100 Mb/s bitrate and FCP

[Cees van Kempen]

I am new in using both the nanoflash and Final Cut Pro. On this forum I have read that shooting 100 Mb/s is the sweet spot for picture quality. At the same time I have read that FCP renders in 50Mb/s, regardless of the higher bitrate of the footage. Does it make sence to shoot in 100 Mb/s anway when working with FCP, or would 50 Mb/s be a more logical choice to start the workflow with anyway?

[George Tasick]

I've just been getting into nanoFlash but from what I can tell you ... for most normal purposes, 100 Mbit/s is excessive for almost all applications.

DVD is around 10 Mbit/s, broadcast HDTV is around 20 Mbit/s and then Blue Ray can be anywhere from 20 Mbit/s to like 280 Mbit/s depending on the read speed of the drive. (But Blue Ray is not really a valid distribution format right now for us indies anyway.)

I'm gearing up for two projects, one in Dubai and the other in Macau. We'll have two nanoFlash recorders on two Sony F900s and they'll be recording at 50 Mbit/s while the HDCAM tape records at 166 Mbit/s as our backup.

I'll be doing all my editing for broadcast and for DVD with the 50 Mbit/s files recorded to the nanoFlash.

The only time I can see using a higher bit rate is for compositing or green/blue screen work. That way you can get a cleaner/faster result and then down sample to your chosen format afterward.

[George Griswold]

Adding to George's points you have to take measures to retain that bit rate in FCP and from what I understand if you apply an effect/ render you are back to 50 Mbps. When it is all said and done you have to output to a standard format. If you were going to bring a green screen directly into After Effects or Motion you may realize the benefits of 100+ bit rates. I used it, but now am sticking with 50 for most shoots.

[Andrew Stone]

I would be very surprised to find out that AE and Motion will render the XDCAM material in 100 Mbit. Although I have not seen it stated my hunch is that the 50Mbit render of XDCAM material limitation is part of QuickTime and not FCP.

I asked this question in another thread this past week, I will ask it again, hoping for Dan Keaton or someone who actually knows... Should one be converting material from the nanoFlash into Apple ProRes or another codec prior to use in FCP, or for that matter After Effects or Color, in order to maintain the bit depth of the material for that is destined for broadcast with stringent broadcast specs?

I am also not looking for the "extolling the virtues" of the XDCAM format, I am talking about retaining bit depth to meet broadcast requirements and also for Color so it has a fighting chance when seriously yanking the color and tonal values.

-Andrew

[Adam Stanislav]

Originally Posted by Cees van Kempen

Does it make sence to shoot in 100 Mb/s anway

Yes it does. You never know when you will re-use your footage in a project where the extra quality will help. Also, while I know nothing about FCP, it is possible that future versions of your software may be able to output 100 Mb/s.

And if you do any kind of editing other than straight cuts from one clip to another, a higher quality of the original is very useful.

[Ronan Fournier]

Maybe the new 80Mb/s bitrate could be a good compromise between FCP XDCAM 4.2.2 codec rendered quality and a higher bitrate for extra quality. You have a few extra details in your pictures without producing too big files…

[Eric Liner]

Originally Posted by Andrew Stone

I would be very surprised to find out that AE and Motion will render the XDCAM material in 100 Mbit. Although I have not seen it stated my hunch is that the 50Mbit render of XDCAM material limitation is part of QuickTime and not FCP -Andrew

You'll probably find my answer unsatisfying as it doesn't reach any definitive ends.

My assumption is that AE will not render/alter your source footage until you choose to export the sequence (in which case you define the codec).

As to the question of QT or FCP performing a default render, I'm assuming that QT does not change the bit rate. While it does recognize the clip as employing the XDCAM-HD 50 codec, it also recognizes the unique bit rate that it's playing back. ("get info" for any clip in QT and you'll see that it's aware of the higher bit rate).

Things start to get confusing with FCP because there's no option for selecting an XDCAM-HD sequence beyond 50mbits/sec. That said, I don't think FCP is changing your source media until a render or export occurs. To be safe though you can set your render settings to render everything in the timeline to Pro Res HQ, or you can choose to work in a Pro Res HQ timeline from the start (or uncompressed for that matter).

