5D workflow - loss of saturation?

commanderspike

commanderspike

Carbonite Member
I am experimenting with workflows and transcoding some 5D footage to the various codecs to see which gives the best results:

XDCAM EX 35mbps 1080p 30p
Prores 442 HQ
Prores LT

XDCAM introduces (or makes visible) more noise than Prores but produces stronger colour saturation and much smaller files than Prores.

However I am losing a lot of colour saturation compared to the original Quicktime H264 file from the camera, at least when played back in Quicktime X on Snow Leopard.

Any idea what's going on? It does seem that gamma is increased, and shadow detail is more visible in the transcoded footage than in the original. But why?
 
How do you transcode?

I use Quicktime in batch via QTAmateur .

Sample 1: 5D2 original and the ProResLT version look identical in terms of saturation.
Sample 2: 5D2 original looks less saturated

There is something off here.

Thanks for looking into it.
 
Sorry forgot to mention that. I'm using Voltaic and have started using MPEG StreamClip too.

Playing back the transcoded footage on my laptop in Quicktime X via HDMI to a 50 inch screen reveals that the footage falls quite a long way short of the HDMI output raw from the camera or the raw footage played on the laptop in Quicktime X, so I'd like to try and get the transcoded footage as close as possible to the original.

I want to delete the master files because they're so large, and only keep the transcoded footage for archiving.
 
are your quicktime preferences set to match final cut gamma?

i've tested all flavors of pro res with 5d footage, saturation seems to maintain itself, pro ress hq is kind of overkill, LT i find is the sweet spot for saving hd space and maintaining the original look, and also easier to cut with then xdcam, intra frame vs long gop.

the lift in gamma is probably do to a conversion in gamma space, pure speculation of course but that's my best educated guess. i'm guessing that the camera records in RGB gamma space, and pro ressing it puts it at rec709, or vice versa, whichever. i haven't found any options to really test it and play with it, i do all my transcoding in compressor. but that seems to be a leading issue from pro ress to pro ress out of after effects too. never had the problem with avid, cuz all the options are in the export to match gamma spaces.

saturation shouldn't be such a big deal though, a simple CC filter and bump the saturation back and it's a easy work around. same with bringing ur blacks back down...
 
Incredibly, I cannot find any preferences for Quicktime X either in Quicktime itself or in the Snow Leopard control panel. But I don't think Quicktime gamma is the issue, as the original footage maintains inky black contrast and colour in Quicktime. In fact on my Macbook screen it looks too dark, while the transcoded footage looks acceptably light, but that's due to my Macbook screen being a bit rubbish. On a TV the original footage looks by far the best - good balance between contrast, shadow detail and highlight saturation.

I have a custom colour profile setup for my Mac's LCD screen. The transcoded footage seems to be taking on the properties of the screen's colour profile, that is - lighter, less saturated, boosted shadow details. The default colour profile looks too dark and the gradient between highlights and darker colours is very sudden and stepped. It looks awful.

Here is the ProResLT footage versus original. Quite a big difference:

***ProResLT***
5dbad.jpg


***Original***
5dgood.jpg


The transcoded and original footage display the same no matter what the screen (i.e. TV via HDMI from laptop) or player (i.e. Quicktime X or VLC Player).
 
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quite possibly a quicktime bug, or it really is a change in gamma space in the transcode. i've seen this happen a lot going from one gamma space to the other, it just has to be CCed accordingly. it's really tough with a simple computer lcd, a real referance monitor is really the only way to tell what's going on, maybe u should take it into apple color or fcp and look at ur waveforms to see where exactly your taking the hit. and you might be able to adjust compressor or transcode programs to compensate accordingly
 
Thanks for that. Well, further tests rule out the Quicktime bug. It's the same in VLC Player. I can roughly achieve the same colour by adjusting gamma and saturation in VLC Player so the transcoded footage matches the original.

I am still confused as to why it's happening though. This is a fresh install of Snow Leopard on a new hard drive, with a fresh install of FCP 7 and Voltaic / MPEG StreamPlayer.

