Discussion:
What's the best way to move forward from DV tape?
(too old to reply)
Peter
2011-07-09 18:19:52 UTC
Permalink
I have about 50 DV tapes, dating back to 1991.

The earliest of those are actually ex Hi-8 tapes which I copied to DV
tapes, by linking a now-gone Hi-8 camcorder to a Sony PC-100.

Now I use a Sony HDR-HC1E which is great but is big and heavy.

Nowadays, DV tape is dead.

I am happy to keep the DV tapes in a safe because I know that high
coercivity magnetic media lasts for many years. Tape is still used for
serious data archiving in businesses. I use DDS4 at work and DLT at
home.

But no new camcorders record to DV, and anyway DV is a hassle for many
purposes where you want unattended recording because the tape fills up
after 1 hour, and the only way round that is to use the camera in a
"webcam" mode (or shop demo mode if you like) whereby one feeds its
composite audio output to e.g. a laptop where the data is recorded to
some piece of software which writes it to a hard disk. And for this to
work, mains power needs to be provided; if one uses the battery then
the camera shuts down after some minutes.

The best replacement for the HC1E appears to be one of these
http://www.parkcameras.com/18746/Sony-HDR-CX700-HD-Flash-Camcorder.html

but obviously it requires the data to be transferred out periodically,
and stored somewhere safe.

Then I need to transfer all those DV tapes to some new format, because
the HC1E will be sold on Ebay.

1) What is the simplest way to transfer the DV tapes to a PC,
losslessly, to some standard format? For PAL DV tapes it will be the
MJPEG DV format, and for the HD DV tapes it will be MPEG.

2) What is the best way to store the data afterwards? I do not believe
DVDs are the long term answer (20-30 years). Some may be OK but they
are unproven.

I store videos as they were taken, with no editing. To produce short
movies I have usee Pinnacle (buggy crap), P/Elements (buggy crap), and
now have Vegas 11 which seems to work. But it is the long term storage
I am interested in.

Maybe the best way will be to transfer (losslessly) the stuff to a PC
and back it up to my DLT tape and take that offsite.

Any suggestions appreciated :)

