DVD Playing HOWTO

DVD Playing HOWTO
Nathan Rowlan, [email protected]
v0.1.8 5 June 2000

A (hopefully) easy to follow explanation on how to get DVD movie play�
back in Linux.
______________________________________________________________________

Table of Contents

1. Introduction

1.1 Goal
1.2 New Versions
1.3 Copyrights and Trademarks
1.4 Thanks
1.5 Translations

2. Requirements

3. Files

4. Installation

4.1 Kernel
4.2 LiViD Utilities

5. Playing

6. Additional Stuff

6.1 Setting up MTRR's

7. Problems

7.1 Run time errors
7.1.1 Illegal Instruction Error
7.2 Compilation errors
7.2.1 `dvd_struct' undeclared...
7.2.2 can't determine absolute dir of '../../../../src/plugin/codec/mpeg2dec/.libs'
7.3 Broken stuff
7.4 Other errors

8. To Do

______________________________________________________________________

1. Introduction

1.1. Goal

The purpose of this is to provide step by step instructions on getting
DVD movies to play in Linux. I will try to be as clear as possible,
but if something is confusing or incorrect, please tell me about it
and I'll fix it. If you have any questions, you can subscribe to the
livid-dev mailing list by sending a blank email to livid-dev-
[email protected].

1.2. New Versions

This howto is available in many formats, including html and tex. The
newest version can always be retrieved from my site at
http://helo.org/dvd/howto/ <http://helo.org/dvd/howto/>. It is highly
recommended that you get the most recent version, as this howto is
being updated quite often.

1.3. Copyrights and Trademarks

This manual may be reproduced in whole or in part, without fee,
subject to the following restrictions:

� The copyright notice above and this permission notice must be
preserved complete on all complete or partial copies.

� Any translation or derived work must be approved by the author in
writing before distribution.

� If you distribute this work in part, instructions for obtaining the
complete version of this manual must be included, and a means for
obtaining a complete version provided.

� Small portions may be reproduced as illustrations for reviews or
quotes in other works without this permission notice if proper
citation is given.

Exceptions to these rules may be granted for acedemic purposes: Write
to the author and ask. These restrictions are here to protect us as
authors, not to restrict you as learners and educators. Any souce code
(aside from the SGML this document was written in) in this document is
placed under the GNU General Public License, available via anonymous
FTP from the GNU archive <ftp://ftp.gnu.org/GNU/COPYING>.

1.4. Thanks

Thanks to the authors of oms and the rest of the LiViD developers, who
have given the project much of their time and work, and also to those
individuals who have given me feedback to make this HOWTO better.

Much of the layout of this HOWTO was gotten from the HOWTO-HOWTO,
written by Mark F. Komarinski. It can be found at
http://www.linuxdoc.org/ <http://www.linuxdoc.org/>.

1.5. Translations

Any translations of this document that I recieve go into
http://helo.org/dvd/howto/trans/ <http://helo.org/dvd/howto/trans/>.
If you would like to translate this howto, please email me at
[email protected].

2. Requirements

This HOWTO assumes you have:

� Linux > v2.2.0

� XFree86 3.3.X

� A DVD-ROM/RAM/RW drive supported in Linux (most are)

� A decent knowledge of bash and english

� A master's degree in Nuclear Engineering

3. Files

First things first, you need to get a kernel with MTRR (more on this
later) and DVD ioctl support. While MTRR's have been in the kernel
since 2.2.11 (correct me if I'm wrong), you will probably need to
update your kernel to get DVD ioctls. There are two ways to skin this
cat, you can either download a development kernel (v2.3.x), or patch a
stable release kernel (v2.2.x), the patches are at
http://www.kernel.dk/ <http://www.kernel.dk/>, and the kernel can be
found on your favorite mirror of ftp://ftp.kernel.org/
<ftp://ftp.kernel.org>.

