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Retaining Compression and Edit Markers in Compressor

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Melissa Goldman
Retaining Compression and Edit Markers in Compressor
on Nov 17, 2011 at 8:24:21 pm

Hi there.

I have a long HD project to make into a DVD stream. I want to downsize it to SD in a quicktime movie before I create the stream, as that downsizing process takes a long time and I need to create multiple versions of the stream. Frame controls are on because without them I'm getting flickery artifacts around the edges, so the process is taking a long time.

My problem is that the compression and edit markers are not retained when I downsize from one QT to another. Is there a way to pass them through when I export a new QT in compressor? Here's what I've done:

1. Saved a self-contained QT from FCP in original settings with DVDSPRO markers.
2. Took the exported HD QT into Compressor (markers are all there at this point), exported a QT that takes the file from 1080i to 480i. Note: In the Compressor QT settings Inspector, there is no option in the Encoder tab to keep metadata, as there is in the MPEG2 settings inspector.
3. When I open that SD QT in Compressor for the purpose of creating the MPG2 stream, all the editing and compression markers are gone (chapter markers remain). This seems like a "dealbreaker" to me, as the compression markers are there for the sake of the stream, not the QT.

Is there any way to export and import just the markers? That step #2 was an overnight render and I'd rather not start it again, if there's a way to import the markers. Should I not worry about this for some reason? Is my workflow all wrong? I really don't want to do an 18 hour render job every time I want to make a stream with new settings. And yes, I have read the Ken Stone pages on compression and all the relevant apple manuals, before anyone asks.

Someone also posted in a thread that they had good luck downsizing in After Effects, which I would consider doing if I could bring in the compression markers. I assume that AE doesn't retain them either?

Thanks!
Melissa


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Jeff Greenberg
Re: Retaining Compression and Edit Markers in Compressor
on Nov 19, 2011 at 2:56:48 am

I think I got compressor to do this exactly the way you wanted - I did it with 4.0, but it should work with 3.5.

Create a QuickTime SD setting as your 'first step' from your original. I'd suggest animation codec or ProRes, to create minimal damage. This is the down convert step you're doing right now.

Then select the entry and choose Job>New Job with target output.

This should create a chain icon (called linking.)

Step 1 does the down convert. Step 2 does whatever you want with the down converted file, which should retain the chapter markers.

It did in the test I did.

Best,

Jeff G


Certified Master Trainer | Adobe, Apple, Avid
------------
You should follow me (filmgeek) on twitter. I promise to be nice.
New! FCPX DSLR workflows; What's new in Media Comopser 6; Full Media Composer 6 basics from macProVideo.com
Come see me speak at the Government Video Expo Nov 30 - Dec 1; Seminar link here
My book (with Richard Harrington and Robbie Carman)- An Editor's Guide to Adobe Premiere Pro
Lynda.com - Compressor Essentials 3.5 and 4
Contact me through my Website


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Melissa Goldman
Re: Retaining Compression and Edit Markers in Compressor
on Nov 21, 2011 at 4:48:53 am

Hi Jeff. Thanks for the step-by-step instructions. I hadn't seen that linking technique before. I went through as you suggested, but it's not retaining the compression and edit markers. The Chapter markers are still coming through, but I can check the intermediate file that's created in the process, and I see when I bring it back into Compressor that there are no additional markers. Do you think they're still being used, but just not showing up in the intermediate file for some reason? Did this technique work for you in the past for compression markers? I tried Compressor 4, still nothing.

(Or do you know another way to export/import them?)

By far the nicest downconversion result I've gotten has been with Compressor's frame controls for MOVs (these same controls seem to have very different effects when done on M2Vs, actually), so I'm really bummed that I can't find a way to keep the markers through this extra step.

Thanks very much.
Melissa


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Jeff Greenberg
Re: Retaining Compression and Edit Markers in Compressor
on Nov 21, 2011 at 12:22:16 pm

Technically, when compressor uses any type of VBR compression, it'll automatically analyze the file; 'cuts' will automatically be detected and an iframe will be put there.

I don't know how low of the final bitrate of your finished work; most of the time, compression markers (as I'm sure you're aware) only really to be used to force iframes when compressing - something that I've only really needed when I want to squeeze the last little bit of the bitrate out of a file. Often I'm using tools other than compressor (especially for mpeg2 files) because apple's encoder is decent, but not the quality of say, MainConcepts.

FCP's scaling algorithm is 'okay' when you tweak the motion tab to 'best' quality; compressor's is better. And FCPs frame controls leave quite a bit to be desired.

M2Vs as a source are a different beast; as far as I can tell, compressor makes some assumptions when it's a 'source" file.

Best,

Jeff G


Certified Master Trainer | Adobe, Apple, Avid
------------
You should follow me (filmgeek) on twitter. I promise to be nice.
New! FCPX DSLR workflows; What's new in Media Comopser 6; Full Media Composer 6 basics from macProVideo.com
Come see me speak at the Government Video Expo Nov 30 - Dec 1; Seminar link here
My book (with Richard Harrington and Robbie Carman)- An Editor's Guide to Adobe Premiere Pro
Lynda.com - Compressor Essentials 3.5 and 4
Contact me through my Website


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Melissa Goldman
Re: Retaining Compression and Edit Markers in Compressor
on Nov 21, 2011 at 8:46:56 pm

Hey Jeff. Thanks for the explanation, I appreciate it. I have not encoded a lot of DVDs, so it's useful information. I am not sure how well the compression function works when Compressor is dealing with a file with no edit or compression markers. Maybe it's not even something I should worry about. I'm using an average bit rate of 4.5. Is that low enough that it will make a difference?

I wasn't using m2v as a source file, just noting that the options are different in Compressor for compressing to qt and m2v, and that the same frame control options seem to produce _drastically_ different effects in each, which I'm not sure I understand.

