Does a DV capture retain the macrovision/copyguard flag?

I've had my Sony mini dv camera for a while but only lately picked up a firewire card so of course I've been reading here a lot and trying all kinds of stuff.

One thing I tried is the dv pass through by connecting my older 8mm and using the av to dv feature to capture to pc. I also did the same with a vcr and copied a couple of my commercial tapes to dv. A couple of issues I'll deal with in another thread but for now I have a copyguard flag question.

My files all copied to my HDD using WINDV but later I also tried to send the dv avi back to my dv camera to see if I could record the dv back from the hdd to the tape. (only a test don't know if I would really use this).

Here's the problem. The material I transferred from my 8mm camera and my dv tapes copied back fine but the pc dv avi which originated from a vhs source produced a copyright error message from the camera.

Does the dv on hdd retain the flag and is there an easy way to remove it?

Originally Posted by gll99

but the pc dv avi which originated from a vhs source produced a copyright error message from the camera.

Does the dv on hdd retain the flag and is there an easy way to remove it?

MV on VHS is an error, AFAIK this error is destroyed during the conversion to digital. You should not have been able to make a copy in the first place.....

If you mean..

That if you capture a copyright VHS w/ MV on it, through your DV cam's
pass-through, then no. It will shut off the dv cam. But, not all dv
cams stop on MV. My canon ZR-10 does this.. beeps and flashes a read
copyright warning, and then shuts down the cams recording.
.
But, on my Sony TRV-22 cam, it passes the MV vhs tape through it, and
allows me to record it. That is, I capture it through firewire with
no problems.

If you capture a MV source to an AVI file, it should not be carrying
the mv signal. That's (MV) something that is recorded onto the vhs tape.
An AVI file is just a stream of BITMAP's.
.
If you are saying what I think you said.. that you captured an MV source
to AVI (w/out shuting down) and then you taped it to VCR, and then tried
to re-capture it again, (I don't know why one would do that) and it failed
to capture, then this gives light to what I have been saying all along in
other threads here.., that VCR's are by default, in ALWAYS-ON mode, for
macrovision.., and your sceario was just a coinsedense at best

Still, I could be wrong

-vhelp 3465

I know this sounds confusing but I'll try again without the other stuff.

I hooked my vcr (composite out) to my sony dv camera (av input) and using the av to dv pass through feature and was able to copy it to my pc via firewire. There was no message from the camera about copy protection. The 2 movies are 2 hours long about 27 gig apiece.
I shut the vcr and later tried to transfer the dv avi from my hdd using WINDV back to my Sony dv camera and that is when I got the copyright warning.

I didn't try to record directly from my vcr to my Sony dv since I was testing the pass through at the time. I only thought of trying a reverse transfer from pc to camera as an afterthought.

Again once converted to digital there should be no MV present. To tell you the truth I find your problem very odd. As I said before the copy error from the cam would be an issue getting the footage to HDD.... not from it.

As MV on VHS is an analog feature only (signal hidden in the invisible lines) which can't be captured (will be compressed out), any problems after converting the footage to DV are not MV related. Maybe your DCR is misinterpreting the DV stream.

Originally Posted by Dragonsf

As MV on VHS is an analog feature only (signal hidden in the invisible lines) which can't be captured (will be compressed out), any problems after converting the footage to DV are not MV related. Maybe your DCR is misinterpreting the DV stream.

I find it puzzling that it is consistent with the 2 captured movies (or cuts thereof) but accepts all of my other captures from dv and 8mm sources. There must be something in the carrier that is passed from analogue vhs to the dv. Maybe this is contained in the dv specs.

While I may never use this feature unless I plan to use my Sony camera in place of my vcr to watch movies but it bugs me when I can't do something so I tried a couple of tests.

1: Using vdubmod I cut a small piece of one movie and using directstream copy I saved that to test1.avi
Result: Still got the message from the camera.

2: Using vdubmod again I loaded a dv clip that originally came from my home dv stuff and appended the file test1.avi. I then saved that using direct stream copy to test2.avi.
Result: The dv camera accepted the clip and recorded it up to the point where the append started then I got the copyright message and the recording stopped.

