Weird Frame Rates from iPhone

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Level 1

49 points

Weird Frame Rates from iPhone

I'm working with some videos taken on my iPhone 4 that were taken indoors at night. The iPhone used some odd frame rates, which differed from video to video. One was 26.99 fps, another was 25.75 fps and the last was 24.3 fps.

The one that was 26.99 I put straight through to Compressor and encoded it as an SD DVD. Everything played back fine. However, the two that were 25.75 and 24.3, I wanted to do some white balancing on them, so I dropped them into Final Cut 7 and FCP automatically chose a sequence editing timebase of 24 fps.

Everything plays fine in FCP and even on Apple's DVD player, but when I exported these as an MPEG-2 for an SD DVD, these two videos play back very choppy on my PS3.

I think the best thing to do would be to use Compressor to change the frame rates of these videos to something normal (29.97 or 23.98) prior to importing them into FCP, but my question is this...

Which codec should I use so that there is no loss of quality? I just want to create another QuickTime movie for each movie with a proper frame rate.

Thank you!

John-Paul

iMac, Mac OS X (10.7.2), 2.93 GHz Intel Core i7, 16 GB RAM

Posted on Nov 26, 2011 9:35 AM

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Answer 1

Nick Holmes

Level 7

30,018 points

Nov 26, 2011 10:58 AM in response to willscarlett

Transcode to ProRes LT -you can't edit the H.264 files that your iPhone produces in FCP anyway.

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Answer 2

willscarlett Author

Level 1

49 points

Nov 26, 2011 12:51 PM in response to Nick Holmes

Thanks for the response, Nick. Why use the LT version and not regular ProRes 422 or the HQ version?

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Answer 3

Nick Holmes

Level 7

30,018 points

Nov 26, 2011 1:06 PM in response to willscarlett

LT is fine for the H.264 files your iPhone or a typical AVCHD camera shoots.

The higher bit rate formats are for cameras that really shoot uncompressed HD, RED and CGI composites that are going back to film.

You can try each one, you won't see a difference except for much larger file sizes. You also need a seriously fast RAID setup to work with the high end formats.

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Answer 4

willscarlett Author

Level 1

49 points

Nov 26, 2011 5:23 PM in response to Nick Holmes

Thanks, Nick. Most of my work I do with a 5D Mark II or Sony HXR-NX5U, but I also mess around with a Canon point and shoot that shoots 720p at 29.97 fps. I've never had to change the format of any of those files to work with them in FCP.

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Answer 5

willscarlett Author

Level 1

49 points

Nov 26, 2011 9:59 PM in response to willscarlett

So I took a look at the ProRes presets and noticed they were all Audio Pass Through. If I want to change the frame rate from whatever weirdo frame rate the iPhone gave it to 29.97 or 23.98, wouldn't having just an audio pass through not make any changes to the audio? How would I handle this one - "Enable" the audio and select the proper frame rate from the video section and the audio will automatically be adjusted?

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Answer 6

Nov 27, 2011 3:46 PM in response to willscarlett

Nick's advice is good ... you appear to be questioning it?

Why don't you give it a go? And report back.

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Answer 7

willscarlett Author

Level 1

49 points

Nov 27, 2011 4:26 PM in response to Johnny Magee

I'm not sure why you think I'm questioning Nick's advice. My question was based off video settings and Nick's reply addressed that. When I entered into Compressor, I discovered that audio might need to be adjusted as well. Hence, my return the forum, in the hopes of doing the conversion properly the first time around.

I will give it a go and report back tho.

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Answer 8

Nov 28, 2011 8:41 AM in response to willscarlett

You probably should enable the audio anyway to convert to 48k 16 bit aff. Usually highly compressed quicktimes, compress the audio also and it's better to convert it before you bring the file into fcp.

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Answer 9

willscarlett Author

Level 1

49 points

Nov 30, 2011 6:35 AM in response to Michael Grenadier

Thanks for the advice, Michael. Enabling audio was the right way to go.

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