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Old 01-31-2013, 03:21 PM
 
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Quote:
Originally Posted by southbound_295 View Post
The article says that it's listening for inaudible tones. Those can be incorporated on a frame by frame basis. ....
It doesn't work like this with digital TV.

With digital TV, reconstruction of the video frames has nothing to do with the reconstruction of the sound as the sound data is separate from the video data and isn't tied to to the frames. Instead timestamps are used and the spec allows a deviation of +15ms to -45ms. It's more like a a video projector with no sound and a separate tape player running with the sound on it. Of course you have to keep them synced.

It is the responsibility of the receiver to take the selected separately sent audio stream (there can be up to 5 different ones) and reconstruct the the sound at the appropriate time with the displayed video. This is why, sometimes, there can be sync problems with the sound not matching the picture. Likewise with ATSC there can be several CC streams sent too. In both cases this allows the user to easily pick different languages if they are present.

They could of course add markers to the stream, but it's my guess they don't do this.
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Old 01-31-2013, 03:37 PM
 
Location: The place where the road & the sky collide
21,888 posts, read 27,162,098 times
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Quote:
Originally Posted by frewroad View Post
It doesn't work like this with digital TV.

With digital TV, reconstruction of the video frames has nothing to do with the reconstruction of the sound as the sound data is separate from the video data and isn't tied to to the frames. Instead timestamps are used and the spec allows a deviation of +15ms to -45ms. It's more like a a video projector with no sound and a separate tape player running with the sound on it. Of course you have to keep them synced.

It is the responsibility of the receiver to take the selected separately sent audio stream (there can be up to 5 different ones) and reconstruct the the sound at the appropriate time with the displayed video. This is why, sometimes, there can be sync problems with the sound not matching the picture. Likewise with ATSC there can be several CC streams sent too. In both cases this allows the user to easily pick different languages if they are present.

They could of course add markers to the stream, but it's my guess they don't do this.
The audio track was separate in analog. the two are tied together, but separate.
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Old 01-31-2013, 03:38 PM
 
5,150 posts, read 6,643,140 times
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Quote:
Originally Posted by frewroad View Post
It doesn't work like this with digital TV.

With digital TV, reconstruction of the video frames has nothing to do with the reconstruction of the sound as the sound data is separate from the video data and isn't tied to to the frames. Instead timestamps are used and the spec allows a deviation of +15ms to -45ms. It's more like a a video projector with no sound and a separate tape player running with the sound on it. Of course you have to keep them synced.

It is the responsibility of the receiver to take the selected separately sent audio stream (there can be up to 5 different ones) and reconstruct the the sound at the appropriate time with the displayed video. This is why, sometimes, there can be sync problems with the sound not matching the picture. Likewise with ATSC there can be several CC streams sent too. In both cases this allows the user to easily pick different languages if they are present.

They could of course add markers to the stream, but it's my guess they don't do this.
Just another way the man is trying to control us with radio waves.

Wegener Network Solutions for Nielsen Rating Information
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Old 01-31-2013, 04:12 PM
 
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Originally Posted by southbound_295 View Post
The audio track was separate in analog. the two are tied together, but separate.
No not really. Sound was transmitted my modulating the TV waveform. Care had to be take as to not have the sound info interfere with the picture.
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Old 01-31-2013, 04:35 PM
 
Location: The place where the road & the sky collide
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Originally Posted by frewroad View Post
No not really. Sound was transmitted my modulating the TV waveform. Care had to be take as to not have the sound info interfere with the picture.
The audio was FM & it was genlocked to the video signal. That was all in the waveform that was broadcast, but it was separated. That's why you could edit audio & video separately. The broadcast signal is a composite.
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Old 01-31-2013, 05:18 PM
 
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Originally Posted by southbound_295 View Post
The audio was FM & it was genlocked to the video signal. That was all in the waveform that was broadcast, but it was separated. .
Sure, so you could use a filter to separate out the electrical signal representing the audio and then amplify it to drive a speaker coil. It was inherently tied to the accompanying video frames. Remember this standard was established in the days of vacuum tubes, discrete passive devices, and no concept at all of digital methods.
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Old 01-31-2013, 05:21 PM
 
