| Author |
Message |
Richard Crowley
Guest
|
 Posted:
Sun Oct 02, 2005 2:09 am Post subject:
Re: What is the latest word on Audio Drift in digitizing vid |
|
|
blackburst wrote ...
| Quote: | Well, I do have several credible cases of such drift when dubbing. And
I work in a TV station and teach TV production in a college, so I'm no
neophyte.
|
To be sure, there are cases of audio drift. But I have never seen any
credible evidence that it is due to DV audio being "unlocked". From
what I have seen here, it is almost always a problem with the capture
process, primarily using a separate sound card with completely
unsynchronized sampling.
|
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 |
blackburst@aol.com
Guest
|
| Posted:
Sun Oct 02, 2005 6:30 pm Post subject:
Re: What is the latest word on Audio Drift in digitizing vid |
|
|
Richard Crowley wrote:
| Quote: | blackburst wrote ...
Well, I do have several credible cases of such drift when dubbing. And
I work in a TV station and teach TV production in a college, so I'm no
neophyte.
To be sure, there are cases of audio drift. But I have never seen any
credible evidence that it is due to DV audio being "unlocked". From
what I have seen here, it is almost always a problem with the capture
process, primarily using a separate sound card with completely
unsynchronized sampling.
From Sony DSR-45 manual (a deck which plays/records both DV & DVCAM),
page 101: |
"There are two modes for audio recording: Lock mode and Unlock mode. In
Lock mode, the sampling frequencies of audio and video are
synchronized. In Unlock mode, which the consumer DV format adopts, the
two sampling frequencies are independent. The lock mode maintains high
compatibility with the higher formats (DVCAM) and is more effective
than the unlock mode in digital processing and smooth transition during
audio editing."
The accompanying chart lists DVCAM as Lock mode and DV as Unlock mode. |
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Richard Crowley
Guest
|
| Posted:
Sun Oct 02, 2005 6:49 pm Post subject:
Re: What is the latest word on Audio Drift in digitizing vid |
|
|
blackburst wrote ...
| Quote: | From Sony DSR-45 manual (a deck which plays/records both DV
& DVCAM), page 101:
"There are two modes for audio recording: Lock mode and Unlock mode.
In Lock mode, the sampling frequencies of audio and video are
synchronized. In Unlock mode, which the consumer DV format adopts, the
two sampling frequencies are independent. The lock mode maintains high
compatibility with the higher formats (DVCAM) and is more effective
than the unlock mode in digital processing and smooth transition
during
audio editing."
The accompanying chart lists DVCAM as Lock mode and DV as Unlock mode.
|
No dispute about what "locked" vs. "unlocked" means.
The confusion seems to be that we're assuming that "unlocked"
implies "audio drift" which it does not. Anyone can prove this
by simply playing back any DV tape.
Note that your quote only speaks of "smooth transiton during
audio editing" as a benefit of "locked". No mention of drift.
In practice I have never encountered "unsmooth transitions"
during editing DV shots, and I've never heard of anyone here
who experienced such a thing either. |
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|
|
Pat Horridge
Guest
|
| Posted:
Mon Oct 03, 2005 4:23 pm Post subject:
Re: What is the latest word on Audio Drift in digitizing vid |
|
|
"Richard Crowley" <rcrowley@xpr7t.net> wrote in message
news:11jvpat22ckffff@corp.supernews.com...
| Quote: | blackburst wrote ...
From Sony DSR-45 manual (a deck which plays/records both DV
& DVCAM), page 101:
"There are two modes for audio recording: Lock mode and Unlock mode.
In Lock mode, the sampling frequencies of audio and video are
synchronized. In Unlock mode, which the consumer DV format adopts, the
two sampling frequencies are independent. The lock mode maintains high
compatibility with the higher formats (DVCAM) and is more effective
than the unlock mode in digital processing and smooth transition during
audio editing."
The accompanying chart lists DVCAM as Lock mode and DV as Unlock mode.
No dispute about what "locked" vs. "unlocked" means.
The confusion seems to be that we're assuming that "unlocked"
implies "audio drift" which it does not. Anyone can prove this
by simply playing back any DV tape.
