There exists multiple digital video communications standards suitable for automated video capture. Most notable examples of well-known high definition interfaces are firewire, HD-SDI and ASI. Now another standard is slowly gaining market-share, especially in the consumer segment. HDMI is a new fully digital interface for home entertainment devices with support for copy-protection. The standard includes some useful functionality that can come in handy controlling video capturing.
The main advantage of HDMI is the growing number of devices that will support it. Even thought the DRM features have been quite expensive to implement the prices will most likely drop fast. Also the interface is quite advanced. The HDMI 1.3 standard specification includes interfaces for deck and tuner control. The most interesting interface is however remote control pass-through, which already has parameters defined for initiating and stopping recording.
In practive if the camera is fully HDMI 1.3 compatible and features the required remote control commands it is possible to use HDMI cables to control video capturing directly from any other HDMI enabled device. For manual capture the auxiliary device could be a monitoring screen and controlling could be achieved using the HDMI’s standard OSD (On-Screen display) and native controls. For automated capture a computer with HDMI capture card would be the best solution.
The problem is that HDMI capture cards on the market do not support controlling external devices. A separate a firewire connection is needed for device control. Of course this limitation is mainly due the current editing suites firewire support. To do automated video capture the software will have to support HDMI interface first. It is probably possible to solve this problem just by upgrading the capture card driver or firmware. This will take a while though.
Best thing about HDMI is that standard PC with fairly simple capture card could used to store raw footage on disk. Naturally real-time encoding would still be too demanding for processors to handle. Due to high resolutions and framerates motion detection would also be best solved with dedicated hardware. Any ways of filtering incoming data makes it easier to process the remaining masses of information. So even though HDMI is a somewhat promising platform for video capture some more advancements in capture technology are still needed. Meanwhile we have more robust alternatives and in the future IT solutions such as e-SATA or Gigabit Ethernet are likely to become more practical than HDMI in content capture.