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FCP gamma shift on export, final QT file codecs & print to tape problems

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Timothy Gassen
FCP gamma shift on export, final QT file codecs & print to tape problems
on Aug 28, 2012 at 6:32:22 pm

I’m a longtime editor, but on the PC side -- I am not a usual FCP user. I've read the FCP FAQ here and searched for hours through this forum and others for answers -- hopefully someone here can help.

Problem #1: I’m finishing now a project in another editor's facility with FCP (version 6 & 7). We are experiencing the dreaded Gamma shift on file export of the final master QT files.

Final files will be used for Blu Ray & DVD encodes, Web use, and eventual broadcast. Test disc encodes show the Gamma shift.

Since many users need file-only output for use outside of FCP (in other applications), surely there must be a way to actually export correct-Gamma QT out of FCP?

The only option I’ve found is trial-and-error Gamma reduction on export through Compressor. (I don't believe there is that option through direct QT Export). Is there any way to export from FCP without a Gamma tag in the QT?

Master File QT Question: For easiest cross-platform use and archive format we are considering M-JPEG (rather than ProRes or uncompressed) for a final master QT codec. What codec are FCP users selecting for best-quality master & archive use?

Problem #2: I’d like to do a tape backup out to DVCAM, but we can’t get FCP to send a full-resolution signal from a sequence to tape. The rendered sequence quality looks fine, but it seems to be re-encoding on the fly in draft quality, even from a converted DV timeline, and even when going “print to tape." In other editors I can output good looking full-resolution DV without adding artifacts -- is FCP unable to output full-resolution DV, or is an add-on breakout box or encoding card necessary?

Again, I'm not a usual FCP user -- Thanks for any help!

Timothy Gassen


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Shane Ross
Re: FCP gamma shift on export, final QT file codecs & print to tape problems
on Aug 28, 2012 at 7:21:08 pm

Are you talking about what the QT files look like when opened in QT? because QT doesn't display the proper gamma. IN fact there is a Preference to ENABLE FCP COLOR COMPATIBILITY in there.

And, if you take what you exported back into FCP...it should like exactly like the timeline you exported. You can load the export into the Viewer, park on the same frame...gang them..and then look at them both, toggling back and forth from viewer to Canvas...and look at both images on the external monitor.

I have delivered dozens...close to 100...digital exports from FCP without issue. When you use QT CONVERSION...you might see that, if you go to another codec. But actually, that's one trick I use to ensure broadcast levels are within 100 and 0 IRE.

Shane
Little Frog Post
Read my blog, Little Frog in High Def


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Timothy Gassen
Re: FCP gamma shift on export, final QT file codecs & print to tape problems
on Aug 28, 2012 at 8:27:20 pm

Hi Shane,

Thanks for the response. I do understand that re-importing a FCP- exported QT back into FCP will appear correct. I am attempting to use FCP QT exports in OTHER applications. Importing back into a PC editor shows the gamma shift. Encoding for DVD and Blu Ray show the gamma shift. Encoding for Web use shows the gamma shift.

I could accept that the export file will display incorrectly in QT Player if the actual file was in the correct gamma. (Also, the "enable FCP compatitbility" box has been checked.) Am I correct that FCP can only export a correct gamma QT if that file is used back within FCP?

Are your digital exports being used in anything other than FCP? Have you encoded for web, DVD or in another (non FCP) editor without a gamma shift? If so then please share your export settings/procedure -- I want this to be my incorrect user setting, not a FCP limitation.

I know this is not only my issue -- I've read hundreds of similar posts from much more experienced FCP users than me.

BTW, whether using direct QT Export, Conversion or Compressor, the gamma shift happens even when rendered out to the same codec as the sequence.

Thank you again for your help! :)

Timothy Gassen
Director/Producer

http://www.purple-cactus.tv


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Shane Ross
Re: FCP gamma shift on export, final QT file codecs & print to tape problems
on Aug 28, 2012 at 9:21:08 pm

I don't know what other systems they go into. My deliverables for many companies, and many networks, has been ProRes 422 or ProRes HQ. So I give them that and they do what they will with it.

If you convert to DVD, especially going from HD to SD, there is a gamma shift anyway, you are going from Rec 709 to Rec 601...different color space. And when you author a BluRay, you are compressing and that changes things slightly too.

But I'm sure the networks I sent my finals to did something to them. I know that ProRes isn't as good as DNxHD in terms of the gamma shift. I wish I had a suggestion to make.

