What's Your Definition Of High Definition?

Every one's talking about streaming in "HD" these days. Ha! Do you mean in 720p, 1080i, HDMI...what? Truth is, most folks probably don't know. The other truth is-just because your streaming video is in the 16X9 aspect ratio and captured at a high bit rate...doesn't mean it's "HD". Sorry. Someone had to tell you.

In 1984 I had my very first media job-as an apprentice sound engineer at "Star City Studios" in Lansing, Michigan-a known hotbed in the media world. My title was a bit misleading, as all I seemed to do was set up microphones and amplifiers for scores of bands from Michigan State University who would come to record their one hit wonders. This, is where I got my first lesson about high definition. That's right. I learned my most important lesson about HD video...in a sound studio.

One day, while plugging in and checking levels on the microphones for a fantastic punk band called "The Obnoxious Pigs", I found the lead singer's level lower than the other members. So, I reached over to the mixing board...and pushed the fader on his channel to the top. The VU meter on that track told me the level was now o.k., but a screaming voice in the background from the real sound engineer told me otherwise. "Dude, you can't get a better signal that way! You have to amplify from the source...THROUGH the chain...to the recorder". I got my very first lesson that would later be called G.I.G.O. during the dot com era. The engineer went on to explain that amplification of a substandard signal enhances the volume of not only the good parts of the original signal...but all the bad parts as well. "You're making a crappy signal...more crappy!" he yelled. Instead, I learned to improve the signal at the source (in this case, the pre-amplifier for the mic)...and then work my way downstream. And so it is with HD streaming video.

If you want to REALLY stream HD video...well, you have to begin with an HD source. What does that mean? Well, loosely...a source video signal that boasts 720 to 1080 scan lines...and is either interlaced or progressive scan. Then...you need to capture that source with a video capture card that is able to handle the size of that incoming signal. These are expensive. You probably don't have one. Truth is, most people are capturing in standard definition. They are just bumping up the bit rates to make the overall signal clearer. If you really want to simulcast your HD sporting event in HD smooth streaming for instance, you will need a pure HD signal path from the downlink (assuming the downlink signal is truly HD), to the production switcher, to the matrix switcher, to the distribution amplifier, to the capture card, to the final streaming file output. If you don't have all this...you aren't webcasting in HD.

On demand in HD is even more fun. Do you know how big a one-hour HD file is??? Around 20 Gigs. And what of the resulting stream size? How does a low quality option of a 5 megabit stream sound? Hmmm. That's probably a bigger stream than the bulk of your viewers can handle. What to do! C'mon fiber! C'mon fiber!

The truth is: HD video is possible, but not practical-yet. Now, you can stream a fantastic looking Windows Media stream in 16X9 at around 1.5 Megabits. If you use HD Smooth streaming, you can push a 5 Megabit, 2 Megabit, and several lower quality streams...and the player will dynamically adjust for each viewer. Or, you could do a great job pushing a high bit rate H.264 stream from a Flash Media Encoder. Is this HD? Well, that depends on what your definition...of high definition is.