Solutions to Improve FCP’s Media Management II

Back in May, I wrote about FcpReconnect as one answer to Apple Final Cut Pro’s less-than-robust media management. In this entry, I’ll cover Matchback Magic, a handy application developed by Philip Hodgetts and Dr. Gregory Clarke of Intelligent Assistance to make FCP media bullet-proof. Through the Assisted Editing product line, they’ve developed a number of workflow tools that leverage the power of XML for Final Cut Pro users.

The essential media management differences between Avid Media Composer and Apple Final Cut Pro stem from the fact that Avid cross-references media files with bin clips through a media database. You can rename clips, but not media and the database files keep everything straight. Matchback Magic was developed out of the need to make FCP media “operator safe” and in effect, to behave more like Avid media.


Matchback Magic is designed for an offline/online editing workflow. The creative editing phase uses proxy media and the final project is relinked to full-quality media for finishing and output. FCP handles this fairly well, but the process is prone to operator error, which can result in files not properly relinking at the end. The main reason for offline/online editing is so that you don’t have to deal with a lot of high-resolution files during the rough cut phase of the project. For instance, it might be an HD job, but cutting with DV25 media makes it possible to cut on a laptop without taxing the system.

Matchback Magic “protects” files against human error by “injecting” metadata from the full-quality master files into the proxy media files. Once that’s done, no matter what happens to the proxy media – change timecode, reel numbers, files names, etc. – Matchback Magic can conform an edit so that the final sequence frame-accurately matches the rough cut and media is properly relinked.

Real world test

I tested this out with the same Cheese Shop project as before. My master files are 1920×1080 ProResLT conversions from H.264 camera files that originated in a Canon EOS 5D Mark II. Reel and timecode information was added using QtChange. These files were further encoded to a second set of anamorphic DV25 files to be used for offline editing. This is my starting point. All media handling at this stage has been outside of FCP, which is typical of a lot of file-based workflows, not just with HDSLR cameras. For example, if you used an AJA KiPro recorder or were supplied converted QuickTime camera masters from a videographer or a film lab, then this would follow the same methodology.

I originally ran into one small, but puzzling issue. Matchback Magic didn’t work correctly until I removed the file extensions (.mov) from both sets of media files. That’s easy to do with the R-Name batch utility, but it wasn’t the way it should work. It turns out that this was related to which metadata from the XML was used to determine file names. After some testing and discussions with the developers, they were able to make a quick modification to the application to correct this issue. An automatic online update to the application and everything was working as expected. No need to worry about the presence or absence of file extensions. One of the beauties of working with a small, but responsive software development company!

Here are the basic steps to follow.

Step 1 – Start a new FCP project and import the folder of full-quality files. Highlight that folder and export an XML file.

Step 2 – Open Matchback Magic. Import the XML file and the folder of matching proxy media. Press Add Matchback Protection. This will insert metadata from the full-quality files into the proxy files. When this step is done, there will be a new FCP project labeled Matchback Magic containing the folder of proxy clips. You may delete this project or rename the project and continue from there as your rough cut starting point. One way to verify that the proxy media has actually been altered is that the modification date will now read as the current date and time.

Step 3 – Edit as you normally would using the proxy media. At this point you may safely change not only the master clip names, but also the media file names. This could potentially be disastrous under normal FCP operations; hence, the beauty of Matchback Magic.

Step 4 – When the cut is locked, create a new, blank sequence with a preset that matches your final quality output. (This isn’t essential, but will save some steps.) Highlight both this blank sequence and the sequence representing the approved cut and export an XML file.

Step 5 – Open Matchback Magic, click the Conform tab, then Read Matchback Information. Open the XML file from Step 4. The information will be displayed in the spreadsheet-style window.

Step 6 – Click Conform Sequence, which takes you back to FCP and an Import XML dialogue window. Select Create New Project (from the pulldown) as the target for the conformed sequence. A new, single sequence will be linked to the full quality media files. As an added touch, the offline media will be on higher tracks of the same timeline. You may compare tracks to verify frame-accuracy between the rough cut and the conformed cut. Sequence clips will display the names (as added or changed during offline editing), while the actual media file names of the full-quality media will remain unchanged.

