For anyone looking into setting up a Home Theater PC (HTPC), the choices for TV tuners are quite vast. Pretty much all people would need is something that can display and record TV shows, though an added bonus would be Microsoft Media Center support. Image quality should be good, and a remote is always nice to have.

The MSI Theater 550PRO we'll be looking at today has all of the above and features ATI's latest Theater 550 chip. We've looked at ATI's own branded 550 Pro (TV Wonder Elite) a few months back, so how does MSI do in their repackaging?

MSI Theater 550PRO

TV Tuners aren't nearly as big and complex as most video cards, and everything you need to power a HTPC is packed into a rather small, red PCI card. We do wonder why they didn't just put all of this into a PCI Express package, but seeing as to how HDTV isn't supported by the product, there's no real need for the additional bandwidth.

Other than the card, MSI tosses in the required cables, including a 7' FM radio antenna, and an AV In breakout box. The box is for input only, and supports S-Video, composite and composite L/R audio. Again, since HD is not supported, so you will not find any component video connections with this product.

A pearl white remote is included with the package, and requires two AAA batteries (included) for operation. The remote is well featured, and offers a number of functions outside of changing channels. You can browse TV channels, pictures, change DVD chapters and radio stations with all the buttons. In TV mode, the remote can also time-shift, not unlike a TiVO. The remote's receiver plugs right into a free USB port and has an effective range of sixty feet, though line of sight works best with this product.

16MB of ram is packed into the MSI Theater 550PRO, and assists in the onboard MPEG-2 encoding. This should make the card more responsive (faster) as it can cache some of the video information rather than passing all of it through the PCI bus.

The Theater 550 Pro chip is the star of the show. ATI has squeezed an audio/video decoder, MPEG-2 encoder, hardware 3D comb filter, hardware noise reduction, digital inter-frequency demodulation and digital audio processing. All of the video processing is done on the one chip, so overhead is cut, and performance is increased. Here's a recap from our TV Wonder Elite review:

Video Decoder
The chip features a 12-bit video decoder, which offers more precise video capture (analog to digital conversion) and outputs more realistic colours.

3D Comb Filter
The Theater 550 Pro supports a 3D motion adaptive comb filter, which supports both NTSC and PAL standards. The filter built into the Theater 550 Pro is based off of the filter ATI uses in Sony televisions, so true CE quality and technology is being transferred to your computer. The 3D comb filter is used on low motion scenes. Examples of these are still pictures, slow moving video or static items like the broadcaster's logo. Usually the 2D filter was used to separate the luminance and chrominance components of the TV signal. This can cause color artifacts around the edges or a dot-crawl effect. The 3D filter analyzes 5 lines of video in the current frame, and also scans ahead 1 frame to analyze the video to see if the picture changes.

2D Comb Filter
A 5-line 2D comb filter is used on the high motion video feeds. A 5-line filter ensures that every pixel is separated with a high degree of accuracy. As a comparison, most other products only use a 3 or 4 line filter. This basically means that the competition is always at least 1 line behind when filter the displayed image. By reading ahead 5-lines before the video is processed, the comb filter can detect similarities in the lines and determine how to separate the signal in the most efficient manner.

Adaptive Comb Filter
Having high quality 2D and 3D comb filters is good, but knowing when to use them is better. This is where the adaptive comb filtering comes into play, the Theater 550 uses a per-pixel algorithm to ensure the best filtering method is applied for each pixel.

Audio/Video Synchronization
Most capture cards on the market today utilize a loop-back cable for the audio stream. Not only is this a hassle, but it is also a cause of a de-synched audio/video stream. ATI have solved this by processing the audio digitally. All audio and video is processed simultaneously and is time stamped to ensure constant matching. All audio is processed through the Theater 550 Pro, digitized with a 12-bit analog to digital converter and sent to the sound card internally.

Automatic Gain Control
Automatic gain control is a system in which the video stream is smoothed of any major fluctuations in signal strength or in brightness or intensity of the light displayed. These differences are often evident on channel changes, where the screen will become extremely bright. The Theater 550 Pro has an advanced AGC algorithm which smoothes out these fluctuations.

Full Frame Rate Recording
The Theater 550 Pro is capable of full onboard MPEG-2 encoding. To accomplish this without the downside of dropped frames, ATI has included 16MB of memory on board the card. This memory gives the card the ability to handle MPEG encoding at up to 15 Mbps. All of these operations occur on a DSP core, so software updated cans be releases to improve some aspects of the video quality and performance. With the encoding being done onboard, the system utilization is greatly reduced, allowing you to use your system without fear of losing quality in your video stream.

Noise Reduction
Noise/snow can be seen in lower quality signals, or video streams. The Theater 550 Pro contains advanced dedicated algorithms which search for a variety of noise in the signal and cancels it out. This is also done on-chip, to reduce CPU utilization.

3:2 Pulldown Support
3:2 pulldown is the process where film content (filmed at 24 fps) is transformed into NTSC analog video (30 fps). Computer monitors generally have a refresh rate of at least 60 Hz, meaning the screen is refreshed at least 60 times a second. With film content running at 24 fps and your monitor refreshing at least 60 times a second a mismatch can occur between the video frame and the display. To avoid this, the Theater 550 Pro uses the 3:2 pulldown, where the frame rate is changed from 24 fps to 30 fps to avoid this mismatch.

The RF modulator TV tuner is what allows you to actually watch TV and is much smaller than ATI's previous generation TV tuner. The smaller size saves on PCB space as well as running much cooler. Given the lack of heatsinks on the card, the MSI Theater 550PRO puts out negligible heat and should not be an issue in even the most crammed of spaces.

Moving from left to right, your input and output options are as follows: Cable TV In (COAX), the FM Radio connection, and the AV In connector for the breakout box we've covered earlier. Overall, the MSI Theater 550PRO supports 3 AV In options. These connections are not just for TV though as you can plug in a variety of devices such as camcorders, DVD players or other video devices that use the above connections.

NEXT