Modify README to mention regmask stripping.

silum · Jul 5, 2016 · 6be9c87 · 6be9c87
1 parent 81d0799
commit 6be9c87
Showing 1 changed file with 12 additions and 17 deletions.
diff --git a/README b/README
@@ -5,22 +5,21 @@ directly with cp/dd/readom, you'll get I/O error (Read of scrambled
 sector without authentication) on all scrambled sectors and any
 workarounds like dd_rescue will just produce damaged MPEG.
 
-dvdread depends on libdvdcss2 and libdvdread4 libraries (these are
-Debian GNU/Linux names for libdvdcss-1.2.x and libdvdread-4.y.z). To
-build dvdread from source, you'll need development versions of the
-libraries (libdvdcss-dev and libdvdread-dev on Debian).
+dvdread depends on libdvdcss (http://download.videolan.org/libdvdcss/)
+and libdvdread (http://dvdnav.mplayerhq.hu/#download) libraries. To
+build dvdread on Debian GNU/Linux system you need to install
+libdvdread-dev package from main repository and libdvdcss-dev one from
+www.deb-multimedia.org.
 
 Example usage:
 ./dvdread /dev/sr0 >akira_decss.iso
 mplayer -dvd-device akira_decss.iso dvdnav://menu
 
-The produced .iso file still contains original DVD region restriction
-mask inside the VIDEO_TS.IFO and VIDEO_TS.BUP files. This mask is a
-single byte at offset 0x23 in the mentioned two files (cf
-http://dvdnav.mplayerhq.hu/dvdinfo/ifo.html). For example, for region 1
-DVDs this byte contains 0xFE. If you burn .iso image onto DVD-R/RW
-disc without first resetting regmask to zero, the resulting disc may
-and most probably will be unplayable by hardware-based DVD players.
+Dvdread looks for DVD region restriction mask inside the VIDEO_TS.IFO
+and VIDEO_TS.BUP files and resets it to 0xC0 if it's not zero and
+doesn't equal to 0xC0 already. This means that the produced deCSSed
+image file can be written onto DVD-R/RW media and the resulting disc
+should be playable in any region.
 
 dvdread prints progress and error messages to stderr and dumps deCSSed
 stream to stdout. If you want to debug, run it with DVDCSS_VERBOSE
@@ -43,14 +42,10 @@ dvdread Operation
 
 dvdread Problems
 
-1. dvdread doesn't modify region mask in VIDEO_TS.IFO/BUP files.
-   Therefore .iso files produced by it require manual zeroing of
-   regmask before writing to DVD-R/RW media.
-
-2. dvdread doesn't reset UOP restrictions too
+1. dvdread doesn't reset UOP restrictions
    (cf https://en.wikipedia.org/wiki/User_operation_prohibition).
 
-3. dvdread may fail due to region mismatch. For some DVDs you may be
+2. dvdread may fail due to region mismatch. For some DVDs you may be
    able to rip using wrong region and for some you may not. This
    happens because drive refuses to decrypt title keys for mismatched
    region and libdvdcss attempts to crack title keys itself. Cracking