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Note: In 2006 I was the Media Manager for a feature film titled "D-Hall". This is the text of an article I wrote about the P2 Card work-flow I used during principal photography. I've since moved on to shooting with the Sony PMW-EX1 which uses Sony SXS Cards, but the workflow is very similar.

By M.L. Belanger

The Panasonic AG-HVX200 HD Camcorder presents an amazing tool for independent film-makers, a $5000 camera capable of shooting 720p HD Video in the DVCPRO-HD format on to reusable P2 cards. It also presents an entirely new tapeless work-flow which requires a whole new focus on media management.

Imagine that you only had two 10-minute HDV tapes to make an entire movie. After you shot each tape, you would need to capture it into Final Cut Pro, then erase the tape to reuse it. Suddenly the process of importing and backing up that footage would become immensely important. That is exactly the situation when using P2 cards, and managing that footage is so vital that I cannot imagine not having a full-time Media Manager on any HVX200 / P2 shoot.

A 4GB P2 holds 10 minutes of 720pn HD footage. It represents about an hour’s work blocking, rehearsing, lighting, and shooting a scene. It also represents the contributions of the director, actors, cinematographer, gaffers and grips, makeup artists, wardrobe coordinators, script supervisor, and many more. Twenty minutes after its been carefully shot it will be completely blank, the only copies of all this hard work having been transfered to computer hard-drives. Is there really ANY room for error in this process?

Welcome to D-Hall

This article details the media management work-flow I used on a mid-budget HD feature film entitled D-Hall. It is a dark and dramatic psychological thriller shot on location at an actual high-school in Chatsworth, CA. I signed on to the project about 7 days before principal photography began.

Because we were shooting during spring break, the high school was only available for 9 days. To pull off this tight shooting schedule, the producer and director decided to shoot approximately 1/2 of the entire script, leaving important footage, effects shots, and large crowd scenes to be captured several months from now during the summer.

The Computer

The media management budget for D-Hall was modest, and in particular the G5 PowerMac I would normally use was unavailable, so D-Hall was captured using the most basic of equipment, a 1GHZ Titanium PowerBook and off-the-shelf Firewire 400 drives. As you will see this minimal setup was up to the challenge of managing more than 100 P2 card downloads and over 800 minutes of raw footage.

The PowerBook is a good solution for P2 downloading because it has a PCM-CIA slot built-in (unlike the new MacBooks for instance, or even the G5 PowerMac). Unfortunately, the P2 card isn’t a ‘normal’ PCM-CIA card, and requires a special driver to mount on the PowerBook. Luckily, Panasonic has made it extremely easy to find this driver by hiding it deep within the bowels of an obscure website that no one knows the address to. It took several emails a few days before production to finally track down the driver I needed. (Thanks to Shane Ross for the link and lots of other great information).

Panasonic Macintosh P2 Driver

In order to import P2 footage for editing, I installed Final Cut Pro version 5.0.4. This is the earliest version you can use, 5.0.3 will not work.

For reference, here are the specs on the PowerBook I used:

PowerBook G4 1GHz Titanium
1GB RAM
60GB hard drive
A single Firewire 400 port.

Storage

Speaking of Firewire 400, I can now tell you that it IS possible to import, play back and even scrub 720p footage from standard off-the-shelf Firewire 400 drives. (I used several external Seagate Firewire 400 drives with capacities from 200GB to 400GB, all daisy-chained to the single Firewire 400 port on the PowerBook) On the entire production of D-Hall I only had 3 instances of dropped frames, and that was on a 1GHz G4 PowerBook. I did note however that using the J, K, and L keys to scan footage would not work correctly and often resulted in a software crash.

Now here is the bad news about tapeless acquisition using P2 cards. You are going to need massive amounts of hard drive space to store all this data. And because you have no tape to fall back on, you are going to need to back up all that data repeatedly to protect it from loss.

Calculating Storage Space

HD footage requires considerable storage space. To calculate the amount of space you will need for a feature film start with the number of pages of script to be shot. In theatrical script format, each page is assumed to equal 1 minute of screen time. In shooting these scenes, the director will usually photograph about 15 minutes of footage for each minute on the screen (thus a 15:1 shooting ratio). You can try and save storage space by assuming a tight 10:1 ratio, but you will regret it later when you run out of storage and have to buy more drives.

A 120 page script times 15 minutes per page gives 1800 minutes of total footage to store. Since each 4GB P2 card holds 10 minutes (assuming you are shooting 720p native) you’ll be downloading 180 cards worth of video. A full card holds 3.6 GB of data, so for a typical feature film you will need about 648 gigs of storage.

