4. NTSC/Analog TV Observations

These days, analog TV is something of a walk in the park for circuitry that can handle more demanding HDTV signals and codecs. We observed only very small, very minor differences among the signal that our Scientific Atlanta Explorer 3300 HD set-top box sent directly to our TV set, one picked up through the M780 and played back in real time, and one from a recording. It's something of a challenge to find noisy signals in this environment, but we found our local NOAA weather affiliate (channel 44 in our broadcast area) used a pretty pixilated Doppler weather display that proved telling as we compared direct viewing to viewing through the M780. We noticed a very slight increase in pixel jitter, particularly when the radar sweep gets to the end of its time series and holds that position for 2-3 seconds before backing up and starting over. There was also a small amount of increase in jaggies on titles on stations like MSNBC, Bloomberg, or CNN that make heavy use of scrolling right-to-left text at the bottom of the screen. Overall, however we give the M780 extremely high marks for doing very little to degrade signals for incoming NTSC material from Time Warner cable.

We also ordered a set of test patterns to look at the card's impact on video playback. We connected an external, standalone standard DVD player up to the M780 through the S-Video input, to let the card grab those patterns from a Video CD, then compared them to the patterns that straightforward Video CD playback on the MCE system's DVD drive produced. (We were nonplussed when the vendor sent us a VCD for an item advertised as a "Test Pattern DVD," but an update to our Plextor 716-SA DVD player enabled us to use this somewhat tricky item nevertheless, though we did have to switch DVD players to a cheaper model that would actually play VCDs back.)

This approach let us isolate any differences between the native playback chain (internal DVD player to MCE) compared to the TV card playback chain (external, standalone DVD player to M780 to MCE). Here again, we noticed very, very little difference between the two paths, so little that we are willing to say that the M780 handles analog video without introducing significant noise or distortion of any kind. This is a definite step up from the previous generation, where visible distortion or degradation was occasionally visible, particularly when dealing with noisy or extremely demanding inputs.

Finally, we used the HQV in the same way as our test pattern DVD: internal DVD player to MCE to establish the basis for comparison; external, standalone DVD player to M780 to MCE to see what impact the TV tuner/capture card had on playback. Here again, we observed little or no discernable differences between the two playback chains. The results appear in the following table.