PAL tallenne, epämusikaalinen?

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31.10.2006
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Converting 24p to PAL

24p material can be converted to the PAL format with the same methods used to convert film to PAL. The most popular method is to speed up the material by 25 / 24. Each 24p frame will take the place of two 50i fields. This method incurs no motion artifacts other than the slightly increased speed, which is typically not noticeable. The ~4% increase in speed raises the pitch by 0.7 of a semitone, which again typically is not noticed. Sometimes the audio is pitch shifted to restore the original pitch.

If 24p footage cannot be sped up, (for example if it were coming through a live NTSC or HD feed) it instead can be converted in a pattern where most frames were held on screen for two fields, but every half second a frame would be held for three fields. Thus the viewer would see motion stutter twice per second. This was the common result when programs were shot on film, edited on NTSC, and then shown in PAL countries. NTSC to PAL conversion also tends to blur each film frame into the next, and so is seen as a sub-optimal way to view film footage.

30p can be preferable over 24p since performing a standards conversion to 50i PAL has fewer technical complexities - any NTSC-PAL converter will do. The larger differences between the 30p and 50i framerates will cause less noticeable motion artifacts upon conversion.[1]

http://en.wikipedia.org/wiki/24p
 
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