This is a very simplified workflow test that demonstrates the power of Matchback Magic. One of the beauties of FCP is how XML can be used to augment the application beyond its inherent design. Other features include the ability to track double-system audio and exporting ALE and Excel files. More of this can be seen in their demo video. The process is bullet proof and actually simpler than FCP’s own Media Manager.

The demo version of Matchback Magic can be used to inject protection information. Even if you don’t think you’ll need it, you can use the demo to protect the files. If it turns out later that you need Matchback Magic to “save” you after all, simply buy and activate the software to enable the other steps.

©2010 Oliver Peters

RED Post – the Easy Way III

If you’ve read some of my past articles about RED, you know I’m not a huge fan of “native” editing using the camera raw files as source clips. I find that an offline/online workflow is still best for smoothly editing RED projects, yet it still retains access to the raw color data during the finishing process. Previously I discussed an easy workflow for Apple Final Cut Pro and Color users, but this isn’t the only solution. As you know, Avid Media Composer 5 and Adobe Premiere Pro CS5 have both integrated support for RED’s camera raw files. In this post, I’m going to discuss a couple of ways to use these tools in a non-native fashion.

Option A:  Avid Media Composer 5 offline-online RED workflow

Thanks to AMA and RED camera’s SDK, Media Composer 5 offers access to RED’s .R3D files. You can import camera files and adjust the source color settings from within the NLE’s interface. You can either edit directly from these files or transcode them to Avid media for a smoother and faster editing experience. Here is a short step-by-step explanation of a Media Composer-based workflow.

Step 1. Access/import RED .R3D files via AMA (Avid Media Access). Camera clips will open inside Media Composer bins, complete with camera metadata.

Step 2. If you want to change the levels/gamma/exposure/balance of the file by altering the camera raw data, then open the Source Settings for each clip and adjust the video.

Step 3. Adjust the clip framing by opening the bin Reformat column and set the option for each clip (center cut, letterboxed, etc.). Remember that your RED clips may have a 2:1 aspect ratio, but your Avid sequence will be either HD 16:9 or SD 16:9 / 4:3.

Step 4. Set the Media Creation render tab to a video resolution of DNxHD36 with a Debayer quality of “quarter”. Since the objective is a good rough cut – not “finishing” – this quality settings is more than adequate for editing and screening your creative edits.

Step 5. Transcode all source clips. This process runs at close to real-time on a fast machine. When transcoding is done, close all AMA bins and do not use them during the edit. You’ll edit with the transcoded media only.

Step 6. Edit as normal until you get an approved, “locked” picture.

Step 7. Now it’s time to switch to “finishing”. Move or hide all Avid media (the transcoded DNxHD36 clips) by taking them out of the Avid MediaFiles/MXF/1 folder(s) on your media hard drive(s). You could also delete them, but it’s safer not to do that unless you really have to. Best to simply move them into a relabeled folder. Once you’ve done this, your edited sequence will appear with all media off-line.

Step 8. Open the AMA bins (with the .R3D files) and relink the edited sequence to the AMA clips. Make sure the “Allow relinking of imported/AMA clips by Source File name” is NOT checked in the Relink dialogue window. When relinking is completed, the sequence will be repopulated with AMA media, which will be the native, camera raw .R3D files. If you want to change the raw color data at this point, you will need to change each source clip and then refresh the sequence to update the color for clips that appear within the timeline.

Step 9. Change the Media Creation settings to a higher video resolution (such as DNxHD 175 X) and a Debayer quality of “full”.

Step 10. Consolidate/transcode your sequence. This will create new Avid media clips at full quality that are only the length of the clips as they appear in the cut, plus handles. Since a transcode using a “full” Debayer setting will be EXTREMELY SLOW, make sure you set very short handle lengths. (Note: If you have a Red Rocket card installed, Avid supports hardware-assisted rendering to accelerate the transcoding of RED media.)

Step 11. Finish all effects and color grading within the NLE as you normally would.

Option B:  Apple FCP / Automatic Duck / Adobe CS5 workflow

You might be asking, why not just edit in Final Cut Pro or Premiere Pro? The hitch is that Final Cut doesn’t support 4K files and Premiere Pro has a good native, but not a good offline-online workflow for RED files. FCP users clearly outnumber Premiere Pro users among professional film and video editors, however, both After Effects and Premiere Pro offer some interesting finishing options. In fact, a number of feature films have used both for all or part of the finishing process. A combination of Apple and Adobe tools creates some interesting scenarios for RED post. (Note: Automatic Duck Pro Import AE 5.0 is required.)

