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Hi! I am a newbie here. But I really need your help on this question.

We are evaluating using VLC as the built-in "portable" video player on a DVD which has preloaded video files.

We have some "copy protection/content security" mechanism on the DVD so these video files can only be play backed by the built-in player on the DVD.

But we seem face a dilemma here. In order for the "copy protection/content security" mechanism to work, we need to add some code in VLC.

But under the VLC’s GPL, we need to publish the whole source codes, including the "copy protection/content security" mechanism part, right?

Does this mean other developers can easily tweak the source codes and build a new player to bypass the decryption/content security?

Hi! I would like to quickly add something to clarify.

We are evaluating using VLC as the built-in "portable" video player on a DVD disc which has preloaded video files.

This DVD disc will work on PC and Mac. And we don't want users to copy all the video files to their hard drive and play backed these copied video using VLC player on their system.

Hi! I am a newbie here. But I really need your help on this question.

We are evaluating using VLC as the built-in "portable" video player on a DVD which has preloaded video files.

We have some "copy protection/content security" mechanism on the DVD so these video files can only be play backed by the built-in player on the DVD.

But we seem face a dilemma here. In order for the "copy protection/content security" mechanism to work, we need to add some code in VLC.

But under the VLC’s GPL, we need to publish the whole source codes, including the "copy protection/content security" mechanism part, right?

Does this mean other developers can easily tweak the source codes and build a new player to bypass the decryption/content security?

If your code is linking VLC, yes, you have to publish the code...
One way is to decrypt with another program and pipe the decoded stream in VLC, but users will be able to use the record button...

but users will be able to use the record button...

Hi! j-b

Please correct me if didn't fully understand what you said by "users will be able to use the record button".

We will take the "record" function out and make a special version of VLC player.

But users can replace our "special VLC player" with another regular VLC , which has record function, right?

And then all the "encrypted" video files can be recorded as regular video files, therefore no "copy protection".

but users will be able to use the record button...

Hi! j-b

Please correct me if didn't fully understand what you said by "users will be able to use the record button".

We will take the "record" function out and make a special version of VLC player.

But users can replace our "special VLC player" with another regular VLC , which has record function, right?

And then all the "encrypted" video files can be recorded as regular video files, therefore no "copy protection".

That is my understanding, yes. Except if you decryption mechanism check if this is the correct VLC or not.

And then still, users could record the screen and the audio via stereomix etc., like with all DRM protected media.
Or they'll find another way to trick your mechanisms.

What I'm trying to say is: Don't bother trying to do a perfect DRM, cause that is not possible. Rather consider the alternative of DRM-free media, which are anyway way more user friendly.

But under the VLC’s GPL, we need to publish the whole source codes, including the "copy protection/content security" mechanism part, right?

If you want to be 100% legit with everything you do, yes, you must publish the source code. But believe me, nobody is going to pursue litigation against you if you don't. Even companies like SonyBMG have included pieces of GPL code in their software, and it didn't hurt them.

So, if I was in your shoes, I would just modify VLC to suit my purposes (remove record button, add the code for the decryption etc) and then put it my DVDs without publishing the source code.

The real problem is that standalone DVD players will not be able to play the disc. So when Average Joe puts the disc in his standalone player and nothing happens, he will be disapointed.
And the really big problem is that when the next version of Windows rolls out, your software may not be compatible with that version. The same way some old games/edutainment titles for Windows XP don't play on Windows 7 pcs. Same for Linux and MacOS. So, everytime a new version of Windows, Linux of MacOS rolls out, you will have to ship a new disc to your customers which will include the latest (modified) version of VLC.

PS: For the record, this has been done in the past with the so called "Movie CDs". These CDs contained video files in a proprietary format, and a special software player inside the disc automatically launched under Windows 95 and played the files. Sounds really similar with what you are intending to do. Needless to say, the software doesn't work in Windows XP/Vista/Seven pcs, so the discs are pretty useless now.
This is why nowadays content is always shipped in some standarized format (ex VideoCD, DVD-Video) and companies try to prevent copying by inserting errors in the non-playable parts of the disc (in segments of the video that are never accesed by the menus). See sony arccos and macrovision ripguard.