Note that your quote only speaks of "smooth transiton during
audio editing" as a benefit of "locked". No mention of drift.
In practice I have never encountered "unsmooth transitions"
during editing DV shots, and I've never heard of anyone here
who experienced such a thing either.
Quite. |
I seem to remeber that even in unlocked mode the audio sync is constrained
to a window of drift and that's measured in samples which is fractions of a
frame.
We use DVCam and DV here a lot and never had a problem with sync that wasn't
tracked to a problem elsewhere in post. |
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blackburst@aol.com
Guest
|
| Posted:
Mon Oct 03, 2005 6:46 pm Post subject:
Re: What is the latest word on Audio Drift in digitizing vid |
|
|
Again and again I hear anecdotal accounts that you've never experienced
out of sync audio from DV, with the implication that it doesn't happen.
I HAVE had several instances of this when dubbing from DV to DVD. So
maybe the problems are with DVD recorders and unlocked audio. You can't
deny that it happens occasionally because it HAS happened to me. And
I've worked in TV for a quarter century.
Pat Horridge wrote:
| Quote: | "Richard Crowley" <rcrowley@xpr7t.net> wrote in message
news:11jvpat22ckffff@corp.supernews.com...
blackburst wrote ...
From Sony DSR-45 manual (a deck which plays/records both DV
& DVCAM), page 101:
"There are two modes for audio recording: Lock mode and Unlock mode.
In Lock mode, the sampling frequencies of audio and video are
synchronized. In Unlock mode, which the consumer DV format adopts, the
two sampling frequencies are independent. The lock mode maintains high
compatibility with the higher formats (DVCAM) and is more effective
than the unlock mode in digital processing and smooth transition during
audio editing."
The accompanying chart lists DVCAM as Lock mode and DV as Unlock mode.
No dispute about what "locked" vs. "unlocked" means.
The confusion seems to be that we're assuming that "unlocked"
implies "audio drift" which it does not. Anyone can prove this
by simply playing back any DV tape.
Note that your quote only speaks of "smooth transiton during
audio editing" as a benefit of "locked". No mention of drift.
In practice I have never encountered "unsmooth transitions"
during editing DV shots, and I've never heard of anyone here
who experienced such a thing either.
Quite.
I seem to remeber that even in unlocked mode the audio sync is constrained
to a window of drift and that's measured in samples which is fractions of a
frame.
We use DVCam and DV here a lot and never had a problem with sync that wasn't
tracked to a problem elsewhere in post. |
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|
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Richard Crowley
Guest
|
| Posted:
Mon Oct 03, 2005 7:49 pm Post subject:
Re: What is the latest word on Audio Drift in digitizing vid |
|
|
blackburst wrote ...
| Quote: | Again and again I hear anecdotal accounts that you've never
experienced
out of sync audio from DV, with the implication that it doesn't
happen.
I HAVE had several instances of this when dubbing from DV to DVD. So
maybe the problems are with DVD recorders and unlocked audio. You
can't
deny that it happens occasionally because it HAS happened to me. And
I've worked in TV for a quarter century.
|
Yes, I have seen exactly the same thing.
But it has never been traced to DV sound being "unlocked".
It is always found to be a problem elsewhere in the chain
(where it could have happened to audio/video from ANY
source).
The connection between "audio drift" and "DV unlocked
audio" just has no credible evidence that anybody here
has ever seen. Dunno why/how you are obsessing on
"DV unlocked audio"? |
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| Back to top |
|
|
Pat Horridge
Guest
|
| Posted:
Mon Oct 03, 2005 9:06 pm Post subject:
Re: What is the latest word on Audio Drift in digitizing vid |
|
|
"Richard Crowley" <rcrowley@xpr7t.net> wrote in message
news:11k2h7pksg5lr65@corp.supernews.com...
| Quote: | blackburst wrote ...
Again and again I hear anecdotal accounts that you've never experienced
out of sync audio from DV, with the implication that it doesn't happen.
I HAVE had several instances of this when dubbing from DV to DVD. So
maybe the problems are with DVD recorders and unlocked audio. You can't
deny that it happens occasionally because it HAS happened to me. And
I've worked in TV for a quarter century.
