Magnetic media has been the most common way to record audio and video for the last several decades. The value of all this content is incalculable, yet its survival is in great danger. Magnetic tape cannot be physically preserved beyond a certain point; components of the tape break down, causing the degradation and eventual destruction of the recorded content.
The only way to preserve the content is migration, copying the recorded content to a new tape or to a digital file, while correcting for signal degradation. The amount of audio and video content in danger — hundreds of millions of hours globally — is too vast to be saved through traditional methods. The scale of the problem is far too large for manual processes to keep up. Without taking action, stations and archiving facilities could suffer irretrievable loss of the world's audiovisual heritage.
A unified solution
To combat this loss, SAMMA Systems created the System for the Automated Migration of Media Assets (SAMMA), an unattended magnetic media migration system. The platform is a comprehensive system designed to migrate large quantities of tape media to digital files. Through the use of expert systems, proprietary software and hardware, and the distillation of decades of magnetic tape preservation and restoration experience, the technology presents a unified solution to the problems of saving videotaped images.
The workflow is simple. An operator loads the system with as many as 58 source tapes. The automation then migrates the material to digital files (and/or to sub master cassettes). Once completed, the operator unloads the source tapes and reloads the next batch of tapes to be copied. The copied digital files are then moved into a local storage system.
The system uses advanced video and audio analysis hardware and software to ensure total quality control throughout the process. The analysis engine provides time-base correction, dropout compensation and frame synchronization. It also creates a log of any errors and the corrections made, all referenced to timecode.
The system makes dynamic decisions about how to proceed based on the real-time analysis. For example, a declining RF envelope during migration may indicate a playback head clog. Should this happen, the system halts the process, loads a calibration tape and rechecks the RF level. If the RF level is still low, the system will load a head cleaning cassette and then recheck the levels. If the original tape is determined to be at fault, a log is made, and the deck is put back into service.
Detailed metadata — such as physical condition (tape stretching and tension) and signal condition (luma and RF levels, motion, and silence) — is collected from each tape. Extensive reports on the condition of a collection of tapes are available both during and after the migration process. The SAMMA system is fully portable, allowing it to be brought to a station's site for transfers. This eliminates the uncertainty, risk and cost of shipping collections off-site.
Centralized intelligence within the system allows several tasks to be completed in a single pass. Multiple tape copies and digital files can be created in the time it used to take to make a single duplication. To take full advantage of the digital domain while sacrificing none of the quality, the system uses real-time MotionJPEG2000 encoding hardware to perform lossless encoding of archival media. The encoder inputs and outputs SDI plus AES audio, and the resultant files are wrapped in MXF.
The robotic tape handlers can contain from three to six to playback decks, depending on the format. A Beta tape version is built to accommodate as many as six decks in single robot. Such a system can migrate tapes to digital files only at the rate of 140 hours of content per day. At seven days per week of operation, this yields a potential of 50,960 hours of migrated content per year.
Effective migration
As broadcasters move from tape-based plants to server-based operations, one of the biggest tasks facing them is retaining access to their existing videotapes. SAMMA provides a high-quality, rapid and highly cost-effective migration of those assets to digital files.
Gilad Rosner is a systems integrator with SAMMA Systems.