Step 1. Ingest your RED .R3D clips into Final Cut Pro using Log and Transfer. Set the preferences to use ProRes Proxy (NOT “native”). Set the color to “as shot”. This requires that the RED plug-in for FCS has been installed. (Refer to the previous article for a more in-depth explanation of this first step.) Please note that it is important to do this with the R3D files and not to start by simply dragging the in-camera-generated H, M or P QuickTime reference files into the FCP browser. Many RED users erroneously consider these to be “proxy” edit files. They are not. They are reference files at different resolutions/sizes that are linked to the R3D files and do not work correctly in this process.

Step 2. Edit normally in FCP until the cut is “locked”.

Step 3. Export an XML of your Final Cut sequence. I prefer using Automatic Duck’s free XML exporter and have had more reliable results with it, but the built-in FCP XML exporter will also work.

Step 4. Launch Adobe After Effects CS5. (Pro Import AE 5 works with CS3 and CS4, too, but you need to use an Adobe CS version compatible with native RED files.) Import the XML file using Pro Import AE 5. Make sure your Automatic Duck preferences are set to “Replace proxy footage with .R3D files.” The result will be an After Effects timeline with settings that match the Final Cut Pro sequence settings, except that all the clips will now be linked to the original camera files.

Step 5. Since the ProRes Proxy files were most likely 2K files, and the newly relinked camera files are the original 4K size, you will need to reset the scale value of each clip in the composition. This reframes the shot to fit inside the 2K frame, just as they did in FCP. Or you can creatively reframe the shots, since you have all the “bleed” of the full 4K frame. Alternatively, you can change the After Effects composition setting to match the 4K size.

At this point you could completely finish the project in After Effects, and there are a number of folks who would advocate that. From my point-of-view, After Effects is a compositing tool, rather than a DI or editing application. With the changes in Premiere Pro CS5, my druthers would be to get the media into that application. I’m only using After Effects as a conduit between Final Cut Pro and Premiere Pro in this process.

You could go from After Effects to Premiere Pro via Adobe’s Dynamic Linking, but I’d rather not. That simply nests the After Effects composition as a single clip on the Premiere Pro timeline. I want the shots available as individual timeline clips, so follow these steps.

Step 6. Launch a new Premiere Pro CS5 project and select a new sequence setting from one of the RED presets, such as a 4K timeline.

Step 7. Highlight all of the .R3D clips in the After Effects composition and Copy.

Step 8. Switch to the Premiere Pro sequence window and Paste. All of the RED clips will now fill up the Premiere Pro sequence. At this point you should have a native 4K sequence with .R3D camera raw media. Corresponding master clips will show up in the Premiere Pro project window.

Step 9. To change the camera raw color settings of the .R3D files, open a clip from the project window and alter its source settings. These changes will automatically update that clip on the timeline.

Step 10. Finish effects and color grading as desired. If you are using this process with the intent of sending files to a DI house for film finishing, then your settings and any grading should be very neutral to allow for maximum latitude at the next stage.

Step 11. Export media. A big selling point of Premiere Pro CS5 to RED users is that it allows you to export DPX image sequences, in addition to all of the standard media options. DPX is the preferred format of most high-end DI solutions, like Quantel Pablo, Autodesk Lustre, etc. Premiere Pro CS5 is one of the few desktop solutions that enables an export of full-resolution 4K DPX files from the edited timeline.

OK, I’ve given you a lot to chew on. In three articles on RED post, I’ve covered quite a few ways to finish RED-acquired projects. Don’t get overwhelmed. Remember that you don’t have to use them all. Simply pick the one that’s best for you and have fun.

©2010 Oliver Peters

RED Post – the Easy Way II

The RED camera company has succeeded in shaking up the industry and getting all other camera manufacturers to rethink what a digital cinema camera should be. This year, the ARRI Alexa presents the first serious challenge by another system designed around a camera raw workflow. Although RED maintains a resolution advantage, which will increase with the forthcoming Epic, there are many other reasons producers might opt for an Alexa, a Panavision Genesis, a Panasonic VariCam/3700/2700/3000 or a Sony F23/F35/F900/F800.

