1 // dvdimgdecss.1.txt - manual page documenting the program dvdimgdecss
2 // Copyright © 2012 Géraud Meyer
3 // This file is part of dvdimgdecss.
5 // This file is released under the same licensing terms as the source code of
6 // the program which it documents; see the header of the file dvdimgdecss.c.
15 dvdimgdecss - CSS descrambling of raw DVD Video images
22 *dvdimgdecss* [*-v*|*-q*] [*-c*] [*--*] 'dvd'
23 *dvdimgdecss* [*-v*|*-q*] [*-c*|*-C*] [*--*] 'dvd' 'file'
28 `dvdimgdecss` is a command line program to remove the CSS scrambling of DVD
31 dvdimgdecss uses libdvdread and libdvdcss, and passes them 'dvd' as is. 'dvd'
32 can be a drive device file or a raw image file.
34 If 'file' is not given, dvdimgdecss only computes (and prints) the sector
35 ranges corresponding to each file pertaining to the DVD Video.
37 If 'file' is given, it furthermore copies 'dvd' to 'file', possibly decrypting
38 the sector ranges corresponding to VOB files. The actual reading and
39 decryption is done by libdvdcss.
45 Print the version information and exit.
48 Increase or decrease the level of verbosity of messages printed to
49 stdout/stderr. The default level is 1, at which only error messages are
50 printed. At level 0 nothing is printed. At level 2, each domain (title)
51 is displayed as it is processed. At level 3, a percentage indicator is
53 The messages printed by libdvdcss are controlled by the environment
54 variable 'DVDCSS_VERBOSE'; libdvdread's messages cannot be silenced.
57 Make libdvdread search for all the title keys and print the result; while
58 copying and decrypting the 'dvd', enable some consistency checks made by
60 While decrypting, libdvdcss will nonetheless retrieve the title keys again;
61 if the cache directory is in use, the keys will simply be read from it.
64 Use libdvdread instead of libdvdcss for reading (and decrypting) the VOB
65 streams of the 'dvd'. This implies *-c*, and avoids a new search of the
66 title keys by libdvdcss. It is not known (yet) whether libdvdread perform
67 additional checks (compared to libdvdcss alone).
73 libdvdcss' environment variables.
76 libdvdread's environment variable. Setting this variable prevents
77 libdvdread from trying to retrieve all the title keys at once, even when
78 the option *-c* is given.
84 libdvdcss' default cache directory for the title keys. Setting
85 `DVDCSS_CACHE=off` in the environment disables the use of the cache.
90 To be interpreted as a bitmask, where each bit set indicates a failure.
91 Because a usage error always sets all the other bits, the values between 128
92 and 254 remain unused; they constitute a range often used by shells (e.g. bash
93 or older versions of ksh) to indicate an abnormal process termination (killed
100 Usage error (invalid option or wrong number of arguments).
103 I/O error. If a file could not be opened, the exit status is 127.
106 Inconsistencies found (probably because of a bug in dvdimgdecss or its
110 Cancellation due to a memory allocation error.
113 No VOBs were found in the DVD; the output file is the same as the 'dvd' if
114 there are no other errors.
119 If the disc can be read without errors, reading directly from the drive has the
120 advantage of making the disc key available to libdvdcss:
123 dvdimgdecss /dev/sr0 dvd.img
125 It is possible to decrypt a file without a drive (without a disc key);
126 furthermore, we bypass the key cache and make libdvdcss print the new keys
130 DVDCSS_VERBOSE=2 DVDCSS_CACHE=off dvdimgdecss dvd.img dvd.img.decss
132 You might then burn the image to an optical disc.
137 It seems, after a look at its source code, that libdvdcss does not report all
138 the error conditions that it encounters.
140 See also the CDimg|tools distribution file 'BUGS'.
145 dvdimgdecss was written by G.raud Meyer.
150 linkpage:cssdec[1], lsdvd(1), vobcopy(1), dvdbackup(1)