(I need to check that CX700 has MANUAL audio level control for the
external mike input, which I need for some applications like filming
in a light aircraft. The HC1E has this, and it is very rare in
consumer cams)
David Ruether
2011-07-09 20:44:02 UTC
Permalink
Post by Peter
I have about 50 DV tapes, dating back to 1991.
The earliest of those are actually ex Hi-8 tapes which I copied to DV
tapes, by linking a now-gone Hi-8 camcorder to a Sony PC-100.
Now I use a Sony HDR-HC1E which is great but is big and heavy.
Nowadays, DV tape is dead.
I am happy to keep the DV tapes in a safe because I know that high
coercivity magnetic media lasts for many years. Tape is still used for
serious data archiving in businesses. I use DDS4 at work and DLT at
home.
But no new camcorders record to DV, and anyway DV is a hassle for many
purposes where you want unattended recording because the tape fills up
after 1 hour, and the only way round that is to use the camera in a
"webcam" mode (or shop demo mode if you like) whereby one feeds its
composite audio output to e.g. a laptop where the data is recorded to
some piece of software which writes it to a hard disk. And for this to
work, mains power needs to be provided; if one uses the battery then
the camera shuts down after some minutes.
The best replacement for the HC1E appears to be one of these
http://www.parkcameras.com/18746/Sony-HDR-CX700-HD-Flash-Camcorder.html
but obviously it requires the data to be transferred out periodically,
and stored somewhere safe.
Then I need to transfer all those DV tapes to some new format, because
the HC1E will be sold on Ebay.
1) What is the simplest way to transfer the DV tapes to a PC,
losslessly, to some standard format? For PAL DV tapes it will be the
MJPEG DV format, and for the HD DV tapes it will be MPEG.
2) What is the best way to store the data afterwards? I do not believe
DVDs are the long term answer (20-30 years). Some may be OK but they
are unproven.
I store videos as they were taken, with no editing. To produce short
movies I have usee Pinnacle (buggy crap), P/Elements (buggy crap), and
now have Vegas 11 which seems to work. But it is the long term storage
I am interested in.
Maybe the best way will be to transfer (losslessly) the stuff to a PC
and back it up to my DLT tape and take that offsite.
Any suggestions appreciated :)
(I need to check that CX700 has MANUAL audio level control for the
external mike input, which I need for some applications like filming
in a light aircraft. The HC1E has this, and it is very rare in
consumer cams)
My solution to this is to keep two low-use Sony Mini-DV
camcorders (I have about 300 tapes). Alternatives are
to buy a couple of low-use cheap camcorders to use as
decks (I prefer Sony for their generally excellent head
alignment) or to transfer the material to the computer
by FireWire and copy the results to multiple hard-drives.
I also would not store the material on DVDs, nor would I
transcode the files to anything else until after editing.
--DR
Frank
2011-07-09 20:58:30 UTC
Permalink
On Sat, 09 Jul 2011 19:19:52 +0100, in 'rec.video.production',
in article <What's the best way to move forward from DV tape?>,
Post by Peter
I have about 50 DV tapes, dating back to 1991.
I know people with hundreds, if not thousands, although they're DVCAM
format and not regular DV.
Post by Peter
The earliest of those are actually ex Hi-8 tapes which I copied to DV
tapes, by linking a now-gone Hi-8 camcorder to a Sony PC-100.
Okay.
Post by Peter
Now I use a Sony HDR-HC1E which is great but is big and heavy.
Big and heavy? You've never used a professional grade
over-the-shoulder camcorder, I presume?
Post by Peter
Nowadays, DV tape is dead.
Well, standard definition is dead, or almost dead, at least in some
parts of the world. Tape is still the standard programme interchange
format, however, especially Sony's HDCAM and HDCAM SR formats.
Post by Peter
I am happy to keep the DV tapes in a safe because I know that high
coercivity magnetic media lasts for many years.
That's an excellent idea, and was recently discussed in one of these
groups.
Post by Peter
Tape is still used for serious data archiving in businesses.
Absolutely, as it's the lowest cost and most reliable means of long
term data archival storage.
Post by Peter
I use DDS4 at work and DLT at home.
Years ago, I used DDS at home, but have never used DLT (or LTO).
Post by Peter
But no new camcorders record to DV,
True.
Post by Peter
and anyway DV is a hassle for many
purposes where you want unattended recording because the tape fills up
after 1 hour, and the only way round that is to use the camera in a
"webcam" mode (or shop demo mode if you like) whereby one feeds its
composite audio output to e.g. a laptop where the data is recorded to
some piece of software which writes it to a hard disk. And for this to
work, mains power needs to be provided; if one uses the battery then
the camera shuts down after some minutes.
A much better method is to use the camcorder's IEEE 1394a (FireWire /
i.LINK) output, thus avoiding needless digital-to-analog and
analog-to-digital conversions.
Post by Peter
The best replacement for the HC1E appears to be one of these
http://www.parkcameras.com/18746/Sony-HDR-CX700-HD-Flash-Camcorder.html
Or the Canon HF G10.
Post by Peter
but obviously it requires the data to be transferred out periodically,
and stored somewhere safe.
Right.
Post by Peter
Then I need to transfer all those DV tapes to some new format, because
the HC1E will be sold on Ebay.
Okay.
Post by Peter
1) What is the simplest way to transfer the DV tapes to a PC,
losslessly, to some standard format? For PAL DV tapes it will be the
MJPEG DV format, and for the HD DV tapes it will be MPEG.
Are you answering your own question here?

DV footage will have been lossy compressed with the DV codec. If you
want to store this footage and maintain maximum possible quality, keep
it in DV format. DO NOT transcode to Motion-JPEG or any other lossy
codec!

You've posted your message using Forte Agent, so I'll assume that
you're a Windows user, in which case you want to losslessly transfer
the footage to your computer over FireWire and store it as DV-AVI
files (about 13 GB per hour of footage).
Post by Peter
2) What is the best way to store the data afterwards? I do not believe
DVDs are the long term answer (20-30 years). Some may be OK but they
are unproven.
Right, forget DVD - they lack long-term reliability. Use a couple of
large external hard disk drives, but also keep the original tapes.
Camcorders and VCRs capable of reading DV tapes will still be
available (on the used market) 20 years from now in case you ever want
to go back to the original tapes for some reason. But note that HDDs
aren't reliable for the long-term either. Flash memory cards are
probably a better choice, but more expensive on a cost-per-byte basis.
Post by Peter
I store videos as they were taken, with no editing. To produce short
movies I have usee Pinnacle (buggy crap), P/Elements (buggy crap), and
now have Vegas 11 which seems to work. But it is the long term storage
I am interested in.
Maybe the best way will be to transfer (losslessly) the stuff to a PC
and back it up to my DLT tape and take that offsite.
You can also do that, backing up the DV-AVI files that I mentioned
above to DLT.
Post by Peter
Any suggestions appreciated :)
Well, I hope that this has helped.
Post by Peter
(I need to check that CX700 has MANUAL audio level control for the
external mike input, which I need for some applications like filming
in a light aircraft. The HC1E has this, and it is very rare in
consumer cams)
A quick look at the specs for the U.S. model, known as the HDR-CX700V,
I see "Mic Level Control : Yes (2steps)".