One of the strategic errors that I feel RED made was to emphasize resolution over workflow. By doing so, their innovative approach was tagged early on by detractors as difficult and time-consuming. It’s actually rather straightforward with a lot of versatility and can be adapted to many different production needs. Unfortunately, no matter how easy it has become today, RED will continue to battle this perception issue. This is exacerbated by RED itself, who has never provided good documentation for its products, especially the post production tools. A byproduct of the “perpetual beta” mode in which the company operates.

Native vs. non-native

I haven’t been a big fan of dealing with the camera raw files during editing, opting instead to pre-grade/render/export the camera files first into an edit-friendly format. If you search through the RedUser forum, you’ll find plenty of posts pointing out that the preferred feature film workflow is to export flat-looking DPX files for conforming and grading in DI systems like daVinci, Pablo and Lustre. This is a common workflow for DI and digital acquisition. I’ve demonstrated some of the latitude such a flat image can offer, even though it isn’t camera raw any longer.

Apple and Assimilate were early adopters of being able to access RED’s raw color data. Since then, RED developed an SDK that has allowed many other NLE manufacturers access to the raw data through this spec. Now others, like Avid and Adobe, can open and manipulate RED files based on the camera raw data. This gives editors wide latitude over how the image can look, without being stuck to a “baked in” camera image as a starting point. It’s like editing from transferred film, yet having access to the original negative in the NLE. I’ve recently reviewed Avid Media Composer 5 and Adobe Premiere Pro CS5 and spent some time testing this out. Both do a very good job with native RED files, but my conclusion is still that an offline/online editing methodology works best for complex, long-form productions.

FCP’s Log and Transfer

Last year, I edited 90% of my projects with Final Cut Pro, so I’ve decided to revisit Apple’s “native” RED workflow with a fresh eye. FCP does not let you work directly with the actual .R3D camera files. Instead, RED files are imported via FCP’s Log and Transfer module. Here you have two options: a) import as native REDCODE (the .R3D file is copied and rewrapped with a QuickTime container); or b) import/transcode to an edit-friendly codec, like one of the ProRes codecs. During Log and Transfer, you may select one of several colorimetry presets or “as shot”. Once imported into FCP, you can’t access the source settings (as in Media Composer or Premiere Pro). Instead, the workflow is designed around Apple Color, where the tools are provided to once again access the camera raw color data.

A lot of the RED appeal is over the fact that the camera records 4K images. 4K refers to a frame size of 4096 x 2048 pixels (2:1 aspect ratio). The RED One camera is capable of various frame sizes, but 4K appeals to indie filmmakers as some sort of Holy Grail. That’s in spite of the fact that most feature film DI is done at 2K sizes and some films are even posted using HD video (1920×1080) as an intermediate step. Avid Media Composer 5 limits you to an HD frame while Adobe Premiere Pro CS5 and After Effects CS5 will let you work at 4K. FCP doesn’t allows 4K, so the effective workaround is to downsample the 4K RED images to 2K (2048×1024). FCP and Color deal with this image size quite effectively and i/o hardware like the AJA KONA3 includes presets for 2K images. I like the idea of 4K at the camera, but I’m perfectly okay with 2K and HD in post.

Size and debayering

The downsample issue is confusing, because it affects image size and debayering – the process that turns raw data into RGB video. Unfortunately, RED hasn’t provided clear information as to what is really happening. The rule of thumb is that 2K images are downsampled as 1:1, while larger images use a 2:1 ratio. Since you have no control over the debayering settings in either Final Cut or Color, the belief expressed by some users is that RED’s own post tools, like REDCINE-X, yield better image quality. I haven’t seen anything that’s an issue in my own testing and some of the threads at RedUser would indicate that the results are comparable in head-to-head testing. You’ll have to judge for yourself.

If you are planning to post via this workflow, then it’s important to think about the right image size before production starts. If you shoot at 4K 2:1 (4096×2048), the resulting 2K 2:1 image (2048×1024) in FCP will either have to be center-cut (a blow-up with some cropping on the edges) to fit an HD (1920×1080) frame  – or it will have to be displayed with a letterbox mask.

