Audio sync problem on ABC News 24 (HD)

I have two LG LCD TVs, one relatively new, the second quite a few years older. Both exhibit temporary audio sync problems when first switching to the channel. The problem usually resolves itself within about 20 seconds, but on one occasion it peristed, on both sets, for two days.

Is this a firmware bug, or is it a transmission anomaly, perhaps due to a weak signal? The video is perfect, and the audio remains in sync until the channel is changed. Sometimes sync can be restored by channel surfing to News 24 from the lower ABC channels.

- Franc Zabkar

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Reply to
Franc Zabkar
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I suggest you have low signal issue, only problem I see is the initial LCD TV startup del;ay before the tuner gets going properly.

Reply to
Grant

It seems highly unlikely to be a weak signal effect.

The audio and video streams have timestamps to show how they're to be synchronized. If these were simply wrong, you'd expect to see lots of complaints.

What may be happening though, is that the ABC24 streams are either not strictly compliant with the standard, or are pushing the limits. This can result in most decoders getting it right, but some, like yours, getting confused.

Of course the problem is that while you're trying to get a solution, what you actually get is a run-around, with the ABC and LG assuming that the other is at fault.

Sylvia.

Reply to
Sylvia Else

On Mon, 12 Nov 2012 19:55:22 +1100, Sylvia Else put finger to keyboard and composed:

My signal is boosted by a masthead amplifier. Analogue reception was OK when boosted, but usually very poor otherwise. The DTV signal strength bar is well into the good section, so I can't believe that signal strength is an issue. Other digital ABC channels have never exhibited this problem.

I'll see what LG has to say. Maybe there are firmware updates. I also have a HD STB that I could try.

- Franc Zabkar

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Reply to
Franc Zabkar

On Mon, 12 Nov 2012 19:55:22 +1100, Sylvia Else put finger to keyboard and composed:

You're right. I rang LG and told them of the problem. It affects my two most recent sets (42LD460 and 37LG30D), but not the older one (32LC7D), so one would think that a firmware update would resolve the issue. The 37LG30D is the worst offender.

LG's customer service acknowledged that a problem existed, but that it was the ABC who were at fault. They claimed that they were currently in communication with the ABC regarding the problem.

- Franc Zabkar

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Reply to
Franc Zabkar

"Franc Zabkar"

** You still live in Shoalhaven, NSW - right ?

TV signals come from Knights Hill ( about 30 kms away to the north ) from well sited towers that have a commanding view of the area. Analogue signals went off the air in June this year and all signals are UHF.

That your analogue signal was very poor until boosted at the antenna and then just " OK " is suspicious - suggests you have unusually long or poor quality co-ax cable installed.

The problem you describe is associated with weak signal conditions or where there is interference and/or ghosting.

With NO broadcast analogue signal to view, it becomes a BIG problem to figure out WTF is going on with TV signals.

The same problem will hit Sydney in about one year.

.... Phil

Reply to
Phil Allison

You need to talk to a good speech therapist or an older experienced teacher in this matter. Almost once a night I hear "that is not synchronised". I don't know what the time accurracy of the time stamps are, but even i can spot it on vaious programs at times on Tv signals.

Reply to
terryc

"Franc Zabkar"

** That sounds like a reference to that two day out of sych event
** That the synch comes good after 20 seconds indicates no inherent problem with the DTV signal, other than it is weak or suffering from ghosting etc. See my other post.

.... Phil

Reply to
Phil Allison

I don't know what you intend by that. The time stamps don't have an accuracy in any real sense. They just specify how the streams should be aligned.

Sylvia.

Reply to
Sylvia Else

Bearing in mind that this is a multiplexed digital data stream, the effects of a poor signal will be data corruption and/or data loss. Either way, one wouldn't expect to see the described behaviour which is that once the sync comes good, it stays good. Rather, one would expect the sync to be lost again from time to time.

Sylvia.

Reply to
Sylvia Else

"Stupider than Anyone Else Alive"

** It is a widely observed reality.

Reality does not give a flying f*ck what fools *expect* it to be.

.... Phil

Reply to
Phil Allison

Few people who see the effect would be capabable of observing that it is caused by a poor signal, so I dispute your claim that it is a widely observed reality.

Sylvia.

Reply to
Sylvia Else

"Stupider than Anyone Else Alive"

** Nonsense.

Fix the weak / ghosty signal on the PARTICULAR channel and problem gone.

Only fools argue from a position of ignorance and that is the only position you have.

.... Phil

Reply to
Phil Allison

"particular" channel?

Franc cites an issue with ABC News 24 (HD), which is only one of the programs to be found multiplexed on the ABC network signal. He appears to have had no problems with any other program on that multiplex.

Sylvia.

Reply to
Sylvia Else

Read the text under it in the article that image is from.

formatting link

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--- news://freenews.netfront.net/ - complaints: news@netfront.net ---
Reply to
Jasen Betts

What in particular?

Sylvia.

Reply to
Sylvia Else

"Stupider Than Anyone Else "

** Well, you can lead a cow to water - but you cannot make her think .....

Moooooooooooo ............

.... Phil

Reply to
Phil Allison

"two different MPEG-TSs can be transmitted at the same time, using a technique called Hierarchical Transmission"...

The diagram does not apper to show that.

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?? 100% natural 

--- news://freenews.netfront.net/ - complaints: news@netfront.net ---
Reply to
Jasen Betts

That's under the heading "Splitter", which is indeed shown on the diagram. The dotted outline appears to be intended to represent its optional nature.

As I've said, it appears that is is not being used, at least in Sydney broadcasts.

Sylvia.

Reply to
Sylvia Else

Fairly typical (on second thoughts, strike "fairly") Phil response that conveys nothing useful.

Sylvia.

Reply to
Sylvia Else

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