OTOH, if you really care about audio quality (and I don't mean to
offend you by this; I'm just stating my opinion), you wouldn't be
using the camcorder's unbalanced microphone inputs anyway. You would
either be using a prosumer-grade camcorder that has balanced three-pin
XLR microphone inputs or, at the very least, a consumer-grade
camcorder with unbalanced plugin-power microphone inputs but in
conjunction with an interface such as the juicedLink CX231 that would
allow you to use good quality balanced microphones.
--
Frank, Independent Consultant, New York, NY
[Please remove 'nojunkmail.' from address to reply via e-mail.]
Read Frank's thoughts on HDV at http://www.humanvalues.net/hdv/
[also covers AVCHD (including AVCCAM & NXCAM) and XDCAM EX].
Peter
2011-07-10 10:12:32 UTC
Permalink
Post by Frank
A much better method is to use the camcorder's IEEE 1394a (FireWire /
i.LINK) output, thus avoiding needless digital-to-analog and
analog-to-digital conversions.
I was not aware the HC1E output anything out of its 1394 connector,
until you pressed the Start Recording button, which in turn means
having a tape in there, which means the thing will stop 1hr later.
Post by Frank
Post by Peter
The best replacement for the HC1E appears to be one of these
http://www.parkcameras.com/18746/Sony-HDR-CX700-HD-Flash-Camcorder.html
Or the Canon HF G10.
Indeed; I am looking at that one instead. It looks a lot better. I
don't need 50P and I don't need 12 MP stills especially as their
quality is not going to be better than a $100 12MP mini camera.
Post by Frank
Post by Peter
1) What is the simplest way to transfer the DV tapes to a PC,
losslessly, to some standard format? For PAL DV tapes it will be the
MJPEG DV format, and for the HD DV tapes it will be MPEG.
Are you answering your own question here?
DV footage will have been lossy compressed with the DV codec. If you
want to store this footage and maintain maximum possible quality, keep
it in DV format. DO NOT transcode to Motion-JPEG or any other lossy
codec!
I thought that HD cams like the HC1E store MPEG on the tape, not DV
like all the SD ones did.

Incidentally, I always wondered how the HC1E manages to get exactly
1hr's recording onto a "1hr" tape, when Mpeg compressibility is so
dependent on the subject matter.
Post by Frank
You've posted your message using Forte Agent, so I'll assume that
you're a Windows user, in which case you want to losslessly transfer
the footage to your computer over FireWire and store it as DV-AVI
files (about 13 GB per hour of footage).
What program should I use?

Also, surely, the HC1E tapes compain Mpeg so one would not end up with
DV, would one?

What would be the two file formats? IIRC, DV output from Elements is
saved as an AVI file (which I realise is a wrapper for whatever
format) and the HD output ought to be stored as MPG, no? I would need
something futureproof, and of course playable directly with e.g. VLC.
Post by Frank
Post by Peter
2) What is the best way to store the data afterwards? I do not believe
DVDs are the long term answer (20-30 years). Some may be OK but they
are unproven.
Right, forget DVD - they lack long-term reliability. Use a couple of
large external hard disk drives, but also keep the original tapes.
Camcorders and VCRs capable of reading DV tapes will still be
available (on the used market) 20 years from now in case you ever want
to go back to the original tapes for some reason. But note that HDDs
aren't reliable for the long-term either. Flash memory cards are
probably a better choice, but more expensive on a cost-per-byte basis.
Post by Peter
I store videos as they were taken, with no editing. To produce short
movies I have usee Pinnacle (buggy crap), P/Elements (buggy crap), and
now have Vegas 11 which seems to work. But it is the long term storage
I am interested in.
Maybe the best way will be to transfer (losslessly) the stuff to a PC
and back it up to my DLT tape and take that offsite.
You can also do that, backing up the DV-AVI files that I mentioned
above to DLT.
That would be my preferred method, as a DLT tape can hold ~ 160GB
which would be around 10-15 DV tapes.
Post by Frank
Post by Peter
Any suggestions appreciated :)
Well, I hope that this has helped.
Sure.
Post by Frank
Post by Peter
(I need to check that CX700 has MANUAL audio level control for the
external mike input, which I need for some applications like filming
in a light aircraft. The HC1E has this, and it is very rare in
consumer cams)
A quick look at the specs for the U.S. model, known as the HDR-CX700V,
I see "Mic Level Control : Yes (2steps)".
Only 2 steps? The HC1E was fully variable. But anyway I am looking at
the Canon G10.
Post by Frank
OTOH, if you really care about audio quality (and I don't mean to
offend you by this; I'm just stating my opinion), you wouldn't be
using the camcorder's unbalanced microphone inputs anyway. You would
either be using a prosumer-grade camcorder that has balanced three-pin
XLR microphone inputs or, at the very least, a consumer-grade
camcorder with unbalanced plugin-power microphone inputs but in
conjunction with an interface such as the juicedLink CX231 that would
allow you to use good quality balanced microphones.
No offence, and a good point. Actually I don't care much for audio
quality. The recordings are mostly amateur stuff like somebody cutting
up a birthday cake :)

