Branching for libburn bugfix release 1.3.0.pl01
This commit is contained in:
4
libburn/branches/1.3.0.pl01/doc/Makefile
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4
libburn/branches/1.3.0.pl01/doc/Makefile
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all clean:
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$(MAKE) -C .. -$(MAKEFLAGS) $@
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||||
.PHONY: all clean
|
729
libburn/branches/1.3.0.pl01/doc/cdtext.txt
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libburn/branches/1.3.0.pl01/doc/cdtext.txt
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|
||||
Description of CD-TEXT
|
||||
|
||||
Guided by Leon Merten Lohse via libcdio-devel@gnu.org
|
||||
by reading mmc3r10g.pdf from http://www.t10.org/ftp/t10/drafts/mmc3/
|
||||
by docs and results of cdtext.zip from http://www.sonydadc.com/file/
|
||||
by reading http://digitalx.org/cue-sheet/syntax
|
||||
by reading source of libcdio from http://www.gnu.org/s/libcdio
|
||||
which quotes source of cdrecord from ftp://ftp.berlios.de/pub/cdrecord/alpha
|
||||
by reading cdrecord.1 from ftp://ftp.berlios.de/pub/cdrecord/alpha
|
||||
|
||||
Language codes were learned from http://tech.ebu.ch/docs/tech/tech3264.pdf
|
||||
Genre codes were learned from libcdio and confirmed by
|
||||
http://helpdesk.audiofile-engineering.com/index.php?pg=kb.page&id=123
|
||||
|
||||
For libburnia-project.org by Thomas Schmitt <scdbackup@gmx.net>
|
||||
|
||||
Content:
|
||||
- CD-TEXT from the view of the user
|
||||
- Content specifications of particular pack types
|
||||
- Format of a CD-TEXT packs array
|
||||
- Overview of libburn API calls for CD-TEXT
|
||||
- Sony Text File Format (Input Sheet Version 0.7T)
|
||||
- CDRWIN cue sheet files
|
||||
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
CD-TEXT from the view of the user:
|
||||
|
||||
CD-TEXT records attributes of disc and tracks on audio CD.
|
||||
|
||||
The attributes are grouped into blocks which represent particular languages.
|
||||
Up to 8 blocks are possible.
|
||||
|
||||
There are 13 defined attribute categories, which are called Pack Types and are
|
||||
identified by a single-byte code:
|
||||
0x80 = Title
|
||||
0x81 = Names of Performers
|
||||
0x82 = Names of Songwriters
|
||||
0x83 = Names of Composers
|
||||
0x84 = Names of Arrangers
|
||||
0x85 = Messages
|
||||
0x86 = text-and-binary: Disc Identification
|
||||
0x87 = text-and-binary: Genre Identification
|
||||
0x88 = binary: Table of Content information
|
||||
0x89 = binary: Second Table of Content information
|
||||
(0x8a to 0x8c are reserved.)
|
||||
0x8d = Closed Information
|
||||
0x8e = UPC/EAN code of the album and ISRC code of each track
|
||||
0x8f = binary: Size Information of the Block
|
||||
|
||||
Some of these categories apply to the whole disc only:
|
||||
0x86, 0x87, 0x88, 0x89, 0x8d
|
||||
Some have to be additionally attributed to each track, if they are present for
|
||||
the whole disc:
|
||||
0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x8e
|
||||
One describes the overall content of a block and in part of all other blocks:
|
||||
0x8f
|
||||
|
||||
The total size of a block's attribute set is restricted by the fact that it
|
||||
has to be stored in at most 253 records with 12 bytes of payload. These records
|
||||
are called Text Packs.
|
||||
A shortcut for repeated identical track texts is provided, so that a text
|
||||
that is identical to the one of the previous track occupies only 2 or 4 bytes.
|
||||
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
Content specification of particular pack types:
|
||||
|
||||
Pack types 0x80 to 0x85 and 0x8e contain 0-terminated cleartext. If double byte
|
||||
characters are used, then two 0-bytes terminate the cleartext.
|
||||
The meaning of 0x80 to 0x85 should be clear by above list. They are encoded
|
||||
according to the Character Code of their block. Either as ISO-8859-1 single
|
||||
byte characters, or as 7-bit ASCII single byte characters, or as MS-JIS double
|
||||
byte characters.
