Having to choose between multiple recording formats has been the bane of broadcasters for many years. This choice was often based on a particular compression format and the resulting image quality, as well as whether the scheme fit into a station's existing infrastructure with the least amount of reconfiguration and picture degradation.
Flexible storage
While the elusive universal standard continues to be out of reach, design engineers at Grass Valley have created a solution: the Infinity production platform. The platform allows a user to choose the removable recording media and compression format that best suits his needs at the moment.
With Grass Valley's new Infinity series, consisting of a camcorder and a digital media player, users can select the storage medium based on the application. In the future, an edit system and server will be introduced to support the line. If this product catches on with broadcasters, the limitations of a single recording format and compression ratio will no longer be an obstacle.
This flexibility of Infinity allows a station to record to an Iomega REV Pro disk one day and on solid-state flash memory the next. An ENG crew covering a press conference might use both, recording the entire event on a REV Pro disk while capturing a sound bite on pro-grade compact flash memory that gets handed off to a team member for immediate airing.
Camera basics
If the station wants to later cover the local college football game in HD, at bit rates of 25Mb/s, 50Mb/s, 75Mb/s or 100Mb/s, in either 720p or 1080i, the same equipment can be used.
The basic Infinity camera starts at $20,000 for an SD/HD version that records on four types of removable media: REV Pro, FireWire, USB and compact flash. It contains codecs for both DV and JPEG2000. The camera processes 1920×1080 HD images with 10-bit, 4:2:2 sampling using JPEG2000.
While some cameras include FireWire connectivity, typically you can't output a full-res file directly from the camcorder. Although some cameras provide tapeless storage, it's only in a single format. Then, there's the issue of having to standardize based on one brand.
The Infinity camcorder includes a color LCD monitor as well as SD audio and HD/SDI video connectors for real-time output. Also provided are Gigabit Ethernet and FireWire connectors. MPEG compression is available as an option.
In addition to serving as a playback and storage device, the Infinity digital media recorder (DMR) provides editing, file management and multichannel file distribution features. The player uses the same media as the camcorder and also provides full baseband video and IT connectivity. While MPEG-2 playback is standard for the DMR, an optional encoder is required to record the format.
The disk cartridges come with 35GB of storage capacity. This provides about 45 minutes of 1080i HD at 75Mb/s and more than two hours of 25Mb/s HDV. For a detailed look into the disk cartridge's technology, see “Iomega's REV Drive” in the July issue of Broadcast Engineering magazine.
Production applications
The pro version of the cartridge will cost about $70. It's based on the existing REV drive technology from Iomega, but the professional disk provides increased bandwidth to support multistream operation. The disks are also attractive for archival applications.
Using the DMR or the camcorder's internal REV Pro disk drive, a station could record a 50Mb/s stream and simultaneously play out another stream. The player can also play out material recorded onto standard REV disks, but that material cannot be streamed and recoded at the same time.
Features
Production crews can use a standard laptop equipped with an external REV drive, creating an HD preview station in the field, with complete VTR emulation. Grass Valley also plans to offer free logging and trimming software tools, either loaded onto every REV Pro disk or as a separate application disk that can be loaded onto a PC.
There are two versions of compact flash memory cards that can be used for the Infinity camcorder, all made by SanDisk. They include the Extreme-III, which comes in sizes up to 4GB for high bit rate HD, and the Ultra-II in sizes up to 8GB for SD and 25Mb/s to 50Mb/s for HD. This form of recording is ideal in harsh weather conditions or in applications where extreme vibration might affect image acquisition. Currently, an Extreme-III card from SanDisk costs about $350.
USB memory sticks are also compatible with the Grass Valley Infinity camcorder and DMR. USB sticks offer less storage capacity than CompactFlash, thus less video record time.
The quickly emerging JPEG2000 compression scheme is designed to be scalable and allows users to encode a file once and decode multiple resolutions for different distribution platforms. Unlike other tapeless systems, which record both a low-res and high-res HD image onto a disk or solid-state memory card, the Infinity camcorder records a single HD file and then, using JPEG2000 compression, decodes at least three lower resolution versions in real time. This conserves space on the storage media.
Another advantage of JPEG2000 is its ability to support the full raster 1920×1080 image, versus the common technique of subsampling horizontal resolution, resulting in 1440×1080-size images being used prior to compression.
Accommodating change
In addition, because JPEG2000 is wavelet-based — as opposed to the DCT scheme for MPEG-2 — there are no blocking artifacts. Artifacts from JPEG2000 appear as a blurring of the image, which Grass Valley says is more acceptable to the human eye. That can be a big benefit when working with lower bit rate material. JPEG2000 also offers true random access to every frame with synchronized digital audio.
In designing the camcorder and media player, which will be available in early 2006, Grass Valley was careful not to give users too much choice; otherwise, they'd need a master's degree in computer programming to use them. With this in mind, the company is anxious to get the camcorder into users' hands.
Those that have previewed it have been suitably impressed with the camera's flexibility and ability to evolve as broadcasters' needs change.
Michael Grotticelli regularly reports on the professional video and broadcast technology industries.