The more serious use is out of a light aircraft, where I have a
miniature mike, tucked up into the headset, going to a Sound
Professionals mike preamp, whose 3.5mm output lead goes into the
camcorder. A better method is to connect directly into the aircraft
intercom but that has other issues which I won't go into (e.g. with 4
people flying there are no spare headset connectors, so one would have
to make up a splitter...

I have been playing with different setups for these flying movies over
the years and still don't have a great solution. My last one is here
http://peter2000.gotdns.com/locarno-dep-26/locarno-dep-26.mp4

You can see the audio quality there varies a great deal, and the best
of it is not bad considering it is coming from a noise cancelling mike
in a noisy cockpit.

Another thing I played with was recording 1 still image per second and
making a movie out of it. This gives a 25x speedup which is actually
pretty good for flying movies which would otherwise be unwatchable.
There were software issues combining these however, and of course
there is no sound track unless one produces one afterwards. I cannot
tell whether the G10 can do 1fps; I used a webcam for such movies and
stored the stills with a little free prop which kept crashing...
Frank
2011-07-10 21:07:50 UTC
Permalink
On Sun, 10 Jul 2011 11:12:32 +0100, in 'rec.video.production',
in article <Re: What's the best way to move forward from DV tape?>,
Post by Peter
Post by Frank
A much better method is to use the camcorder's IEEE 1394a (FireWire /
i.LINK) output, thus avoiding needless digital-to-analog and
analog-to-digital conversions.
I was not aware the HC1E output anything out of its 1394 connector,
until you pressed the Start Recording button, which in turn means
having a tape in there, which means the thing will stop 1hr later.
Most camcorders, if you insert a recordable tape (check the write
protect slider/tab thingie to ensure that it's not write protected)
and select Record/Pause mode, will output a signal. Give it a try.
Post by Peter
Post by Frank
Post by Peter
The best replacement for the HC1E appears to be one of these
http://www.parkcameras.com/18746/Sony-HDR-CX700-HD-Flash-Camcorder.html
Or the Canon HF G10.
Indeed; I am looking at that one instead. It looks a lot better. I
don't need 50P and I don't need 12 MP stills especially as their
quality is not going to be better than a $100 12MP mini camera.
Post by Frank
Post by Peter
1) What is the simplest way to transfer the DV tapes to a PC,
losslessly, to some standard format? For PAL DV tapes it will be the
MJPEG DV format, and for the HD DV tapes it will be MPEG.
Are you answering your own question here?
DV footage will have been lossy compressed with the DV codec. If you
want to store this footage and maintain maximum possible quality, keep
it in DV format. DO NOT transcode to Motion-JPEG or any other lossy
codec!
I thought that HD cams like the HC1E store MPEG on the tape, not DV
like all the SD ones did.
You were asking about DV, sir, not HDV (even your subject line says
"DV tape"). I addressed the situation where you have DV footage that
you want to preserve.

If it were high definition 1080i50 HDV footage, instead of standard
definition 576i50 footage, I would make the same recommendations
except that the copy on your computer would be an .m2t file containing
MPEG-2 video and MPEG-1 Layer II audio instead of a DV-AVI file
containing DV video and LPCM audio.
Post by Peter
Incidentally, I always wondered how the HC1E manages to get exactly
1hr's recording onto a "1hr" tape, when Mpeg compressibility is so
dependent on the subject matter.
While the MPEG-2 video compression standard specifies the use of both
CBR (Constant Bit Rate) and VBR (Variable Bit Rate) encoding, HDV, in
both its 720 (JVC) and 1080 (Sony and Canon) forms, is always
CBR-encoded.

