mirror of
https://github.com/mpv-player/mpv
synced 2025-02-22 15:56:59 +00:00
Remove technical description of DVDs and libdvdread implementation.
It is out of place in the user-level documentation and there are more exhaustive sources elsewhere. git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@24344 b3059339-0415-0410-9bf9-f77b7e298cf2
This commit is contained in:
parent
b13b7a54c2
commit
74e2767527
@ -141,50 +141,6 @@ In case of DVD decoding problems, try disabling supermount, or any other such
|
||||
facilities. Some RPC-2 drives may also require setting the region code.
|
||||
</para></note>
|
||||
|
||||
<formalpara>
|
||||
<title>DVD structure</title>
|
||||
<para>
|
||||
DVD disks have 2048 bytes per sector with ECC/CRC. They usually have an UDF
|
||||
filesystem on a single track, containing various files (small .IFO and .BUP
|
||||
files and big (1GB) .VOB files). They are real files and can be copied/played
|
||||
from the mounted filesystem of an unencrypted DVD.
|
||||
</para>
|
||||
</formalpara>
|
||||
|
||||
<para>
|
||||
The .IFO files contain the movie navigation information (chapter/title/angle
|
||||
map, language table, etc) and are needed to read and interpret the .VOB content
|
||||
(movie). The .BUP files are backups of them. They use
|
||||
<emphasis role="bold">sectors</emphasis> everywhere, so you need to use raw
|
||||
addressing of sectors of the disc to implement DVD navigation or decrypt the
|
||||
content.
|
||||
</para>
|
||||
|
||||
<para>
|
||||
DVD support needs raw sector-based access to the device. Unfortunately you must
|
||||
(under Linux) be root to get the sector address of a file. That's why we don't
|
||||
use the kernel's filesystem driver at all, instead we reimplement it in
|
||||
userspace. <systemitem>libdvdread</systemitem> 0.9.x does this.
|
||||
The kernel UDF filesystem driver
|
||||
is not needed as they already have their own builtin UDF filesystem driver.
|
||||
Also the DVD does not have to be mounted as only the raw sector-based access is
|
||||
used.
|
||||
</para>
|
||||
|
||||
<para>
|
||||
Sometimes <filename>/dev/dvd</filename> cannot be read by users, so the
|
||||
<systemitem>libdvdread</systemitem> authors implemented an emulation layer
|
||||
which transfers sector addresses to filenames+offsets, to emulate raw
|
||||
access on top of a mounted filesystem or even on a hard disk.
|
||||
</para>
|
||||
|
||||
<para>
|
||||
<systemitem>libdvdread</systemitem> even accepts the mountpoint instead of
|
||||
the device name for raw access and checks <filename>/proc/mounts</filename>
|
||||
to get the device name. It was developed for Solaris, where device names
|
||||
are dynamically allocated.
|
||||
</para>
|
||||
|
||||
<formalpara>
|
||||
<title>DVD decryption</title>
|
||||
<para>
|
||||
|
Loading…
Reference in New Issue
Block a user