Shane
Little Frog Post
Read my blog, Little Frog in High Def


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Timothy Gassen
Re: FCP gamma shift on export, final QT file codecs & print to tape problems
on Aug 28, 2012 at 9:35:07 pm

Thanks again for your thoughts, Shane.

Yes, ProRes is a good delivery codec. Since you are sure networks "do something" to your files then my guess is they are correcting the gamma at their end, for their use.

My footage in this issue is all SD material, BTW.

Any FCP users have thoughts on M-JPEG as a final master file codec and how to get full-res firewire output to tape?

Thanks! :)

Timothy Gassen
Director/Producer

http://www.purple-cactus.tv


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Shane Ross
Re: FCP gamma shift on export, final QT file codecs & print to tape problems
on Aug 28, 2012 at 9:38:33 pm

[Timothy Gassen] "Any FCP users have thoughts on M-JPEG as a final master file codec"

Photo JPEG is what many stock footage houses use. That's how they are encoded when I get them.

[Timothy Gassen] "how to get full-res firewire output to tape?"

If you only have firewire, no IO device...then DV is your only option, as that is the only SD Firewire format out there. So even if you finished in ProRes...you will end up with the DV codec. So what you need to do is drop your clips into a DV sequence, or bring back in your exported file into a DV sequence...render, then output. Yeah, it will make it less than the great ProRes you finished in. But that would happen if you output to DV from an IO box anyway. DV is the lowest end SD broadcast format out there.

Oh, except for those smaller local markets that take DVD

Shane
Little Frog Post
Read my blog, Little Frog in High Def


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Timothy Gassen
Re: FCP gamma shift on export, final QT file codecs & print to tape problems
on Aug 28, 2012 at 10:06:13 pm

Thanks again, Shane.

Photo-JPEG is for progressive files; Motion-JPEG is for interlaced (SD footage).

Yes, we've created a DV sequence and re-rendered specifically for the purpose of going out to DV via firewire. Quality in the sequence is fine -- but that is NOT what is being sent out by FCP through the firewire. It is as-if FCP is still sending out draft-quality even though the timeline is rendered as DV. My thought that this was a bug with THIS machine, but perhaps it is a FCP limitation?

(Media 100, BTW, can send superior DV quality out because it converts its DV on import to the M-JPEG codec, not using DV at all for edit, and then can export back through firewire without a re-encode.)

So perhaps this is another limitation of FCP -- the inability to send out DV in actual resolution through firewire?

Timothy Gassen
Director/Producer

http://www.purple-cactus.tv


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Shane Ross
Re: FCP gamma shift on export, final QT file codecs & print to tape problems
on Aug 28, 2012 at 10:09:26 pm

[Timothy Gassen] "Photo-JPEG is for progressive files; Motion-JPEG is for interlaced (SD footage)."

You are correct sir! Sorry, been a while since I dealt with SD.

[Timothy Gassen] "So perhaps this is another limitation of FCP -- the inability to send out DV in actual resolution through firewire?"

No limitation that I know of. I did that quite often...and the quality was always exactly what I had in the timeline. FCP always delivered the same quality out of firewire...it's just a data transfer...one's and zeros.

Shane
Little Frog Post
Read my blog, Little Frog in High Def


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Timothy Gassen
Re: FCP gamma shift on export, final QT file codecs & print to tape problems
on Aug 28, 2012 at 10:15:58 pm

Yes, that is what firewire SHOULD deliver -- send a data copy -- but our video seems to be re-encoded on the fly, with added mosquito noise not visible on playback of the actual rendered timeline.

We did a test "print to tape" form a non-DV timeline and it output immediately to DV without a re-encode -- something that I think is not supposed to happen, lol -- so this is why I'm guessing there is a bug in the "print to tape" function on this machine. It appears to be sending draft quality, not making a data-copy from the timeline.

Suggested fixes? ;)

Timothy Gassen
Director/Producer

http://www.purple-cactus.tv


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Rafael Amador
Re: FCP gamma shift on export, final QT file codecs & print to tape problems
on Aug 30, 2012 at 9:37:11 am

[Timothy Gassen] "Photo-JPEG is for progressive files; Motion-JPEG is for interlaced (SD footage)."
Phoo JPEG is for progressivo or interlaced footage. Belongs to the same family that M-JPEG but is much more modern.
M-JPEG (A andB) are legacy codec. QT can play them but they don't even show as an export option

[Timothy Gassen] "(Media 100, BTW, can send superior DV quality out because it converts its DV on import to the M-JPEG codec, not using DV at all for edit, and then can export back through firewire without a re-encode.) " M-JPEG was the first codec used to digitize Analog video in many devices, but is a 20 years old solution.
FC is better because doesn't need to convert the DV footage. Works native; with the original stuff; full quality as is on tape.