So I don't know why it's just me that is having this strange colour / gamma adjustment between the original footage and Prores.

XDCAM takes less of a hit to colour & contrast, but is noisier and produces larger files.

But strangely, just now my ProresLT files have grown to 3 times the size of the original footage MOVs. When before, it was nice and small.

S*T*R*A*N*G*E

>___<"
 
>are your quicktime preferences set to match final cut gamma?

At least this solved my problem.

Try this:

I use Quicktime in batch via QTAmateur .
 
What is 'Quicktime in batch'?

I tried QTAmateur to playback the 5D file. It's gamma on playback is now somewhere between Quicktime X and Prores. QTAmateur, it must be noted, plays back the original 5D H264 without stuttering like Quicktime X and Quicktime 7 Pro do. Oh and the preferences in Quicktime X - erm, there aren't any. Were Apple asleep while they made Quicktime X?

Anyway, I looked at the PRORES transcoded footage in Finder's 'get info'. It lacks an entry for 'colour profile' whilst the original H264 footage has '(1-1-6)' for colour profile.

XDCAM footage has HD 1-1-1 for the colour profile.

I tried assigning a colour profile (list was the same as in Displays for my LCD panel) in the adjustments panel in Voltaic but it didn't seem to make any difference.

On Google there are similar problems, termed 'prores gamma shift'. But my problem is that all formats seem to be affected, not just PRORES.

Any idea why PRORES LT files are coming out 3x the size and 3x the bit rate of the original footage? Even though quality is set to medium and bitrate to automatic in both Voltaic and MPEG StreamClip?
 
QuickTime has a funky way of interpreting gamma in video files, no matter what the codec, no matter how you set the gamma in your NLE. It's a QuickTime issue... Remember, FCP uses QuickTime as its video decoding engine...
 
>What is 'Quicktime in batch'?

I only use the batch tool in QTAmateur.

File->Batch Export.
 
i still chalk it up to change in gamma space, i don't the 5d is making the files in rec709, which is your gamma space for HD, it's probably making it in RGB and transcode to pro res is making it 709, i see the same thing happening out of avid to after effects. if you set ur output to 709 and bring it to AE, AE is natively RGB and all ur gamma gets pushed and ur blacks get washed out along with saturation. the information is still there u just have to re CC

ur pro res files will always be bigger, only pro res proxy will be bigger by a few megabytes compared to the originals. ur turning a LONG GOP codec with insanely high compression to a intra frame codec that has reduced file size for HD content, but extracts its information fromt he primary source data. it may equate out to the same megabits in bandwidth using pro res LT, but that's pretty much what you get with that kind of bandwidth in pro res itself as a intra frame codec. all the new codecs are just reduced bandwidth versions of the same flavor. exact same thing that avid does with their dnxhd.

i find xdcam to be a very crappy codec, transcodes badly, and falls apart easily. if it's just saturation and blacks ur worrying about ur gonna have no choice but CCing ur footage, i've had to do the same with all 5d footage i've worked with, u can try some other pieces of software that reacts with quicktime differently. i've tried using autodesk cleaner, and it gives u a lot more control over ur transcode. i've even found cases where it oversaturates the footage and increases TOO much contrast. each program will have a different algorithm for the transcode even if ur using the same codec.

i've seen different results in compressor, out of fcp itself, cleaner, adobe media encoder, sorenson squeeze, and avid. my favorite results are compressor, even though it works slower. lot of controls u can use to maximize quality and data interpolation, and i also find that oddly enough it does it more efficiently. my file sizes out of compressor end up being smaller if i put it out of fcp with the exact same settings.

weird right? give compressor a try if u have it and see if u get the same results.
 
ydgmdlu said:
QuickTime has a funky way of interpreting gamma in video files, no matter what the codec, no matter how you set the gamma in your NLE. It's a QuickTime issue... Remember, FCP uses QuickTime as its video decoding engine...
Click to expand...

