• Get involved.
    We want your input!
    Apply for Membership and join the conversations about everything related to broadcasting.

    After we receive your registration, a moderator will review it. After your registration is approved, you will be permitted to post.
    If you use a disposable or false email address, your registration will be rejected.

    After your membership is approved, please take a minute to tell us a little bit about yourself.
    https://www.radiodiscussions.com/forums/introduce-yourself.1088/

    Thanks in advance and have fun!
    RadioDiscussions Administrators

DTV infomation page?

J

jras20

Is there a good infmation web site that will tell how DTV can split off of one channel to diffrent channels? I'm trying to explain to my Uncle on how it works, I can argue to him till I am blue in the face, and he still wont understand that it is that same channel frequency, but is splitted to a diffrent channel.
 
there used to be a site named tvradioworld.com, that had the main tv channel with thier digital channels with it.
i just checked it and now it has changed to just radio stations only.
 
jras20 said:
Is there a good infmation web site that will tell how DTV can split off of one channel to diffrent channels? I'm trying to explain to my Uncle on how it works, I can argue to him till I am blue in the face, and he still wont understand that it is that same channel frequency, but is splitted to a diffrent channel.
Click to expand...

Its all in one digital stream...same as all the sat channels from one transponder carrying all those channels...
You can have two HD channels in one DTV assignment...if he understands about TDM telephony (ISDN, etc), then he should be able to grasp HDTV and subchannels. Its the same for DS0s as for DTV subchannels. Its all in the bit stream...the TV knows what is what...(well its told by the stream what is what ;)=
Remember, what CHANNEL number you see is NOT always the real TV channel they are on...I have 4,6,12 in my area on 40, 21 and 50 respectively with their digitals...and later it will be 40, 21, and back to 12 for the 3rd one! BUT the DTVs all show 4-1, 6-1 and 12-1 now....but thats not technically correct
 
jras20 said:
Is there a good infmation web site that will tell how DTV can split off of one channel to diffrent channels? I'm trying to explain to my Uncle on how it works, I can argue to him till I am blue in the face, and he still wont understand that it is that same channel frequency, but is splitted to a diffrent channel.
Click to expand...

- The video and audio of each channel is converted to a series of numbers, representing the displacement of air in the case of audio, or the brightness of a spot in the case of video.

- The numbers corresponding to each channel are assembled into a stream.

- Each stream is sliced into packets of 188 numbers. A "protocol ID" (PID) is attached to each block, indicating what the numbers in that block are - 0041 = Telemundo audio, 0034 = NBC video, 0051 = Weather Plus audio, whatever.

- PSIP "metadata" is attached, telling your TV what packets go with what channel, and what to tell you, the viewer, that channel is. PSIP metadata gets its own PID and is also transmitted in 188-number packets.

- Each data packet is broadcast as soon as there's an available gap in the transmission stream.

- Your TV receives the data packets.

- If you've selected 4-1 (NBC) on your TV, then your TV looks in the PSIP and finds the video is on PID 0034 and the audio on PID 0031. It routes any packets on 0034 to be decoded as video, and those on 0031 to be decoded as audio. Everything else is ignored.

- If you change to 4-2 (Telemundo), then it reads the video on 0044; the audio on 0041; and everything else is ignored.
 
Status
This thread has been closed due to inactivity. You can create a new thread to discuss this topic.


Back
Top Bottom