[Timothy Gassen] "Problem #2: I’d like to do a tape backup out to DVCAM, but we can’t get FCP to send a full-resolution signal from a sequence to tape. The rendered sequence quality looks fine, but it seems to be re-encoding on the fly in draft quality, even from a converted DV timeline, and even when going “print to tape." In other editors I can output good looking full-resolution DV without adding artifacts -- is FCP unable to output full-resolution DV, or is an add-on breakout box or encoding card necessary?"
FC supports DV, DVCPro (SD/HD) and Prores through FW. All full quality and in RT, without any kind of picture reprocessing. What is on your sequence, gets on the FW. On Print to Video, FC just reads the footage or render files.
Do you have set External Video > FW?
rafael

http://www.nagavideo.com


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Timothy Gassen
Re: FCP gamma shift on export, final QT file codecs & print to tape problems
on Aug 30, 2012 at 3:55:32 pm

Hi Rafael,
Thanks for your comments!

I haven't found any resources that confirm P-JPEG is for interlaced SD footage. In any case, it doesn't render correctly for our SD footage, showing field-dominance issues on export of the kind I've seen with progressive-interlaced conflicts.

M-JPEG, I'm told, can be re-inserted in FCP as a legacy export option, and I've read it's an option many FCP users wish had never been deleted.

The Media 100 DV input to M-JPEG was as a firewire import, not an analog encode. DV has been a great acquisition format, but degrades greatly as an edit format. Working natively in DV is not the best quality solution, at least in FCP. The M-JPEG-encoded DV footage in Media 100 has been great in image quality. (I'm not knockingh FCP as a whole -- different apps do different things well.)

Regardless, it seems I've been unable to get the firewire on the FCP machine at the facility I'm working at to give the actual rendered file out to tape. It could be the "print-to-tape" function is not working correctly in this install -- but it appears to be sending draft quality out, not the rendered sequence. I'm thinking I'll have to bring final QTs back into a Media 100 if I want a quality firewire out to DVcam...

Thanks again for everyone's help.

Timothy Gassen
Director/Producer

http://www.purple-cactus.tv


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Timothy Gassen
Re: FCP gamma shift on export, final QT file codecs & print to tape problems
on Aug 30, 2012 at 4:12:03 pm

FYI: here's some info I found on M-JPEG vs P-JPEG. I'm new to using either as a final QT codec, so I'm learning! :)

"Both the M-JPEG codecs (A&B) allow fields and a field order to be specified, and if used the fields are compressed separately and then combined. This prevents artifacts from mushing fields together, and at lower quality settings this can make a significant difference. For this reason alone, anyone working with interlaced video should use the MJPEG codecs and not the Photo JPEG codec.

At quality levels below 100%, chroma is downsampled respective to the
quality level selected, but Photo JPEG samples at 4:2:0 (ie. vertical
samples) while the MJPEG codecs sample at 4:2:2 (ie. horizontal
samples). In terms of video footage, this relates to a fields issue and is another reason why you should use MJPEG codecs for interlaced footage instead of Photo JPEG."

I hope the info helps other users...

Timothy Gassen
Director/Producer

http://www.purple-cactus.tv


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Rafael Amador
Re: FCP gamma shift on export, final QT file codecs & print to tape problems
on Aug 31, 2012 at 1:51:38 am

[Timothy Gassen] "I haven't found any resources that confirm P-JPEG is for interlaced SD footage."
Have you find any that says is only for progressive?
To make a codec progressive-only makes no sense. That means that you couldn't use it for HD.
M-JPEG was only for interlaced because at that time all video was interlaced.
As long as I know every (modern) codec is field-order agnostic. it has to be able to work as Upper/lower and Progressive.

[Timothy Gassen] "M-JPEG, I'm told, can be re-inserted in FCP as a legacy export option, and I've read it's an option many FCP users wish had never been deleted."
A couple of versions back of QT.7 you still had the option (QT Preferences) of "Show Legacy codecs". In the last QT.7 version, the options don't exist anymore.

