THEATER 550 PRO

At the heart of all three cards we’re evaluating today is ATI’s latest video processing chip, THEATER 550 PRO. THEATER 550 PRO is the newest in a long line of ASIC’s, replacing the THEATER 200 chip, first introduced by ATI in 2002 with the ALL-IN-WONDER 9700 PRO.

THEATER 200 introduced a number of firsts for ATI. For instance, THEATER 200 was ATI’s first decoder chip to feature a 2D 3-Line comb filter. By moving to three lines, THEATER 200 was designed to more accurately process composite video signals, resulting in a cleaner, sharper picture. THEATER 200 also featured dual 12-bit analog-to-digital converters (ADCs), another industry first (competing solutions offered 9 or 10-bit ADCs).

With THEATER 550 PRO, ATI bumps the video quality notch up one bit further, and rounds the package out with an integrated MPEG-2 encoder.

THEATER 550 PRO chip

New comb filter

The key to THEATER 550 PRO’s improved video quality is its motion adaptive 3D comb filter. Up until the THEATER 550 PRO, 3D comb filters were only found in television sets. In fact, ATI claims that the THEATER 550 PRO’s 3D comb filter is the same one ATI uses in Sony televisions.

In addition to the 3D comb filter, ATI also integrated a more advanced 5-Line 2D comb filter, two more lines than used in THEATER 200. The chip analyses the incoming signal, and decides which comb filter would be best for optimal video quality. The 3D comb filter is used for scenes with little movement, such as slow moving video, static items in a scene, or still pictures. The 2D filters uses previously for these applications would sometimes have color artifacts around the edges of objects (you’ll really see this when someone on TV wears a striped shirt), or you’d see a dot-crawl effect.

The 2D comb filter reads ahead 5 lines before the video is processed, detecting similarities in the lines and determining how to separate the signal in the most efficient manner. Unlike the 3D comb filter, the 2D comb filter is used in fast motion video.

Audio synchronization

Another cool new feature THEATER 550 PRO supports is digital audio processing. In more traditional video solutions, including RAGE THEATER and THEATER 200, audio is sent through a loop-back cable to your sound card. This is inconvenient for users who use their line input connection on their sound card for other devices, and is also more difficult to install for less experienced computer users who aren’t as familiar with working within a PC. With THEATER 550 PRO, the audio stream is passed directly into the THEATER 550 PRO chip, digitized with a 12-bit ADC, and then sent to the sound card internally. A loop-back cable isn’t necessary.