Now the Really Bad News

But actually, you’ll need three times that amount. P2 cards store information in a format called MXF, basically a set of folders containing video, audio, icons, and other bits of information. Unfortunately Final Cut Pro cannot read this MXF data directly, but must import it and convert it into Quicktime videos before you can view or edit it. Even worse, in the importing process certain bits of the MXF data are lost, including lots of usefully info about what mode the camera was in, the lens zoom, focus, and iris settings, etc. None of it is vital to the editing process but it goes against my nature to throw it away, so my first step with a P2 card is to make an exact copy of all this MXF data to an “MXF” drive. Consider this hard drive your “Digital Negative.” Its only purpose is to sit on a shelf in case you need it later, for instance to replace Qicktime footage you have accidentally erased. It is also hoped that future versions of Final Cut Pro will work directly with MXF data so for legacy purposes you want to have it around.

In fact, its so important that I am an advocate of making two copies of the MXF data onto two different MXF drives. At the end of production these two drives are split up and stored separately as extra “insurance”.

As I mentioned before, in order to view and edit your footage it has to be imported in to Final Cut Pro and converted to Quicktime format. The Qicktime files are saved on a third drive which I call the “Work Print.” Since you will eventually be editing this footage in Final Cut Pro, an external, firewire raid array is preferable to allow for real-time effects. Something like G-Tech’s G-Raid is a no-brainer for this.

Thus a basic feature film with a 15:1 shooting ratio and a 120 page script needs at least three 650 GB hard drives, which in real-world terms translates to three terabyte drives.

720P Native Format

The HVX200 offers a number of different HD shooting modes, with a bewildering array of frame rates, resolutions, and interlace and pulldown modes. Luckily there is one mode that stands out from the rest as the most logical choice for feature film production. It is also the HD mode that offers the most recording time per P2 card, 720 Progressive Native.

D-Hall was shot on the HVX200 in 720P native mode. As I was present during much of the discussion over which mode to use I can offer these insights as to why 720p native was chosen.

1. 720p offered the option of over or undercranking the camera for slow-motion and hi-speed effects.

2. 1080 was discussed, but the feeling was that the camera’s native resolution (a closely guarded secret known only to Panasonic) is probably much closer to 720p and the 1080 information is most likely heavily interpolated, thus we would have been wasting bandwidth to record “fake” data which could just as easily be generated in an edit bay down the line.

3. In 720p native mode, only 24 frames per second are stored (as opposed to 2.5 times more data in 720p mode which uses a 3:2 pulldown method), thus maximizing the number of minutes stored on each P2 card. In fact the data rate for 720p native is not even double that of mini-DV footage.

All of the storage calculations from the previous section assume the use of 720P Native mode. Note that regular 720P mode is NOT the same and will result in 2.5 more bandwidth usage for the exact same end result. (Final Cut Pro strips out duplicate frames when importing any 24p footage so 720P material essentially ends up as 720P Native once it’s been imported)

Getting Organized

The biggest requirement of a Media Manager is organization. You must be methodical when handling P2 footage. In a matter of minutes you’ll be copying, importing and erasing something that is irreplaceable and represents man people-hours of work. There is no room for error.

My first step was to pre-build folders on the MXF drives to hold the card contents. For D-Hall I made a separate folder for each day of shooting, and within each one, about 25 folders for individual cards. As I sent cards out into the field, I numbered each one progressively (card 01, card 02, etc) and as each card came back in I would download its contents into the appropriate folder. Color-coding full folders and locking them is also a really good idea.

No, I mean REALLY Organized

You really can’t be too organized in this process. Keep in mind that the crew on set is working under enormous pressure and needs all the help you can provide in making things easy and foolproof. At one point, I received what should have been cards number 01 and 02, but in boxes 02 and 03. The explanation was that they couldn’t find the 01 box. There were only boxes for 09 and 10 apparently.

After a quick trip to the set I discovered that there was indeed no box for card 01. Only a box for number 10 and a second box for h0... yes, boxes 01 and 04 upside down! After that I included a line under each number to help avoid future confusion. And don’t think that the crew was just making a dumb mistake. With 1000 details to process in real-time, they needed as many backups and safeguards as they could get.

Copying P2 Cards to the MXF Drives

The first step with a full P2 card that has just arrived from the set is to copy its contents to the two “Digital Negative” drives. We discovered early-on that it was possible to download a P2 card to two drives simultaneously with only a 20% increase in copy time (thanks to Albert Cheng our Camera Operator for that trick). Simply drag the CONTENTS folder and the LASTCLIP.TXT file from the card to the matching folder on first drive, then again to the second to start a tandem copy. When the copy is complete label the folders a different color and lock them immediately.

Importing P2 Card Data to the Quicktime Drive

After the MXF data was copied and locked, I would then move to Final Cut Pro and import the footage creating Quicktime files on the “Work Print” drive. In FCP I created a pre-built bin structure. I had 25 numbered bins to accept each day’s imports and would label them as they had been filled.

To import footage from a P2 card, I would first select the bin I wanted to import in to, then set it as the logging bin. Next I would select File > Import > Panasonic P2... The resulting window would allow me to type a reel name for the P2 card. I was careful to use the day’s date together with the card number to create a unique reel for each card. Thus in the future if I need to locate any lost footage I can return to the MXF files on either MXF drive and find it in the appropriate folder (You can import from MXF files stored on a hard drive as well as directly from a P2 card. Just click the ‘+’ sign next to the Volumes/Paths popup in the Import window)

The last step in importing is to click the ‘Import All’ button at the bottom of the window. The MXF data for all clips is read off the P2 card, converted to Quicktime, and stored on the appropriate scratch disc (which in this case was my “Work Print” external drive). There is an option to import a single clip but I never used it for D-Hall.

