of each minute but not for the 10's of minutes.

20th August 2008, 12:24	#11 \| Link
IanB Avisynth Developer Join Date: Jan 2003 Location: Melbourne, Australia Posts: 3,167	Note! ShowSMPTE(23.976) is an Avisynth special. There is no definition (at least that I can find) about how to do the drop count for the NTSC Film rate. I just implemented a progression average approach so that 86313.686 frames in 1 hour counts as 86400, like for 29.97 107892.108 frames in 1 hour counts as 108000. The drop pattern occurs such that the error is never more than 0.5 count i.e. when the error is 0.5 count I jump a 1 count so the error then become -0.5 count. SMTPE(29.97) dictates that you jump 2 counts at the start of each minute but not for the 10's of minutes.