And the two-channel stereo MPEG-1 Layer II audio normally used in the
HDV format is encoded at a constant bitrate of 384 kbps (192 kbps per
channel). And if it's four-channel, as supported by a few HDV
camcorders and VCRs, then the per-channel datarate is halved to 96
kbps, thus keeping the total audio datarate at the same 384 kbps.
Post by Peter
Post by Frank
You've posted your message using Forte Agent, so I'll assume that
you're a Windows user, in which case you want to losslessly transfer
the footage to your computer over FireWire and store it as DV-AVI
files (about 13 GB per hour of footage).
What program should I use?
Good question, and one that I can't really answer in any specific way.
The best answer that I can give to you is to use whatever works most
reliably on your given system.
Post by Peter
Also, surely, the HC1E tapes compain Mpeg so one would not end up with
DV, would one?
What would be the two file formats? IIRC, DV output from Elements is
saved as an AVI file (which I realise is a wrapper for whatever
format) and the HD output ought to be stored as MPG, no? I would need
something futureproof, and of course playable directly with e.g. VLC.
VLC is an excellent choice - and as mentioned above, for DV it would
be a DV-AVI file (.avi) and for HDV it would be an .m2t file.
Post by Peter
Post by Frank
Post by Peter
2) What is the best way to store the data afterwards? I do not believe
DVDs are the long term answer (20-30 years). Some may be OK but they
are unproven.
Right, forget DVD - they lack long-term reliability. Use a couple of
large external hard disk drives, but also keep the original tapes.
Camcorders and VCRs capable of reading DV tapes will still be
available (on the used market) 20 years from now in case you ever want
to go back to the original tapes for some reason. But note that HDDs
aren't reliable for the long-term either. Flash memory cards are
probably a better choice, but more expensive on a cost-per-byte basis.
Post by Peter
I store videos as they were taken, with no editing. To produce short
movies I have usee Pinnacle (buggy crap), P/Elements (buggy crap), and
now have Vegas 11 which seems to work. But it is the long term storage
I am interested in.
Maybe the best way will be to transfer (losslessly) the stuff to a PC
and back it up to my DLT tape and take that offsite.
You can also do that, backing up the DV-AVI files that I mentioned
above to DLT.
That would be my preferred method, as a DLT tape can hold ~ 160GB
which would be around 10-15 DV tapes.
Post by Frank
Post by Peter
Any suggestions appreciated :)
Well, I hope that this has helped.
Sure.
Post by Frank
Post by Peter
(I need to check that CX700 has MANUAL audio level control for the
external mike input, which I need for some applications like filming
in a light aircraft. The HC1E has this, and it is very rare in
consumer cams)
A quick look at the specs for the U.S. model, known as the HDR-CX700V,
I see "Mic Level Control : Yes (2steps)".
Only 2 steps? The HC1E was fully variable. But anyway I am looking at
the Canon G10.
I know. It pained me to write "2steps" (even with the missing blank
space, which happened because I did a copy-and-paste from the Sony Web
site and I wanted to quote it accurately, errors and all).
Post by Peter
Post by Frank
OTOH, if you really care about audio quality (and I don't mean to
offend you by this; I'm just stating my opinion), you wouldn't be
using the camcorder's unbalanced microphone inputs anyway. You would
either be using a prosumer-grade camcorder that has balanced three-pin
XLR microphone inputs or, at the very least, a consumer-grade
camcorder with unbalanced plugin-power microphone inputs but in
conjunction with an interface such as the juicedLink CX231 that would
allow you to use good quality balanced microphones.
No offence, and a good point. Actually I don't care much for audio
quality. The recordings are mostly amateur stuff like somebody cutting
up a birthday cake :)
The more serious use is out of a light aircraft, where I have a
miniature mike, tucked up into the headset, going to a Sound
Professionals mike preamp, whose 3.5mm output lead goes into the
camcorder. A better method is to connect directly into the aircraft
intercom but that has other issues which I won't go into (e.g. with 4
people flying there are no spare headset connectors, so one would have
to make up a splitter...
I have been playing with different setups for these flying movies over
the years and still don't have a great solution. My last one is here
http://peter2000.gotdns.com/locarno-dep-26/locarno-dep-26.mp4
You can see the audio quality there varies a great deal, and the best
of it is not bad considering it is coming from a noise cancelling mike
in a noisy cockpit.
Another thing I played with was recording 1 still image per second and
making a movie out of it. This gives a 25x speedup which is actually
pretty good for flying movies which would otherwise be unwatchable.
There were software issues combining these however, and of course
there is no sound track unless one produces one afterwards. I cannot
tell whether the G10 can do 1fps; I used a webcam for such movies and
stored the stills with a little free prop which kept crashing...
I'm not sure about the 1 frame per second capability, but I'll view
your video as soon as I get back - must run out on an errand right
now or else it will be too late and tomorrow's schedule is already
filled.

