If you’re in the market for purchasing HD professional video equipment of any kind, you’ll eventually ask yourself,
“What is the difference between HDMI and HD-SDI?”
By this time, everyone knows what HDMI is. HDMI is a connection on every HD TV, BlueRay player, and PS3; but is it the best choice for us to use in the video production industry?
Here are 7 reasons why you may want to reconsider using HDMI:
HDMI was developed by a myriad of consumer electronics companies, movie producers, and cable providers. The primary objective of all these companies was not just to develop a cable that can transmit both audio and video within a single connection – though that is handy. These companies where looking for a way to protect their content and in doing so standardized the use of HDCP in all their components.
HDCP, or high-bandwidth digital content protection, is a type of security protocol that forces the source device (such as a BlueRay player) to generate a security key in order for the TV to display your content. This protection actually requires a handshake between the source device and the output device, which is often why most TV’s won’t even display an HDMI input on their source list when nothing is plugged in.
HD-SDI was created by the broadcasting industry to be the very best way to transmit HD video. Because of this, HD-SDI has no use for HDCP.
2. HDCP is SLOW
HDCP slows down the connection speed from input to output, this means that HD-SDI will respond quicker and smoother while video switching.
HDMI connections are similar to those of USB in that there is no way to lock the connection in place; whereas HD-SDI uses locking BNC connectors that guarantee your cable won’t get pulled out.
HD-SDI uses standard coax cable (RG-6) which is drastically cheaper to produce than HDMI, which uses a proprietary cable.
HMDI cables can only run up to 30 feet before they require some type of amplifier or repeater. HD-SDI can run to lengths of 300 meters before needing help.
Because of HDCP, HDMI is not backwards compatible with VGA without a device that generates HDCP keys. HD-SDI can easily be scaled down.
7. Time Code
HD-SDI carries video signal and time code in one cable. HDMI has no time code support.
On the consumer market, HDMI does a fantastic job holding the position of being the standard HD video connection. In the professional video industry where things like quality, durability, speed, time code, and flexibility are all must haves, HD-SDI is the way to go.
Can you think of another benefit of using HD-SDI?