"High Noonn" DVD??

[Fabian Keil]

Nikola Lečić <nikola.lecic at anthesphoria.net> wrote:

> On Sun, 16 Nov 2008 16:08:27 +0100
> Fabian Keil <freebsd-listen at fabiankeil.de> wrote:
>  
> > Nikola Lečić <nikola.lecic at anthesphoria.net> wrote:
> > 
> > > On Sat, 15 Nov 2008 14:46:00 +0100
> > > Roland Smith <rsmith at xs4all.nl> wrote:
> > > 
> > > > OK, that's nice to know. All the DVDs that I have play fine with
> > > > mplayer, but they're probably all region 2 disks. So I should be
> > > > able to play region 1 disks with mplayer?
> > > 
> > > That's exactly what I am trying to do at this moment, with no
> > > success. I'm in the region 2 and I set my DVD drive accordingly
> > > (with a small C programme). Now I got some region 1 DVDs and
> > > libdvdcss is not sufficient as such.
> > 
> > Which programs did you try?
> > Do you get an error message?
> 
> I tried mplayer, vlc and ogle and experienced the same symptoms like
> when this DVD drive was in virgin state (with no region-code set) and
> when I tried to play normal region 2 DVD, which means:
> 
>   * vlc - no output at all
>   * mplayer - sound ok, video scrambled in colourful squares, producing
>     a lot of errors like this:
> 
> a52: CRC check failed!  0.046 ct: -0.029  21/ 18 11%  1% 23.4% 0 0 
> a52: error at resampling
> A:   1.5 V:   1.7 A-V: -0.197 ct: -0.036  23/ 20 11%  0% 22.8% 0 0 
> demux_mpg: 24000/1001fps progressive NTSC content detected, switching framerate.
> a52: CRC check failed!  0.045 ct:  0.100  34/30 ??% ??% ??,?% 0 0 a52: error at resampling

If this was a classical "wrong region code"
problem, the disc shouldn't play at all.

I just had a quick look at:
/usr/ports/multimedia/mplayer/work/MPlayer-1.0rc2/libdvdcss/libdvdcss.c
An excerpt from the comment on top:

 * \li \b DVDCSS_METHOD: sets the authentication and decryption method
 *     that \e libdvdcss will use to read scrambled discs. Can be one
 *     of \c title, \c key or \c disc.
 *     - \c key is the default method. \e libdvdcss will use a set of
 *       calculated player keys to try and get the disc key. This can fail
 *       if the drive does not recognize any of the player keys.
 *     - \c disc is a fallback method when \c key has failed. Instead of
 *       using player keys, \e libdvdcss will crack the disc key using
 *       a brute force algorithm. This process is CPU intensive and requires
 *       64 MB of memory to store temporary data.
 *     - \c title is the fallback when all other methods have failed. It does
 *       not rely on a key exchange with the DVD drive, but rather uses a
 *       crypto attack to guess the title key. On rare cases this may fail
 *       because there is not enough encrypted data on the disc to perform
 *       a statistical attack, but in the other hand it is the only way to
 *       decrypt a DVD stored on a hard disc, or a DVD with the wrong region
 *       on an RPC2 drive.

Maybe there's a communication problem that prevents
libdvdcss from detecting that the first two methods
aren't working properly and that the last one has
to be used.

You could try patching mplayer to only use the last one.

>   * ogle - the flood of these kernel messages with syslogd eating a lot
>     of CPU:
> 
> Nov 16 22:21:58 black kernel: acd0: setting up DMA failed
> Nov 16 22:21:58 black kernel: ata2: FAILURE - non aligned DMA transfer attempted
> 
> After setting the region of my DVD drive to 2, I never experienced
> such errors (after uncountable number of local DVDs) until I got there
> region 1 ones. That's why I was so confident that libdvdcss is a
> problem.

I think it's only part of the problem.

> > Did you try playing or ripping the discs on a GNU/Linux system?
> 
> Hmm, my home is currently FreeBSD-only. :-) But I managed to try it and
> - -- yes, it works. Strange. In the light of your post about LITE-ON
> DVDRW LH-20A1S 9L08, is it possible that DVD drive causes all these
> problems?

I assume this could be a controller problem as well.
Trying another drive is probably the easiest way to
find out.

Fabian
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