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CONVERSION of Audio for PAL / NTSC / FILM

Posted on February 28, 2010 at 12:54 AM

Some notes on CONVERSION of Audio for PAL / NTSC / FILM Ifthe PAL version was a frame-to-frame transfer, and is thus runningfaster than the original film (25fps vs 24, or even PAL video at 25 andHD video at 23.98), the key is to first get your stems back up to filmspeed, which would involve an SRC using 47952 as the source samplerate. THEN, when it's back at film speed (48k), you could do theNTSC>PAL SRC, the 4.1% thing. Maybe? Try just the center channelusing the fastest setting as a test, and if it works you can do thewhole thing at "Best" quality. Of course, the pitch will be faster(about 1/4 step) as well, in sync with the faster speed of the film. Toget it in sync but at the original pitch you have to do a wholetime-compression/pitch-shift thing which is a whole different process.

25 to 23.976, Divide those two numbers, and you get1.0427093760427093760427093760427. When truncated and expressed aspercentage, it becomes 104.27094% which is the number that you feedtime conversion software such as, Prosoniq Timefactory or Nuendotimestretch

NTSC to PAL would be 23.976/25 = 0.95904 = 95.904%

NTSC to PAL SR = 48000(25/23.976) = 50050 rounded.

PAL to NTSC SR = 48000(23.976/25) = 46034 rounded.

A time-stretch version is recommended, vs SRC conversion.

MPEX2 in Nuendo is apparently a good tool.

cheers

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