|
||||
More info to 0x8e is given below.
|
||||
|
||||
Pack type 0x86 (Disc Identification) is documented by Sony as "Catalog Number:
|
||||
(use ASCII Code) Catalog Number of the album". So it is not really binary
|
||||
but might be non-printable, and should contain only bytes with bit7 = 0.
|
||||
|
||||
Pack type 0x87 contains 2 binary bytes, followed by 0-terminated cleartext.
|
||||
The two binary bytes form a big-endian index to the following list.
|
||||
0x0000 = "Not Used" (Sony prescribes to use this if no genre applies)
|
||||
0x0001 = "Not Defined"
|
||||
0x0002 = "Adult Contemporary"
|
||||
0x0003 = "Alternative Rock"
|
||||
0x0004 = "Childrens Music"
|
||||
0x0005 = "Classical"
|
||||
0x0006 = "Contemporary Christian"
|
||||
0x0007 = "Country"
|
||||
0x0008 = "Dance"
|
||||
0x0009 = "Easy Listening"
|
||||
0x000a = "Erotic"
|
||||
0x000b = "Folk"
|
||||
0x000c = "Gospel"
|
||||
0x000d = "Hip Hop"
|
||||
0x000e = "Jazz"
|
||||
0x000f = "Latin"
|
||||
0x0010 = "Musical"
|
||||
0x0011 = "New Age"
|
||||
0x0012 = "Opera"
|
||||
0x0013 = "Operetta"
|
||||
0x0014 = "Pop Music"
|
||||
0x0015 = "Rap"
|
||||
0x0016 = "Reggae"
|
||||
0x0017 = "Rock Music"
|
||||
0x0018 = "Rhythm & Blues"
|
||||
0x0019 = "Sound Effects"
|
||||
0x001a = "Spoken Word"
|
||||
0x001b = "World Music"
|
||||
Sony documents the cleartext part as "Genre information that would supplement
|
||||
the Genre Code, such as 'USA Rock music in the 60s'". Always ASCII encoded.
|
||||
|
||||
Pack type 0x88 records information from the CD's Table of Content, as of
|
||||
READ PMA/TOC/ATIP Format 0010b (mmc3r10g.pdf, table 237 TOC Track Descriptor
|
||||
Format, Q Sub-channel).
|
||||
See below, Format of a CD-TEXT packs array, for more details about the content
|
||||
of pack type 0x88.
|
||||
|
||||
Pack type 0x89 is yet quite unclear. It might be a representation of Playback
|
||||
Skip Interval, Mode-5 Q sub-channel, POINT 01 to 40 (mmc3r10g.pdf 4.2.3.6.3).
|
||||
If so, then this seems not to apply to write type SAO, because the CUE SHEET
|
||||
format offers no way to express Mode-5 Q.
|
||||
See below, Format of a CD-TEXT packs array, for an example of this pack type.
|
||||
|
||||
Pack type 0x8d is documented by Sony as "Closed Information: (use 8859-1 Code)
|
||||
Any information can be recorded on disc as memorandum. Information in this
|
||||
field will not be read by CD TEXT players available to the public."
|
||||
Always ISO-8859-1 encoded.
|
||||
|
||||
Pack type 0x8e is documented by Sony as "UPC/EAN Code (POS Code) of the album.
|
||||
This field typically consists of 13 characters." Always ASCII encoded.
|
||||
It applies to tracks as "ISRC code [which] typically consists of 12 characters"
|
||||
and is always ISO-8859-1 encoded.
|
||||
MMC calls these information entities Media Catalog Number and ISRC.
|
||||
The catalog number consists of 13 decimal digits.
|
||||
ISRC consists of 12 characters: 2 country code [0-9A-Z], 3 owner code [0-9A-Z],
|
||||
2 year digits (00 to 99), 5 serial number digits (00000 to 99999).
|
||||
|
||||
Pack type 0x8f summarizes the whole list of text packs of a block.
|
||||
See below, Format of a CD-TEXT packs array, for details.
