On Mon, Oct 26, 2015 at 10:39 AM, Moritz Barsnick <[email protected]> wrote:
> > And I suppose this begs the question, where do the numbers 30000 and > 1001 come from to begin with? > > From the same page, different section: > > To make the resulting pattern less noticeable, designers adjusted the > original 60 Hz field rate down by a factor of 1.001 (0.1%), to > approximately 59.94 fields per second. > > So that's just how it was defined, in analog times: A factor applied to > the synchronous rate of 30 or 60 Hz. (I wish they had solved it > differently. What a pain these numbers are. But sort of appropriate for > the land[s] of inches per yard per mile. I digress.) Thanks for pointing out the 1.001 math. I'm totally aware of the reasons why 29.97/59.94 exists, but I never internalized the actual math behind it. So is the bottom line that FFmpeg favors overt pedanticism in regards to defining frame rates, hence the need for the user to actually provide it with the actual math required to define a true NTSC framerate? Is it bad form to simply use the "ntsc" and/or "ntsc-film" aliases, instead of using the fractional forms? _______________________________________________ ffmpeg-user mailing list [email protected] http://ffmpeg.org/mailman/listinfo/ffmpeg-user