Yes, I have seen exactly the same thing.
But it has never been traced to DV sound being "unlocked".
It is always found to be a problem elsewhere in the chain
(where it could have happened to audio/video from ANY
source).
The connection between "audio drift" and "DV unlocked
audio" just has no credible evidence that anybody here
has ever seen. Dunno why/how you are obsessing on
"DV unlocked audio"?
I suspect it a similar response to mine the first time I discovered about DV |
audio being unlocked.
Being in the industry for some years now I immediately expected there to be
all sorts of sync issues.
Once I'd investigated and discovered that the unlocked actually means
loosely locked I was less worried and for all the years I've been using DV
in post I've never had an issue with sync related to unlock DV audio. It's
always been another post problem.
There are often issues with DVD recording and audio sync slippage (not here
at VET thank goodness) but it's not always DV related and I'm sure it's not
unlocked audio related. |
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blackburst@aol.com
Guest
|
| Posted:
Mon Oct 03, 2005 9:28 pm Post subject:
Re: What is the latest word on Audio Drift in digitizing vid |
|
|
Richard Crowley wrote:
| Quote: | Yes, I have seen exactly the same thing.
But it has never been traced to DV sound being "unlocked".
It is always found to be a problem elsewhere in the chain
(where it could have happened to audio/video from ANY
source).
The connection between "audio drift" and "DV unlocked
audio" just has no credible evidence that anybody here
has ever seen. Dunno why/how you are obsessing on
"DV unlocked audio"?
|
Well, the originator of the post started with "audio drift", and I have
tried to make dubs from a DV camcorder direct to a standalone DVD
recorder, via both firewire and composite, with NO other equipment in
the chain, and found the audio out of sync.
I thought the Sony unlocked audio quote might be the answer.
I STILL don't have a clue why my dubs lose sync about 1/2 the time. |
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|
|
AnthonyR
Guest
|
| Posted:
Mon Oct 03, 2005 11:45 pm Post subject:
Re: What is the latest word on Audio Drift in digitizing vid |
|
|
<blackburst@aol.com> wrote in message
news:1128356887.648007.123550@f14g2000cwb.googlegroups.com...
| Quote: |
Richard Crowley wrote:
Yes, I have seen exactly the same thing.
But it has never been traced to DV sound being "unlocked".
It is always found to be a problem elsewhere in the chain
(where it could have happened to audio/video from ANY
source).
The connection between "audio drift" and "DV unlocked
audio" just has no credible evidence that anybody here
has ever seen. Dunno why/how you are obsessing on
"DV unlocked audio"?
Well, the originator of the post started with "audio drift", and I have
tried to make dubs from a DV camcorder direct to a standalone DVD
recorder, via both firewire and composite, with NO other equipment in
the chain, and found the audio out of sync.
I thought the Sony unlocked audio quote might be the answer.
I STILL don't have a clue why my dubs lose sync about 1/2 the time.
|
Can you tell me which model dvd standalone you are using?
Perhaps it's a problem with that hardware or firmware?
You can try a google and see if you're not alone using that brand or model
recorder.
Also an inline time base corrector between the two might help, as years ago
that's what
I had to do to get good dvd's out of my early philips standalone dvd
recorder.
I had worse than out of sync audio problems, I use to get audio that would
drift and then quickly try and catch up
crealting a blirp type audio glitch. The TBC eliminated it but I've since
sold that unit and seen newer dvd recorders
selling with built in TBC now as almost standard feature on the good ones.
AnthonyR. |
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| Back to top |
|
|
blackburst@aol.com
Guest
|
| Posted:
Tue Oct 04, 2005 2:02 am Post subject:
Re: What is the latest word on Audio Drift in digitizing vid |
|
|
AnthonyR wrote:
| Quote: | Can you tell me which model dvd standalone you are using?
Perhaps it's a problem with that hardware or firmware?
|
It has happened on several:
Emerson EWR10D4
Go Video VR3930
LiteOn LVW-5005
Sony DVD recorder/VCR combo, number unrecalled
| Quote: |
You can try a google and see if you're not alone using that brand or model
recorder.