|
||||
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
Format of a CD-TEXT packs array:
|
||||
|
||||
The attributes are represented on CD as Text Packs in the sub-channel of
|
||||
the Lead-in of the disc. See doc/cookbook.txt for a description how to write
|
||||
the readily formatted CD-TEXT pack array to CD, and how to read CD-TEXT packs
|
||||
from CD.
|
||||
|
||||
The format is explained in part in MMC-3 (mmc3r10g.pdf, Annex J) and in part by
|
||||
the documentation in Sony's cdtext.zip :
|
||||
|
||||
Each pack consists of a 4-byte header, 12 bytes of payload, and 2 bytes of CRC.
|
||||
|
||||
The first byte of each pack tells the pack type. See above for a list of types.
|
||||
|
||||
The second byte tells the track number to which the first text piece in
|
||||
a pack is associated. Number 0 means the whole album. Higher numbers are
|
||||
valid for types 0x80 to 0x85, and 0x8e. With these types, there should be
|
||||
one text for the disc and one for each track.
|
||||
With types 0x88 and 0x89, the second byte bears a track number, too.
|
||||
With type 0x8f, the second byte counts the record parts from 0 to 2.
|
||||
|
||||
The third byte is a sequential counter.
|
||||
|
||||
The fourth byte is the Block Number and Character Position Indicator.
|
||||
It consists of three bit fields:
|
||||
bit7 = Double Bytes Character Code (0= single byte characters)
|
||||
bit4-6 = Block Number (groups text packs in language blocks)
|
||||
bit0-3 = Character position. Either the number of characters which
|
||||
the current text inherited from the previous pack, or
|
||||
15 if the current text started before the previous pack.
|
||||
|
||||
The 12 payload bytes contain pieces of 0-terminated texts or binary data.
|
||||
A text may span over several packs. Unused characters in a pack are used for
|
||||
the next text of the same pack type. If no text of the same type follows,
|
||||
then the remaining text bytes are set to 0.
|
||||
|
||||
The CRC algorithm uses divisor 0x11021. The resulting 16-bit residue of the
|
||||
polynomial division gets inverted and written as big-endian number to bytes
|
||||
16 and 17 of the pack.
|
||||
|
||||
|
||||
The text packs are grouped in up to 8 blocks of at most 256 packs. Each block
|
||||
is in charge for one language. Sequence numbers of each block are counted
|
||||
separately. All packs of block 0 come before the packs of block 1.
|
||||
|
||||
The limitation of block number and sequence numbers imply that there are at
|
||||
most 2048 text packs possible. (READ TOC/PMA/ATIP could retrieve 3640 packs,
|
||||
as it is limited to 64 kB - 2.)
|
||||
|
||||
|
||||
If a text of a track (pack types 0x80 to 0x85 and 0x8e) repeats identically
|
||||
for the next track, then it may be represented by a TAB character (ASCII 9)
|
||||
for single byte texts, resp. two TAB characters for double byte texts.
|
||||
(This should be used because 256 * 12 bytes is few space for 99 tracks.)
|
||||
|
||||
The two binary bytes of pack type 0x87 are written to the first 0x87 pack of
|
||||
a block. They may or may not be repeated at the start of the follow-up packs
|
||||
of type 0x87.
|
||||
|
||||
The first pack of type 0x88 in a block records in its payload bytes:
|
||||
0 : PMIN of POINT A1 = First Track Number
|
||||
1 : PMIN of POINT A2 = Last Track Number
|
||||
2 : unknown, 0 in Sony example
|
||||
3 : PMIN of POINT A2 = Start position of Lead-Out
|
||||
4 : PSEC of POINT A2 = Start position of Lead-Out
|
||||
5 : PFRAME of POINT A2 = Start position of Lead-Out
|
||||
6 to 11 : unknown, 0 in Sony example
|
||||
The following packs record PMIN, PSEC, PFRAME of the POINTs between the
|
||||
lowest track number (min 01h) and the highest track number (max 63h).
|
||||
The payload of the last pack is padded by 0s.
|
||||
The Sony .TOC example:
|
||||
A0 01
|
||||
A1 14
|
||||
A2 63:02:18
|
||||
01 00:02:00
|
||||
02 04:11:25
|
||||
03 08:02:50
|
||||
04 11:47:62
|
||||
...