3: Again with vdubmod, I used test1.avi from step1 and using the free Panasonic dv codec I saved the clip using full processing mode.
Result: The camera accepted the clip with no problems.

My conclusion (right or wrong) is that the copyright info is not a header type flag but is carried as part of the signal itself (That is why I did test 2). In step 3 when I reencoded the DV (from dv to dv using the Panasonic codec) the information was not retained because of the re-encode.

I still wish that I had a better explanation or solution.

- could you post a sample PIC and couple of AVI frames so we can
test this on our equipment ??

Maybe results would vary from user to user (pending system setup, etc)

-vhelp 3466

Here are a few frames from the original dv.

sample.avi

They are a bit gray but that's another issue. I was going to start another thread later after my research is done.

There must be something in the carrier that is passed from analogue vhs to the dv. Maybe this is contained in the dv specs.

No I don't think so, and even if that was the case you can still make a DVD with it correct? Exporting the material back to DV cam would be the last of their concerns, being able to capture it to hard drive would though. On top of that since your creating a new file I'd imagine there would have to be some sort of licensing involved.

I could be wrong, maybe you have stumbled upon some sort of new protection but I have never heard of it and VHS and MV are sort of personal pet peeve.

Anyhow have you tried this with another app? Convert/transfer a small clip using Windows Movie Maker then attempt to send it back to the cam.

@thecoalman

Thanks for your comments.

I don't think it's a new protection scheme since these tapes are not new by today's standard. VSH of Air force one and You've got mail.

Since yesterday, I tried to go vhs vcr to dv camera tape and the copyright message came up so at least I know for sure that the input is copy protected.

I'm suspicious of the default dv codec used by Windv. When I used the Panasonic codec to recompress in vdub I was able to transfer the clip to the camera with no problem.

Your suggestion to try another transfer tool on the original clip is a good one. It will eliminate another possibility. Windv just makes it so easy.

After that I can try to recapture a smaller clip of one vhs movie to dv using a different tool than WinDV and see if that makes a difference when I try to send it back to the camera.

Like I said it's not the end of the world if I can't get it done any other way except through recompression since I may never really use it but hey it's a hobby and part of the learning curve.

Cheers!

I'd try DVIO or DVApp for sending the avi file back to the
DCR

Originally Posted by Dragonsf

I'd try DVIO or DVApp for sending the avi file back to the
DCR

Thanks for the tip but.....

Tried both apps and made new clips. When I tried to send them back I could see them in the camera lcd display but got the copyright message when I tried to record. The vhs to DV avi must carry some kind of copyright signal because my own transfers from my dv tapes and analogue tapes transferred via pass-thru auto encoded to dv can easily be transferred back to the camera. Puzzling to say the least

Macrovision uses bogus timing signals/errors and picture elements in the overscan area. Timing issues will be removed by the DV recording but picture elements may not. Could the flashing white lines in the lower left corner be some kind of SCMS-like signal?

Originally Posted by junkmalle

Macrovision uses bogus timing signals/errors and picture elements in the overscan area. Timing issues will be removed by the DV recording but picture elements may not. Could the flashing white lines in the lower left corner be some kind of SCMS-like signal?

Interesting, but you think when he did a full processing encode to DV from this file and it worked, that it would of also encoded that flashing white bar?

Originally Posted by BSR

Originally Posted by junkmalle

Macrovision uses bogus timing signals/errors and picture elements in the overscan area. Timing issues will be removed by the DV recording but picture elements may not. Could the flashing white lines in the lower left corner be some kind of SCMS-like signal?

Interesting, but you think when he did a full processing encode to DV from this file and it worked, that it would of also encoded that flashing white bar?

That occured to me but we haven't seen the reencoded file. Maybe some relationship of the Y, U and V components is changed when reencoding? I did my own reencode and the bars are still there. I haven't tried recording them to my DV cam yet...

@BSR & junkmalle

The 2 movies I transferred both have fairly wide bottom scan lines on them but they don't show up on my tv with the test DVD I made from them so I just ignored them.

