Render Compression Issue

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Level 1

29 points

Render Compression Issue

I'm editing footage from a Canon 60D, 1080p, and have been editing it at full quality, as it has been functioning quite well thus far. The issue is when I render footage and then export it. While rendering, a loss in quality occurs. Through render compression, the image loses color information and degrades in overall quality. I've checked by render compression settings, which point to my sequence settings. I've included an image of my sequence settings in this post. Any advice? I need to do some color work and can't have the image quality degraded as a result of rendering, or anything else for that matter.

MacBook Pro, OS X Mountain Lion, 13-inch, Mid 2009

Posted on Apr 20, 2013 2:35 PM

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Answer 1

GoldenA Author

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29 points

Apr 20, 2013 2:36 PM in response to GoldenA

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Answer 2

Meg The Dog

Level 6

13,561 points

Apr 20, 2013 3:09 PM in response to GoldenA

In your Sequece Settings, have you looked at your Video Processing Tab?

MtD

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Answer 3

GoldenA Author

Level 1

29 points

Apr 20, 2013 3:10 PM in response to Meg The Dog

Yeah, here's what I have:

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Answer 4

Meg The Dog

Level 6

13,561 points

Apr 20, 2013 3:28 PM in response to GoldenA

Oh, sorry, didn't look closely at your first post. You need to convert your source material to ProRes before you ingest into FCP, and then edit in a ProRes timeline. FCP7 - H.264 does not work. Once you convert your footage, you won't have this problem.

MtD

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Answer 5

GoldenA Author

Level 1

29 points

Apr 20, 2013 3:30 PM in response to GoldenA

Gotcha, I'm a ways into the project. Is there a way to convert everything at this point to ProRes? Also, when I'm ready to export, do you have a recommendation for receiving the highest quality on render and export?

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Answer 6

Meg The Dog

Level 6

13,561 points

Apr 20, 2013 3:41 PM in response to GoldenA

Highest quality output = Export QuickTime without conversion. It is lossless.

To convert your current sequence, you can try to use Media Manger by selecting your sequence and the going to File > Media Manager.

You will need to check your new sequence carefully to make sure the scenes are correct. H.264 is a long GOP compression meaning that several frames are grouped together, so stuff may slip around a bit.

Best practice would be to convert your source elements and rebuild the timeline with a ProRes codec.

MtD

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Answer 7

GoldenA Author

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29 points

Apr 20, 2013 3:57 PM in response to Meg The Dog

Alright, if I were to rebuild the timeline with a ProRes codec, would I then convert my source elements via the Media Manager?

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Answer 8

Meg The Dog

Level 6

13,561 points

Apr 20, 2013 4:09 PM in response to GoldenA

No, you preferably want to convert you source clips first, then edit. Once you have (all) your source material converted and then edit in the same codec on your timeline, you will have solved your quality problem, and the clips that you have converted will ready to move, after editing, into color correction.

The alternate method of using Media Manager to convert those clips you have already used in your sequence is an attempt to preserve the work you have already done - but it is not ideal as any source material you have not used to this point is going to require conversion anyway.

Your other option would be to use edit software that supports unconverted H.264 like Adobe Premiere or FCP-X.

Also note - in the example of using the media manager I posted, in your case you will want to set the frame rate to 23.98.

MtD

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Answer 9

GoldenA Author

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Apr 20, 2013 4:14 PM in response to Meg The Dog

Alright, I'm transcoding my H264 media to ProRes now in Compressor. Thanks for all your help. Is there a way to transcode via FCP7 through import, or must I use either the Media Manager or Compressor? When I export, is FCP7 referencing the transcoded media?

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Answer 10

GoldenA Author

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Apr 20, 2013 4:22 PM in response to GoldenA

Also, is there a reason why the ProRes transcode doubles the overall size of the media? I figure compression should lessen the size.

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Answer 11

Meg The Dog

Level 6

13,561 points

Apr 20, 2013 4:59 PM in response to GoldenA

You kind of have it backwards - H.264 is the very compressed format, Pro Res is the high quality codec.

The file size is growing because H.264 is highly, highly compressed video. H.264 is designed for image acquisition and delivery, but not editing or post production. When you transcode to ProRes, your are 'unpacking" the video that has been compressed (jammed) together as tightly as possible into blocks of frames - into distinct frames with a much greater storage of data per frame. This is why many high end cameras, and many DSLR shooters record on devices that use the ProRes codec - it bypasses the tremendous compression of H.264.

ProRes is a much better codec than H.264, which is why once your material is in ProRes, it will maintain quality as you move through editing and color correction, delivering an excellent quality master file that you can then compress into any delivery codecs you need.

MtD

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Answer 12

GoldenA Author

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29 points

Apr 20, 2013 5:02 PM in response to GoldenA

Alright, this makes much more sense now. Thank you so much. Looks like I'll be transcoding for a very, very long time, or possibly using Premiere Pro CS6 and its native SLR timeline preset.

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