Thanks!
Melissa


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Brad Wright
Re: Retaining Compression and Edit Markers in Compressor
on Nov 19, 2011 at 3:07:24 pm

I wrote on how to use compression markers in this article. This should solve your problems.

http://www.lafcpug.org/Tutorials/basic_hdvideo_to_dvd.html

Brad Wright is software engineer, so it may be difficult to understand what he is saying. He is always happy to explain his greater detail.


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Melissa Goldman
Re: Retaining Compression and Edit Markers in Compressor
on Nov 21, 2011 at 4:48:19 am

Hi Brad. Thanks for the article. I tried the method you suggested over the weekend, but actually the SD MOV created through the method you described looks significantly worse (grainier, less crisp) than the SD MOV that I created with Compressor from the HD MOV using the frame control settings. I tried making my DVD stream from that QT and it looks _extremely_degraded, although it's good that the method you suggested retains the compression and edit markers.

Do you know of a way I could get better results doing the downsizing straight from FCP? Or another way I could retain or import the compression markers in Compressor after downsizing?

Thanks very much.
Melissa


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Brad Wright
Re: Retaining Compression and Edit Markers in Compressor
on Nov 21, 2011 at 2:20:36 pm

Are you comparing the video on an external calibrated television connect to Final Cut Pro? This is the most important step for checking your video.

Because you are going from 1080i to 480i, you want to preview your footage in SD before you send it to Compressor. This is where you want to check your SD footage for problems. Try resizing your footage from 1080i to 480i to ProRes in Compressor and compare the two sets of footage side by side. They should look identical. The reason for creating an SD master of you footage is that you can fix the problems in it by using Compression markers or through blurring.

Brad Wright is software engineer, so it may be difficult to understand what he is saying. He is always happy to explain his greater detail.


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Melissa Goldman
Re: Retaining Compression and Edit Markers in Compressor
on Nov 21, 2011 at 8:51:48 pm

I always thought that it looking good on the computer was necessary but not sufficient for it to look good on a television. I definitely don't want it to play back ugly on a computer, even if the final output is DVD. My plan was to check it on the NTSC monitor once it looked ok on the computer. Am I thinking about this backwards?


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Brad Wright
Re: Retaining Compression and Edit Markers in Compressor
on Nov 21, 2011 at 9:06:53 pm

The computer monitor is designed for displaying colors in RGB while the television is calibrated for decoding Ycbcr video. They are different color spaces. Because you are working with interlaced video, you can't see it on a computer monitor which is progressive. This becomes really important when dealing with field order problems.

Brad Wright is software engineer, so it may be difficult to understand what he is saying. He is always happy to explain his greater detail.


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Melissa Goldman
Re: Retaining Compression and Edit Markers in Compressor
on Nov 21, 2011 at 9:22:48 pm

I fully appreciate why you need to check color on a calibrated monitor, what I don't understand is why it would ever be acceptable for it to look bad on a computer. The situation I'm dealing with is that it already looks bad on my computer monitor.

If the video already looks bad on the progressive computer monitor, that seems like reason enough to look for problems in the workflow, no? Even if it looked OK on a TV, I wouldn't be satisfied if playback looked bad on a computer. I haven't heard of a scenario where the progressive monitor looked bad but the interlaced TV looked good. Again, let me know if there's a problem with my logic or workflow. Thanks very much.


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Brad Wright
Re: Retaining Compression and Edit Markers in Compressor
on Nov 21, 2011 at 9:28:49 pm

I really can't tell what you are seeing, so I'm guessing. What you could be seeing is interlaced video lines which are jagged edges around anything that is moving in the video. These interlaced lines don't appear on your television, but without them your video doesn't retain the smooth motion that it originally had. Shoot me an email at support@dvdxdv.com. I'd love to take a look at it and further help you.

Brad Wright is software engineer, so it may be difficult to understand what he is saying. He is always happy to explain his greater detail.


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Brad Elliott
Re: Retaining Compression and Edit Markers in Compressor
on Nov 22, 2011 at 5:41:24 pm

I realize your question involves keeping marker info but you may want to consider another approach.

I have had the most success with getting HD to SD DVDs with the following:

1) Make a SD version of your final HD seq. in FC(I have had limited success with Compressor doing the down convert for SD DVD from HD.)
2) Add markers as needed and then you will only need to be making DVD files from the FC SD QT which will keep the marker info.

1st pass I do not change the frame controls in the presets.

You may want to do some short tests with the current problem areas to see if it helps to have compression markers or not. They have have helped me in some instances but I do use them until after I have tried the above and am still finding problems.



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Melissa Goldman
Re: Retaining Compression and Edit Markers in Compressor
on Nov 22, 2011 at 6:00:39 pm

Thanks for that idea and for responding.

I tried basically that same thing yesterday, but I was wasting hours dealing with problem title cards and other nitpicky things that did not like being moved from an HD sequence to an SD sequence. But it did give me an idea. This is my current plan, in case anybody cares about an update. And please tell me if this sounds like it'll give me problems!

I tried shrinking the timeline in After Effects, which, while pretty slow, did look great. So I'm going to to create an SD quicktime from After Effects and then swap that back into my Final Cut timeline (which already has the compression and chapter markers inserted. Then I'll export to Quicktime using Current Settings with DVDSPro Markers (which I think (?) should just pass the video through rather than recompressing). Why didn't I think of this before??

By the way, the reason I'm worried about the compression markers is because there were some motion artifacts in the previous version of the DVD that I made. Because of some specific quirks about my project and workflow, I have reason to think that compression markers will be helpful all around.

THANK YOU EVERYONE FOR YOUR HELP! I really appreciate it.


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