the lessons of Prores workflows

[8salacious9]

So it seems that there are many workflows that people use, some straightforward some complex, this discussion is to help newbies understand the point of Prores and its uses.

For the purposes of keeping things simple, we will from the beginning exclude Prores 4444 because for 90% of users here it will be overkill, also Prores (LT) will be ignored because right now we are trying to keep things simple.

so that leaves us with:

Apple ProRes 422 (HQ): This codec preserves visual quality at the same high level as Apple ProRes 4444, but for 4:2:2 image sources. With widespread adoption across the video post-production industry, Apple ProRes 422 (HQ) offers visually lossless preservation of the highest-quality professional HD video that a (single-link) HD-SDI signal can carry. This codec supports full-width, 4:2:2 video sources at 10-bit pixel depths, while remaining visually lossless through many generations of decoding and reencoding. The target data rate of Apple ProRes 422 (HQ) is approximately 220 Mbps at 1920 x 1080 and 29.97 fps.

Apple ProRes 422: This codec offers nearly all the benefits of Apple ProRes 422 (HQ), but at 66 percent of the data rate for even better multistream, real-time editing performance.

Apple ProRes 422 (Proxy): This codec is intended for use in offline workflows that require low data rates but full-resolution video. The target data rate is roughly 30 percent of the data rate of Apple ProRes 422.

So where do we start?

well firstly unless you understand why you need to use 422 (HQ) then you neednt bother, this is for keeping things simple however it will be covered at a later date so we will keep it here.

secondly, 422 proxy is not considered a deliverable format... it is mainly for offline editing !

so whats the point in it all?

ok well h.246 is a distribution format - so you want to show it on the web for example

h.246 is not designed for editing.. yes its native in adobe (apparently) but still not designed as an editing codec

so lets begin with scenario A (more to be added later):

Scenario A - no colour correcting/grading in fcpx
shoot 30 second clip > transfer to mac > open up fcpx > create a timeline matching your clips FPS > create new event > import media > choose clip and click on create proxy > leave for mac to render > you now have a proxy version (422 proxy) and still keep the native h.246

but wait theres more.. you need to click on the apple sign while fcpx is still open then select preferences.. click on the playback option, make sure playback:use proxy is selected, now your mac should have smooth editing performance, but you will notice that the image quality is shite, thats because if you look above "The target data rate is roughly 30 percent of the data rate of Apple ProRes 422"

*please note that selecting optimise media will create a 422 version of your h.246 file and as such will almost triple in size and i dont understand the point of optimised media at this point as i only use fcpx for cutting*

so I use FCPX mainly for cutting and lining up the clips to create my scene using proxy (via preferences playback options) then i would select the preferences select optimised or original media then select higher quality, the reason why i select this before exporting is because (unless apple have changed it) that when the playback using proxy is selected, it will export using the proxy files which you dont want unless you want to show someone a digital version of vomit.

i would then export to 422 - now heres why, you are telling final cut to export to final cut 422 which is then opening up the colour space, now im kind of tricking you when i say this because the colour space isnt increased.. its increasing the amount i can work with before it gets f'd up


to be continued i need to sleep - feel free to comment and correct me if im wrong or you want to add in info.

 

[bellabell]

One of the reasons offline editing was so necessary before was because raw files and high quality codecs were such render hogs and color correction was done on film reels. Now, most of the stuff we work on starts at ProRes 422 HQ and ends at ProRes 422HQ. It's online from start to finish. I use it to export for AE too.

 

[jax_rox]

Of note: ProRes 4444 is useful for the fact that it carries an alpha channel, and also that it is essentialy RGB (as opposed to cut-down chroma subsampling). Broadcast standards are 4:2:2 minimum chroma subsampling, though DSLR has injected itself into broadcast quite readily.

I think there's a bit of confusion where you mention '4:2:2 image sources' - this is not 100% correct; indeed cameras that 'only' capture 4:2:2 chroma subsampling will record into ProRes 422 if they're configured to. But, you can take 4:2:0 or 4:4:4 sampled files and encode them into ProRes 422. If you took 4:2:0 files like DSLR H.264 files and encoded in ProRes 422, you would gain nothing (apart from file size). If you took Alexa ProRes 4444 files and encoded them in ProRes 422, you would lose half your chroma subsampling. Whether this is for you or not depends on your workflow and deliverables.

 

[8salacious9]

Of note: ProRes 4444 is useful for the fact that it carries an alpha channel, and also that it is essentialy RGB (as opposed to cut-down chroma subsampling). Broadcast standards are 4:2:2 minimum chroma subsampling, though DSLR has injected itself into broadcast quite readily.

I think there's a bit of confusion where you mention '4:2:2 image sources' - this is not 100% correct; indeed cameras that 'only' capture 4:2:2 chroma subsampling will record into ProRes 422 if they're configured to. But, you can take 4:2:0 or 4:4:4 sampled files and encode them into ProRes 422. If you took 4:2:0 files like DSLR H.264 files and encoded in ProRes 422, you would gain nothing (apart from file size). If you took Alexa ProRes 4444 files and encoded them in ProRes 422, you would lose half your chroma subsampling. Whether this is for you or not depends on your workflow and deliverables.

