MDOC

I'm an ex-engineer in satellite communications. I would like to know details in how DTV channels are modulated and demodulated, the whole works. Or maybe you can steer me somewhere. Thanks...

cowboyup4christ

The best place to start would be to talk with one of the engineers from your local broadcaster they would have that information

MDOC

If you're up 4 him, so am I. Thanks.

divxhacker

Currently, DTV transmitters use an MPEG-2 audio/video format, and the converter boxes convert them to NTSC video.

Some converter boxes use hardware rendering chips, where others use software rendering chips. Hardware rendering seems to work best, depending on how the chips are used by the computer controller.

Some DTV tuners tell you the dimensions of the video stream, but they don't say much about the bitrate of the video or audio streams. The bitrates differ between channels, depending on the broadcaster's encoding hardware, and their settings for each channel. Channels with more action tend to require a higher bitrate to avoid looking ugly.

There is something interesting I am noticing in the lineup here in L.A. The broadcaster TBN (Trinity Broadcasting Network) is running all its channels at 50% strength for some reason, but the quality is always at 100%. None of the other channels are coming in that weak - they are all at 100% strength.