Cobalt Digital HD8021 Hi-Definition/Standard-Definition Converter
Urbana, Illinois-based Cobalt Digital has been making its successful range of behind-the-scenes converters since 1997. In that time, Cobalt products have been used in countless (and disparate) applications ranging from broadcast, mobile and post-production video facilities to theme parks, museums and corporate boardrooms. A testament to their rugged construction and low emissions, Cobalt converters are installed on NASA’s Space Shuttle launch tower.
Cobalt Digital continues its legacy of useful and cost-effective conversion products with the introduction of its HD8021 multi-converter ($2995).
Features
At its core, the Cobalt Digital HD8021 is a 10-bit high-definition and standard-definition converter. The unit measures 10.3 x 5.9 x 1 inch deep and is powered by a 5VDC adapter with locking connector. A 12-volt option is available for use with Anton Bauer-compatible battery systems ($125).
In addition to its high-quality HD-to-SD and monitoring-quality SD-to-HD conversion, the HD8021 can perform numerous other functions including 1080/720 HD-format cross conversion, SD/HD-to-XGA conversion, interlace and progressive mode cross conversion and 3:2 pull-down.
The HD8021 also provides a DVE processor for performing aspect ratio changes, as well as a flexible reticule overlay engine that can be individually configured and enabled/disabled for each of the video outputs.
Speaking of outputs, the HD8021 derives a set of two re-clocked serial digital HD/SD outputs and a separate set of two image-processed serial digital HD/SD outputs from its single dual-rate serial digital input.
The HD8021 also provides two separate sets of analog outputs. The first of the analog outputs is on a HD-15 (XGA) connector and can output dual-rate HD or SD video. Analog HD signals on this output can be configured for YPbPr or RGB with either embedded tri-level or bi-level signals or H & V sync. Standard-definition signals output on this connector can be configured for RGB or YPbPr (at Betacam, MII or SMPTE levels) with embedded bi-level sync.
The second analog output set is standard definition-only and utilizes its three BNC connectors in a unique manner: the user can configure the set of BNC connectors as three composite outputs, one composite output and one Y/C output, or as a single component output configured for RGB or YPbPr (at Betacam, MII or SMPTE levels) with embedded bi-level sync.
Image processing within the HD8021 is full 10-bit and utilizes a 24-tap spatial filter. High-definition video down-converted to standard-definition is de-jittered to reduce chroma phase jitter of SD analog signals. Signals available at the various analog outputs are encoded at 12-bits to preserve the 10-bit video signal.
The HD8021’s input accepts a range of 10-bit HD 1080 and 720 signals in segment frame (sF), progressive (p) or interlaced (i) modes, as well as SD NTSC and PAL signals in interlaced frame mode.
Incoming HD 1080 rates/modes supported by the HD8021 are 23.98 (sF/p), 24 (sF/p), 25 (i/p), 29.97 (i/p) and 30 (i/p).
Incoming HD 720 rates/modes supported by the HD2081 are 25, 29.97, 30, 50, 59.94 and 60 (progressive). The HD8021 can also accept HD 720 frame rates of 23.98 and 24 (segment frame or progressive) when delivered within a 59.94 or 60 transportation wrapper. Standard-definition signals accepted are NTSC 29.97 and PAL 25 (interlaced).
Processed signals can be output as: HD 1080 at 23.98, 50, 59.94, or 60 (interlaced), 25, 29.9 or 30 (progressive) and 23.98 or 24 (p/sF); HD 720 at 25, 29.97, 30, 59.94 or 60 (progressive) and 24 (embedded in 60p); SD 576 (PAL) at 25 or SD 486 (NTSC) 29.97 (interlaced). A detailed conversion chart is available on the Cobalt Digital website.
In Use
The Cobalt Digital HD8021 can perform such a vast amount of useful conversion operations and ancillary functions that it seems almost cruel to use it in a set-and-leave, hidden-behind-the-racks manner. Alas, since it is lacking all the front-panel bells and whistles of a rack-mount interface (and priced accordingly), the HD8021 is destined to live an anonymous life, tirelessly performing amazing feats of conversion from behind the scenes.
Most conversion, aspect and overlay settings are made using the four banks of surface-mounted DIP switches accessible on the top of the unit. Each of the four switch banks has 10 individual on/off switches, the total of which, at first glance, makes configuring the HD8021 a bit of a challenge.
Thanks to the division of functions into logical groups and comprehensive key printed on the top of the unit, my fears were quickly allayed. The helpful legend also gives many quick-reference descriptions of settings for common conversion tasks.
The first bank of switches sets the conversion mode (SD to HD, HD to SD, HD 720/1080 cross, etc.); the second bank controls matters related to aspect ratio (letterbox, center cut, pillar box, user-defined etc.) with separate settings for the HD and SD outputs; the third bank individually configures the HD and SD analog outputs (RGB/YPbPr mode, HD/SD levels, SD BNC output modes etc.); and the fourth bank controls the reticule overlay settings (enable/disable overlay for the various outputs, enable/disable center cross, 4 x 3 and 16 x 9 safe area reticules, reticule-follows-zoom mode, etc.).
Some of the HD8021’s more esoteric and user-customizable settings – such as DVE aspect pan left/right (default is center) and reticule line thickness and overlay levels – are accessible via a combination of rotary and pushbutton encoders located on the internal circuit board (mercifully, there are only four screws to remove to gain access).
In putting the HD8021 through its paces, I discovered that it is not nearly as “dumb” as the typical set-and-leave device. In several instances, it made intelligent decisions based on the incoming signal, despite my chosen conversion settings. It knew, for instance, when set to up-convert SD to HD to pass through the signal unchanged and when I unexpectedly presented a HD signal at the input.
Along the same lines is the HD8021’s auto-sensing dual-rate mode. The benefit here was that as I changed the input standard between HD and SD, the single HD analog output (on the HD-15 connector) automatically followed suit, allowing a single connection to my multi-rate monitor (as opposed to using separate HD and SD connections and constantly switching inputs at the monitor). My pre-defined format-specific aspect ratio settings and overlays were also switched automatically – very cool!
My one complaint with the HD8021 was that includes no provision for audio following. This means that, depending on the conversion process selected, a delay of up to a several frames can be introduced between the audio running outside the box and the processed video signals appearing at the HD8021 outputs.
Summary
Despite the fact that it’s hard to look at a black box, set-and-leave device and find love, the Cobalt Digital HD8021 quickly endeared itself to me. It provides the kind of security that allows an engineer to confidently say, “Yes, I can do that” to his boss or clients.
With its multiple simultaneous outputs, wide-ranging conversion settings and customizable overlay options, the HD8021 is an ideal and inexpensive solution to most SD/HD transition woes.
Stephen Murphy, contributing editor of Pro Audio Review magazine, has over 20 years experience in audio/visual production. He can be reached at www.smurphco.com.
Key Features:
HD/SD up/down converter; 1080/720 cross conversion; 3:2 pull down; interlaced/progressive frame mode conversion; HD/SD serial digital and analog outputs; XGA output; aspect ratio conversion; 10-bit video path and 12-bit analog encoding; reticule overlay engine; 5-year warranty.
Price: $2995
Contact: Cobalt Digital Inc. at www.cobaltdigital.com; 800-669-1691