Location: The place where the road & the sky collide
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Quote:
Originally Posted by frewroad View Post
Sure, so you could use a filter to separate out the electrical signal representing the audio and then amplify it to drive a speaker coil. It was inherently tied to the accompanying video frames. Remember this standard was established in the days of vacuum tubes, discrete passive devices, and no concept at all of digital methods.
Look, NTSC was a composite signal & was genlocked. ATSC uses genlock as well. You can think whatever you want, but quit trying to make me look like I don't know what I'm talking about. It's unseemly.
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Old 01-31-2013, 05:51 PM
 
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Originally Posted by southbound_295 View Post
You can think whatever you want, but quit trying to make me look like I don't know what I'm talking about. It's unseemly.
I think based on evidence. You first said

"The article says that it's listening for inaudible tones. Those can be incorporated on a frame by frame basis. "

Now you are saying the video is completely separate from the audio. Since audio isn't sent in frames, then you have contradicted yourself. The term "genlock" has no meaning in this discussion.

The point is that frame rate has nothing to do with digital audio and given that, then I'd stick to what I said earlier, I think they are using the term "tone" to keep from getting into a more technical discussion of what they are doing. As I said earlier, any audio these days can be easily be fingerprinted without having to add anything to it.
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Old 01-31-2013, 06:08 PM
 
Location: The place where the road & the sky collide
21,888 posts, read 27,162,098 times
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Quote:
Originally Posted by frewroad View Post
I think based on evidence. You first said

"The article says that it's listening for inaudible tones. Those can be incorporated on a frame by frame basis. "

Now you are saying the video is completely separate from the audio. Since audio isn't sent in frames, then you have contradicted yourself. The term "genlock" has no meaning in this discussion.

The point is that frame rate has nothing to do with digital audio and given that, then I'd stick to what I said earlier, I think they are using the term "tone" to keep from getting into a more technical discussion of what they are doing. As I said earlier, any audio these days can be easily be fingerprinted without having to add anything to it.
It's senseless to discuss this sort of thing with you. I thought that you were being remarkably civil.

It all goes back to the stations shuffling. I worked in the industry as a tech & know the politics. I'm not going to continue this because you just keep trying to make yourself right. Google ATSC genlock.

It all goes back to WCCB. They either have to take the CW, sell the station, or attempt to lure a network to signup for them to be an affiliate, unless they want to be a real, old-fashioned "indy". With a network O & O in the market & metering, it's less likely to get an affiliate agreement other than the CW. I still say, if a network offers to buy them they should sell & buy in another market. They over-played their hand & it's going to cost them. It's unlikely that a network will play ball with them now until they lose Fox & that will lower the value. If they really screw it up, they can drag their feet on the CW & lose that to WHKY
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Old 01-31-2013, 06:15 PM
 
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Quote:
Originally Posted by southbound_295 View Post
I worked in the industry as a tech & know the politics.
I also don't rely on personal accolades and anecdotes. Factual technical information does not depend upon it. It's OK to offer an opinion, I suppose based on this, but arguments like this basically amount to saying "I know more than you". You don't know this because I have not said anything about my background and I just as soon we stay away from those kinds of contests.
" I still say, if a network offers to buy them they should sell & buy in another market. They over-played their hand & it's going to cost them."
WCCB is a family owned business and it always has been. They have been through tough times before when ABC dropped them. It's not for us to say or pass judgment over what the family should or not do. That choice is theres. I have far less issues with WCCB's support for the local community, what their license requires, than I do for corporate owned WSOC & WBTV. As I said about WHKY, money may not be the only motivating factor.

WHKY has some, IMO, serious issues with broadcast quality and coverage. It's my opinion that CW would not wish to go with them as a first choice. They would lose many viewers.
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