Thursday, 18 April, 2013

Editing Arri Alexa files in an Avid Media Composer

I wrote about this a couple of year ago here...

But now, in 2013, a lot has changed. There are plenty of Alexas in India, and many have RAW recorders - Codex and Gemini. Also, scores of films shot on Alexa have been released and a few have also had commercial success. 

Quite a lot of the workflow has been ironed out, but some holes remain. For a movie that will release tomorrow I did a fair bit of fire-fighting since the 'DIT' had somehow lost the source name while transcoding files for Avid. I really don't understand how these things happen.

Avid has a good set of resources on Arri Alexa workflows on the Avid site.

As usual, Oliver Peters blog is linked to.

I've put together a more detailed Avid-specific workflow guide...

For a movie shot on Arri Alex as ProRes4444 2k or ArriRAW.

On set DIT converts Alexa ProRes4444 or ArriRAW media to Avid DNxHD36 .mxf files
On set sound mixer provides .wav files of recorded location sound.

DIT sends DNxHD36 .mxf files and .wav files to editor's assistant

Editor's assistant copies .mxf files to Avid Media files folder. 
Sound .wav files are imported into Avid into Audio bins - day wise
DNxHD36 files get populated into bins by dragging the .mdb file to a bin, or
DNxHD36 files get populated into bins by copying them from the media tool to bin

These are video master clips representing camera clips. These will not be renamed.

Editor's assistant then drags all these video master clips to a sequence.
Then he/she syncs each video file to the corresponding audio files. 
Syncing by eye-matching with the clap on screen, or by matching timecode if sound mixer has managed to match picture timecode and audio timecode.

From this sync sequence sub-clips are made to a new bin, one sub-clip per video clip.
These are auto synced to get new autosync sub-clips.
Autosync sub clips are renamed as per shots they represent.
Editor's assistant then makes scene wise bins and populates them with auto-sync sub-clips.

Editor's assistant then puts a watermark on a new layer in the sync sequence and exports this timeline for the director's viewing for dailies. Sometimes, the director visits the edit facility from time to time and views rushes with the Director so he can pass on notes and ideas.

On another system, the editor reviews the assistant editor's bins, builds a cut, and refines it.

Some editors I've met insist that the DIT does all the syncing, naming of clips, making bins and creating dailies - all this on set. Because that's how 'it's done in Hollywood'. No truth in that. Even in Hollywood, a DIT will only sync if TC is matched. And a DIT never names clips, makes bins etc. That's always a competent and non-lazy assistant editor's job. 

The DIT will move on to some other job, after a movie has been shot, but the editor and his/her assistant have to intimately know all the footage, camera files, master clips,  subclips etc since they have to hand over it all to the sound facility and later the DI facility. The DIT doesn't remain on the project till that time. The editor and his/her assistant do.

And by the way, for an Alexa shoot destined for theatrical release. Alexa shoots at 24fps. That is 24.000 fps not 23.976 fps. The Avid project is 1080p24 not 1080p23.976. 
There are a few countries who see TV at 29.97 fps, where 30 means 29.97, 50 means 59.94 and 24 means 23.976.
But In the hundred year history of cinema, 24 fps means 24.000 fps. So unless your film will only be seen on TV and in the US and nowhere else in the world, please do everything at 24fps for release in cinemas anywhere in the world, for prints on film or DCP - 24fps only.