Regards, and good luck!
--
Frank, Independent Consultant, New York, NY
[Please remove 'nojunkmail.' from address to reply via e-mail.]
Read Frank's thoughts on HDV at http://www.humanvalues.net/hdv/
[also covers AVCHD (including AVCCAM & NXCAM) and XDCAM EX].
Peter
2011-07-10 21:32:36 UTC
Permalink
Post by Frank
Most camcorders, if you insert a recordable tape (check the write
protect slider/tab thingie to ensure that it's not write protected)
and select Record/Pause mode, will output a signal. Give it a try.
I recall this works, but the camera shuts down after some tens of
seconds - unless mains power is connected up.
Post by Frank
Post by Peter
Post by Frank
Post by Peter
The best replacement for the HC1E appears to be one of these
http://www.parkcameras.com/18746/Sony-HDR-CX700-HD-Flash-Camcorder.html
Or the Canon HF G10.
Indeed; I am looking at that one instead. It looks a lot better. I
don't need 50P and I don't need 12 MP stills especially as their
quality is not going to be better than a $100 12MP mini camera.
Post by Frank
Post by Peter
1) What is the simplest way to transfer the DV tapes to a PC,
losslessly, to some standard format? For PAL DV tapes it will be the
MJPEG DV format, and for the HD DV tapes it will be MPEG.
Are you answering your own question here?
DV footage will have been lossy compressed with the DV codec. If you
want to store this footage and maintain maximum possible quality, keep
it in DV format. DO NOT transcode to Motion-JPEG or any other lossy
codec!
I thought that HD cams like the HC1E store MPEG on the tape, not DV
like all the SD ones did.
You were asking about DV, sir, not HDV (even your subject line says
"DV tape"). I addressed the situation where you have DV footage that
you want to preserve.
OK; The HC1E records HD MPEG to DV tapes, hence my mixed up
terminology.
Post by Frank
If it were high definition 1080i50 HDV footage, instead of standard
definition 576i50 footage, I would make the same recommendations
except that the copy on your computer would be an .m2t file containing
MPEG-2 video and MPEG-1 Layer II audio instead of a DV-AVI file
containing DV video and LPCM audio.
That's correct; Pinnacle and Elements both produce an M2T file. Only
VLC manages to play it.
Post by Frank
Post by Peter
Incidentally, I always wondered how the HC1E manages to get exactly
1hr's recording onto a "1hr" tape, when Mpeg compressibility is so
dependent on the subject matter.
While the MPEG-2 video compression standard specifies the use of both
CBR (Constant Bit Rate) and VBR (Variable Bit Rate) encoding, HDV, in
both its 720 (JVC) and 1080 (Sony and Canon) forms, is always
CBR-encoded.
I know this is a tangent but surely the data rate of the mpeg
compressed video varies according to the subject, so I can't see how
even CBR fits exactly on the tape. But I won't worry about it.
Post by Frank
And the two-channel stereo MPEG-1 Layer II audio normally used in the
HDV format is encoded at a constant bitrate of 384 kbps (192 kbps per
channel). And if it's four-channel, as supported by a few HDV
camcorders and VCRs, then the per-channel datarate is halved to 96
kbps, thus keeping the total audio datarate at the same 384 kbps.
Post by Peter
Post by Frank
You've posted your message using Forte Agent, so I'll assume that
you're a Windows user, in which case you want to losslessly transfer
the footage to your computer over FireWire and store it as DV-AVI
files (about 13 GB per hour of footage).
What program should I use?
Good question, and one that I can't really answer in any specific way.
The best answer that I can give to you is to use whatever works most
reliably on your given system.
Obviously, I can use any of the video editing programs, but that seems
an overkill. I wondered if there are simple programs which will just
get the video off the tape (interfacing to a camcorder) and write out
the AVI or M2T file. But it's no big deal.
Post by Frank
Post by Peter
Also, surely, the HC1E tapes compain Mpeg so one would not end up with
DV, would one?
What would be the two file formats? IIRC, DV output from Elements is
saved as an AVI file (which I realise is a wrapper for whatever
format) and the HD output ought to be stored as MPG, no? I would need
something futureproof, and of course playable directly with e.g. VLC.
VLC is an excellent choice - and as mentioned above, for DV it would
be a DV-AVI file (.avi) and for HDV it would be an .m2t file.
VLC can also transcode i.e. convert formats, but I have rarely managed
to get this to work usefully because there are so many combinations of
formats and bit rates that without knowing the right ones one ends up
with an unplayable video. They need a few "presets" in there.
Frank
2011-07-11 00:01:38 UTC
Permalink
On Sun, 10 Jul 2011 22:32:36 +0100, in 'rec.video.production',
in article <Re: What's the best way to move forward from DV tape?>,
Post by Peter
Post by Frank
Most camcorders, if you insert a recordable tape (check the write
protect slider/tab thingie to ensure that it's not write protected)
and select Record/Pause mode, will output a signal. Give it a try.
I recall this works, but the camera shuts down after some tens of
seconds - unless mains power is connected up.
Correct; basically, you'll need an AC power source - or maybe a motor
generator or a very big battery with an inverter that can drive an AC
adapter.

I've run Webcams for days at a time, but the camcorder used (DV in
this case, not HDV) was always being powered via its AC adapter. This
wasn't a problem for me as it was an "indoor" application, not out in
the field where the nearest AC power (mains) outlet might be two miles
away.

