CoreMelt plugins for Final Cut Pro, Final Cut Express, After Effects and Motion

Updated: 9/9/08 after testing with latest Red tools

The RED gives you not only a stupid amount more resolution than any affordable digital camera it gives you more color information as well. Dealing with the resolution of RED footage is one challenge, but this is mostly just render time and disk space and common editing software is well equipped to work in any resolution. The other challenge of working with RED is keeping the maximum color information possible and this is where there are significant problems due to limitations in most editing software. Without the right knowledge you will throw away most of your color information. 8 bit YUV has only 256 levels for each color channel compared to 1024 in 10 bit. If you inadvertently put your RED footage through any stages which can only process in 8 bit YUV you are losing crucial data that will limit your ability to do a good color grade on your final master. The danger is that software will in some cases "silently" discard that information by rendering in 8 bit YUV. Making sure your entire workflow is "10 bit clean" will have significant advantages when you get to the final color grading stage, even if your delivery format is only 8 bit YUV video for broadcast.

Below is two suggested workflows which aim to be a good compromise in keeping the most usable color information without involving render farms or excessive file wrangling. These workflow are a tradeoff between speed and image quality and assumes you're going to finish inside FCP, if you want absolute highest quality you will want to reconform back to R3D files from FCP and use something like Scratch to finish from DPX files.

A much faster solution than the above is to convert the R3D files to a 10 bit color codec, do an online edit directly on these files and then comp / grade / final output still in the same codec. Final Cut Pro / Motion / After Effects / Color provides all the tools to do this but there are some areas to watch out for. This workflow may particularly be of interest to Indie film makers who intend to do their post work in a HD format and then do a video to film transfer for screenings. The preservation of 10 bit color in the final master can considerably improve the quality of the resulting print. Affordable 10 bit Displays are also just starting to appear on the market, preserving this information in your digital master will future proof your media assets for repurposing down the line.

Why ProRes?

Apple's ProRes 422 (HQ) will give the best real time performance in FCP and has excellent image quality overall. Its a good overall choice unless you intend to do any heavy compositing especially blue/green screen, in which case a codec with less compression is better suited, in that case consider using CineForm 2K/HD 12 bit codec or Gluetools 10 bit Cineon Codec. There are seperate workflow articles on using those routes coming soon. You must use a YUV codec as FCP is currently limited (as of version 6.0.4) in not being able to work with RGB sequence settings at greater than 8 bit precision.

Red Cine to ProRes HQ 10 bit

Red's REDCODE RAW is effectively a read only codec, but FCP can directly edit this codec and render back to Pro Res HQ or another quicktime codec preserving the 32 bit YUV color. The trick in this case that even though your clips are REDCODE RAW, when you set your sequence setting to a high color depth YUV codec FCP will render on the fly to your destinaton codec preserving color information.

There is two ways to go from here, the fastest option is shown in the diagram above, use Red's Log and Transfer plugin to directly convert your R3D files to ProRes inside Final Cut Pro, and finish in the same format without leaving FCP. There are some fairly major drawbacks to this, the Log and Transfer plugin currently only works (v 0.01) at half res and the log and transfer plugin uses a lower quality conversion from R3D than REDCINE does. Depending on your deadline and budget this might be an acceptable way to go and you can still finish preserving 10 bit color with very little extra work.

For projects where higher quality is desired, the way to go is to first do an offline either using the above method, or instead by using Quicktime Proxies from the camera or from Red Alert. Then Export an FCP XML and use Crimson to convert the XML to a format that RedCine can understand and do a full "virtual telecine" grade on your footage inside RedCine and export as ProRes HQ. Crimson has provided an excellent video overview of this process here. RedCine uses a higher quality debayer algorithm and has much more advanced grading control, so this method will give you a much better result than using just the Log and Transfer plugin or converting direct from Quicktime proxies. Adam Wilt's write up of the various export options for REDCINE and some issues to watch out for.

If you went for option two, you then need to use the Crimson "Roundtrip" option to bring your exported RedCine files back inside FCP to a new seuqnce. Either way you now have a timeline which consists of your final selected edits and are ready to do a 10 bit online finish.

WARNING: FCP can only render a limited set of effects and transitions in high precision.

