Being an early adopter of tapeless cinematography, I generally notice these inquiries on the blogs, bulletin boards, listserves and forums. Tapeless being the new technology and work?ow, there are kinks to work out, learn curves to scale. This article will address the issue of tapeless cinematography?s archiving image and sound assets with a reasonable yet secure system.
Film set the narrative and commercial image acquisition standard over the past century, but the process from set to edit can be prohibitive. Since the late 1960?s, analog tape has been used for broadcast, corporate communications, with the emergence of digital tape & disc formats, for almost every media industry. Both ?lm and tape provide instant archival mediums for their video, audio and metadata assets, but with the domination of non linear editing systems across all media industries, these formats require digital capture of these assets into the digital realm. Tapeless image (and audio) acquisition is emerging on set as an alternative to ?lm, tape and optical disc based recording. Solid state?s current high cost necessitates using it as a temporary archive analogous to a ?lm camera?s magazine conveying assets to a more affordable archive: computer hard disk drives.
New tapeless cinematography systems abound from traditional sources like Sony, Panasonic, JVC, traditionally ?lm based camera manufacturers Arri and Panavision, and new players like Red, Silicon Imaging and Phantom to name a few. Parallel to hardware developments are the video format and codec developments. These developments indicate the multiple paths being explored in camera and solid state form functions, video formats and codecs, and post work?ow.
The following is a case study of a multi-camera, tapeless feature production “Blackout” shot on two Panasonic AG-HVX-200?s, using a nonlinear edit system (in this case, Apple?s Final Cut Pro) for syncing, dailies assembly and eventually, picture edit to illustrate some of the bene?ts of tapeless acquisition to digital post.
Fundamentally, storytelling assets take the form of image, sound and metadata recorded onto a medium. The medium can be ?lm, tape, optical disc based or solid state non-volatile memory. Digital assets may be further de?ned as uncompressed or compressed, the latter requiring a codec to access the images. Metadata might be in the analog form of keycode, footage/frames and timecode for ?lm. Digital metadata may include user bits, timecode and other shot, production or camera data. Metadata may be also recorded visually in the form of a clapper slate relaying production, scene, take, camera reel and date information.
“Blackout” was shot in the summer of 2006 with a $400,000 budget and goal for theatrical release. The production was based on multi camera, dual system sound coverage. The script supervisor controlled scene, take, director?s circle takes and assigned reel numbers in sequential order. The Camera Department controlled the slate and image recordings at 720 24pn onto P2 cards, the Audio Department provided audio recording onto CF cards.
The medium dictates how we access the recorded assets. Film and tape are generally linearly accessed in real time, played down and captured as assets into your system or ?lm is transferred to tape then captured. Assets on optical disc and solid state devices can be accessed non linearly. Film, tape and optical disc create instant, relatively long term archives at the point of capture. Solid state devices comprised of non volatile computer memory currently at the $50/GB may not be cost effective as the archival medium*. Developing a disc based archive for your assets, one that is cost effective while setting up your project for post, mitigates the effort while providing a redundant data set that can survive device and human error as a near term archival solution.
If media type dictates capture process, then video format describes the computer and storage subsystem. Any video format contains pixel dimension, frame progression, metadata and the raw encoded video and audio ?les, usually lossy or losslessly compressed. With video codecs, there?s no such thing as a free lunch. The video compression is a tradeoff between disk space, video quality and the hardware to decompress it. An uncompressed video format requires large drive arrays to achieve the volume and speed needed, or a compressed video format requires more CPU power to decode producing a comparable image. Compression may employ lossy (or visually lossless) techniques that may reduce the quality of the image and require more CPU during playback, but make playback possible through a modest computer system. When specifying a computer system, consider the video and audio streams and don?t overlook the required system overhead, anticipated graphics needs or the number of simultaneous video streams.
Using the DVCProHD video format, the production speci?ed the deliverable to be 720×1280 at 24 progressive frames per second. This codec requires approximately 40 mbps, easily provided using an Apple G4 667MHz Powerbook and Firewire 400 external hard drive to provide 2+ streams for video for assemblies.
the system
Using high de?nition tape as the benchmark cost per unit time, until solid state storage reaches the tape comparable $1/minute price point, the following alternative is suggested for any tapeless project: choose a metadata key, copy the assets as DATA from the solid state medium to a mirrored array (safety through drive redundancy), then log and transfer into your NLE onto a striped array (speed through drive redundancy) as your MEDIA.