I took my 15 frame sample clip and tried that and it failed with the same message. I reencoded with the panasonic dv codec and the camera takes it. Yes, the scan lines are still there. I didn't do any other processing to the clip. In vdub just before reencode I also changed from full processing to fast re-encode and tried that too. That output was also accepted by the camera. I don't know if it just defaulted to the pana codec anyway cause when you don't select a codec it defaults to uncompressed RGB on fast recompress which of course the camera will not accept.

btw) all my own transfer dv tests are type 2. Hope the panasonic output is also?

Edit after I wrote the above:
Just to cover another point, I transferred another clip from the camera to a type 1 dv instead of type 2 and sent it back to the camera but that failed due to the copyright also.

gll99,

I got a chance to send your sample to my camcorder. Right away it pops up a "copyrighted material" message and stops. After reencoding I no longer got the message and the video recorded normally.

Out of curiosity I tried recording some commercial video tapes on my camcorder (it doesn't have passthrough). An unprotected tape recorded without any problems. A Macrovision protected tape caused the camcorder to stop recording after 5 or 10 seconds with the "copyrighted material" message. But since it did record several seconds I sent the video to the computer. The Macrovision protected tape had similar flashing lines in the lower left corner. The unprotected tape did not. I had no problems sending both these back to the camcorder. Sample from MV VHS tape:

https://www.videohelp.com/forum/images/guides/p1342952/mvsamp.avi

So maybe your Sony camcorder is embeding some sort of SCMS signal in the DV stream.

In that case,I'd crop out the lower 16 lines and replace them with a black border

Originally Posted by Dragonsf

In that case,I'd crop out the lower 16 lines and replace them with a black border

I actually did that but for a different reason. I had done a quick DV conversion to DVD using Neodvd7 trial and that is the only time the scan lines showed on my tv. I didn't like the overall results. I'm fond of Mediostream products but for DV to DVD conversion the quality just wasn't there. With the other mpeg2 encoders I tried the scan lines didn't show on my tv.

As far as sending vhs source dv to my camera, unless I planned to do some other filtering, it would be quicker just to do a fast recompress since I know that works too.

@junkmalle

At least I know that your camera reacted just like mine to that dv clip.

I suspect that your own short clip from the commercial vhs got written to tape without that signal that is why your camera didn't react when you sent it back. I can probably get a few frames like that too but not 10 seconds worth. I did manage to transfer a few frames to my camera tape from the pc dv avi before the camera could stop it just by pressing record multiple times on my cam record lcd touch button. I could try that again and resend it to the pc then back to the camera but I have a feeling that it would work and wouldn't prove much.

The main thing for me I guess is that I learned some limitations of the process, some new tools but also how to use the pass-thru on my camera. Making a dvd from dv input produced much better results than it was using vhs vcr to my bt878 based capture card. My original caps had noise and a peach fuzz appearance (best way I can describe it ) but the dv final conversion to DVD is very close to the vhs tape on my 32" set.

Among other things, my Star Trek Movie collection is on tape and I wanted to test the process before I try to backup those tapes. I'm still experimenting with the conversion to DVD to see if I have the best possible methods but that's a story for another day.

Thanks for the help.

It was a weak joke. I found something interesting:
http://66.102.7.104/search?q=cache:0IRiLH1v-gMJ:www.dtcp.com/data/wp_spec.pdf+5C+conte...otection&hl=de

There seems to be a 5C copy protection scheme within DV.

Expressing this is my own terms.

There is some type of encryption passed from vhs to dv and vis versa. Using this, the vcr and my Sony camera can recognize the data as copyrighted but my current computer hardware (cpu,bios, chipsets etc...) and software programs aren't even looking at the info. Re-encoding destroys the encryption (whatever it is).
The weakness from the designers perspective is that my camera did not protect the firewire bus and lets me transfer the data to the computer. Mine is DCR HC30 manuf. 2004, maybe newer models have blocked this option.

In the future computers will probably be designed with chips that check any transfer bus like the firewire,USB etc.. to make sure no copyrighted data passes though it.

A new underground mod chip industry will emerge!

