Downconverting a HDV Timeline in FCP5... at DVinfo.net

Go Back   DV Info Net > Apple / Mac Post Production Solutions > Final Cut Suite

Final Cut Suite
Discussing the editing of all formats with FCS, FCP, FCE


Reply
 
Thread Tools Search this Thread
Old November 5th, 2006, 04:01 AM   #1
Major Player
 
Join Date: Dec 2005
Location: Melbourne, Australia
Posts: 595
Downconverting a HDV Timeline in FCP5...

Hi Everyone,

After much research and experimentation I decided many months ago to do all my Sony Z1P filming in HDV and then downconvert in-camera for the edit (using Final Cut Pro 5). It's worked really well, and generally trouble free.

However, a lot of my friends have been shooting in HDV and editing in HDV as well. Even on dual G5s with 1GB of RAM editing in native HDV seemed to a lot slower for them (mainly due to rendering time) than editing in DV on my eMac.

But the main problem they all had was, once they finished their work, they had HEAPS of issues exporting to a Quicktime file.

If they exported using Quicktime Conversion using the same settings as their timeline (50i HDV), it all worked fine, however, when viewed full screen on a 1024 x 576 monitor, the image showed heaps of "lines" (I guess you'd call them "jaggies"). When you viewed the footage at 100% (which only showed a small section of the entire image due to the screens resolution) the image looked fine - so I guess it was simply due to the fact the computer 'created' these artifacts when it had to resize/downsize the image in realtime. As the film was made for being viewed on this screens it wasn't really acceptable.

The next step was to try downconverting to SD.

Now I've tried this a few times and it's NEVER worked properly. Can you downconvert HDV footage in FCP using QT Conversion? I seem to think not. Every time I've tried it the audio/vision has gone out of sync in certain spots. I'm presuming this is due to the way HDV works with its intraframe and interframe (temporal) techniques. I'm guessing when the cuts are not on "i frames" you get a sync issue. However, I have no real evidence to back this up.

What my friends ended up doing was exporting using Compressor using the HDV 50i preset. It exported fine - but you get the same issues as exporting as HDV 50i using QT Conversion.

I haven't tried exporting using Compressor and a SD preset. However, I'm presuming that the same problem will occur as with the QT Conversion.

I did a test just then, creating a new Uncompressed Timeline and dragging the HDV footage into it and exporting. No jaggies, and the audio is in sync, however the picture quality is very bad.

So I guess the question is:

WHAT'S THE BEST METHOD TO EXPORT A HDV TIMELINE TO A SD QUICKTIME FILE?

Thanks in advance!

Chris!
Chris Hocking is offline   Reply With Quote
Old November 5th, 2006, 04:13 AM   #2
Major Player
 
Join Date: Jun 2004
Location: Oxfordshire, UK
Posts: 416
Have you tried exporting the HDV timeline (1080i/50 I assume?) using Compressor: Advanced Format Conversion:DV PAL Anamorphic.

Worked well for me.

(Actually, not sure if this is a useful comment, but the following also works for me, but it gives poorer results than Compressor, so I don't use it: Export using Quicktime Conversion with settings: DV-PAL 16:9, 48kHz, etc, etc,.. I'd go for Compressor as above though. )
__________________
Martin at HeadSpin HD on Blu-ray
Martin Mayer is offline   Reply With Quote
Old November 6th, 2006, 05:33 AM   #3
Major Player
 
Join Date: Dec 2005
Location: Melbourne, Australia
Posts: 595
Thanks for your reply Martin!

Are you sure everything was OK (ignoring quality) when you exported using Quicktime Conversion?? As I said, everytime I've tried QT Conversion of HDV footage, it has gone "out of sync" at various stages during the footage. What version of FCP are you using?

No, I haven't tried exporting a HDV timeline using Compressor, but it is something on my to-do list (just to see if it works!). But if it does work, then it makes me wonder why QT Conversion apparently doesn't work. Maybe it's because Compressor recompresses every individual frame, and has the ability to handle HDV's large GOPs, whereas QT Conversion doesn't.

I'm also curious as to why Compressor would return better results than QT Conversion. Does anyone have a technical answer to that?

I guess I just want to know for sure whether it's a bug in FCP or just a limitation of the HDV format.

