FCP 6: poor export quality in mp4

Question

FCP 6: poor export quality in mp4

Hello, I have a Final Cut Pro 6 project, 90 minutes.
It is a multiclip project: 2 little minidv tapes of a live concert of my band.
I have done all the editing and I have just exported the project in mpeg4. This is not the first time, I have done this 4 or 5 times in the past and everything was OK. This time instead I have bad quality at every camera change: at every change, the image starts all pixelated, than after some frames, the quality is back to 100%.
It seems a key-frame issue... but I am not expert.
Here are the export setting:
- File Format: MP4
- Video Format: H.264
- Data Rate: 4500 Kbit/sec
- Image Size: 768 x 576 SD
- Frame Rate: Current
- Key Frame: Automatic

In The "Video Options" tab: Profile "Main" is the only checked, and encoding mode is "faster".

Again, I believe I have always used this settings, so I cannot understand what is the problem this time.
Thank you!

MacBook Pro 2.2 15", Mac OS X (10.6.2)

Posted on Jul 24, 2010 8:19 AM

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Answer 1

matthew6

Level 1

35 points

Jul 24, 2010 12:24 PM in response to Roberto Ficarella1

The first thing I would do is try running it through compressor. If that doesn't work, the only thing that's coming to mind is that you might try setting compression markers at each cut where the quality goes out.

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Answer 2

Zak Ray

Level 4

3,469 points

Jul 24, 2010 12:31 PM in response to matthew6

Compression markers are automatically added by FCP upon export to every edit point.

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Answer 3

matthew6

Level 1

35 points

Jul 24, 2010 1:17 PM in response to Zak Ray

Thanks Zak, I had forgotten that. In the event you're exporting to mp4 from a quicktime of an already edited sequence, and not from the sequence itself, then what I said might help, otherwise Zak's right. It wouldn't do any good to add them at edit points. You may also try adjusting the keyframe rate from automatic and see if something else works.

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Answer 4

Jul 25, 2010 9:01 AM in response to matthew6

I am not exporting from a previous edited sequence, I have done all the editing (switching between camera 1 and 2) in my project.
What would you suggest as the keyframe rate?

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Answer 5

Zak Ray

Level 4

3,469 points

Jul 25, 2010 9:05 AM in response to Roberto Ficarella1

As Matthew says, try running it through Compressor with Auto keyframes instead of exporting directly from FCP. If that doesn't work, try the framerate of your project.

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Answer 6

Jul 29, 2010 6:24 AM in response to Zak Ray

Thanks for your help.
I tried to use Compressor (never used it: I am quite new to video editing in FCP, I used iMovie).
The result is OK, I mean there are no big-pixel frames. I have just some questions for you: as you can see from the pic here:
http://img245.imageshack.us/img245/8593/fcp.jpg
- I choose constant bit rate, but I cannot set it higher than 2048. In FCP I could set the bit rate much higher (I used 3000 or even 4000 kbps).
- auto key frame is not allowed from what I see
- as regard the frame rate: is the frame rate of the FCP project the one I found in:
sequence menu -> settings -> editing time base ???
- last: in FCP I exported as mpeg4 with H264. Here from what I see, H264 are totally different codecs, isn't it?
Thank you

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Answer 7

Tom Wolsky

Level 10

150,980 points

Jul 29, 2010 6:28 AM in response to Roberto Ficarella1

One is in Kbps and the other is in kbps, kilobytes and kilobits.

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Answer 8

Jul 29, 2010 6:34 AM in response to Tom Wolsky

You mean, if I used to compress from FCP at 4000 kbps, I can choose 500 Kbps from Compressor?

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Answer 9

Tom Wolsky

Level 10

150,980 points

Jul 29, 2010 6:46 AM in response to Roberto Ficarella1

Correct.

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Answer 10

Zak Ray

Level 4

3,469 points

Jul 29, 2010 7:01 AM in response to Roberto Ficarella1

You can also use an H.264 setting, click the Video settings in the Encoder pane to adjust bitrate.

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Answer 11

Jul 29, 2010 7:26 AM in response to Roberto Ficarella1

I can never stress the use of the presets enough. At least as a starting point. Export this via Compressor and use the Apple TV preset. Don't change anything. See how it looks to you. Make adjustments from there.

Those presets are really dialed in these days, and they produce very nice looking files, if you give them the chance.

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Answer 12

Jul 29, 2010 7:36 AM in response to thrillcat editorial

Thanks for your suggestion, I will try.
I am not a video-format expert. What I need is a movie file with nice quality, to be seen on the mac/PC itself. No streaming needed, no web...

Message was edited by: cioto

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Answer 13

Jul 29, 2010 7:44 AM in response to Tom Wolsky

(Replying to Tom Wolsky, as regard the data rate...)

I have re-exported the project, and I believe this is not true, or not true in my case!
My movie has been exported OK, but the quality is low, so I checked the data rate in quick time player, and it is 2000Kbit/s, not Kbyte/s !!

Message was edited by: cioto

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Answer 14

Jul 29, 2010 8:10 AM in response to thrillcat editorial

thrillcat editorial wrote:
I can never stress the use of the presets enough. At least as a starting point. Export this via Compressor and use the Apple TV preset. Don't change anything. See how it looks to you. Make adjustments from there.

Those presets are really dialed in these days, and they produce very nice looking files, if you give them the chance.

Thanks for your suggestion for using apple TV preset.
My project is in 768x576 pixel so I would like the destination file to be the same format, but this format is not selectable from the menu (I tried apple tv sd, sd anamorphic and hd).

Can you help me?

Thank you!

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Answer 15

Jul 29, 2010 8:12 AM in response to Roberto Ficarella1

Duplicate the AppleTV preset. Select the new one, go to the Geometry tab and for Dimensions, select 100% of source. Save the preset and use that.

Out of curiosity, what creates a 768x576 frame size?

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