This is where you hit a problem. FCP can only render a limited amount of effects in 10 bit color, and if you choose one which is not capable then it will truncate your color information to 8 bit with no warning. In particular only the the Cross Dissolve transition can render in 10 bit color, any other transitions and wipes will truncate color data, of the other effects included it’s hit and miss. See pages III-241 and II-389 of the FCP manual for a full list of which transitions, effects and filters can render in high precision and see my other paper “Codecs and Effects Limitations for 10 bit online workflows with FCP 6”. If you want you can keep going with a printed list of which effects and filters are safe to use taped on the monitor of your work station. Thats possibly going to cramp your style when editing . . .To preserve 10 bit color, you must render all effects and transitions using plugins capable of “high precision rendering”.

The solution is to use third party plugins instead of the built in wipes and transitions. However, many of the available FCP plugins work using the After Effects API and those plugins can only render in 8 bit. To preserve your color information you must use FxPlug or FxScript API plugins which are capable of high precision rendering.

The CoreMelt plugin packs all render in high precision color in this way, CoreMelt PolyChrome Transitions is a drop in replacement for many of the most common FCP transitions and wipes plus a range of additional wipes and transitions. All of these are guaranteed to render in high precision using the GPU of your graphics card. So you can use these freely without worrying about throwing away color information. In many cases they also render faster than the built in transitions and wipes. If you need to do more effects work on your edit, the CoreMelt Motion and Editing Packs and FxFactory Pro pack have another 250+ effects again all of which render in high precision to keep the full range of your 10 bit color information.

If any shots need to be completed in After Effects, Motion or another compositing package then you need to make sure that the project settings are set for 16 bit color and that they render them back to the same 10 bit codec your footage is in. The CoreMelt plugins will also render high precision color correctly inside Motion and After Effects CS3.

Moving on, complete your edit dropping in the completed shots from Motion or Another compositing app as needed. If you've used only the above plugins or other third party plugins which can render in high precision in FCP then your completed online has still preserved the full 10 bit range that came from the RED. One thing to note here is that ProRes does not alway behave nicely in non-Apple applications, there are sometimes gamma shifts or other problems. One suggested solution is to use Avid's DNxHD codec to interchange with non-Apple applications in 10 bit color.

The Color Double Shuffle

If you’re going to grade in Apple Color it’s important to realise that you need to render out clips with filters on them and replace them in your timeline and that all transitions are rendered by FCP once you have returned from Color. So if you used the built in transitions, your color information during transitions and wipes would have been truncated to 8 bit during this final stage of the online workflow. Although you final output may be mainly for broadcast (which is only 8 bit YUV) preserving the 10 bit color in your final master, both in the digital media file and on tape (when archiving to 10 bit formats) can have considerable benefits if in future you intend to do a video to film transfer, DVD or HD-DVD mastering or any other repurposing of your media.

Summary of RED 10 bit clean FCP / Color online workflow

1. 1) Edit your offline either using Log and Transfer or Quicktime Proxies
2. 2) Export an FCP XML.
   
3. 3) Use Crimson to Generate a RedCine XML
   
4. 4) Do your virtual telecine grade in RedCine, export all clips to ProRes HQ
   
5. 5) Generate a roundtrip XML from Crimson, import your graded ProRes clips into a new FCP sequence
   
6. 6) online edit in FCP. Only use filters and transitions capable of high precision rendering.
   
7. 7) Create any motion graphics files or comps in 16 bit color in Motion or After Effects, drop them into FCP timeline after rendering them to the 10 bit online codec.
   
8. 8A) Finish inside FCP potentially using color grading plugins (eg Colorista)
   
9. 8B) Finish using Color to Grade: In FCP render out all effects filters and replace them as clips on the timeline. FCP -> “Send to Color”, then color grade your timeline in Apple Color with 16 bit internal color. Color -> “Send to FCP”, render timeline and take it back to Final Cut Pro. Render the transitions on the timeline, then export your final master as a digital media file or to 10 bit tape format.

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RED, Red Alert and Red Cine are trademarks of the RED Digital Cinema company, nothing in this article should be construed as an endorsement of the CoreMelt plugins by RED Digital Cinema. Final Cut Pro and ProRes 422 are trademarks of Apple.