Again, thanks for your time Martin! I'm glad to hear HDV is at least working for you!
Chris Hocking is offline   Reply With Quote
Old November 6th, 2006, 10:19 AM   #4
Wrangler
 
Join Date: Oct 2002
Location: Los Angeles, CA
Posts: 2,100
Chris, couple things:

1-Friends exporting then getting "lines":

You're seeing interlace lines. You can't export a scaled-up version without deinterlacing somehow, and then view on a computer display...it's the nature of computer displays. Read up on fields on Adam Wilt's site and you'll understand.

2-Your own exports via QT Conversion:

If your audio is falling out of sync using this method, then something is up. Exporting HDV generally works just as well as any other codec. I'd start by troubleshooting your install, maybe reinstalling FCP. There is no reason why it shouldn't work, I've done it plenty.

3-Compressor:

Compressor will generally give you the best results, and allow the most flexibility. You can change aspect ratios easily (side-cut, letterbox, anamorphic), and also add a little bit of sharpening for downconverts.

Compressor has it's own processing math outside of Quicktime. You have more control over how good the scaling is, as well as frame rate conversions. So if you're asking how could it be better, it's because it has it's own processing and doesn't farm out to Quicktime.

Keep this in mind though, if you're trying to view 1080i50 HDV on a computer display, there's no method that's going to give you very good results without pre-processing. You're going to see that interlace combing.
__________________
My Work: nateweaver.net
Nate Weaver is offline   Reply With Quote
Old November 6th, 2006, 10:27 AM   #5
Major Player
 
Join Date: Jun 2004
Location: Oxfordshire, UK
Posts: 416
Quote:
Originally Posted by Chris Hocking
Are you sure everything was OK (ignoring quality) when you exported using Quicktime Conversion??
It seemed OK, but I wouldn't claim to have examined the output in any detail, as I have always assumed, as Nate supports, Compressor does a better job than vanilla Quicktime in any application.

Quote:
What version of FCP are you using?
FCP 5.1.2, Compressor 2.3 and QT 7.1.3
__________________
Martin at HeadSpin HD on Blu-ray
Martin Mayer is offline   Reply With Quote
Old November 10th, 2006, 10:54 PM   #6
Major Player
 
Join Date: Dec 2005
Location: Melbourne, Australia
Posts: 595
Thanks Nate! Thanks Martin!

One of these days I'll actually sit down and have a play with FCP and HDV and work out what my friends were doing wrong. Once again, I guess it comes down to user error.
Chris Hocking is offline   Reply With Quote
Old November 11th, 2006, 09:24 AM   #7
Major Player
 
Join Date: Feb 2005
Location: Cambridgeshire, UK
Posts: 112
Chris, there is no need to over-complicate this.

Here is what I do and it is by far the best way of down-converting a HDV timeline to SD. It simply produces the best possible results by far.

You have your HDV timeline, hit Command A to select all the timeline, then hit Command C to copy, then open a new sequence (make sure the 'warn for new presets when opening new sequence' is turned on in your settings) and set it up as an uncompressed 8-bit standard def anamorphic one.

Then simply hit Command V to paste your HDV sequence into this new uncompressed SD sequence. A red render line will appear. Render it out and continue as usual.

I do the above, then save the new timeline as a standard QuickTime Reference movie and open that in Compressor or Bitvice or whatever MPEG encoder I want to use to encode it.

This results in the sharpest DVDs I've ever seen.
Nigel Cooper is offline   Reply With Quote
Old November 11th, 2006, 12:44 PM   #8
Trustee
 
Join Date: Aug 2005
Location: Berkshire, UK
Posts: 1,562
Amen, bro.

Quote:
Originally Posted by Nigel Cooper
This results in the sharpest DVDs I've ever seen.
Exactamundo, dude. :)

The key is to down-rez to a format BETTER than DV. DV is good, but it's not perfect. After all, transcoding (DV to DV) is a generation step - lossy, introducing grit and dirt. Downconverting should enhance things.

I've always gone from HDV to DVCPro-50, but Uncompressed is the same but more so. Perhaps we should remind everyone that there's an FCP preference to use the 'Best' scaling rather than 'Fastest' (sub FCP4.5) or 'Normal' (FCP5.1 default).

