[MPlayer-dev-eng] aes & bluray

[Nico Sabbi]

Il venerdì 11 settembre 2009 11:55:13 Reimar Döffinger ha scritto:
> On Fri, Sep 11, 2009 at 11:42:40AM +0200, Nico Sabbi wrote:
> > Il venerdì 11 settembre 2009 11:32:06 Reimar Döffinger ha scritto:
> > > Either way I admit I would simply like to have libavformat
> > > _also_ support decrypting (because lavf already has some other
> > > decryption stuff, so this could be some kind of common way to
> > > handle all kinds of encryption, MXF, ASF, AACS etc.), and I
> > > would also like it if the scrambling control checks would be
> > > re-added in the demuxers in a well-tested way so that people
> > > trying to play encrypted files (e.g. when people do a simple
> > > file copy from a DVD) at least get a proper warning instead of
> > > just strangely broken playback. Overall I just have the feeling
> > > that at the demuxer layer it would solve a whole bunch of
> > > problems more.
> >
> > well, in this case we need a .decrypter member to inizialize at
> > demux_open() according to the stream type.
> > I don't particularly like the idea, but...
>
> Do you _know_ that this is needed or are you just guessing? As
> said, I have not found much documentation, particularly about CSS
> at the demuxer level so I don't know if the demuxer really needs to
> know the stream type. I do know that DVB and HD-DVD can be
> distinguished with nothing more than the value of
> PES_scrambling_control.

I'm reasonably certain on good basis: that field is  2 bits wide, thus 
it can't cover all possible current and future encryption methods.
There are already: css, dvb, hd-dvd and bd, thus that field is already 
short of space (0 means not scrambled).