|
||||
13 53:24:25
|
||||
14 57:03:25
|
||||
yields
|
||||
88 00 23 00 01 0e 00 3f 02 12 00 00 00 00 00 00 12 00
|
||||
88 01 24 00 00 02 00 04 0b 19 08 02 32 0b 2f 3e 67 2d
|
||||
...
|
||||
88 0d 27 00 35 18 19 39 03 19 00 00 00 00 00 00 ea af
|
||||
|
||||
Pack type 0x89 is yet quite unclear. Especially what the information shall
|
||||
mean to the user of the CD. The time points in the Sony example are in the
|
||||
time range of the tracks numbers that are given before the time points:
|
||||
01 02:41:48 01 02:52:58
|
||||
06 23:14:25 06 23:29:60
|
||||
07 28:30:39 07 28:42:30
|
||||
13 55:13:26 13 55:31:50
|
||||
yields
|
||||
89 01 28 00 01 04 00 00 00 00 02 29 30 02 34 3a f3 0c
|
||||
89 06 29 00 02 04 00 00 00 00 17 0e 19 17 1d 3c 73 92
|
||||
89 07 2a 00 03 04 00 00 00 00 1c 1e 27 1c 2a 1e 72 20
|
||||
89 0d 2b 00 04 04 00 00 00 00 37 0d 1a 37 1f 32 0b 62
|
||||
The track numbers are stored in the track number byte of the packs. The two
|
||||
time points are stored in byte 6 to 11 of the payload. Byte 0 of the payload
|
||||
seems to be a sequential counter. Byte 1 always 4 ? Byte 2 to 5 always 0 ?
|
||||
|
||||
Pack type 0x8f summarizes the whole list of text packs of a block.
|
||||
So there is one group of three 0x8f packs per block.
|
||||
Nevertheless each 0x8f group tells the highest sequence number and the
|
||||
language code of all blocks.
|
||||
The payload bytes of three 0x8f packs form a 36 byte record. The track number
|
||||
bytes of the three packs have the values 0, 1, 2.
|
||||
Byte :
|
||||
0 : Character code for pack types 0x80 to 0x85:
|
||||
0x00 = ISO-8859-1
|
||||
0x01 = 7 bit ASCII
|
||||
0x80 = MS-JIS (japanese Kanji, double byte characters)
|
||||
1 : Number of first track
|
||||
2 : Number of last track
|
||||
3 : libcdio source states: "cd-text information copyright byte"
|
||||
Probably 3 means "copyrighted", 0 means "not copyrighted".
|
||||
4 - 19 : Pack count of the various types 0x80 to 0x8f.
|
||||
Byte number N tells the count of packs of type 0x80 + (N - 4).
|
||||
I.e. the first byte in this field of 16 counts packs of type 0x80.
|
||||
20 - 27 : Highest sequence byte number of blocks 0 to 7.
|
||||
28 - 36 : Language code for blocks 0 to 7 (tech3264.pdf appendix 3)
|
||||
Not all of these Codes have ever been seen with CD-TEXT, though.