Also an inline time base corrector between the two might help, as years ago
that's what
I had to do to get good dvd's out of my early philips standalone dvd
recorder.
I had worse than out of sync audio problems, I use to get audio that would
drift and then quickly try and catch up
crealting a blirp type audio glitch. The TBC eliminated it but I've since
sold that unit and seen newer dvd recorders
selling with built in TBC now as almost standard feature on the good ones.
AnthonyR.
|
Wouldn't a TBC slow down the signal a bit? I hate what some TBCs do to
the signal, and it prevents using firewire. I have a For.A FA-310, and
it really craps things up. I wish they made TBCs without proc amps.
(OTOH, it's a great way to defeat some copy protection schemes!) |
|
| Back to top |
|
|
AnthonyR
Guest
|
| Posted:
Tue Oct 04, 2005 2:21 am Post subject:
Re: What is the latest word on Audio Drift in digitizing vid |
|
|
<blackburst@aol.com> wrote in message
news:1128373332.795991.297420@g49g2000cwa.googlegroups.com...
| Quote: |
AnthonyR wrote:
Can you tell me which model dvd standalone you are using?
Perhaps it's a problem with that hardware or firmware?
It has happened on several:
Emerson EWR10D4
Go Video VR3930
LiteOn LVW-5005
Sony DVD recorder/VCR combo, number unrecalled
I don't believe any of those models have a built in tbc. |
| Quote: |
You can try a google and see if you're not alone using that brand or
model
recorder.
Also an inline time base corrector between the two might help, as years
ago
that's what
I had to do to get good dvd's out of my early philips standalone dvd
recorder.
I had worse than out of sync audio problems, I use to get audio that
would
drift and then quickly try and catch up
crealting a blirp type audio glitch. The TBC eliminated it but I've since
sold that unit and seen newer dvd recorders
selling with built in TBC now as almost standard feature on the good
ones.
AnthonyR.
Wouldn't a TBC slow down the signal a bit? I hate what some TBCs do to
the signal, and it prevents using firewire. I have a For.A FA-310, and
it really craps things up. I wish they made TBCs without proc amps.
(OTOH, it's a great way to defeat some copy protection schemes!)
Well the tbc I had use was a datavideo tbc-1000 I don't believe it has any |
proc-amp features.
And I don't know about slowing down the signal, it accepts audio in as well,
so it might adj for that?
But it had solved my audio problems when I was doing direct to dvd
recording. Of course my audio problems
were on analog tape, but I have had some audio problems from a defective
sony camcorder so I think
possibly it might be your camera itself, try a different one and a fresh
tape and capture to see.
Perhaps the problem is in your camera? Have you tried another model?
And a different source tape? That might help identify your problem.
Good Luck,
AnthonyR. |
|
| Back to top |
|
|
blackburst@aol.com
Guest
|
| Posted:
Tue Oct 04, 2005 6:46 pm Post subject:
Re: What is the latest word on Audio Drift in digitizing vid |
|
|
AnthonyR wrote:
| Quote: | blackburst@aol.com> wrote in message
news:1128373332.795991.297420@g49g2000cwa.googlegroups.com...
AnthonyR wrote:
Can you tell me which model dvd standalone you are using?
Perhaps it's a problem with that hardware or firmware?
It has happened on several:
Emerson EWR10D4
Go Video VR3930
LiteOn LVW-5005
Sony DVD recorder/VCR combo, number unrecalled
I don't believe any of those models have a built in tbc.
You can try a google and see if you're not alone using that brand or
model
recorder.
Also an inline time base corrector between the two might help, as years
ago
that's what
I had to do to get good dvd's out of my early philips standalone dvd
recorder.
I had worse than out of sync audio problems, I use to get audio that
would
drift and then quickly try and catch up
crealting a blirp type audio glitch. The TBC eliminated it but I've since
sold that unit and seen newer dvd recorders
selling with built in TBC now as almost standard feature on the good
ones.
AnthonyR.
Wouldn't a TBC slow down the signal a bit? I hate what some TBCs do to
the signal, and it prevents using firewire. I have a For.A FA-310, and
it really craps things up. I wish they made TBCs without proc amps.
