Just upgraded from an old analog tv to a Samsung DTV. The first
problem I noticed is the lip sync audio-to-video time delay on NBC's
national digital programs. While analog broadcast has some small time
delay, digital has 2x-3x more delay, making it almost impossible to
watch. Local station in-house digital programming does not have any
more delay than analog, but as soon as they switch to national
programming, the delay goes to hell. ABC & CBS does not have nearly
the delay that NBC has. I brought the problem to the attention of the
local NBC station, but they said & did nothing.
Does anyone else notice the problem, or is it generated by my local
station?

KC

On Fri, 25 Apr 2008 06:14:25 -0700, KC wrote:
Just upgraded from an old analog tv to a Samsung DTV. The first
problem I noticed is the lip sync audio-to-video time delay on NBC's
national digital programs. While analog broadcast has some small time
delay, digital has 2x-3x more delay, making it almost impossible to
watch. Local station in-house digital programming does not have any
more delay than analog, but as soon as they switch to national
programming, the delay goes to hell. ABC & CBS does not have nearly

I might suspect some of each...

I work for a NBC local station, hopefully not yours(grin). We had some
issues locally that kicked in when we installed a character generator to
do severe weather. It put some delay in the video but the
audio went via a different route - ended up being sent before the video.
That doesn't happen in nature and is VERY noticeable! We ended up buying
a audio delay and dialing in 150ms in the other path. Since local
material bypassed the HD character generator, local stuff was fine.

I'm not entirely convinced there isn't a problem in New York too though.
I've seen the lip sync *change* dramatically during a program.

We're in the process of replacing our main control board for HD, which
should keep all the audio and video in the same path & get this side gear
like character generators out of the way. I might expect your local NBC
station (again, hopefully that's not us!) will be taking similar steps. A
lot of stations have had to cut corners to get HD on the air at all
and it's going to take awhile to put together the budget to do HD the way
it should be done. (that new transmitter & antenna weren't cheap, and a
lot of stations have to buy it all twice! - luckily we only had to buy
once...)

"KC" wrote in message
...
Just upgraded from an old analog tv to a Samsung DTV. The first
problem I noticed is the lip sync audio-to-video time delay on NBC's
national digital programs. While analog broadcast has some small time
delay, digital has 2x-3x more delay, making it almost impossible to
watch. Local station in-house digital programming does not have any
more delay than analog, but as soon as they switch to national
programming, the delay goes to hell. ABC & CBS does not have nearly
the delay that NBC has. I brought the problem to the attention of the
local NBC station, but they said & did nothing.
Does anyone else notice the problem, or is it generated by my local
station?

KC

You didnt mention what your A/V setup is, but what source are you using for
your video/audio?

D

On Apr 25, 7:14*pm, "Deke" no wrote:
"KC" wrote in message

...

Just upgraded from an old analog tv to a Samsung DTV. *The first
problem I noticed is the lip sync audio-to-video time delay on NBC's
national digital programs. *While analog broadcast has some small time
delay, digital has 2x-3x more delay, making it almost impossible to
watch. Local station in-house digital programming does not have any
more delay than analog, but as soon as they switch to national
programming, the delay goes to hell. *ABC & CBS does not have nearly
the delay that NBC has. *I brought the problem to the attention of the
local NBC station, but they said & did nothing.
Does anyone else notice the problem, or is it generated by my local
station?

KC

You didnt mention what your A/V setup is, but what source are you using for
your video/audio?

D

The same problem exists OTA or cable. Input is via the rf connector.

KC

On Apr 25, 12:50*pm, Doug Smith W9WI wrote:
On Fri, 25 Apr 2008 06:14:25 -0700, KC wrote:
Just upgraded from an old analog tv to a Samsung DTV. *The first
problem I noticed is the lip sync audio-to-video time delay on NBC's
national digital programs. *While analog broadcast has some small time
delay, digital has 2x-3x more delay, making it almost impossible to
watch. Local station in-house digital programming does not have any
more delay than analog, but as soon as they switch to national
programming, the delay goes to hell. *ABC & CBS does not have nearly

I might suspect some of each...

I work for a NBC local station, hopefully not yours(grin). *We had some
issues locally that kicked in when we installed a character generator to
do severe weather. *It put some delay in the video but the
audio went via a different route - ended up being sent before the video.
That doesn't happen in nature and is VERY noticeable! *We ended up buying
a audio delay and dialing in 150ms in the other path. *Since local
material bypassed the HD character generator, local stuff was fine.

I'm not entirely convinced there isn't a problem in New York too though.
I've seen the lip sync *change* dramatically during a program.

We're in the process of replacing our main control board for HD, which
should keep all the audio and video in the same path & get this side gear
like character generators out of the way. *I might expect your local NBC
station (again, hopefully that's not us!) will be taking similar steps. *A
lot of stations have had to cut corners to get HD on the air at all
and it's going to take awhile to put together the budget to do HD the way
it should be done. *(that new transmitter & antenna weren't cheap, and a
lot of stations have to buy it all twice! - luckily we only had to buy
once...)

Thanks Doug. A very informative reply. Sounds very similar to what I'm
seeing. I forwarded it to the local station engineer.