It may be a Quicktime issue but do you mean at playback or during transcoding? On playback it effects other playback software like VLC too. Also remember that I'm playing back the source footage fine - a Quicktime file in Quicktime. It's only the transcoded footage which has funky gamma. Maybe I'll try a different wrapper in StreamClip over than .mov because if Quicktime is funky with gamma it's clearly doing it at the transcoding stage not at the playback stage.

Any thoughts about missing colour profile in transcoded Prores footage?

I don't mind the inconsistency across different workflows and software. It's simply that I've been unable to match the source gamma / saturation / contrast of the source footage yet, which means having to adjust that on 100% of the footage I process which just seems really time consuming and unnecessary.

Having said that, it will be worth playing around with the Adjustments tab in Voltaic and Streamclip, and saving that as a preset for use each time. Can't stand the washed out look of transcoded footage when played back on a big screen, compared to the original .mov files which look so much better and punchy.

I also dislike that in order to get clips which can be edited quickly without overloading the CPU, I have to loose quality and double file sizes! Anyone got some terabyte storage drives to sell me?

I mean seriously, what's that all about? Worse quality but larger file size!?
 
well in all justice, pro res LT or even SQ, ur not losing quality (other than ur gamma issues) 5d II is about 45 mbps in bandwidth for the encoding correct? somewhere in that ball park, look at your bandwidth in a clip with pro res LT, 45-55 mbps isssh. it baselines off all your quality in your footage, if anything, all your loss in quality came from encoding it in h.264 to begin with, it's lossless when you go to pro ress.

my cheap way of storage, get a storage dock, 50-80 dollars, where u can insert internal disks in, 3.5 inch or 2.5 inch, they make them with usb, firewire, and esata ports. equals out to a single disc external hard drive, and a one tb hd internal disc is another 80 bux.

i mean that's the sacrifice with the 5d, and in the past the only solution for a lossless transcode was uncompressed, pro ress was the solution for that. and give it some time, more software optimization and faster hardware, one day h.264 and all long gop codecs will cut like butter and the transcode won't have to come till finishing stages.
 
My Prores clips come out at around the 90mbps mark. A lot of space is wasted. I can get almost the same quality out of compressing the 140MB 5D .mov file down to a 8MB MPEG 4 H264 .mp4 file but that resulting file is still slow to edit (in seeking), despite it's amazing file size.

This gamma issue is a pain because I don't really want to have to apply colour correction to every clip in my timeline every time I edit. It's a hassle I could do without, so I am intent on fine tuning my transcoding workflow and sticking with it. I am not really into colour grading. I prefer the footage to be as close to what my eye sees while shooting as possible, and adhering to the in-camera colour profiles if possible.

I really need to find out what's causing this colour change... Everyone else have the same results? And what is the 1-1-6 colour profile in my source footage direct from the 5D? Is that the colour profile selected in camera? The footage was shot on 'Faithful'.
 
i'm out of state right now from my house, i'll post up some pics with my results and my past 5d projects. color and gamma rendition really did stay the same to me, as far as i can see. i'll get some grabs to compare with u when i can.
 
commanderspike said:
It may be a Quicktime issue but do you mean at playback or during transcoding? On playback it effects other playback software like VLC too. Also remember that I'm playing back the source footage fine - a Quicktime file in Quicktime. It's only the transcoded footage which has funky gamma. Maybe I'll try a different wrapper in StreamClip over than .mov because if Quicktime is funky with gamma it's clearly doing it at the transcoding stage not at the playback stage.
Click to expand...
Please read this thread for a discussion of the QT gamma issue (though it applies to Adobe Premiere, it should still provide some insights): http://www.dvxuser.com/V6/showthread.php?t=185494

Also open this article and scroll to the Additional Information section for an explanation of what QuickTime is doing when trying to interpret or render gamma: http://kb2.adobe.com/cps/402/kb402801.html

Something like this tool might be the answer, if you can find a compatible version for your operating system: http://aeportal.blogspot.com/2008/02/quicktime-gamma-stripper.html

I've experienced this issue myself numerous times when working on OS X (with FCP and QuickTime Player). It's very frustrating.

I agree with you that it seems like an issue being introduced during transcoding. And it's an issue in the QuickTime wrapper.
 
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