(OTOH, it's a great way to defeat some copy protection schemes!)
Well the tbc I had use was a datavideo tbc-1000 I don't believe it has any
proc-amp features.
And I don't know about slowing down the signal, it accepts audio in as well,
so it might adj for that?
But it had solved my audio problems when I was doing direct to dvd
recording. Of course my audio problems
were on analog tape, but I have had some audio problems from a defective
sony camcorder so I think
possibly it might be your camera itself, try a different one and a fresh
tape and capture to see.
Perhaps the problem is in your camera? Have you tried another model?
And a different source tape? That might help identify your problem.
Good Luck,
AnthonyR.
|
It happened with both my Panasonic PVGS15's from work (3 of them) and
my home Panasonic 3-chip DV.
But I just bought 2 Sony DSR45 DV/DVCAM decks for my studio. I'll let
you know if it happens with them! |
|
| Back to top |
|
|
AnthonyR
Guest
|
| Posted:
Tue Oct 04, 2005 9:56 pm Post subject:
Re: What is the latest word on Audio Drift in digitizing vid |
|
|
<blackburst@aol.com> wrote in message
news:1128433567.515883.254670@g14g2000cwa.googlegroups.com...
| Quote: |
AnthonyR wrote:
blackburst@aol.com> wrote in message
news:1128373332.795991.297420@g49g2000cwa.googlegroups.com...
AnthonyR wrote:
Can you tell me which model dvd standalone you are using?
Perhaps it's a problem with that hardware or firmware?
It has happened on several:
Emerson EWR10D4
Go Video VR3930
LiteOn LVW-5005
Sony DVD recorder/VCR combo, number unrecalled
I don't believe any of those models have a built in tbc.
You can try a google and see if you're not alone using that brand or
model
recorder.
Also an inline time base corrector between the two might help, as
years
ago
that's what
I had to do to get good dvd's out of my early philips standalone dvd
recorder.
I had worse than out of sync audio problems, I use to get audio that
would
drift and then quickly try and catch up
crealting a blirp type audio glitch. The TBC eliminated it but I've
since
sold that unit and seen newer dvd recorders
selling with built in TBC now as almost standard feature on the good
ones.
AnthonyR.
Wouldn't a TBC slow down the signal a bit? I hate what some TBCs do to
the signal, and it prevents using firewire. I have a For.A FA-310, and
it really craps things up. I wish they made TBCs without proc amps.
(OTOH, it's a great way to defeat some copy protection schemes!)
Well the tbc I had use was a datavideo tbc-1000 I don't believe it has
any
proc-amp features.
And I don't know about slowing down the signal, it accepts audio in as
well,
so it might adj for that?
But it had solved my audio problems when I was doing direct to dvd
recording. Of course my audio problems
were on analog tape, but I have had some audio problems from a defective
sony camcorder so I think
possibly it might be your camera itself, try a different one and a fresh
tape and capture to see.
Perhaps the problem is in your camera? Have you tried another model?
And a different source tape? That might help identify your problem.
Good Luck,
AnthonyR.
It happened with both my Panasonic PVGS15's from work (3 of them) and
my home Panasonic 3-chip DV.
But I just bought 2 Sony DSR45 DV/DVCAM decks for my studio. I'll let
you know if it happens with them!
|
OK, but were you playing the same footage (same dv tape) with all 3 cameras?
cause what happenned to me, was a bad camcorder recorded bad audio on dv
tape, which carried over
to any camcorder i played that tape on.
So did you try capturing new material on new tape using another camera and
testing audiio drift on recorder?
Or are you just substituting equiptment using this same dv tape (which might
have the problem recorded on it).
Just an idea!
Good luck,
AnthonyR. |
|
| Back to top |
|
|
Guest
|
| Posted:
Wed Oct 05, 2005 7:45 pm Post subject:
Re: What is the latest word on Audio Drift in digitizing vid |
|
|
No, this has happened several time swith various tapes - NEW tapes. I
keep a tape in the home miniDV to record the family. When it's filled,
I dub to DVD, but I have audio mismatch about 70% of the time.
