Sean Oneil
Forum Replies Created
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Here’s the math:
23.976 / 24 = 29.97 / 30 = 99.9%
Sean
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Do NOT do 99.92%. Do 99.9% percent like you have been. That is the right percentage.
When CharlieX did the math, he forgot that 23.98 really means 23.976.
If you’d like to take the math out of the equation, just use Cinema Tools to convert a quicktime from 24 to 23.98. It adjusts the audio speed perfectly.
Sean
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[Tippytink] ”
ok, so I think your speed change idea did work. When I make each of the wav files 99.9% in speed, they fit perfectly. Not sure exactly what that means…”Not to be bitter or anything, but that’s essentially what I suggested you do earlier today, and I explained why:
[Sean ONeil] “When convering film to video, it is generally slowed down by .1% to match the timing signals of televisions. So 24fps becomes 23.976fps (FCP rounds the number to 23.98)….Cinema Tools can conform your quicktimes from 23.98 to 24 and vice-versa.”
Sean
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[Tippytink] “1080i, 24p and the exports look fine. When getting advice from the company that set up up they feel that doing a 24p export at 1080i may make a progressive output, but I am confused on why there is not a 1080p option. It just makes me a uneasy. Any solid info on this would be great.”
What you are saying here doesn’t make any sense. You say there’s no option for 1080p, yet you are using one by outputting 1080p24. There’s no such thing as 1080i/24p. 1080i is interlaced, 29.97 frames per second. 1080 24p is 24 frames per second, progressive-scan.
There is such thing as 1080p60, and yes, FCP does not support it. Nor do most professional VTRs, switchers, monitors, etc.
Final Cut likes to work with 1080 23.98p (normally called psf instead of p, but that’s not important). This is “telecine speed”. When convering film to video, it is generally slowed down by .1% to match the timing signals of televisions. So 24fps becomes 23.976fps (FCP rounds the number to 23.98).
Cinema Tools can conform your quicktimes from 23.98 to 24 and vice-versa. This will slow down or speed up the audio to match. This probably has something to do with your sync issue.
Sean
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[Anders Haavie] ”
I have 5 gig ram so I guess that shouldn’t be a problem. Anyone else seen this behavour ?”You’re not supposed to have 5 gigs in a Mac Pro.
Look at the doc Wayne posted.
Sean
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[Tom Brooks] “But even modern day tube TVs are still interlaced. Correct?”
Correct. But most can also do 480p.
Sean
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[Tom Wolsky] “Assuming the consumer is watching your material on a television set, which is less and less often the case.”
What else are you talking about? I’m talking about delivering video on a tape for either broadcast, DVD, or HD-DVD/Blu-ray. I didn’t know we were talking about h264 encoding for ipod video or whatever. People who encode video for the web will always create a progressive scan image. Whether you deliver them an interlaced format or not. Nobody puts interlaced video on YouTube. So that’s a bit irrelevant.
Here’s a good article to read:
https://www.hometheaterhifi.com/volume_7_4/dvd-benchmark-part-5-progressive-10-2000.htmlKeep in mind this was written in 2000. Nowadays, every single new TV or DVD player can deinterlace either film or video properly.
Sean
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[walter biscardi] “30p does not interchange with 60i at all. They look completely different.”
Yes it does. You are incorrect.
Certain cameras will give a different looking picture if you record in different modes.
After a piece is shot, and it exists on a computer or digital videotape, you can convert it back and forth between 30p and 60i ten million times and it will look identical.
Sean
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[rafalaos] “I do not agree with you about this Sean. Our eyes and brain can not tell one field from the next but you can catch even quite small differences.
My first job in a TV station (some 22 years ago) was to preview programs and movies before to be broadcasted. We used to watch with the 1’C or Betacam at double speed (other wise no way to watch everything) and belive me that we could catch an small drop in luma or a drop-line in a single field. Just training the eyes.”Ok first of all, you’re right there is noticeable difference which is normally called “interlace flicker”. I mentioned this in the paragraph below the one you quoted. But what you don’t understand is that the difference can only be seen on CRT monitors. Hence why you noticed it 22 years ago. LCD monitors do not work that way. Everything is progressive on those, regardless of what format the source is. When playing back 60i footage on an LCD computer monitor, if you see “scan lines”, it’s because the monitor is line-doubling each individual field and displaying them sequentially. Kind of like watching 1080i60 w/ Cinema Display mode in FCP. Digital Televsions don’t do that. They combine each field automatically, creating a 30p image. As does a progressive-scan DVD player.
Secondly, the interlaced flicker you can see on a CRT (but not any other type of display) is not what defines the “film look” vs. the “video look”.
Furthermore, it’s all irrelevant as far as we’re concerned. Whether you shoot, edit, and/or master 30p or 60i – it makes no difference WHATSOEVER to the consumer. The two formats are interchangeable, and the consumer is going to view one type of signal or the other depending on the TV and/or DVD player he or she has. Regardless of what format it was worked on in post.
The thing that throws a wrench into this is when 24fps is mastered at 60i using 3:2 pulldown (like any DVD movie) on a progressive-scan television. A consumer TV/DVD Player can deinterlace this properly by using reverse telecine and converting it to 30p – but it can only achieve this if the 3:2 cadence is consistent. That’s why shooting 24p but editing in 60/30 i/p is a bad idea.
Sean
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Ahh, someone already posted this. Administrators, please delete this thread.
Sean