It's interesting you say that encoding to Prores from a h.264 source gains you nothing, various tests if seen across the net all come to the conclusion that it improves colour correction ability because it opens it up in a 10bit space, not that it's giving you more colours but rather more steps to play with if you get what I mean.

What i don't understand is why would anyone encode from 4444 to 422? (If I wrote that somewhere I edit it out)

 

[ShockingMind]

encoding to Prores from a h.246 source gains you nothing,

Is that typo?? do you mean h.264 or is it something different??

Interesting comment about PRoRes4444 didn't know about that Alpha channel!!

 

[8salacious9]

Is that typo?? do you mean h.264 or is it something different??

Interesting comment about PRoRes4444 didn't know about that Alpha channel!!

yeah typo lol im trying to do multiple things at once and seem to malfunction sometimes.

glad you learned about the aplha channel!thats the whole point of this thread, share the knowledge grow the community!

 

[ShockingMind]

Cool!! But ya need to be careful when explaining technical info as typos can lead to confusion!!

I use XDCAM instead of PRORES for small scale projects and test shoots, mainly to save disk space. It's slightly 'lighter' than ProRES but I can't really see much visual difference between them. And if it's good enough for Phillip Bloom to use (albeit a few years ago)...

 

[wheatgrinder]

for the windows users, just replace prores with cineform and all the same stuff about up-sampling from 8 bit 4:2:0 to 10 bit 4:2:2 applies

There are other options too.. 5dtorgb is one that works multiplatform (mac and windows at least)

 

[ItDonnedOnMe]

It's interesting you say that encoding to Prores from a h.264 source gains you nothing, various tests if seen across the net all come to the conclusion that it improves colour correction ability because it opens it up in a 10bit space, not that it's giving you more colours but rather more steps to play with if you get what I mean.

Right - you don't gain anything, you just make it more likely you'll preserve what was originally there.

I'm not sure this is really as much of a concern these days though. In older versions of FCP the bit-depth of the format you edited in could affect the rendered output, but the last couple versions have given the option to always render in high-bit space and compress the rendered footage back to prores instead of the editing format. I believe this is the default behavior in FCPX.

For the purposes of keeping things simple, we will from the beginning exclude Prores 4444 because for 90% of users here it will be overkill, also Prores (LT) will be ignored because right now we are trying to keep things simple.

I'm not sure why you'd exclude LT - I use it all the time for DSLR footage on projects where I'm not going to do a lot of post-processing, and never use Proxy because of the quality and extra steps required. If you're not specifically going to broadcast I think it makes more sense to just encode everything to LT and use it through the whole process. Although honestly if you're just using FCPX I don't see much reason to convert at all unless you're working on an older system; my 2 year old macbook handles native h.264 editing without a problem.

 

[8salacious9]

for the windows users, just replace prores with cineform and all the same stuff about up-sampling from 8 bit 4:2:0 to 10 bit 4:2:2 applies

There are other options too.. 5dtorgb is one that works multiplatform (mac and windows at least)

I have used 5dtorgblite and can confirm good results. That's useful to know about windows users, I'm planning on building a pc 10x more powerful than my mac and need to learn the workflow all over again

 

[8salacious9]

Right - you don't gain anything, you just make it more likely you'll preserve what was originally there.

I'm not sure this is really as much of a concern these days though. In older versions of FCP the bit-depth of the format you edited in could affect the rendered output, but the last couple versions have given the option to always render in high-bit space and compress the rendered footage back to prores instead of the editing format. I believe this is the default behavior in FCPX.



I'm not sure why you'd exclude LT - I use it all the time for DSLR footage on projects where I'm not going to do a lot of post-processing, and never use Proxy because of the quality and extra steps required. If you're not specifically going to broadcast I think it makes more sense to just encode everything to LT and use it through the whole process. Although honestly if you're just using FCPX I don't see much reason to convert at all unless you're working on an older system; my 2 year old macbook handles native h.264 editing without a problem.

To be honest I had mixed results with LT but as I wrote above I still had more to write, I was going to cover it much later on, in alot of production companies Iv seen they have never used LT, the only place Iv seen recommend it was on mr.blooms website.

And I always almost use some kind of effects from after effects and I'm sure alot of users here do too hence i went for what is current first, but your right alot of modern computers can handle h.264 with some simple cutting etc.

 

[ItDonnedOnMe]

I often run stuff through AE as well, but that doesn't really have anything to do with the proxy workflow you're describing in your scenario. I'd still be inclined to do the cuts in FCPX native, export just the selected clips you need as HQ, render in AE to either HQ or 4444 (if you need the alpha), and then cut those back into your sequence in FCPX - no need for prores proxy.

To me the main reason to pre-convert footage is if you're planning to do a lot of work in motion - there the performance with prores should be significantly better than h.264, and having all your footage converted in your FCPX sequence simplifies things when you 'send to' motion. Again though, in that situation it would be better to convert to LT, standard or HQ rather than proxy.