[Timothy Gassen] "DV has been a great acquisition format, but degrades greatly as an edit format. Working natively in DV is not the best quality solution, at least in FCP. "
Right, but you capture and edit DV and change your sequence codec (Uncompressed or prores) to avoid further DV recompression. You don't render again in DV.


[Timothy Gassen] "Regardless, it seems I've been unable to get the firewire on the FCP machine at the facility I'm working at to give the actual rendered file out to tape. It could be the "print-to-tape" function is not working correctly in this install -- but it appears to be sending draft quality out, not the rendered sequence. I'm thinking I'll have to bring final QTs back into a Media 100 if I want a quality firewire out to DVcam..."
Most of us we have been working for years with DV and printing back to tape without problems.
Do you have FC set to full quality playback?


[Timothy Gassen] ""Both the M-JPEG codecs (A&B) allow fields and a field order to be specified, and if used the fields are compressed separately and then combined. This prevents artifacts from mushing fields together, and at lower quality settings this can make a significant difference. For this reason alone, anyone working with interlaced video should use the MJPEG codecs and not the Photo JPEG codec."
The guy who wrote that has certain idea but he didn't understood it.
M-JPEG is a codec from before the NLEs and needs a way to specify Upper or lower first encoding. However this won't makes any sense in QT because QT do not manage field order. QT only needs to know if the stuff is interlaced or progressive, because on both cases CHROMA is compressed in different ways.
Photo-JPEG is a codec developed for NLEs. Is your NLE who will set the field order of the compressor.
Have a look to the date of that document.

[Timothy Gassen] "At quality levels below 100%, chroma is downsampled respective to the
quality level selected, but Photo JPEG samples at 4:2:0 (ie. vertical
samples) while the MJPEG codecs sample at 4:2:2 (ie. horizontal
samples). In terms of video footage, this relates to a fields issue and is another reason why you should use MJPEG codecs for interlaced footage instead of Photo JPEG.""

That's absolutely wrong. the class of information that should be trashed from internet.
This link contains the best info on QT codec that have been done so far:

http://onerivermedia.com/codecs/

Click on the "422C" tab.
rafael

http://www.nagavideo.com


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Timothy Gassen
Re: FCP gamma shift on export, final QT file codecs & print to tape problems
on Aug 31, 2012 at 3:15:44 pm

Rafael (and all),

Thanks again for your responses and patience as I try to learn & figure this out!

As for P-JPEG vs M-JPEG, I found this, credited to "Sam Bushell,
QuickTime Engineering" - "If you're compressing non-interlaced content, use Photo JPEG. If you're compressing interlaced content in software in the abscence of any hardware or expected hardware, you should choose Motion JPEG A."

Again, I am not an expert and I dont' know which codec is appropriate, so I'll try more P-JPEG tests along with M-JPEG...

BTW, we were able to (after much hoop-jumping) re-insert the M-JPEG codec back into Compressor. We must not be running the newset version of QT, where that option isn't allowed...

As for our DV out problem: Yes, we changed our sequence to a better codec for the edit, but I thought it needed to be copied back to another sequence and re-rendered as DV before it could be sent back through firewire to a DV/DVcam deck? We did try sending to firewire from our uncompressed-codec sequence and it DID go to firewire, but again in what appears to be the "draft quality" that we got from our DV sequence. Again, the video played from our timeline looks OK -- the video sent through the firewire has additonal "mosquito-noise" artifacts. All our settings are set to Full/Best...

Thank you all again for your thoughts and suggestions!

Timothy Gassen
Director/Producer

http://www.purple-cactus.tv


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Timothy Gassen
Re: FCP gamma shift on export, final QT file codecs & print to tape problems
on Sep 2, 2012 at 8:29:46 pm

FYI: To turn on Quicktime legacy codecs in Snow Leopard: open Terminal then "Shift + Command(⌘) + N" and enter the following code:
qtdefaults write LegacyCodecsEnabled yes

After more test encodes, P-JPEG is not working for our SD footage. There is no control for field dominance in the export to P-Jpeg, and it appears to be upper-dominant, causing obviuous confilict with our lower-dominant SD footage.

M-JPEG quality is good, but a shame that in order to use the gamma correction on export that we have to go through Compressor, and can't do a straight QT Export or use Conversion...

FYI: After tests, a gamma correction of 1.3 in Compressor appears to make our final QT files have the same gamma as the original master footage...

Timothy Gassen
Director/Producer

http://www.purple-cactus.tv


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