Color scales the 2K image in the Geometry room as it renders. Since the majority of producers using this workflow are mainly interested in a proper HD image (1920×1080), I would recommend that the original footage be recorded in either 4K 16:9 (4096×2304) or 4K HD 16:9 (3840×2160), aka “quad HD”. The former gives you a little wiggle room for minor reframing, while the latter is an even multiple and will provide the most accurate downsampled image.

RED step-by-step with Final Cut Studio

Let’s take a look at the recommended Apple Final Cut Studio/RED workflow using an offline/online approach and camera raw files. Experienced RED owners who use FCP will be very familiar with this workflow. It’s also clearly described in RED’s FCP whitepaper. On the other hand, if you are about to approach your first RED project and have some trepidation about post, then this is for you. I’ll assume that you didn’t plunk down five grand for a RED Rocket accelerator card and don’t have the budget for a high-end finishing facility using Assimilate Scratch, Quantel Pablo, Avid DS or similar tools. In short, you are looking for the best way to leverage Apple Final Cut Studio and get the most out of your RED files.

Step 1: Download and install the RED Final Cut Studio Installer. This adds the QuickTime codec and the support modules for Final Cut Pro and Color. (The whitepaper is also included in this download.)

Step 2: Copy the RED camera files to your local hard drive array for editing. Back-up the files to other archive media and store in a secure location. (Avoid any illegal characters – like slashes, number signs, etc. – when you label folders.)

Step 3: Start a new FCP project. Use FCP’s Log and Transfer module to import the RED camera files. Set the L&T preferences to a target format of ProRes Proxy. Apply a color preset, like “daylight” if desired or leave “as shot”. This preset will be applied globally to all clips imported in this session.

Step 4: Edit your sequences as you normally would do. If you need to apply certain “looks” to satisfy the producer or client, use the FCP color correction tools for a temporary adjustment. Remember that this is offline editing. The goal is a good rough cut and ultimately an approved, “locked” picture cut.

Step 5: Once the cut is “locked”, use FCP’s Media Manager to generate a version of the final sequence for finishing. Run Media Manager and “create offline” to generate a new FCP project. Set the desired target sequence settings  – most likely Pro Res HQ or Pro Res 4444 (1920×1080 24p 48kHz). Set handle lengths as desired.

Step 6: Open the new media-managed FCP project. Open the Log and Transfer tool. Change the L&T preferences to “native” and “as shot”. Select the master clips (media is currently off-line) and batch capture. The corresponding portions of these RED clips will now be re-imported as native files.

Step 7: Select the final sequence and “Send to Color”. Remember that all of the Color compatibility considerations still apply. Long sequences should be first broken down into shorter sequences. Speed ramps should be “baked in”. In short, do all the usual pre-flight preparation required by the FCP-Color roundtrip.

Step 8: Thanks to the RED Installer, Color has now gained a RED tab in the Primary In room. Camera raw adjustments include gamma, colorspace, temperature, tint, gains, ISO and more. This is similar to making camera raw adjustments to digital still photos in Photoshop. All clips with the native REDCODE codec can be modified by these settings. These changes are on a clip-by-clip basis, but you can copy-and-paste or drag the Primary In settings from one clip to multiple clips.

The rest of the color grading steps follow standard Color operation. Adjust the Geometry settings as desired, render and send back to FCP. There are no raw OLPF (optical low-pass filtering) controls for detail enhancement or sharpening within the RED tab. If you feel that the image is slightly soft, then apply some sharpening within the Color FX room.

It doesn’t really make a lot of difference whether you follow this approach or prep the files first and never return to the native .R3D files. Both methods work and result in great images. It really boils down to what works for you. The process isn’t as hard as people make it out to be. Jump in, test a bit first and then you’re ready to rock!