OCCASIONALLY, there is a break in "control track", if my wife rewound a
tape to look at it and re-cued it, and that is one of the possible
causes. The DVD recorder "burps" when it sees this.
AnthonyR wrote:
| Quote: | blackburst@aol.com> wrote in message
news:1128433567.515883.254670@g14g2000cwa.googlegroups.com...
AnthonyR wrote:
blackburst@aol.com> wrote in message
news:1128373332.795991.297420@g49g2000cwa.googlegroups.com...
AnthonyR wrote:
Can you tell me which model dvd standalone you are using?
Perhaps it's a problem with that hardware or firmware?
It has happened on several:
Emerson EWR10D4
Go Video VR3930
LiteOn LVW-5005
Sony DVD recorder/VCR combo, number unrecalled
I don't believe any of those models have a built in tbc.
You can try a google and see if you're not alone using that brand or
model
recorder.
Also an inline time base corrector between the two might help, as
years
ago
that's what
I had to do to get good dvd's out of my early philips standalone dvd
recorder.
I had worse than out of sync audio problems, I use to get audio that
would
drift and then quickly try and catch up
crealting a blirp type audio glitch. The TBC eliminated it but I've
since
sold that unit and seen newer dvd recorders
selling with built in TBC now as almost standard feature on the good
ones.
AnthonyR.
Wouldn't a TBC slow down the signal a bit? I hate what some TBCs do to
the signal, and it prevents using firewire. I have a For.A FA-310, and
it really craps things up. I wish they made TBCs without proc amps.
(OTOH, it's a great way to defeat some copy protection schemes!)
Well the tbc I had use was a datavideo tbc-1000 I don't believe it has
any
proc-amp features.
And I don't know about slowing down the signal, it accepts audio in as
well,
so it might adj for that?
But it had solved my audio problems when I was doing direct to dvd
recording. Of course my audio problems
were on analog tape, but I have had some audio problems from a defective
sony camcorder so I think
possibly it might be your camera itself, try a different one and a fresh
tape and capture to see.
Perhaps the problem is in your camera? Have you tried another model?
And a different source tape? That might help identify your problem.
Good Luck,
AnthonyR.
It happened with both my Panasonic PVGS15's from work (3 of them) and
my home Panasonic 3-chip DV.
But I just bought 2 Sony DSR45 DV/DVCAM decks for my studio. I'll let
you know if it happens with them!
OK, but were you playing the same footage (same dv tape) with all 3 cameras?
cause what happenned to me, was a bad camcorder recorded bad audio on dv
tape, which carried over
to any camcorder i played that tape on.
So did you try capturing new material on new tape using another camera and
testing audiio drift on recorder?
Or are you just substituting equiptment using this same dv tape (which might
have the problem recorded on it).
Just an idea!
Good luck,
AnthonyR. |
|
|
| Back to top |
|
|
AnthonyR
Guest
|
| Posted:
Wed Oct 05, 2005 9:57 pm Post subject:
Re: What is the latest word on Audio Drift in digitizing vid |
|
|
<blackburst@aol.com> wrote in message
news:1128523522.525990.326400@o13g2000cwo.googlegroups.com...
| Quote: | No, this has happened several time swith various tapes - NEW tapes. I
keep a tape in the home miniDV to record the family. When it's filled,
I dub to DVD, but I have audio mismatch about 70% of the time.
OCCASIONALLY, there is a break in "control track", if my wife rewound a
tape to look at it and re-cued it, and that is one of the possible
causes. The DVD recorder "burps" when it sees this.
Ahh, now we're getting somewhere. yes, this blurp could be the dvd recorder |
getting thrown off
and causing the audio mismatch.
Perhaps, you can try, pre0striping the tape, people use to do it years ago
to avoid such problems in computer editing
software? You know record the miniDV tape completely in one shot with cap on
just to lay down a steady stream of time code.
Then rewind and use the tape as you wish. I believe the original time code
will prevent this disruption of time code when the dvd recorder
encounters blank spots from f/f and rewinds during shooting.
This might help a lot. Good Luck,
AnthonyR. |
|
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