Originally Posted by gll99

The weakness from the designers perspective is that my camera did not protect the firewire bus and lets me transfer the data to the computer. Mine is DCR HC30 manuf. 2004, maybe newer models have blocked this option.

This is what I find odd about this entire scenario, it's protected from going back to cam but not going out from the cam. What's the point and why did they not just not stop it at the source? This would require each device to recognize the copy protection..... It's almost comical. I'd imagine the reason I haven't seem other posts like this is because there isn't many people sending video back to the cam, I' don't even think there's many that reallize you can do this.

Anyhow you learn something new everday here.....

A little searching turned up things like this:

http://news.thomasnet.com/fullstory/458642

"Chip provides 3-port IEEE 1394 physical layer, AVLink, and digital video (DV) decoder in one device and supports Digital Transmission Content Protection system and broadcast-flag copy protection."

And an ExtremeTech article about DTCP (and other protocols):

http://www.extremetech.com/article2/0,1558,1231547,00.asp

"Compliant devices determine which access and copying activities are legal by examining two bits of Copy Control Information (CCI) transmitted with each packet of protected content."

So what we have here is DTCP without the encryption and authentication layer, just the CCI layer. It should be easy to zero out the CCI bits from the DV file. But once the encryption/authentication layer is implemented it will be much harder.

An actual device (software):

http://www.gocyberlink.com/english/digital_home/tech.jsp

And yes, in a future of "trusted computing" all the doors will be locked:

https://www.videohelp.com/forum/viewtopic.php?t=274204

How long do you think it will be before Microsoft, Intel, and the MPAA/RIAA disable the transmission of all non encrypted, non DTCP compliant material?

Originally Posted by junkmalle

How long do you think it will be before Microsoft, Intel, and the MPAA/RIAA disable the transmission of all non encrypted, non DTCP compliant material?

As far as analog goes they can stick this up their ass.

http://www.datavideo.us/products/tbc_1000_main_page.htm

My capture device will never see that signal.

Originally Posted by thecoalman

Originally Posted by junkmalle

How long do you think it will be before Microsoft, Intel, and the MPAA/RIAA disable the transmission of all non encrypted, non DTCP compliant material?

As far as analog goes they can stick this up their ass.

http://www.datavideo.us/products/tbc_1000_main_page.htm

My capture device will never see that signal.

Be sure to keep your old computer, O/S and software. Once the new trusted systems become widespread they will no longer accept input from any non-compliant DV encoder!

gll99:

I have found your research and posts the most helpful.

I just recently bought a powerful PC and DVD burner (but unfortunately, without a firewire port). One of the things I planned to do is to back up a large collection of original VHS movies to DVD, adding menus, submenus and all that you are able to do with a DVD authoring software.

I have the same Sony DV camcorder model (DCRHC30) and a JVC 4-head VCR (about 10 years old, but still working). Without much technical knowledge, I hooked the VCR to the DV cam and play the VHS movie for testing. The movie played at the LCD screen of the camera just fine. Then I hooked the DV cam to the PC VIA A USB PORT (I dont have a firewire, yet), played the tape on the the VCR and started capturing the footage with Windows Movie Maker. Thats where my problems started. My PC got frozen and had to be rebooted as many time as I tried to transfer the footage. Then I thought that I would just record the VHS footage directly to the cam, but got the copyright error message.

After this, every VHS tape (original) I try to play could not bee seen at the LCD screen of the cam, just heard the sound of the movie. Is this consistent with your findings?

After reading tons of information in this forum, I know now two importatnt things:

1- I need a firewire card as a footage transferring device, and
2- There should be no tape within the cam when transfering footage to the PC (from the VCR via the DV cam). Too bad I will know if this works for me until I get the firewire card.

If I understood well from your writtings on this forum that you were succesful of transfering video to your pc doing pretty much the same process (but with firewire). Please tell me if the resulted video you transfer to the pc (avi-dv files, right?) allowed you to burn a DVD and how would you rate its quality? and, if this works, you dont really need a canopus, or dazzle or DVD express hardware/software to capture your analog video, correct?

Thanks in advance for your kind reply.