This system builds 2 copies of the assets as DATA on two drives to protect against device failure and a third copy of the rewrapped assets as your project MEDIA on a separate volume, generally a striped (fast) array. This is roughly the equivalent of a negative and work print or dubbing shot tapes and digitizing the medium into your NLE. If production insists on individual external drives, P2 Genie can automatically copy the card to multiple volumes.
Since production used a timecode clapper slate for syncing video and audio and the assets to the story with a traditional scene/take/reel coding system, the natural link was unique reel numbers where each reel was attributed to a P2 card load. Reel numbers became the key ?eld that tied the assets (DATA and MEDIA) to the script.
parts list
- current laptop**
- IEEE 1394a/b based RAID 1 mirrored array
- IEEE 1394a/b based RAID 0 striped array
- 17-21″ monitor
- UPS
On “Blackout”, the HD Tech station was setup in the holding area located in a church community room, a few blocks away from the set in a secure, stable environment. When the company moved off site, the setup took over a corner inside the location vehicle, a modi?ed RV used for still photo productions with a generator. In either case, runners would bring shot & write protected (locked) P2 cards to the HD Tech station. Insert the P2 card into the reader slot, check the reel number on the slate, copy the card contents to the asset archive into a reel named folder on the RAID1 mirrored array, then transfer into the NLE and onto the RAID 0 striped array using the assigned reel number. Audio followed video. At the end of each shooting day, cards were copied to the DATA archive, then transfered to the MEDIA array.
the simple HD Tech package, TiBook 667mHz, RAIDO striped (top) and RAID1 mirrored (bottom) arrays and note the rotated monitor to the left (lens adaptor employed inverted the picture necessitating monitor rotation). Not shown uninterruptable power supply.
video & audio
For example, a formatted Panasonic P2 card contains the volume “NO NAME” generated by the camera, inside that is a folder “CONTENTS” and a text document “LAST CLIP.TXT”. CONTENTS is the folder and all folders inside contain the assets, it is also your access point*** if you want to log, view or transfer these assets. Check the reel number on the ?rst slate, create & name a folder in the archive with the reel number, then copy “CONTENTS” into it.
Screen capture illustrates archive folder hierarchy, from reel numbered folder to MXF folders.
Using the reel number quickly refers to the script notes, the creation date served for the shoot date. copy speeds vary, but 1GB/min using OSX4.8 and Final Cut Pro v 5.0.4, almost 2GB/min was experienced with FCP ST 2 and Leopard (OSX.5).
Next operation was to Log & Transfer the assets from the P2 card into the NLE. With the card still mounted, in write protect mode, navigate to NO NAME, check the visual slate to con?rm the reel number and set the reel to match, select all the clips and let it rip. Make sure FCP?s scratch disc is set to the MEDIA striped array?s volume, this is where the MEDIA will reside. Log and transfer re-wraps the MXF?s l video & audio essence and metadata into a Quicktime wrapper. For DVCProHD and most HDV codecs, this is more of a copy, not a transcoding process. Other codecs may require
transcoding to Prores 422 or another post friendly codec, another step in the process.
For Blackout, production purchased 8 bare 320 GB drives, 2 for each week of production for the DATA archive and one 1TB G-Raid RAID0 array for the edit MEDIA. Using 720 24PN (roughly 40mbps), we could get approximately 13 hours of footage on each pair, just enough for a 2 camera shoot at this framerate and video format.**
Lastly, compare the ?rst ?le name and the number of ?les in NO NAME/CONTENTS/VIDEO folder to the DATA and MEDIA copies. There are better ways to accomplish this, but it was my idiot check. Then and only then, I was satis?ed that I had one original and two copies, I would unmount the P2 card, un-write protect it, and erase the card for reuse. Trashing the folder and .txt ?le into the trash or erasing (reformatting) the card should work. The runner would pick up the P2 media inside it?s case with the opening sealed with white tape to signify unloading. If the Camera Department ever had a card that was locked or untaped, they were instructed to return the card to HD Tech for assessment.