KC

In article
,
KC wrote:
Just upgraded from an old analog tv to a Samsung DTV. The first
problem I noticed is the lip sync audio-to-video time delay on NBC's
national digital programs. While analog broadcast has some small time
delay, digital has 2x-3x more delay, making it almost impossible to
watch. Local station in-house digital programming does not have any
more delay than analog, but as soon as they switch to national
programming, the delay goes to hell. ABC & CBS does not have nearly
the delay that NBC has. I brought the problem to the attention of the
local NBC station, but they said & did nothing.
Does anyone else notice the problem, or is it generated by my local
station?

Analogue should have no noticeable delay in its basic form. If it has it's
down to some extra processing, usually in the video. And the broadcaster
*should* compensate for this.

However, most modern TVs add in some video processing or have an inherent
video delay by their nature. Better ones delay the audio to retain sync.
Can be a problem where a CRT set used mainly as a monitor with an AV
system is replaced with a newer type - as I discovered with my DLP setup.
Ie the sound came direct from the AV setup which also switched the picture
source.

However, you appear to have a problem with only one channel which rules
out this. I'd suggest you ask neighbours if they have the same problem as
it could be a funny with the tuner in your set. The reason I say this is I
have several DTV tuners here and they all produce slightly different
delays to the sound (ignoring that produced by the TV itself) so it is
just possible for this sort of fault on just the one channel - or rather
group of channels.

--
*24 hours in a day ... 24 beers in a case ... coincidence? *

Dave Plowman London SW
To e-mail, change noise into sound.

On Apr 25, 12:50*pm, Doug Smith W9WI wrote:
On Fri, 25 Apr 2008 06:14:25 -0700, KC wrote:
Just upgraded from an old analog tv to a Samsung DTV. *The first
problem I noticed is the lip sync audio-to-video time delay on NBC's
national digital programs. *While analog broadcast has some small time
delay, digital has 2x-3x more delay, making it almost impossible to
watch. Local station in-house digital programming does not have any
more delay than analog, but as soon as they switch to national
programming, the delay goes to hell. *ABC & CBS does not have nearly

I might suspect some of each...

I work for a NBC local station, hopefully not yours(grin). *We had some
issues locally that kicked in when we installed a character generator to
do severe weather. *It put some delay in the video but the
audio went via a different route - ended up being sent before the video.
That doesn't happen in nature and is VERY noticeable! *We ended up buying
a audio delay and dialing in 150ms in the other path. *Since local
material bypassed the HD character generator, local stuff was fine.

I'm not entirely convinced there isn't a problem in New York too though.
I've seen the lip sync *change* dramatically during a program.

We're in the process of replacing our main control board for HD, which
should keep all the audio and video in the same path & get this side gear
like character generators out of the way. *I might expect your local NBC
station (again, hopefully that's not us!) will be taking similar steps. *A
lot of stations have had to cut corners to get HD on the air at all
and it's going to take awhile to put together the budget to do HD the way
it should be done. *(that new transmitter & antenna weren't cheap, and a
lot of stations have to buy it all twice! - luckily we only had to buy
once...)

I began a dialog with the local NBC station engineer. Here's his
opinion of the problem:

"Part of the problem (foundational) is that SMPTE (creates standards
for television) chose not to include a method to synchronize video and
audio packets in the new digital standards in order to leave more
bandwidth available to improve quality. As a result, there is no way
to exactly re-match video/audio once they are separated from one
another. Networks and stations throughout the country struggle with
this problem and vendors are working hard to develop equipment to help
meet and "hopefully" correct this issue.
My (his) personal position is that SMPTE failed to ensure a standard
that enables video and audio to remain synchronous throughout the
encoding and decoding process. This failure to create a solid
standard now requires each network and station to have to go out and
purchase additional equipment to correct for a flawed standard. We
are building on a cracked foundation."

All that being said, I see a huge national backlash against digital TV
come Feb. '09. A large portion of folks will buy new DTV's, only to
find out they have a nice picture they can't stand to watch because of
lip sync problems. I see congress & the FCC being swamped with
complaints. The whole mess is easily comparable to government "aid"
from the FEMA!!!

KC

In article
,
KC wrote:
I began a dialog with the local NBC station engineer. Here's his
opinion of the problem:

"Part of the problem (foundational) is that SMPTE (creates standards
for television) chose not to include a method to synchronize video and
audio packets in the new digital standards in order to leave more
bandwidth available to improve quality.

I'm not in the US but I'll bet that's ********. Such constraints will be
to pack the maximum number of channels into a given bandwidth thinking the
punters won't notice or care.

--
*"I am " is reportedly the shortest sentence in the English language. *

Dave Plowman London SW
To e-mail, change noise into sound.

Dave Plowman (News) wrote:

In article
,

snip

"Part of the problem (foundational) is that SMPTE (creates standards
for television) chose not to include a method to synchronize video and
audio packets in the new digital standards in order to leave more
bandwidth available to improve quality.


I'm not in the US but I'll bet that's ********. Such constraints will be
to pack the maximum number of channels into a given bandwidth thinking the
punters won't notice or care.

Exactly. Those despicable and disingenuous DTV transition PSAs (or are
they paid spots?) drive me nuts and ought to be challenged since they
represent government propaganda, declaring that 'digital is better'
and 'better picture' and all sorts of other unctuous claims, instead
of making a factual declaration that the spectrum space is being
reclaimed for Homeland Security and private auctions and alerting
the populace dependent on OTA reception to the deadline without the
dog and pony show.

Michael