On Wed, 2009-10-07 at 19:18 -0500, Chuck Cole wrote: > > There is a magical piece of coax with multiple signals on it, they could > > be NTSC, PAL, HDTV, FM, AM, etc. utilizing one of many "channel plans". > > > > The TV tuner card is connected to the coax and is capable of providing a > > digital representation of various analog signals, most importantly in > > this case, NTSC. > > He never said any of that was within his question. THAT was part of my inquiry. Because it wasn't necessary, people with experience using VLC with Video4Linux knew exactly what he meant. > > To tune into a *channel*, you must tell the TV tuner card (and thus, > > VLC) what *frequency* to tune. This value is expressed in kilohertz > > because that is the resolution a lot of 'tuner cards', which Video4Linux > > supports, are capable of. > > Mine are already channelized and frequency is not explicit. Your *software*, the application actually talking to the drivers, is specifying a frequency for the drivers. It's using a channel map to determine which frequency 'channel 4' is on. VLC is a little less user friendly (or more tech friendly, depending on how you view it) and doesn't mess around with channel maps. VLC requires that you specify a frequency for any tuner input, it does not accept channel names/numbers. You must select the tuner, broadcasting standard (PAL/NTSC/SECAM/etc) and the analog frequency that you wish to view. > Further, tuners and analog frequency are not within VLC as was > originally the ONLY context. They are absolutely *configured* within VLC. If you meant "VLC is not decoding the raw analog data" I think that is extremely obvious to anyone on this list. > The analog signals have that capability, but the digital VLC interface of this question does not have anything but digital data. And since the output of the TV tuner card is simply a digitized signal, it also has those sub channels. Again, nobody said they built an analog computer and ported VLC to it. > Mine select TV channel numbers and their drivers do the rest. That is 100% digital and never touches analog frequencies except by > the way chips in the tuners translate digital commands to tuner parameters within those chips. No. The drivers nor the hardware have any idea what 'channel 4' is. If you use DScaler (a free windows TV tuner card application) you'll notice that it too is using specific frequencies (not channel names) with the same drivers. Just because you're not having to type in the frequency doesn't mean the software isn't doing it for you. > Didin't ask your opinion of that. He mentioned very low kilohertz for some reason when the much higher megahertz range seemed more > relevant. Yu could try reading the context and threads of this before pontificating. I read the entire thread multiple times, he said "channel 13 is 211.25 mHz, or 211250 kHz" that is absolutely correct for "Standard" cable and Broadcast NTSC. It's not "very low" and it's the exact same frequency no matter if he specified it in terahertz or hertz. You do realize that 211.25MHz is the same as 211,250 KHz, which is the same as 211,250,000 Hz right? > > "No: frequency selection in that is ONLY by choosing digital data, but > > not handling actual analog signals in any direct way. It's > > only a digital data format issue, and the data would be in some psuedo-code. Frequency per se is not an issue, but > > digital encoding > > format for that data type or the data format to read brand and model of tuner would be relevant." > > > > I hope you realize how incredibly ignorant this statement was by now. > > Not ignorant, it's 100% accurate for what VLC itself does, and THAT was the question. It is not a "digital data format issue" and there is no "pseudo-code". The frequency *is* the issue as he was trying to tune into a specific channel and needed to know which frequency to configure VLC to tune. I suspect I've done a great deal more work with TV tuner cards, drivers, and the software that users actually see than you have. If you're going to try to be pedantic about something on a public mailing list, try choosing something you can speak intelligently about.