©2010 Oliver Peters

Levels – Avid vs. FCP

One of the frequent misconceptions between Avid and Final Cut editors involves video levels. Many argue that FCP does not work within the proper video level standards, which is incorrect. This belief stems from the fact that FCP is based on QuickTime and permits a mixture of consumer and professional codecs. QuickTime Player often changes a file’s appearance as compared with FCP, when it is used to play the file directly. QuickTime Player is trying to optimize the file to look its best on your computer monitor; however, it isn’t actually changing the file itself. Furthermore, two identical clips will appear to be different within each NLE’s interface. Avid clips look flatter and more washed out inside Media Composer. FCP clips will be optimized for the computer display and appear to have more contrast and a different gamma value. This is explained well by Janusz Baranek in this Avid Community thread.

Contrary to popular opinion, both NLEs work within the digital video standards for levels and color space – aka Rec. 601 (SD) and Rec. 709 (HD). Digital video levels are generally expressed using an 8-bit/256-step scale. The nominal black point is mapped to 16 and the white point to 235, which permits level excursions without clipping: 0-16 for shadow detail and 235-255 for highlight recovery. This standard was derived from both camera design and legacy analog NTSC transmission. On most waveform monitors digital 0, analog 7.5 IRE and 16 on this scale are all the same level. Digital 100 (700 millivolts on some scopes), analog 100 IRE and 235 on the scale are also equal. Higher and lower levels will be displayed on a waveform as video above 100/100IRE/235 and below 0/7.5IRE/16.

I want to be clear that this post is not a right/wrong, good/bad approach. It’s simply an exploration in how each editing application treats video levels. This is in an effort to help you see where adjustments can be made if you are encountering problems.

Avid Media Composer/NewsCutter/Symphony

Video captured through Avid’s i/o hardware is mapped to this 16-235 range. Video imported from the computer, like stills and animation can have either a full range of 0-255 (so called “full swing”) or a digital video range of 16-235 (so called “studio swing”) values. Prior to AMA (Avid Media Access), Avid editors would determine these import values in the Media Composer settings, by selecting to import files with RGB values or 601/709 values. You can “cheat” the system by importing digital camera files with an expanded range (spreading the levels to “full swing” of 0-255). Doing so may appear to offer greater color grading latitude, but it introduces two issues. First, all clips have to be color corrected to adjust the levels for proper output values (legal for broadcast). Second, some filters, like the BCC effects, clip rendered files at 16 and 235, thus defeating the original purpose.

It has now become a lot more complex in the file-based world. The files you import are no longer just stills and animation, but also camera and master files from a variety of sources, including other NLEs, like FCP – or HDLSRs, like the Canon 5D. Thanks to AMA in Media Composer 5, this is now automatically taken care of. AMA will properly import files at the right levels based on the format. A digital graphic, like a 0-255 color bar test pattern, is imported at the full range without rescaling the color values from 0-255 to 16-235. A digital video movie from a Canon 5D will be imported with values fitting into the 16-235 range.

Because of the nature of how Avid handles media on the timeline, it is possible to have a full range (0-255) clip on the same timeline next to a studio range clip (16-235) and levels will be correctly scaled and preserved for each. Avid uses absolute values on its internal waveform (accessed in the color correction mode), so you are always able to see where level excursions occur above 235 (digital 100) and below 16 (digital 0).

I would offer one caveat about AMA importing.  Apparently some users have posted threads at the Avid Community Forums indicating some inconsistencies in behavior. In my case, everything is working as expected on multiple systems and from various Canon HDSLR cameras, but others haven’t been so lucky. As they say, “Your mileage may vary.”

Apple Final Cut Pro

If you capture video into FCP using one of the hardware options and a professional codec (uncompressed, ProRes, IMX, DV/DV50/DV100), then the media files will have levels mapped to 601/709 values (16-235). From here, the waters get muddy, because the way in which those levels are handled in the timeline is based on your processing settings. This affects all imported files, as well, including graphics, animation and media files from cameras and other NLEs.

Confusion is compounded by FCP’s internal waveform monitor, which always represents video with a relative 0-100 percent scale. These display numbers do not represent actual video levels in any absolute sense. When you process in YUV, then the full display area of the waveform from top to bottom equals a range of 0-255. The “legal” digital video standard of 16-235 is represented by the area within the 0-100% markings of the scope. However, when you process in RGB, then the portion within the 0-100% marks represents the full 0-255 range. Yes – in an effort to make it simple, Apple has made it very confusing!

