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HELP! Audio Conversion from a FCP 23.98 Source to a 29.97 fps SD DVD
Hello All,
I recently successfully converted my 23.98 fps 1920×1080 HD 16:9 fcp project to a mpeg-2 SD NTSC DVD with dolby digital 2.0 ac3 sound using compressor and dvd studio pro.
It worked great for the video. Very solid quality. No aspect ratio or framerate problems. The dvd plays on all my computers and dvd players. So, video is awesome.
My problem is with the audio on the dvd.
I converted the video from 23.98 to 29.97 fps. So, around 6 frames each second were added to my video during the conversion. My sound, which was in perfect synch before the video conversion, now goes in and out of synch each second. At the beginning of each second it starts in synch. Slowly, as time progresses it grows out of synch so that by the end of each second, it is around 6 frames out of synch (this must be related to the extra 6 frames per second added to my video during the 23.98 fps to 29.97 fps conversion). Then, when a new second starts, the sound is synched with the video again before slowly going out of synch. This happens throughout the entire film. The effect is not very apparent and it isn’t blatantly and obviously out of synch, but I can tell. It annoys me and just will not do. It just makes the entire film seem…off.
What I need is a way to make/convert the audio (which was perfectly synched to the 23.98 fps version of the film) to synch up perfectly with the 29.97 version of the film. Please HELP ME! I am stuck.
I need these dvds for academic and professional use, so the sound and video need to synch correctly (hopefully, perfectly).
I have final cut pro studio 2 on my powerpc g5 as well as adobe cs4 master collection on my pc.
Does anybody have any answers for me? Help will be greatly appreciated. (Supremely appreciated.)
Thanks.
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4 Replies
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A couple of things…
Your video does not need to be converted to 29.97 for an NTSC DVD. Many ‘Hollywood’ DVD’s are 23.976. All DVD players add pulldown on the fly for viewing on a 29.97 monitor.
Even if you did convert your video…assuming you added the pulldown correctly to get to 29.97, your audio should still be in sync. 23.976 and 29.97 are compatible with each other. True 24 fps is not…it is with 24fps that you need to pull up the audio.
Note that FCP and its documentation uses the shorthand term 23.98 fps, however in reality it is 23.976. If your material somehow is actually 24 fps or 23.98 fps (I mean really 23.98…not 23.976) this might be the cause of your problem. It will also be a problem if your pulldown was added improperly during the conversion. Just leave everything at 23.98 and you will be fine. No need to be going through this at all.
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Thanks John. I will burn the dvd at the same settings, but without the frame rate conversion. Will post back again in a few days after the dvd is burned to let you know if it worked. Please if you have time, check the post because I may still need help.
I am not sure about the sound being recorded at 24fps. All I know is we shot on S16mm at 24fps and recorded sound separately on a fostex. Then, we digitized the footage to hdcam 23.98. So, my fcp sequence is 23.98fps.
My post-production sound guy delivered me the sound as two tracks (stereo). he used protools and output it as one large track that I dropped into my 23.98 fcp timeline and synched up perfectly with the footage using a 2 pop and tail pop. Worked great.
The sound being out of synch only happens when I do the conversion to 29.97 fps (I was told north american dvd players could only play SD NTSC 29.97fps). In fcp and when I make quicktimes using the 1920×1080 HD 16:9 23.98 fps sequence/film, the resulting qt file is still perfectly synched.
Hopefully, when I make the next dvd keeping it at 23.98 fps, there will be no sound problem and it will play on all my dvd players. Ill let you know.
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John’s on the money.
Just drop that 1920×1080 into DVD studio pro. It will make a beautiful 23.98 fps DVD. Something wonky happened when you did the conversion to 29.97.
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Thanks guys.
The dvd came out great at 23.98 fps and the sound is perfectly synched. I guess that just means the 23.98 to 29.97 conversion messed up my video/sound synch.
Glad to know that 23.98 fps will play just fine on stand alone SD NTSC DVD players.
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