DVD video file editing

[mudxdresser]

Does anyone here have the technical knowledge to know how to format and insert a single frame into the chain of files that make up a DVD? I presume that each link in the video file chain must point to the next one internally somehow and have heard there is a way to hack into it and modify that but have never found a person that knew how to do it. I would very much like to be able to construct a frame with a serial number in it, preferably embedded in a steganographic watermark, to be able to tell who pirates my videos. My intent would be to proceduralize the process so that I could insert unique serial numbers fast enough to make the process viable.

I've looked at commercial products that require Internet connections to allow play but all of them can be defeated by screen capture programs such as CamStudio since the serial number is not actually embedded in a frame. Actually, there could be some commercial potential for this technique if such a process is actually feasible.

Thanks for any technical suggestions but please, let's forgo turning this into a debate on the why I should or shouldn't want to do this to deter piracy. I fully understand that such a technique would require positive identification of customers and a very specialized contract to bypass "fair use". All that I can handle, I just need help on the technical solution of how to insert that frame.

[Fred588]

I think it would be easy enough to add a serial number to a frame of video prior to rendering the DVD image file, but this would mean rendering a new image file (DVD image) for each copy. That would be pretty inefficient for more than a very small number of copies. There are, I am told, programs that can edit an ISO file and that might mean you could swap out a single piece (such as a file containing the serial number) but a pirate could easily do the same thing assuming they knew about the existence of a serial number. But you'd still have to burn each DVD copy one at a time. I know that isn't a solution for you.

Does anyone here have the technical knowledge to know how to format and insert a single frame into the chain of files that make up a DVD? I presume that each link in the video file chain must point to the next one internally somehow and have heard there is a way to hack into it and modify that but have never found a person that knew how to do it. I would very much like to be able to construct a frame with a serial number in it, preferably embedded in a steganographic watermark, to be able to tell who pirates my videos. My intent would be to proceduralize the process so that I could insert unique serial numbers fast enough to make the process viable.

I've looked at commercial products that require Internet connections to allow play but all of them can be defeated by screen capture programs such as CamStudio since the serial number is not actually embedded in a frame. Actually, there could be some commercial potential for this technique if such a process is actually feasible.

Thanks for any technical suggestions but please, let's forgo turning this into a debate on the why I should or shouldn't want to do this to deter piracy. I fully understand that such a technique would require positive identification of customers and a very specialized contract to bypass "fair use". All that I can handle, I just need help on the technical solution of how to insert that frame.

[Chimerix]

I remember having this discussion some years back. I did a fair bit of research, and while people with more knowledge than me all agreed it should theoretically be possible, no one had any practical solution. I was even curious enough to attempt it on a crude scale: I took an existing project (a graduation ceremony, I think), went to a spot near the end, and put a big "10" on the screen for about 10 seconds. Exported it to MPEG, taking careful note of the settings I used. I authored the DVD and burned an image. I then switched the "10" to a "01" and re-exported using the same settings. I replaced the previous MPEG file in the existing authoring project and burned a second image.

These two images were, to the limit of the (very decent) tools I had at hand, identical, with the exception of that one segment in the video. I thought that if I could identify which VTS segment they were in, I could simply swap those files and voila! A serialized, "watermarked" DVD.

It turns out, I could not manipulate ANY of those files. If I replaced any component of one DVD with any component of the other, the DVD would fail to play in its entirety. Sometimes it would refuse to play at all.

Now, I only spent an afternoon on this, largely waiting on computers, so the testing was not exhaustive. But what it did lead me to believe is that manipulation of such a delicate structure is way harder than it sounds.

It's becoming moot, I think. The DVD is dead. Adobe discontinued Encore two versions ago; Apple discontinued DVD Studio Pro. SD is dying, and taking the DVD with it.

[mudxdresser]

Yes, I do agree the DVD is going the way of the dinosaur, however, there is still a lot of hardware out there that will play 'em so that still gives me a distribution window should I be able to solve this issue. And yes, I'm aware that I could do this by rendering a separate DVD for each serial number but that is too time consuming, I need to be able to edit those DVD files to be able to implement a batch process.

Nice attempt at inserting a frame in your experiment! Can see that there is an untested assumption in the procedure however, that is that the authoring software renders exactly the same files each time. Only takes one bit difference in any way and the whole chain could end up totally different. The only hope I have is that there is a rigid specification under there controlling how those files are built so there should be some way to edit into it. I've certainly done magic myself resurrecting corrupted databases internally or hacking game files with nasty little checksums all over the place.

Thanks for the comments!

[Chimerix]

Nice attempt at inserting a frame in your experiment! Can see that there is an untested assumption in the procedure however, that is that the authoring software renders exactly the same files each time. Only takes one bit difference in any way and the whole chain could end up totally different. The only hope I have is that there is a rigid specification under there controlling how those files are built so there should be some way to edit into it. I've certainly done magic myself resurrecting corrupted databases internally or hacking game files with nasty little checksums all over the place.

Indeed. There were two encoding processes, the conversion to MPEG, and the muxing for the DVD, that I had insufficient control over to ensure consistency. Like I said, at the time I did this, I only devoted an afternoon to the experiment, and the hardware/software of the day was not speedy, so only a few iterations of the test were possible.

Were I to go back to it, my first step would be to burn two identical DVDs from the same image, swap files between the two, and see how that goes. I always tell my students "never overlook the obvious" when troubleshooting.

[mudxdresser]

Had a thought, is there any correlation between chapter breaks and files on the DVD? If there is then it might be possible to make a one frame chapter and possibly learn to manipulate it.

[mudxdresser]

By way of follow up, there is indeed a way to join a frame to an existing VOB file chain. Turns out there are a number of shareware programs that will do the job. The trick to finding them is to use a search string of something like "join VOB files". So yes, there is a way to embed a serial number in a DVD. Now if I could figure out a way of incrementing a serial number without having to edit it and render it into a VOB, this could be practical enough to use to register DVD's with hidden serial numbers.

[Boggy Man]

By way of follow up, there is indeed a way to join a frame to an existing VOB file chain. Turns out there are a number of shareware programs that will do the job. The trick to finding them is to use a search string of something like "join VOB files". So yes, there is a way to embed a serial number in a DVD. Now if I could figure out a way of incrementing a serial number without having to edit it and render it into a VOB, this could be practical enough to use to register DVD's with hidden serial numbers.

If the programs support command lines, then perhaps there could be a way to accomplish all this using a scripting language.

[mudxdresser]

I've used macros/scripts before but that'd be a tall order getting something like that to work in video. Still, maybe there might be a way to do it instead with streaming video as, actually, the way things are going, that would be a lot more useful since using DVD's is fading out.

[Nessie]

In graphics and printing, the word for something like this is "variable data" or "mail merge". It's the numbering you may see on invoices, or the way that "Dear (insert your name here)" appears on the junk mail you get.

But all you need is a number that increments. That's just the page counter character and that's in every word processing program anyway.

You could use Word, maybe. Make a page with nothing but a footer in it. Add the page counter character with a prefix before it to represent the video you want to use. Then add pages and let the numbers behind roll forward until you have as many as you want. You'll have to export your way to jpegs that become the single frame addition in your video.

Good luck,
Nessie