- check reel number
- make folder named with reel number
- Copy card to mirrored array as DATA to folder named with reel
- Copy card to Striped array as MEDIA, log with reel name
- Compare copies and erase card. Tapeless Cinematography Workflow v2
audio follows video
At the end of each shoot day, the audio recordist would bring me approximately 2GB of audio ?les that we?d transfer to the DATA archive, convert (from BWAV to QT) and import into FCP onto the MEDIA array. The next morning, thiCamera A.
Blackout was spec?d to deliver 720 high de?nition video at 24 frames per second with dual system sound. Recording the video in the DVCProHD video format and using a titanium 667MHz powerbook, I was able to copy, log and transfer, sync (or merge) picture and sound, even start a rough assembly on set.
Compare this tapeless, DATA archive and edit MEDIA cost per unit time, and you see the savings. Contemporary bare (or internal) hard drive prices are 17¢/GB and are still headed south. With this work?ow (2 DATA copies and one MEDIA copy), it would cost production about $3/min in the equivalent DVCProHD tapestock.
Recap
The beauty of this process is, by taking a second pass at your digital cinematography material, you?ve created a system where your production is archived on redundant drives and across multiple volumes. This reduces the chance of device failure or operator error negatively impacting the production.
Redundant hard drives are excellent for DATA and MEDIA archives, but are
less than stellar long term storage mediums. On the horizon are Bluray data discs as read & write drives drives reach the marketplace and 50 GB media become available, but archival stability is unknown. LTO tape back-ups provide digitally lossless compression onto tape which has been used for the past 25 years so it is of better known archival stability at the cost of access speed.
The system you use may be different because of speci?c production needs, new technology, or more resources. Above all, the HD Tech?s goals are to protect the data and be able to put your ?nger on any image or audio. Communicate with your collaborators, the camera and audio departments as well as the script supervisor. Set up a system to protect each other, but in the HD Tech?s case, get camera and sound reports with ?les and ask camera to not erase any cards if they ?nd an unaccounted locked and full card. Leverage the computer system?s search functionality and have a backup plan. File/folder names are pretty safe bets, but also at your disposal are Spotlight Comments, disk images and various database solutions to manage your data. Don?t forget about audio, it should follow video, so to speak. Be consistent so audio can be found intuitively by anyone. Keeping a log of all HD Tech processes is suggested, comparable to the audio or camera logs.
Consider the production?s rhythms, P2 cards will come throughout the day, but usually provide you with a few hours in the morning of quiet time with a rush of cards and the audio cards toward the end of the day.
footnotes
* current cost per GB and per minute of 1080 60i (where applicable) of Si storage by medium:
32GB P2……….$52
16GB SxS…….$54
16 GB red CF..$34
16 GB CF…….$25
16 GB SDH….$08
500GB SATA (bare) ….$0.17
50 GB XDCAM discs.. $1.22
DVCProHD tape…………….$0.64/minute
BCT-124SRL HDCAM SR..$1.00/minute
35mm ?lm……………………$1.85/minute
** newer macBookpro?s are designed with ExpressCard slots, which work great with Sony?s SxS media, but fear not P2 users, Panasonic?s ?rewire P2 deck, the AJ-PCD20 or Duel System?s DuelAdaptor can bridge this chasm, or a G4 powerbook.
*** Most tapeless cameras implement a form of the MXF standard (Media eXchange Format), unfortunately, there are several standards. Panasonic and Sony use the MXF format, but are mutually exclusive. A Sony EX-1 will label the top folder “BPAV.” The MXF standard includes the speci?c folder hierarchy and contained metadata and essence ?les, the complete folder structure is required for proper transfer of essential ?les, aka the media and metadata ?les.
Resources
- Wikipedia for digital cinematography, P2 media, vXDCAM, MXF format
- HD Log X, Imagine Products
- data archive assistant, P2 Genie
- Final Cut Pro, Titanium Powerbook 667 MHz, Apple, Inc
- RAIDTech 800 RAID array, Wiebetech
- G-Raid RAID array, G-Technology
- 744T digital audio recorder, Sound Devices
- Panasonic AJ-PCD20
- Duel systems, DuelAdaptor
words and photos by {encode=”michael@vittiphoto.com” title=”Michael Vitti”}