Have you considered wind and/or solar power?
Post by Peter
Post by Frank
Post by Peter
Post by Frank
Post by Peter
The best replacement for the HC1E appears to be one of these
http://www.parkcameras.com/18746/Sony-HDR-CX700-HD-Flash-Camcorder.html
Or the Canon HF G10.
Indeed; I am looking at that one instead. It looks a lot better. I
don't need 50P and I don't need 12 MP stills especially as their
quality is not going to be better than a $100 12MP mini camera.
Post by Frank
Post by Peter
1) What is the simplest way to transfer the DV tapes to a PC,
losslessly, to some standard format? For PAL DV tapes it will be the
MJPEG DV format, and for the HD DV tapes it will be MPEG.
Are you answering your own question here?
DV footage will have been lossy compressed with the DV codec. If you
want to store this footage and maintain maximum possible quality, keep
it in DV format. DO NOT transcode to Motion-JPEG or any other lossy
codec!
I thought that HD cams like the HC1E store MPEG on the tape, not DV
like all the SD ones did.
You were asking about DV, sir, not HDV (even your subject line says
"DV tape"). I addressed the situation where you have DV footage that
you want to preserve.
OK; The HC1E records HD MPEG to DV tapes, hence my mixed up
terminology.
Okay, no problem.
Post by Peter
Post by Frank
If it were high definition 1080i50 HDV footage, instead of standard
definition 576i50 footage, I would make the same recommendations
except that the copy on your computer would be an .m2t file containing
MPEG-2 video and MPEG-1 Layer II audio instead of a DV-AVI file
containing DV video and LPCM audio.
That's correct; Pinnacle and Elements both produce an M2T file. Only
VLC manages to play it.
Pretty much all contemporary NLEs support HDV. Are you sure that you
aren't running into limitations of the speed of your computer
hardware?

In fact, if you have the appropriate DirectShow filters installed on
your system, any DirectShow-based playback application, such as good
old Windows Media Player, should play your HDV .m2t files just fine.

Of course, Pinnacle software is often noted for having problems doing
even simple things. :)
Post by Peter
Post by Frank
Post by Peter
Incidentally, I always wondered how the HC1E manages to get exactly
1hr's recording onto a "1hr" tape, when Mpeg compressibility is so
dependent on the subject matter.
While the MPEG-2 video compression standard specifies the use of both
CBR (Constant Bit Rate) and VBR (Variable Bit Rate) encoding, HDV, in
both its 720 (JVC) and 1080 (Sony and Canon) forms, is always
CBR-encoded.
I know this is a tangent but surely the data rate of the mpeg
compressed video varies according to the subject, so I can't see how
even CBR fits exactly on the tape. But I won't worry about it.
I wouldn't call it a tangent, or even slightly OT (off-topic), as it
directly relates to the subject at hand (which has now been changed
from DV to HDV).

Firstly, in HDV, both the video compression and the audio compression
are CBR, just like DV/DVCAM/DVCPRO in that respect.

Because of that, if one knows the linear recording density (and I
stress linear, since we're talking about helical recording here), the
tape speed (about 18.812 millimeters per second as I recall), and the
physical length of a given cassette tape, then it's just a matter of
simple arithmetic to compute the recording time per tape.

Secondly, it's exactly because it's CBR that scenes of very high
motion will sometimes break apart in HDV. What's happening is that the
codec is constrained by the constant bit rate limitation of the format
and can't devote more bits to complex scenes with high degrees of
motion. This where VBR encoding can be useful, but both DV and HDV are
CBR formats and don't use VBR encoding for either the audio stream or
the video stream.

A big difference between the video encoding in the DV25 formats (DV,
DVCAM, and DVCPRO) is that DV25 is intraframe encoded whereas HDV is
interframe encoded.

In 1080i59.94 HDV there are 15 frames per GOP, or Group Of Pictures.
In 1080i50 HDV, it's 12 frames per GOP.

This is why a tape dropout in HDV will often result in a half-second
disruption in the playback whereas a dropout in one of the DV25
formats may affect only one or two frames.

The bottom line, however, is that both DV and HDV are completely and
totally CBR formats, thus recording time is a constant for a given
tape speed and length of tape stock.

If you have an application that requires greater recording time, then
it's necessary to switch from the Mini-sized tapes and start using the
Standard-sized tapes, which will give you about 276 minutes instead of
about 60 minutes.

I should probably also mention that virtually all tape-based video
formats use CBR recording techniques for the simple reason that the
tape itself moves at a constant, not variable, rate.

