Not All High Definition Is the Same
The ultimate goal of high definition is to reproduce all the color and detail the human eye can see. We're not there yet, but we're getting closer all the time. High definition displays and sources have advanced tremendously in the past two years; a trend that will only accelerate as digital processing becomes more powerful and less expensive to implement.
In order to understand just how far we've come and where we're going, let's look at the past and future of high-quality video formats, starting with yesterday's high-end progressive scan DVD players.
- Standard Definition Progressive Scan video from components, such as high-end DVD players and game consoles, introduced a data rate of .81 Gigabits per second at 60Hz scan rate with 8-bit color depth. Progressive scan video is available via component video connections.
- From Standard Definition to today's High Definition HDTV (High Definition Television) as we know it today introduced higher resolutions of 720p (progressive) or 1080i (interlace). Both are High Definition. With high definition, data rate increased from 0.81 Gbps to 2.23 Gbps, almost three times the amount of data per second.
The single digital connection launches: HDMI 1.0
- From High Definition to "Higher Definition" Going beyond HDTV resolution, new formats such as HD DVD and Blu-ray Disc players now enable the best HD has to offer today: 1080p content. Many manufacturers have their own saying for this, such as "True HD" or "Full HD."
The data rate is double that of HDTV, 4.46 Gbps. Many HDMI™ cables can't support this, especially at longer lengths. Enter a new High Definition Multimedia Interface specification of 1.2 and 1.2a, which also introduces support of high-resolution SACD and DVD-Audio (192 kHz/24-bit resolution over eight channels). Certainly, that's an incredible amount of data to travel down the same cable.
- From Higher Definition to "Ultra-High Definition." As technology advances, content and sources will enable picture and sound that goes beyond the best HD has to offer today. Higher frame/refresh rates (120 Hz compared to today's 60 Hz) remove jitter for a smoother, more lifelike picture. Advances in color will reproduce all the colors the eye, exceeding even 10-bit and 12-bit Deep Color, sometimes also referred to in the PC world as 30-bit and 48-bit color (10 or 12 bits each for Red, Green, and Blue.)
Today, Blu-ray Disc, HD DVD, and PS3 already offer some of these capabilities and the future will bring even more advances. These future advances in color and frame rates will take the data rate requirements higher than even the latest version of the HDMI ™standard, which enables 4.46 Gbps and extends the possible bandwidth up to 10.2 Gbps by using equalization to compensate for signal loss.