Next, you need to get the LiViD utilities. This can be done two ways:

� Get the LiViD utilities from CVS, so you can update it as it is
being updated by the developers. (recommended)

The following commands will retrieve them:

# mkdir ~/livid
# cd ~/livid
# export CVSROOT=:pserver:[email protected]:/cvs/livid
# cvs login
(Logging in to [email protected])
CVS password:

There is no password for anonymous, just press enter.

# cvs -z3 co -P ac3dec oms mpeg2dec mgadvd

They should download into their respective directories.

� If you don't like CVS (freak!), you can download the most recent
nightly tarball of LiViD. This contains more than you need, but if
you are really afraid of using CVS for some reason, suit yourself.

It can be found at:

http://linuxvideo.org/developer/data/livid.tar.gz

4. Installation

4.1. Kernel

If you have a development kernel (2.3.x), you should already have DVD
ioctl support, so you just need to make sure you have MTRR support
enabled in the kernel configuration, and then compile and install it
as you normally would.

If you want to patch your exisiting kernel, start by going to

http://www.kernel.dk/

and downloading the correct patch for your kernel.

If don't know how to install or patch your kernel, you should go read
the Kernel HOWTO at:

http://howto.tucows.com/LDP/HOWTO/Kernel-HOWTO.html

4.2. LiViD Utilities

To install the LiViD utilities, you need to make sure you have
/usr/local/lib somewhere in /etc/ld.so.conf.

The following commands should compile and install the LiViD utilities
on your system. If you have problems, please see the "Problems"
section.

ac3dec:

# cd ~/livid/ac3dec
# ./autogen.sh
# make
# make install

mpeg2dec:

# cd ~/livid/mpeg2dec
# ./autogen.sh
# make
# make install

oms:

# cd ~/livid/oms
# ./autogen.sh
# ./configure
# make
# make install

Now the necessary LiViD utilities should be installed. oms needs some
special fifo pipes to be created for the DVD data to travel over.
These can be made with the following commands (if they don't already
exist):

# mkfifo /tmp/video
# mkfifo /tmp/audio

One last thing to do. Oms needs /dev/dvd to be a symlink to where your
DVD drive resides, such as /dev/hdb1 or /dev/scd0. If it is at
/dev/cdrom, you would create the link by typing:

# ln -s /dev/cdrom /dev/dvd

It is generally a good idea not to make a symlink to a symlink,
because it adds unnecessary I/O. Replace /dev/cdrom with the correct
device that your dvd drive is on.

5. Playing

To play a DVD, you need to be running X in 16-bit color mode. With the
DVD in the drive, type:

# ac3dec /tmp/audio& mpeg2dec /tmp/video& oms

If all has gone well, some text should fly by, followed by it asking
you if you want it to look up the name of the disk in the DVDDB. It
is safe to say yes. Then, the oms panel should pop up. Click the play
button and the video window should appear and begin playing.

6. Additional Stuff

6.1. Setting up MTRR's

** Note to Matrox video card owners **

If you have matroxfb compiled into the kernel,
chances are that your MTRR's are already set
up. You can probably just skip this section.

Setting up your MTRR's can increase video performance quite a bit in
some cases, so it is a good idea to do it. First, you need to make
sure you have MTRR support in your kernel by typing:

# ls /proc/mtrr

If it tells you that there is no such thing as /proc/mtrr, you need to
recompile your kernel with MTRR support (it is under "Processor type
and features" in menuconfig).

Once you know MTRR is working, you need to know the base memory
address of your video card, and how much video ram it has. The
easiest way to do this is to look at the output of X as it starts up.
Because the output usually scrolls off the screen and is lost when it
switches to a different tty, you need to redirect the output of X to a
file (xoutput) so you can go back and look at it to get the needed
values. This can be done by typing:

# startx 2> xoutput

The line having the needed information is probably somewhere towards
the middle of xoutput, and should look something like:

(--) SVGA: PCI: NVidia Riva TNT2 rev 17, Memory @ 0xee000000, 0xe2000000

Once you have located that, write down the last memory address, in
this case 0xe2000000. Depending on your hardware, you may or may not
have multiple memory addresses shown, so don't worry if yours looks a
little different. With this information recorded, you can delete
xoutput.

