[MPlayer-dev-eng] aes & bluray

[Nico Sabbi]

Il venerdì 11 settembre 2009 10:20:42 Reimar Döffinger ha scritto:
> On Fri, Sep 11, 2009 at 04:51:56AM +0100, Jonathan Nell wrote:
> > 2009/9/10 Nico Sabbi <nicola.sabbi at poste.it>:

> > > I didn't read the specs, but unless decryption can't be
> > > implemented otherwise I'd prefer to keep it in the stream
> > > layer, just like for CSS
>
> And why? I really think it is a mistake to do it there for CSS
> already. The encryption part of CSS does not really depends on a
> physical medium at all and could be used for any MPEG stream - if
> it wasn't always implemented "at the wrong place".

because different media could use different encryptions in the same 
mux format, think for example of dvd and hd-dvd: both use mpeg-ps as a 
container but with very different encryptions. 
Even though there's nothing stream-specific in the encryption method, 
as a matter of fact the media type (thus the stream) involves an 
encryption algorithm.

>
> > Yup, it only makes sense in the stream layer. There's nothing
> > sensible to pass to the demux layer until the transport stream
> > has been decrypted.
>
> Maybe things are completely different for BluRay, but for HD-DVD
> the TS

PS

> itself isn't encrypted, just _some_ of its contents.
> And for what I can tell, a file can even be partially encrypted.
> Are you sure that the only reason why your code doesn't work for
> HD-DVD is exactly because you are handling things at the stream
> layer whereas it would be the same code if done at the demuxer
> layer?