Playback

Having all the footage almost instantly available as it is shot means a shift in the way production is done. At lunch the director, producer, and even actors would wander by to check what we had just shot. This can be both good and bad. Often our 2nd 2nd AD would be come by frantically looking for missing talent who had neglected to tell him there were in Media Management. Having a walkie to hear his frantic “eyes on” calls would have helped immensely. In the end I required the actors get permission before walking with me to view footage.

On at least two occasions I was able to provide digital continuity by pulling up previously shot footage to see where a prop had been placed, etc. My hi-tech solution for getting this into on-set was to take a photograph of the PowerBook’s screen using my digital SLR and carry the camera over to the location.

Portability

We were lucking on D-Hall to be shooting for the entire 9-day stretch at one location. I was able to set up the Media Management room once and not have to move it (although I did pack up the laptop and one of the MXF drives each night and take them with me for security purposes). On a typical feature film a more easily movable system would be required. D-Hall’s second phase of shooting will be captured on a road-case mounted portable G5 system with a 23” HD monitor and removable hard drive system.

Split Clips

The HVX-200 had two P2 slots, and when both are occupied with blank cards the camera will fill one, then switch on-the-fly to the second card. This switch invariably happens mid-shot and happens so fast that no frames are lost.

Unfortunately, when this information is imported in to FCP, the resulting shot is split into two separate clips. As part of my logging process I would find these split clips, copy the first and second halves to a scratch timeline to verify they did indeed go together, and then name them appropriately

Naming Clips

The HVX-200 uses a sequential clip number plus some random suffix characters to name each clip. The result is that each clip appears in order, but its name is essentially a meaningless serial number in FCP. Luckily each clip starts with an on-camera slate marking the script scene number and take. My first step in processing imported clips would be to transcribe this information into the appropriate fields in FCP

Once I had figured out any clips missing slates, located all the split clips, etc I would then rename the clips based on the script scene and take, and finally refile them into new bins based on scene order.

I was also able to meet with Gabe Montero, our script supervisor, at least once a day to go over his logs and double-check them against the clips as they came in. This process helped confirm that we’d gotten everything that was photographed and helped us both figure out misnamed clips, etc. Gabe would also have a running count of script pages shot per day, which when combined with the amount of data I had stored per day could be used to calculate a running shooting ratio for the movie.

One problem Gabe encountered in logging for a tapeless format was trying to keep reel numbers correct as shooting progressed. The first issue was that the camera might be loaded with cards 01 and 02, but Gabe would have no way of knowing when the switch happened from one card to another. The solution was to log the reel numbers in pairs, thus reel 01-02. More difficult was the pace of the production, which often had card swaps happening so quickly (and at a distance from the Video Village area where Gabe and the Director sat watching an HD monitor) that Gabe would be unaware that new cards had been loaded. Our daily double-checks would find these mislogged reels as well.

After Gabe had updated his logs he would provide me with photocopies which I would transcribe into the appropriate fields in FCP during my down time. I was able to log approximately half of the footage we shot while on set.

A 4 GB P2 card holds 10 minutes of 720p native footage. The camera has two P2 slots and can thus record for 20 full minutes before reloading. For much of the shooting of D-Hall we had 6 cards in play and thus the production crew was never waiting for blank cards. One one day near the middle of production we had only 4 cards to work with (a loaned set were needed by their owner) and I had more work keeping up with the pace of production. (Basically I had no time for logging or other incidentals, but downloading and recycling cards still went fine).

Sequences for easy viewing

The HVX-200 automatically creates a new clip each time the camera is started and stopped. This makes it easy to log individual clips and move them in to new bins based on scene number for instance, but difficult to scan through a set of clips looking for a particular shot. To solve this I would often do a “straight drop” of footage from an individual card or even a particular scene. I would create a new sequence, select all the appropriate clips, and drop them into the time-line, then save this sequence in the appropriate bin. Then I could open this sequence and scrub through its contents quickly to locate what I needed.

UPS

Some time around our third day of shooting we lost electrical power in the media management room. This wouldn’t have been a problem since we were running on a laptop, but unfortunately the bus-powered firewire drives I had requested weren’t available, so all three of our drives were running off of A/C. Luckily I was out of the room dropping of P2 cards on the set, so no video was playing back at the time.

Its really no surprise that we lost power, what with two different productions running lights and tapping in to power all across the school campus, it was bound t happen. Interestingly enough we actually lost power to at least 2 different builds, to a set of plugs that had been retrofitted in for the schools computers, but not to the other plugs in the rooms.

The lesson to be learned here is Uninterruptable Power Supply. You must have one, end of discussion. To calculate the wattage you need, add up the power consumption of each device you need power too, and add a bit more for safety.