Detecting DRM protected files

[Martijn van Rheenen]

Would agree on putting in in the properties too, I will look into that. I am
just finishing the MP4 reading part right now...

2011/3/29 Lukáš Lalinský <lalinsky at gmail.com>

> On Tue, Mar 29, 2011 at 2:28 PM, Martijn van Rheenen <rheenen at gmail.com>
> wrote:
> > MP4 DRM protection:
> > Something with a 'drms' atom should be detected, if it's present, the
> file
> > is DRM protected. But I can not find proper documentation on the MP4
> > fileformats to know where to find this atom (I know it should be in the
> > 'moov' atom, but then the info I found stops...)
>
> It seems to be at moov.trak.mdia.minf.stbl.stsd.drms. Just checking
> for the presence of the atom should be probably enough. I've tried it
> on a file that I found somewhere and it seems to work.
>
> https://github.com/lalinsky/taglib/commit/97cd58bc
>
> > WMA DRM protection:
> > In TagLib's asffile.cpp you could add to the list of ByteVector's at the
> > near-top of the file:
> > static ByteVector
> >
> asfContentEncryptionGuid("\x22\x11\xB3\xFB\xBD\x23\x11\xD2\xB4\xB7\x00\xA0\xC9\x55\xFC\x6E");
> > static
> >
> ByteVector asfExtendedContentEncryptionGuid("\x29\x8A\xE6\x14\x26\x22\x4C\x17\xB9\x35\xDA\xE0\x7E\xE9\x28\x9C");
> > Then in ASF::File::read():
> > Change:
> > else {
> >   obj = new UnknownObject(guid);
> > }
> > To:
> > else {
> >   if (guid == contentEncryptionGuid || guid ==
> > extendedContentEncryptionGuid) {
> >     d->tag->setDRMProtected(true);
> >   }
> >   obj = new UnknownObject(guid);
> > }
>
> This part seems fine, but I think that the information should go into
> ASF::Properties, not ASF::Tag (especially not defining a new WM
> attribute). Any chance you have a file I can test this against?
>
> Lukas
> _______________________________________________
> taglib-devel mailing list
> taglib-devel at kde.org
> https://mail.kde.org/mailman/listinfo/taglib-devel
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mail.kde.org/pipermail/taglib-devel/attachments/20110329/458056f1/attachment.htm