Audio sync problem on ABC News 24 (HD)

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.

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.

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

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

"Franc Zabkar"

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

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.

"Franc Zabkar"

.... Phil

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.

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.

"Stupider than Anyone Else Alive"

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

.... Phil

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.

"Stupider than Anyone Else Alive"

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

"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.

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

What in particular?

Sylvia.

"Stupider Than Anyone Else "

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

.... Phil

"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.

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.

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

Sylvia.