Next you need to create a new MTRR. In order to do that, you have know
how much ram your video card has in hex. Here are some common values:

4MB -- 0x400000
8MB -- 0x800000
16MB -- 0x1000000
32MB -- 0x2000000

To add the MTRR, type:

# echo "base=0xe2000000 size=0x2000000 type=write-combining" >| /proc/mtrr

Substituting "0xe2000000" and "0x2000000" with the base address and
amount of video ram specific to your system.

Now you should have MTRR set up, and just to make sure, type:

# cat /proc/mtrr

And you should get output that looks remotely similar to:

reg00: base=0x00000000 ( 0MB), size= 128MB: write-back, count=1
reg01: base=0xe2000000 (3616MB), size= 32MB: write-combining, count=1

Again, the number of entries will probably be different from these,
don't sweat it.

7. Problems

7.1. Run time errors

This is a (small) list of known run-time errors.

7.1.1. Illegal Instruction Error

If you use a non-Intel chip (K6 especially), and you are getting this
error when you try to run mpeg2video, try editing nist/configure.in,
lines 129 and 130:

CFLAGS="$CFLAGS -DHAVE_MMX -DLINUX -march=i686 -fschedule-insns2 -malign-doub
CXXFLAGS="$CXXFLAGS -DHAVE_MMX -DLINUX -march=i686 -fschedule-insns2 -malign-

replace "-march=i686" in both with "-march=i586", and then recompile
and reinstall.

7.2. Compilation errors

This is a running list of common compilation errors that have known
fixes.

7.2.1. `dvd_struct' undeclared...

The most frequent problem people have when trying to compile these
utilities stems from oms looking in the wrong place for the kernel
headers. By default, it uses /usr/include/[linux|asm], but those
headers are from a stable kernel so that when you compile a normal
program, it will be using stable headers. oms needs to use non-stable
(or patched) kernel headers, so when oms tries to compile, many things
are undeclared and compilation fails. The best way to fix this is to
edit the oms Makefile and -I/usr/src/linux/include to the CFLAGS and
CXXFLAGS. (thanks to Adam Powell for this info)

These commands should do it:

# mkdir /usr/include/old
# mv /usr/include/linux /usr/include/old/linux
# mv /usr/include/asm /usr/include/old/asm
# mv /usr/include/scsi /usr/include/old/scsi
# ln -s /usr/src/linux/include/linux /usr/include/linux
# ln -s /usr/src/linux/include/scsi /usr/include/scsi
# ln -s /usr/src/linux/include/asm /usr/include/asm

7.2.2. can't determine absolute dir of '../../../../src/plu�
gin/codec/mpeg2dec/.libs'

Another common error is with the oms/src/plugin/codec/mpeg2dec/.libs
directory. For some reason or another, this directory does not exist,
and it needs to for compilation. To fix it, just make the directory:

# mkdir src/plugin/codec/mpeg2dec/.libs

7.3. Broken stuff

Features that don't currently work as intended:

� None of the chapter seek buttons work very well (crash).

� Once stopped, it doesn't like to start again (crash).

� Audio/video like to skip every second or so.

� Extreme slowdowns at beginning of chapters with mpeg2dec.

� Sometimes ac3dec doesn't close properly, and must be killed via
"killall ac3dec".

7.4. Other errors

If your problem isn't listed here, then likely the current CVS code
has a bug in it. The best thing to do is just to wait a few days, and
then try updating from CVS. There is a mailing list where you can ask
questions, to subscribe send a blank email to livid-dev-
[email protected].

8. To Do

� Get someone with a Matrox card to send me a list of things they did
to improve performance. (dent!!!)

� Makefile options (HAVE_MMX, HAVE_3Dnow, etc)

� -march=k6 for mpeg2dec

� add easy MTRR stuff (framebuffer)

� add need for region coding to be set on most drives:
www.linuxtv.org/dvd