Editing 1080i HDV using Lumiere HD

by Dave Brewis

The HDV format is an interesting compromise between quality and manageable data, in that HDV cameras are capable of capturing at HD resolution*, but actually encode the data to an MPEG2 transport stream before recording to tape.

MPEG2 is not compressed one frame at a time, but in groups of pictures. This is problematic for NLEís because to display a particular frame of video they must fetch and decompress multiple frames, before displaying the desired frame. This is often called Long-GOP editing.

We are at an early stage within the life of the HDV format and editors/producers who wish to work with the format donít have many choices. KDDI's MPEG Edit Studio Pro LE comes with JVC HDV camcorders, and Pinnacle Systems now support Long-GOP editing, but the world awaits native solutions from Apple and AVID.

The arrival of the new HDV camera from Sony, the HDR-FX1, has accelerated the need for an editing solution. This camera captures at 1080i 60. We bought the European version, the HDR-FX1 E, which captures at 1080i 50, and have been waiting for a solution to the problem of Long-GOPop editing since it was released.

That solution is now here, or it is for For Final Cut Pro users in any case.

Proxy editing involves capturing HDV from source, and converting your captured clips into proxy clips using a QuickTime friendly codec.

Using these proxy clips, you can take advantage of Final Cut Pro's realtime effects/transitions and so on, before onlining your finished program using the original material. This ensures no loss of quality throughout the editing process.

Lumiere HD:

Lumiere HD facilitates the editing of HDV 'by proxy'. Until recently, Lumiere HD has only supported JVC HDV cameras, but version 1.3 supports Sony's HDR-FX1.

So how exactly does it work?

Well, first of all, Lumiere is not a FCP plug in. It's a separate application which you use to capture your rushes (as an MPEG2 transport stream) before de-multiplexing to create an MPEG2 program stream incorporating separate video and audio files.

From these files you create QuickTime friendly files editable within FCP, allowing you the benefits of FCP real time effects etc.

On finishing your edit, you must then create an offline copy of your final sequence using appropriate HD settings, before 'reconnecting' your MPEG2 program stream.

What you'll end up with is a HDV final edit, in HDV resolution.

Sound convouluted? Well, it is a bit. And I haven't even mentioned getting your final edit back out to camera/deck yet.

Is it worth it? Well, if you want to edit material shot in HDV you don't have a lot of choice. So here's how to use Lumiere HD..Ö

Capture

First you must launch Lumiere HD, which is a separate application. You then capture your footage from within this app: You have transport controls like you do in the Log and Capture window of FCP, and can navigate to the desired place on your tape where you wish to begin capturing.

You must name the MPEG 2 transport stream (.m2t) you are about to capture and choose a destination. I recommend naming a folder 'm2t' in your project folder, in which you will capture your rushes.

Program Stream

Once captured, the .m2t files need to be de-multiplexed, or in other words, the audio needs to be separated from the video.

With 'Program Stream' selected you must select a destination for your .m2v video files and your .aif audio files. I simply create a folder named 'm2v' and a folder named 'aif' in my project folder, and specify them as destinations accordingly.

Clicking 'Demultiplex' begins the process, which is reasonably quick -.. around 3 x real time on a G5 2.5GHz.

Timeline Codec

Next you must convert the .m2v files into the QuickTime .mov files using the codec of your choice for realtime editing in the FCP timeline.

With Timeline Codec selected, you select your source folder (the one containing your .m2v's), and a destination for your resultant .mov files (a folder named 'mov' in your project folder for example).

You're ninvited here to choose your codec. You can choose any codec you have in your QuickTime codec list. I use DVPAL anamorphic because at 25fps it matches the frame rate of my HDV camera.

Also make sure you check the tick box next to 'Create FCP XML', and the one next to Anarmorphic. Then click on the button 'Audio Files?' and select the 'aif' folder you created.

Click GO and wait. This process takes around 2 x real time. Once finished you're invited to name your XML file.

Phew! Now You Can Edit!

Open FCP, create a new project and and create a sequence with your chosen codec (DVPAL for me). Remember to make the sequence Anarmorphic.

Now Import the .xml file you generated. This brings in all your rushes, which you can now play back and edit in real time.

'Onlining'

Once you have a finished edited sequence you must online it using the source MPEG2 program stream that you created during the de-multiplexing process..

Select the edited sequence, and using the Media Manager make it offline, whilst simultaneously creating a new custom uncompressed HD sequence.

I recommend the following settings for this sequence..

Frame size: 1440 X 1080
Pixel Aspect Ratio: Square
Checked anamorphic
Field Dominance: Upper (Odd)
Editing Timebase: 25 if you shot with the FX1E in Europe, 29.97 if you used the FX1.
Compressor: Uncompressed 10bit (Recommended)
Quality: 100%
Audio: 48Khz

Give your new sequence a name.

Select it and reconnect your media selecting the .m2v files you created.

Export

You have a true 1080i HDV sequence for which you have not compromised quality.

Conclusion: Lumiere HD is a necessary workflow tool for those of us who need or want to edit in HDV. Eventually Apple and others will build in native support for HDV in to their NLE software, and the notion of Proxy editing of HDV material will be redundant. Certainly the next version of Final Cut Pro HD will support HDV. Until then, Lumiere HD lights the way.

* The Sony HDR-FX1 HDV camera actually captures 1440 x 1080 pixels but flags the frame aspect ratio as 'anamorphic' so the viewer gets to see a 1920 x 1080 pixel image. This works in much the same way as DVCAM 16:9 setting.. 720 x 576 pixels are captured but with the anamorphic flag selected an NLE would display a 16:9 frame.