-Eric

[Cees van Kempen]

Thank you all for your replies. there is clearly a lot to learn for me about FCP, After Effects etc. I suppose I play it safe when shooting 100Mb/s in normal circumstances. I came to the question because I will be on an expedition in Africa shortly, where I have to drop my footage to Nexto drives in the field and my only power source is the 12 volt plug of the outboard engine we use to travel down the river, for charging my batteries. So I have to look for the optimum in picture quality / bit rate and time / battery power to offload my footage. I suppose I'better go for 50 Mb/s over there.

[Aaron Newsome]

If you shoot at 100Mbps and render from FCP to ProRes422 HQ (220Mbps), you will have better quality than if you shoot 50Mbps.

A higher bitrate of capture will give you a more detailed image period. FCP will read the full bitrate of what's in the file always.

The fact that FCP's "RENDER" codec is limited to 50Mbps has nothing to do with reading the files and is irrelevant if you rendering to a higher quality codec anyway, like uncompressed , ProRes422 HQ or 4444. You'd most likely be doing this anyway if you're color correcting or adding effects. Remember, with color correction, you're ADDING information to data. Information that was not there before. You'll want to add and render that information with precision.

[Julio Veas P.]

Correct me if I am wrong

1.- setting the timeline to 50 mbit/s isn´t at all important since FCP is reading the files as they are even if they are in a higher bit rate.

2.- Setting the render codec to prores 422, HQ or any other equivalent assuming we are on the above timeline, will give us better quality in final output.

3.- (I am not sure about this), sending my finished timeline to color, grade it as you want and sending it back to FCP with the workflow above, should preserve better quality since color is capable of render in any of the prores high quality settings, so keeping up with the final render in FCP.

[Bruce Schultz]

Not being that much of a FCP expert, perhaps I'm missing something here?

Why not just input the 100Mbs footage as ProRes or ProRes HQ through a Compressor droplet or MPEG Streamclip, set the FCP render output to the same ProRes setting, and not worry about the 100Mbs>50Mbs issue after that? Of course this means more storage space for the ProRes files, but the quality problem seems fixed by going this route.

[Aaron Newsome]

I wouldn't get too caught up in what the RENDER codec for the sequence is set to in FCP. If you use Compressor to output your final, Compressor ALWAYS reads from the source media and ignores the rendered files completely. When using Compressor, you could set the render codec for the sequence to be crap quality DV or something and your final output will still be rendered from the source files, ignoring the rendered files.

Usually I set the render codec to ProRes Proxy or 422 so that most of the realtime effects still work without rendering.

Again, the only time you're likely to experience any issues with a 50Mbs limit is if you are rendering a final output file using FCP's XDCAM HD 422 codec. I've never needed to do that so the 50Mbs limit is of no consequence to me. I've I have many steps for the footage to pass through, I'm usually doing that in a ProRes or uncompressed format anyway. Then at the end, I am creating a final output file for viewing and for me that's never XDCAM.

[Eric Liner]

[QUOTE=Bruce Schultz;1493659
Why not just input the 100Mbs footage as ProRes or ProRes HQ through a Compressor droplet or MPEG Streamclip, set the FCP render output to the same ProRes setting, and not worry about the 100Mbs>50Mbs issue after that? Of course this means more storage space for the ProRes files, but the quality problem seems fixed by going this route.[/QUOTE]

Because FCP handles XDCAMHD natively. When you're dealing with many hours/terabytes of footage, much of which won't make the final cut, it doesn't make sense to waste the time or storage space to move everything over to Pro Res. The quality of your source footage won't be compromised/altered until after your edit-- when you choose an export/finishing codec.

[Bruce Schultz]

Here's a complimentary issue as I see it.

If you are producing two data streams for 3D work, they both must match identically, frame-to-frame or else visual havoc will ensue. When I shoot these 2 data streams I use the I-Frame only codec as well as genlocked and timecode synched cameras to insure maximum fidelity of both data streams to each other. In this situation I would want to keep that fidelity throughout post production as I can't have a B or P frame out of sync from one data stream relative to it's corresponding frame. So in this particular instance, ingesting, editing, and outputting in Prores is preferable to saving storage space and editing XDCAM natively.

My point being that one-size-fits-all production/post production philosophies do not in fact fit all.