Sometimes an FCP sharpen filter at about 5-9 (it initiates at 100) can do a Listerine job on the final cut, add a 'ting!' to things, but that assumes you shot HDV with a sharpness of 8-10, lower than standard.

Another method is to export from an HDV timeline to DVCPro-HD 1080i as a self contained QT file (very important for sync issues), deinterlace with something like DVFilm, then use Compressor with frame controls to scale down to progressive SD, again with a hint of sharpening (assuming you haven't sharpened yet). Feeding a progressive source into a scaler gets great results. Saving sharpening until last really helps.

The result is Super16, with the luminosity of shadow detail, the filmic roll-off of highlights, the 'there-and-then' of filmic motion (rather than 'here-and-now' of video), and a satisfying sharpness of the subject.

I also output deinterlaced HDV (acutally DVCPro-HD) to Photo-JPEG 75% 1280x720 QuickTime for playback in KeyNote. It helps those who need to know why delivery as HD video is infinately superior to SD interlaced productions in my tiny world of event bases video (VGA allows 1280x720/25p video to play back in PowerPoint).
Matt Davis is offline   Reply With Quote
Old November 11th, 2006, 02:38 PM   #9
Major Player
 
Join Date: Feb 2005
Location: Cambridgeshire, UK
Posts: 112
Quote:
Originally Posted by Matt Daviss
I've always gone from HDV to DVCPro-50, but Uncompressed is the same but more so.
I personally steer well clear of both DVCPRO50 and DVCPROHD codecs as they are both almost as bad as HDV as far as codecs go. They are both lossy, just a different kind of lossy. So if you move transfer from one lossy codec (HDV) to another different type of lossy codec (DVCPRO) you are taking one hell of a generation loss hit.

Going from HDV to uncompressed 8-Bit is the only way to go in my opinion. Forget 10-Bit as that is still a bit twitchy in FCP right now, besides HDV camcorders simply won't benefit from 10-bit anyway as they don't acquire footage anywhere near that colour space to start with and dropping a HDV timeline into an uncompressed 10-bit timeline is NOT going to bring it up to 10-bit colour space anyway; 8-bit is more than enough and is beyond HDV quality anyway.

But DO NOT convert HDV to DVCPRO50 or DVCPROHD as it is quite simply the most futile method I know of and it will degrade the quality as you move from one lossy codec to another lossy codec. Remember both these codecs are lossy and they are both very different hence the serious generation loss.

Do a test, HDV to uncompressed 8-bit and then HDV to DVCPRO and check out the results side-by-side on a professional grading monitor and you will soon see that HDV to DVCPRO is a pretty crap way to go.
Nigel Cooper is offline   Reply With Quote
Old November 12th, 2006, 04:47 AM   #10
Major Player
 
Join Date: Feb 2005
Location: Cambridgeshire, UK
Posts: 112
Quote:
Originally Posted by Matt Daviss
Perhaps we should remind everyone that there's an FCP preference to use the 'Best' scaling rather than 'Fastest' (sub FCP4.5) or 'Normal' (FCP5.1 default).
Which is under Sequence Settings under the Video Processing tab. Called Motion Filtering Quality.

Correct me if I'm wrong Matt?
Nigel Cooper is offline   Reply With Quote
Old November 12th, 2006, 05:04 AM   #11
Major Player
 
Join Date: Jun 2004
Location: Oxfordshire, UK
Posts: 416
Matt, Nigel:

Comparing these two workflows:

1a HDV clips on HDV timeline
1b from that, use Compressor to produce SD/MPEG2 for DVD

or

2a HDV clips on HDV timeline
2b drop HDV clips on an uncomp. 8-bit anamorphic timeline, render
2c use Compressor to produce SD/MPEG2 for DVD

Surely, with just straight cuts in the HDV, workflow 2 gives the same result as workflow 1?

However, with colour correction, complex transitions and graphics etc added after 2b - on the 8-bit uncomp timeline, ONLY THEN will workflow 2 give a better result for SD/DVD?