When you set the sequence processing to YUV, with “white” as “white”, then all timeline video is mapped to a “studio swing” range of 16-235. On the scope 0% = 16 and 100% = 235. If you import a “full swing” color bar pattern (0-255), the values will be rescaled by the sequence processing setting to fall into the 16-235 range.

When you set the sequence processing to YUV, with “white” as “superwhite”, you’ve extended the upper end of the range, so that the 16-235 scale now becomes 16-255. The 0-255 color bar pattern is now effectively rescaled to 16-255; however, so is any video as well. Digital video that used to peak at 100% will now peak at 120%.

The YUV processing issues are also affected by the 8-bit, versus “high-precision” rendering options. When you elect to process all video as 8-bit, excursions above 100% and below 0% caused by color correction will be clipped. If you change to “high-precision YUV”, then these excursions are preserved, because they fall within the 0-16 and 235-255 regions. Unfortunately, certain effects and transition filters will still clip at 0% and 100% after rendering.

One way to fully protect “full swing” 0-255 levels is to work in RGB processing. A 0-255 color bar pattern will be correctly displayed, but unfortunately all video is spread to the full range, as well. This would mean that all clips would have to be color corrected to adjust for proper video levels. The only way that I’ve found for FCP to display both a 0-255 and a 16-235 clip on the same timeline and maintain correct levels is to apply a color correction filter to adjust the levels on one of these clips.

For general purposes, the best way to work with FCP is to use the ProRes family of codecs and set your sequence settings for YUV processing, white=white and high-precision rendering. This offers the most practical way of working. The only caveat to this is that any “full swing” file will be rescaled so that levels fall into the 0%-100% (16-235) “studio swing” range. If you need to preserve the full range, then FCP’s color correction filters will allow you to expand the range. The levels may appear to clip as you make the adjustment, but the rendered result will be full range.

Real world examples

I’ve done some quick examples to show how these level issues manifest themselves in actual practice. It’s important to understand that for the most part, the same clip would appear the same in either Media Composer of Final Cut as viewed on a broadcast monitor through output hardware. It will also look the same (more or less) when displayed to a computer screen using each app’s full screen preview function.

The following screen grabs from my tests include a 0-255 color bar chart (TIFF original) and a frame from an H.264 Canon 5D clip. The movie frame represents a good spread from shadow to highlights. I imported the files into both Avid Media Composer 5 (via AMA) and Apple Final Cut Pro 7. The FCP clips were rendered and exported and then brought into MC5 for comparison. The reason to do this last step was so that I could check these on a reasonably trustworthy internal scope, which displayed an 8-bit range in absolute values. It is not meant to be a direct comparison of how the video looks in the UI.

Click any image to enlarge.

Imported into Final Cut. ProResHQ with YUV processing. White as white. Note that the peak white of both images is 100%.

Imported into Final Cut. ProResHQ with YUV processing. White as SuperWhite. Note that peak white of both images exceeds 100%.

Imported into Final Cut. ProRes4444 with RGB processing. Note the boundary limits at 0% and 100%.

Imported into Media Composer 5 using AMA. Note that the color bars are a 0-255 range, while the Canon clip is 16-235.

FCP7 YUV export, imported into MC5 via AMA. Note that the color bar pattern has been rescaled to 16-235 and is no longer full range.

FCP7 YUV export with SuperWhite values, imported into MC5 via AMA. Note that the color bar pattern has been rescaled to 16-255 and is no longer full range. It has a higher top-end, but black values are incorrect. This also alters the scaling values of the levels for the Canon clip. Color correction filters would have to be applied in FCP for a “sort of correct” level match between the bars and the Canon clip.

FCP7 RGB export, imported into MC5 via AMA. Note that the color bar pattern exhibits the full 0-255 range. The Canon clip has also been rescaled to 0-255. Color correction filters would have to be applied in FCP to the Canon clip to bring it back into the correct relative range.

I have revisited the YUV settings in FCP7. This is a ProResHQ sequence rendered with high-precision processing. I have applied a color corrector to the color bars, expanded the range and rendered. Note the regions above 100% and below 0%.

FCP7 YUV export (color correction filter applied to the color bars), imported into MC5 via AMA. Note that the color bar pattern spreads from 0-255, while the Canon clip is still within the standard 16-235 range.

©2010 Oliver Peters