Audio sync problem on ABC News 24 (HD)

[Franc Zabkar]

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
--
Please remove one 'i' from my address when replying by email.

 

[Grant]

On Mon, 12 Nov 2012 09:53:53 +1100, Franc Zabkar <fzabkar@iinternode.on.net> wrote:

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.

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.

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

 

[Sylvia Else]

On 12/11/2012 9:53 AM, Franc Zabkar wrote:

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

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.

 

[Franc Zabkar]

On Mon, 12 Nov 2012 19:55:22 +1100, Sylvia Else
<sylvia@not.at.this.address> put finger to keyboard and composed:

It seems highly unlikely to be a weak signal effect.

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.

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.

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
--
Please remove one 'i' from my address when replying by email.

 

[Franc Zabkar]

On Mon, 12 Nov 2012 19:55:22 +1100, Sylvia Else
<sylvia@not.at.this.address> put finger to keyboard and composed:

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.

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
--
Please remove one 'i' from my address when replying by email.

 

[Phil Allison]

"Franc Zabkar"

It seems highly unlikely to be a weak signal effect.

My signal is boosted by a masthead amplifier. Analogue reception was
OK when boosted, but usually very poor otherwise.

** 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

 

[terryc]

On 12/11/12 19:55, Sylvia Else wrote:

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.

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.

 

[Phil Allison]

"Franc Zabkar"

LG's customer service acknowledged that a problem existed, but that it
was the ABC who were at fault.

** That sounds like a reference to that two day out of sych event

They claimed that they were currently
in communication with the ABC regarding the problem.

** 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

 

[Sylvia Else]

On 13/11/2012 10:38 AM, terryc wrote:

On 12/11/12 19:55, Sylvia Else wrote:

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.

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.

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.

 

[Sylvia Else]

On 13/11/2012 10:41 AM, Phil Allison wrote:

"Franc Zabkar"

LG's customer service acknowledged that a problem existed, but that it
was the ABC who were at fault.

** That sounds like a reference to that two day out of sych event


They claimed that they were currently
in communication with the ABC regarding the problem.


** 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.

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.

 

[Phil Allison]

"Stupider than Anyone Else Alive"

** 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.


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.

** It is a widely observed reality.

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



..... Phil

 

[Sylvia Else]

On 13/11/2012 11:32 AM, Phil Allison wrote:

"Stupider than Anyone Else Alive"

** 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.


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.


** It is a widely observed reality.

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

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.

 

[Phil Allison]

"Stupider than Anyone Else Alive"

** 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.


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.


** It is a widely observed reality.

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


Few people who see the effect would be capabable of observing that it is
caused by a poor signal,

** 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

 

[Sylvia Else]

On 14/11/2012 6:33 PM, Phil Allison wrote:

"Stupider than Anyone Else Alive"

** 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.


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.


** It is a widely observed reality.

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


Few people who see the effect would be capabable of observing that it is
caused by a poor signal,


** Nonsense.

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

"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.

 

[Phil Allison]

"Stupider than Anyone Else Alive"

** 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.


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.


** It is a widely observed reality.

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


Few people who see the effect would be capabable of observing that it is
caused by a poor signal,


** Nonsense.

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

"particular" channel?

** Yep.

Signal strength and interference effects like ghosting and EMI vary widely
from one channel to another.

Franc cites ..

** Not relevant to the topic.

BTW: Franc is a bullshitting idiot.



.... Phil

 

[Sylvia Else]

On 14/11/2012 6:52 PM, Phil Allison wrote:

"Stupider than Anyone Else Alive"

** 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.


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.


** It is a widely observed reality.

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


Few people who see the effect would be capabable of observing that it is
caused by a poor signal,


** Nonsense.

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

"particular" channel?

** Yep.

Signal strength and interference effects like ghosting and EMI vary widely
from one channel to another.

ABC1, ABC2 and ABC24 [*] are all transmitted as part of a SINGLE bit
stream. There is no conceivable way that signal strength and
interference effects could impact on ABC24 but not on ABC1 and ACB2.

Sylvia.

[*] And some other stuff.

 

[Phil Allison]

"Stupider than Anyone Else Alive"

are all transmitted as part of a SINGLE bit
stream.

** Absolute crap !!!!!!!

FFS read up on how Australian DTV really works.

There is no conceivable way that signal strength and interference effects
could impact on ABC24 but not on ABC1 and ACB2.

** Utter garbage, the HD signal from ABC24 has a much higher data rate for
starters.


As per fucking USUAL you have over snipped and ignored two most important
facts:

Fact #1

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

Fact #2

" Franc is a bullshitting idiot."

Plus the over riding fact that YOU are a know nothing, raving nut case
bitch.

FOAD.



.... Phil

 

[Sylvia Else]

On 14/11/2012 11:55 PM, Phil Allison wrote:

"Stupider than Anyone Else Alive"

ABC1, ABC2 and ABC24 [*] are all transmitted as part of a SINGLE bit
stream.

** Absolute crap !!!!!!!

FFS read up on how Australian DTV really works.

I did. A good while back. It's you who have a flawed understanding.

There is no conceivable way that signal strength and interference effects
could impact on ABC24 but not on ABC1 and ACB2.


** Utter garbage, the HD signal from ABC24 has a much higher data rate for
starters.

More of the bits in the single bit stream are allocated to ABC24. So it
has a higher *average* bit rate. But the bits for the other channels
*when they are arriving* do so at the same rate. Since fewer of then are
allocated to those channels, those channels have a lower *average* bit rate.

Sylvia.

 

[Phil Allison]

"Stupider than Anyone Else Alive"

ABC1, ABC2 and ABC24 [*] are all transmitted as part of a SINGLE bit
stream.

** Absolute crap !!!!!!!

FFS read up on how Australian DTV really works.

I did. A good while back.

** Its NOT a single bit stream in this country.

Fuck off.


..... Phil

 

[Franc Zabkar]

On Wed, 14 Nov 2012 21:24:44 +1100, Sylvia Else
<sylvia@not.at.this.address> put finger to keyboard and composed:

are all transmitted as part of a SINGLE bit
stream. There is no conceivable way that signal strength and
interference effects could impact on ABC24 but not on ABC1 and ACB2.

Thanks very much for that insight. I found the following article.

"What is the difference bewteen a Digital and a RF TV channel?"
http://vk3khb.gak.net.au/atv/dtv-chnls.html

====================================================================
In the old system one TV channel equated to one "Radio Frequency" RF.
In the new system many TV channels share the one Radio Frequency. As
many Digital TV channels can effectively hide inside one RF TV channel
some additional addressing must be used. These Digital TV channels are
allocated as "Logical Channel Numbers" or "Digital Streams".
====================================================================

Logical Channel Number 2 (RF Channel #12) is assigned to the ABC. In
Melbourne the single frequency is 226.5 Mhz.

The one bit stream incorporates all the following channels:

02 ABC 1
21 ABC1
22 ABC2/4
23 ABC3
24 ABC NEWS
200 ABC DiG Radio
201 ABC DiG Jazz

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.