This is where media such as flash memory cards, hard disk drives, and
solid state drives come in handy. As long as they're fast enough to
handle the maximum datarate, they don't care if the data is CBR or VBR
encoded.
Post by Peter
Post by Frank
And the two-channel stereo MPEG-1 Layer II audio normally used in the
HDV format is encoded at a constant bitrate of 384 kbps (192 kbps per
channel). And if it's four-channel, as supported by a few HDV
camcorders and VCRs, then the per-channel datarate is halved to 96
kbps, thus keeping the total audio datarate at the same 384 kbps.
Post by Peter
Post by Frank
You've posted your message using Forte Agent, so I'll assume that
you're a Windows user, in which case you want to losslessly transfer
the footage to your computer over FireWire and store it as DV-AVI
files (about 13 GB per hour of footage).
What program should I use?
Good question, and one that I can't really answer in any specific way.
The best answer that I can give to you is to use whatever works most
reliably on your given system.
Obviously, I can use any of the video editing programs, but that seems
an overkill. I wondered if there are simple programs which will just
get the video off the tape (interfacing to a camcorder) and write out
the AVI or M2T file. But it's no big deal.
For HDV ingest via an IEEE 1394a link to a computer, either use
whatever your favorite NLE offers or else try Paviko's free HDVSplit
program.

HDVSplit utility for HDV capturing with scene split - HDV capture
utility
http://strony.aster.pl/paviko/hdvsplit.htm

For DV ingest via an IEEE 1394a link to a computer, you've got many
choices. If you need a list, just let me know (via e-mail). Many of
them are freeware.

Keep in mind that for DV, you need to make a choice as to whether you
want to create DV Type 1 .avi files or DV Type 2 .avi files.

I assume that you know the difference between the two, as well as the
pros and cons of each type.

HDV, whether 720 or 1080, has no such consideration, by the way.
Post by Peter
Post by Frank
Post by Peter
Also, surely, the HC1E tapes compain Mpeg so one would not end up with
DV, would one?
What would be the two file formats? IIRC, DV output from Elements is
saved as an AVI file (which I realise is a wrapper for whatever
format) and the HD output ought to be stored as MPG, no? I would need
something futureproof, and of course playable directly with e.g. VLC.
VLC is an excellent choice - and as mentioned above, for DV it would
be a DV-AVI file (.avi) and for HDV it would be an .m2t file.
VLC can also transcode i.e. convert formats, but I have rarely managed
to get this to work usefully because there are so many combinations of
formats and bit rates that without knowing the right ones one ends up
with an unplayable video. They need a few "presets" in there.
Yes, and I think that the transcoding capability was sort of an
after-thought type of add-on. At least in my experience, it sometimes
produces the expected results and sometimes it doesn't, but there are
so many ways to transcode a file that it really doesn't bother me too
much. I still feel that VLC media player is a great program and
frequently recommend it to people.
--
Frank, Independent Consultant, New York, NY
[Please remove 'nojunkmail.' from address to reply via e-mail.]
Read Frank's thoughts on HDV at http://www.humanvalues.net/hdv/
[also covers AVCHD (including AVCCAM & NXCAM) and XDCAM EX].
Justin
2011-08-02 04:17:16 UTC
Permalink
Post by Peter
I have about 50 DV tapes, dating back to 1991.
Hi Pete, I skimmed over everyone's response and I think they covered
everything to level far beyond me. But I thought I would add my small
bit of paranoia to the pile of knowledge.
I had a similar problem but some of my tapes were Video8 going back to
1986. I bought a TRV480 Digital 8, and converted everything via
Firewire to my Sony HC96. Now they are all on MiniDV. Then I
transferred all the footage from the MiniDVs to my PC (Windows at the
time) in uncompressed DV video. Then I copied them to *two* external
2.5" Western Digital hard drives. I keep one at home, and one in my
safety deposit box.
Some my background is Information Tech, both drives were formatted to
NTFS to avoid the 4GB filesize limit of FAT32. Then I switched to Mac,
and accessing NTFS using a free utility called NTFS-3g was super slow,
but I still wanted to avoid the filesize limit. Now OS X supports exFAT
- basically FAT64, and there is no real filesize limit that I will
encounter. Both drives were reformatted and I can access them on
Windows, Mac and my Linux machine. (whew)
I use the same strategy for AVCHD footage. I make a DMG file which is
basically an ISO file. If I have 2.5GB of space used on my SD card I
make a 2.6GB DMG file, copy the entire folder/directory structure to
that DMG file. This way iMovie sees the DMG file as a drive and I can
import the footage while preserving the date/timecodes.
The problem is that DMG is Mac only - ISO is a standard. Maybe I'll
convert to ISO, but if I ever need to open a DMG on a PC or linux, there
are utilities to do exactly that.

Sorry for the long winded post...

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