Gear Talk > Software & Accessories

So ProRes 422 is a lossy format? Why would degrade before editing???

(1/3) > >>

cayenne:
Hi all,

I'm finding out that for some reason, using the 5D3, with ALL-I raw footage in FCPX.....you cannot successfully do the XML roundtrip with Davinci Resolve Lite anymore.

The work around for this, I heard, was to have FCPX create the 'optimized media' which transcodes your footage into ProRes.

I was looking around and found that ProRes is a LOSSY format....so, I'm losing information to do this??
I hear about people using ProRes all the time, are people not freaking out about going to all the trouble to take good HD footage, and then start degrading it when they begin to edit it??

Is there a lossless intermediate codec people work with, preferably one that works in FCPX?

I mean, I don't use mp3's on my home stereo, I rip my stuff to flac, to keep the fidelity there....I'd assume this would be even MORE important for video???

Where am I missing something here?

TIA,

cayenne

Midphase:
First of all, if superior image quality and a workflow that makes sense are top priorities for you...you probably shouldn't be using FCP X.

On a less snarky note...Pro Res is lossless but very robust and if you go up to Pro Res HQ or Pro Res 4444, the difference between that and uncompressed is negligible.

Eventually you'll want to master in a more robust and industry standardized format like Pro Res anyway, many commercial releases are mastered to Pro Res 4444 before being sent to Blu Ray duplication.

So yes, you're suffering a wee bit of data degradation, but IMHO it's nothing that you're bound to notice, the ALL-I codec in the 5D is much harsher on your data than Pro Res...which is why many people including myself are waiting for the new firmware update so that we can use a higher quality external recorder.

cayenne:

--- Quote from: Midphase on March 20, 2013, 10:14:33 PM ---First of all, if superior image quality and a workflow that makes sense are top priorities for you...you probably shouldn't be using FCP X.

On a less snarky note...Pro Res is lossless but very robust and if you go up to Pro Res HQ or Pro Res 4444, the difference between that and uncompressed is negligible.

Eventually you'll want to master in a more robust and industry standardized format like Pro Res anyway, many commercial releases are mastered to Pro Res 4444 before being sent to Blu Ray duplication.

So yes, you're suffering a wee bit of data degradation, but IMHO it's nothing that you're bound to notice, the ALL-I codec in the 5D is much harsher on your data than Pro Res...which is why many people including myself are waiting for the new firmware update so that we can use a higher quality external recorder.

--- End quote ---

Hmm...I'm a bit confused, you're saying ProRes is lossless (as in no loss of information), but on wikipedia it says it is a lossy format.

http://en.wikipedia.org/wiki/ProRes_422

So, I'm confused....doesn't make sense to me that you would want to use lossy formats before your final putput. I mean with stills, you stay with and edit with RAW to have the best possible information, and only when your finished you output in a lessor format (jpeg usualy).

I'm surprised to hear that the use of what appears to be a lossy format, ProRes is used for editing before output. Or, is wiki pedia wrong on this one and ProRes is really lossless?

Thanks in advance!!!

cayenne

Rofflesaurrr:
While you can have an entirely uncompressed workflow, it's not ideal for most scenarios. You would use either the Quicktime Uncompressed or Animation codec, and footage would require about 10GB/minute of storage space. Your disk system will also have to sustain about 150MB/sec transfer rate, which means RAID 0 or SSD. The 5D's ALL-I codec isn't a RAW or uncompressed format to begin, so there isn't much reason to have an uncompressed workflow. If you were using REDCODE RAW or ARRIRAW, then yes. Transcoding to ProRes 422 would be ideal (ALL-I is only 4:2:0). Hope this helps.

Axilrod:

--- Quote from: cayenne on March 21, 2013, 11:03:08 AM ---Hmm...I'm a bit confused, you're saying ProRes is lossless (as in no loss of information), but on wikipedia it says it is a lossy format.

http://en.wikipedia.org/wiki/ProRes_422

So, I'm confused....doesn't make sense to me that you would want to use lossy formats before your final putput. I mean with stills, you stay with and edit with RAW to have the best possible information, and only when your finished you output in a lessor format (jpeg usualy).

I'm surprised to hear that the use of what appears to be a lossy format, ProRes is used for editing before output. Or, is wiki pedia wrong on this one and ProRes is really lossless?

Thanks in advance!!!

cayenne

--- End quote ---

Prores is a standard for editing and there won't be any perceivable differences in quality.  Your thought process is a little overkill for DSLR footage, it's 8-bit 4:2:0 H.264, it's lossy by nature and can't really get any worse to start with.  More or less a lot of the stuff you are reading just doesn't apply to DSLR's since they aren't actual video cameras.

Also, if you're shooting in ALL-I, you don't need to optimize media.  The whole point of shooting in ALL-I is that it's already optimized for editing, it's not about better image quality at all.  I've seen lots of test results and pretty much all of them found that IPB looked equal or better to ALL-I. I shot ALL-I on one shoot and never did again and haven't ever had the desire to again. 

Trust me I've tried every different conversion/workflow possible with DSLR footage to squeeze the most image quality out of it as possible, and there is nothing that will make you say "wow that's a big difference, I'm sticking with that!"  If you want to take advantage of the stuff you're talking about you need to get a real video camera. 

More or less, if you were to shoot in ALL-I and do all these conversions, and then were to shoot the same thing in IPB and just pull the H.264 files into FCPX and not convert anything, then export, you probably wouldn't be able to see a difference in the resulting files at all.  Now if your movies were getting projected on a 100 inch screen or if it was for broadcast or something it may be worth doing all that stuff, but if it's just for the web it wont make the slightest bit of difference. 

All of this round tripping and using Resolve and stuff is just way overkill for DSLR stuff, you should be able to do everything you need to within FCPX.  DSLR footage is compressed from the getgo and you can only do a minimal amount of color correction before the image starts to degrade, and that threshold is way below FCPX's capabilities so going to resolve is unnecessary.  It's like going to After Effects to make a simple 2D plain white piece of text, you can do that in FCPX much faster and just as well so why complicate things?  Simplify your workflow and only try to branch out when you are absolutely sure what you are trying to accomplish cannot be done within your NLE. 

I've edited almost 400 music videos in the last couple of years and aside from using After Effects here and there I never once went outside of FCPX for color correction.  If you want to expand FCPX color controls get Magic Bullet Looks, but throwing Resolve into the mix is just complicating things.  Now if you had a Blackmagic Design Cinema Camera that was shooting 12-Bit 4:2:2 RAW, then yes, it would be worth using Resolve, but not for 8-Bit 4:2:0 compressed footage.

Navigation

[0] Message Index

[#] Next page

Go to full version