Thursday, August 14, 2008

Cutting in HD on Avid MC 3

Jay Cassidy, A.C.E. is editing a feature film using HD media, which is an anomaly now, but which will certainly become commonplace.

What is truly remarkable, though, is his editing system consists of an off-the-shelf Apple Mac G5, an external Firewire hard drive, two monitors, an audio interface, Avid Media Composer 3 software… and no other hardware. No Adrenaline box, no Mojo, no Matrox / Blackmagic / Kona etc., no special cards. No nothing.

Until recently, you had to have some sort of added hardware to even work in standard definition. But now that he’s worked in HD Jay says “I’m never going back.” And with the simplicity of his system and the picture quality, it is easy to see why.

BROTHERS, directed by Jim Sheridan, was shot on 3 perf film, telecined to HDCam with one track of production audio, then digitized at Deluxe Digital in Avid’s DNxHD 36 codec. Portable hard drives were used to transfer the media to the cutting rooms. As the film will ultimately be scanned for a DI, the higher resolution HDCam SR wasn’t used. Multitrack audio was sunk to picture in the editing room.

According to Jay “the virtue of HD is image quality.  Since the advent of digital editing, we’ve been bemoaning the loss of picture quality of the electronic image vs. workprint.   With DNxHD36, the moaning is over, the image quality is only limited by the display method - monitor, projector, whatever.”

The Editing System

Jay has 3 Avid systems, all on Mac platforms. In another unusual arrangement he is using no shared media (Unity / Xserve). Each system has independent, mirrored storage, and bins are shared over Apple’s Bonjour chat client.

The storage is G Tech firewire drives, connected via the FW 800. The G Tech drives are designed for media play-out, unlike consumer drives. “We've gone through nearly 25 G Tech drives, G Raid, G Raid2, SATA, mini's, etc.   When a film's done, the drives go on the shelf, (as there’s) usually no point in recycling them. Partially because unpredictable future requests always occur.”

As Jay notes, all drives eventually fail - two drives have failed in two years. Therefore he has redundant media, often in several cities, as mobility has also been important on his last few projects. 

Two of the systems are Apple OS 10.4 (Tiger), while Jay’s system is 10.5 (Leopard), and all are running Media Composer 3.0. Jay points out that Avid released its latest software specifically for Leopard, but found there was a serious flaw in the OS with Firewire. Apple has not been fast to solve the problem, so Avid released a update that would run on Tiger (OS 10.4). Jay is using 3.0, while the two other systems are on 3.0.1.

The biggest change with MC 3.0 is in overall performance. Everything is faster. Specifically now MC can use all available processors for complex tasks such as rendering or exporting / compressing. This in terms of the application is called ‘multi-threaded’. Previous versions could only use single processors. Now that up to 8 processors can be in one system, this offers a nice performance boost.

HD Image Quality

The picture quality with DNxHD 36 is excellent. Jay has two 24” Dell monitors. The one on the right serves as a client / playback monitor connected to the DVI port. The left monitor is for the Avid project, timeline, and ScriptSync.

“It is possible to install a second graphic card in the computer and work with three DVI screens, retaining the screen real estate of "two computer monitors and a client monitor."   With the introduction of the MojoDX, this solution may not be necessary.”

Because he doesn’t have a Mojo or Adrenaline box Jay isn’t connected to a separate HD TV monitor. And he isn’t digitizing in his editing room, so again no external hardware is needed. To screen edits, Jay has a Microtek DLP projector, which displays on the nearest white wall. The projector is connected to the DVI output of the computer, and displays at 1024 x 786,

“(T)he hardware helps, but the software-only image "full screen" on a good-sized DVI monitor is so far beyond the best SD image on the best SD monitor, that HD software-only editing is a viable option.”

“Working without hardware also means the threshold of pain is lowered when considering HD over SD.   It was not an easy sell to get this production to work in HD and the fact that we could keep the equipment so simple worked in our favor.” 

Other Features

Audio comes from the Apple optical port into a Apogee Digital to Analogue converter, which has a headphone out and powers two speakers for projection. "A happy unintended consequence of getting this device was the discovery that, if the audio output of the computer was optical instead of USB or the minijack, the "mute" button in the Composer software actually worked!”

One feature of MC 3 Jay hasn’t experimented with is the new title module, Avid FX. Titles for his shows are created in After Effects, so he is staying with the familiar here.

The most useful new feature in MC 3 for the editing team is the timecode overlay, which for Jay is “completely great” and “really well designed.” With no rendering involved, a timeline can now carry a great deal of information burned in the screen, with a great deal of control over size, font, placement, color, and text.

For outputs to sound and music BROTHERS is exporting Quicktime movies at half rez (965x540) using the Photo JPEG codec. The later was found to work best by trial and error - part of the nightmare of QT codecs.

Another important feature of this workflow is that everyone is working at the same speed, 23.976. The audio was recorded at 48.048 at 24 fps on a Diva, which when imported into the Avid played at the correct speed for sync.


The Avid ScriptSync module is essential to Jay’s workflow, and has been for years. He and his assistants have learned how to update and line the shooting script in such a way that Jay never bothers opening a scene bin, but edits exclusively working from the Avid script.

Early in post a laptop was setup for the director in Dublin, where he screened dailies using ScriptSync.

(Using Avid’s ScriptSync will be the subject of a future post)


For screenings, two methods have been used. As Jay writes…

“1.  Output from Avid via Adrenaline or Nitris hardware to HDCAM tape.   This method for important screenings and previews.  On a 2K or 4K projector, the picture is in proper color space, etc. and the DNxHD 36 image is impeccable on a 40+ screen.    Image quality is no different than a finished film projected via  DCinema.

2.  On a few occasions, we've projected directly from the computer via the second DVI port, treating the 2K projector as a second screen.  This method requires no Avid hardware and the rate-limiting-step is the graphics card in the computer.   As well, the color space is not correct so the image is a brighter and the black is less black.   Image-wise, it's not out of the ball park and we've used it when we wanted to see the film on a large screen without going through the gymnastics of an output to tape.

We've very interested in the MojoDX because we could eliminate #2.   As we've done in Standard Def, computer to projector via SDI Mojo - HD SDI  to Projector via the MojoDX would eliminate the "output to tape" step for screenings.   That's if you want to live dangerously - playing out directly from the Avid live in front of an audience!”


The final stage of the edit will be the DI. As Jay points out, an editor does one of these maybe once a year and every time it is completely different, so what you did last time isn’t necessarily relevant. Each facility has its own system, many of which are proprietary and unique.

BROTHERS directed by Jim Sheridan
Editor Jay Cassidy, A.C.E.
Assistant Editor Tommy Park
VFX Editor/Associate Editor/Assistant is Geraud Brisson

Systems: G5 Quad Core (editor), G5 Dual Core (assistant), G4 laptop, MacBookPro laptop


Anonymous JHaygood said...

Thanks for all the great info. I've been on Final Cut for the past year or so and while the HD is nice, I can't wait to do another show on Avid...

3:44 PM  

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