(Don't get me wrong, I'm not criticising the workflow 2 - I too am seeking the optimum way to get SD/DVD from HDV footage! I am just trying to understand the process going on here.)
__________________
Martin at HeadSpin HD on Blu-ray
Martin Mayer is offline   Reply With Quote
Old November 12th, 2006, 05:10 AM   #12
Major Player
 
Join Date: Feb 2005
Location: Cambridgeshire, UK
Posts: 112
I'd agree Matt, with straight cuts only any option will be fine. But once there is a single transition or graphic, option 2 will be best as dropping to an uncompressed 8 bit timeline will make graphics and transitions look beautiful again.

I could be wrong though as I don't know the scientific of re-sizing and rendering. Could be that Compressor prefers an 8-bit file as opposed to a HDV file; perhaps.
Nigel Cooper is offline   Reply With Quote
Old November 12th, 2006, 08:17 PM   #13
Trustee
 
Join Date: Aug 2005
Location: Berkshire, UK
Posts: 1,562
Quote:
Originally Posted by Nigel Cooper
Do a test, HDV to uncompressed 8-bit and then HDV to DVCPRO and check out the results side-by-side on a professional grading monitor and you will soon see that HDV to DVCPRO is a pretty crap way to go.
DVCPro50 for SD is 4:2:2, so when I down sample from HDV sourced material, I don't get DV style blockiness in strong colours. I can mix video and motion graphics.

DVCPro-HD is also 4:2:2 and I take 1080i down to 720p to make a master file I can use to transcode to WMV for playback in PowerPoint - that being a fairly ubiquitous HD playback platform in my industry.

Either way, HDV is an origination format, and a pretty painful editing format. Uncompressed may be the way to go for high end work, but in my tests, my clients don't see the difference between an Uncompressed workflow and a DVCPro-HD workflow. If they did, they wouldn't want stuff originated on HDV.

All compressed formats will suffer some form of degradation, but DCT is a hulluva lot stronger than MPEG. Easier to edit, too.
Matt Davis is offline   Reply With Quote
Old November 12th, 2006, 10:47 PM   #14
Trustee
 
Join Date: Aug 2005
Location: Berkshire, UK
Posts: 1,562
Quote:
Originally Posted by Nigel Cooper
But once there is a single transition or graphic, option 2 will be best as dropping to an uncompressed 8 bit timeline will make graphics and transitions look beautiful again.
Steve Mullen has done a great deal of testing here. The bottom line IIRC was that FCP processes at 4:4:4 internally, so if you change the timeline codec to something other than HDV once your edit is done, then re-render all steps, you'll get HDV rushes processed in an uncompressed space then re-rendered to your chosen codec.
Matt Davis is offline   Reply With Quote
Old November 13th, 2006, 03:24 AM   #15
Major Player
 
Join Date: Feb 2005
Location: Cambridgeshire, UK
Posts: 112
Quote:
Originally Posted by Matt Daviss
DVCPro50 for SD is 4:2:2, so when I down sample from HDV sourced material, I don't get DV style blockiness in strong colours. I can mix video and motion graphics.
I agree, but you are still taking a serious generation loss as far as your sourced material is concerned.

The DVCPro50 codec should only really be used if you shot on DVCPro50 to start with i.e. you are keeping to the same codec.

Doing it my way via 8-bit uncompressed you are not taking a hit on the quality as you are not moving from a Lossy codec to another Lossy codec.

As for storage, it is really cheap, 500 GB for around 100 (probably much cheaper in the USA. Basically getting a couple of Terrabites together is no big deal.
Nigel Cooper is offline   Reply
Reply

DV Info Net refers all where-to-buy and where-to-rent questions exclusively to these trusted full line dealers and rental houses...

Professional Video
(800) 833-4801
Portland, OR

B&H Photo Video
(866) 521-7381
New York, NY

Z.G.C.
(973) 335-4460
Mountain Lakes, NJ

Abel Cine Tech
(888) 700-4416
N.Y. NY & L.A. CA

Precision Camera
(800) 677-1023
Austin, TX

DV Info Net also encourages you to support local businesses and buy from an authorized dealer in your neighborhood.
  You are here: DV Info Net > Apple / Mac Post Production Solutions > Final Cut Suite

Thread Tools Search this Thread
Search this Thread:

Advanced Search

 



Google
 

All times are GMT -6. The time now is 01:21 AM.


DV Info Net -- Real Names, Real People, Real Info!
1998-2017 The Digital Video Information Network