|
||||
0x00 = Unknown
|
||||
0x01 = Albanian
|
||||
0x02 = Breton
|
||||
0x03 = Catalan
|
||||
0x04 = Croatian
|
||||
0x05 = Welsh
|
||||
0x06 = Czech
|
||||
0x07 = Danish
|
||||
0x08 = German
|
||||
0x09 = English
|
||||
0x0a = Spanish
|
||||
0x0b = Esperanto
|
||||
0x0c = Estonian
|
||||
0x0d = Basque
|
||||
0x0e = Faroese
|
||||
0x0f = French
|
||||
0x10 = Frisian
|
||||
0x11 = Irish
|
||||
0x12 = Gaelic
|
||||
0x13 = Galician
|
||||
0x14 = Icelandic
|
||||
0x15 = Italian
|
||||
0x16 = Lappish
|
||||
0x17 = Latin
|
||||
0x18 = Latvian
|
||||
0x19 = Luxembourgian
|
||||
0x1a = Lithuanian
|
||||
0x1b = Hungarian
|
||||
0x1c = Maltese
|
||||
0x1d = Dutch
|
||||
0x1e = Norwegian
|
||||
0x1f = Occitan
|
||||
0x20 = Polish
|
||||
0x21 = Portuguese
|
||||
0x22 = Romanian
|
||||
0x23 = Romansh
|
||||
0x24 = Serbian
|
||||
0x25 = Slovak
|
||||
0x26 = Slovenian
|
||||
0x27 = Finnish
|
||||
0x28 = Swedish
|
||||
0x29 = Turkish
|
||||
0x2a = Flemish
|
||||
0x2b = Wallon
|
||||
0x45 = Zulu
|
||||
0x46 = Vietnamese
|
||||
0x47 = Uzbek
|
||||
0x48 = Urdu
|
||||
0x49 = Ukrainian
|
||||
0x4a = Thai
|
||||
0x4b = Telugu
|
||||
0x4c = Tatar
|
||||
0x4d = Tamil
|
||||
0x4e = Tadzhik
|
||||
0x4f = Swahili
|
||||
0x50 = Sranan Tongo
|
||||
0x51 = Somali
|
||||
0x52 = Sinhalese
|
||||
0x53 = Shona
|
||||
0x54 = Serbo-croat
|
||||
0x55 = Ruthenian
|
||||
0x56 = Russian
|
||||
0x57 = Quechua
|
||||
0x58 = Pushtu
|
||||
0x59 = Punjabi
|
||||
0x5a = Persian
|
||||
0x5b = Papamiento
|
||||
0x5c = Oriya
|
||||
0x5d = Nepali
|
||||
0x5e = Ndebele
|
||||
0x5f = Marathi
|
||||
0x60 = Moldavian
|
||||
0x61 = Malaysian
|
||||
0x62 = Malagasay
|
||||
0x63 = Macedonian
|
||||
0x64 = Laotian
|
||||
0x65 = Korean
|
||||
0x66 = Khmer
|
||||
0x67 = Kazakh
|
||||
0x68 = Kannada
|
||||
0x69 = Japanese
|
||||
0x6a = Indonesian
|
||||
0x6b = Hindi
|
||||
0x6c = Hebrew
|
||||
0x6d = Hausa
|
||||
0x6e = Gurani
|
||||
0x6f = Gujurati
|
||||
0x70 = Greek
|
||||
0x71 = Georgian
|
||||
0x72 = Fulani
|
||||
0x73 = Dari
|
||||
0x74 = Churash
|
||||
0x75 = Chinese
|
||||
0x76 = Burmese
|
||||
0x77 = Bulgarian
|
||||
0x78 = Bengali
|
||||
0x79 = Bielorussian
|
||||
0x7a = Bambora
|
||||
0x7b = Azerbaijani
|
||||
0x7c = Assamese
|
||||
0x7d = Armenian
|
||||
0x7e = Arabic
|
||||
0x7f = Amharic
|
||||
E.g. these three packs
|
||||
42 : 8f 00 2a 00 01 01 03 00 06 05 04 05 07 06 01 02 48 65
|
||||
43 : 8f 01 2b 00 00 00 00 00 00 00 06 03 2c 00 00 00 c0 20
|
||||
44 : 8f 02 2c 00 00 00 00 00 09 00 00 00 00 00 00 00 11 45
|
||||
decode to
|
||||
Byte :Value Meaning
|
||||
0 : 01 = ASCII 7-bit
|
||||
1 : 01 = first track is 1
|
||||
2 : 03 = last track is 3
|
||||
3 : 00 = copyright (0 = public domain, 3 = copyrighted ?)
|
||||
4 : 06 = 6 packs of type 0x80
|
||||
5 : 05 = 5 packs of type 0x81
|
||||
6 : 04 = 4 packs of type 0x82
|
||||
7 : 05 = 5 packs of type 0x83
|
||||
8 : 07 = 7 packs of type 0x84
|
||||
9 : 06 = 6 packs of type 0x85
|
||||
10 : 01 = 1 pack of type 0x86
|
||||
11 : 02 = 2 packs of type 0x87
|
||||
12 : 00 = 0 packs of type 0x88
|
||||
13 : 00 = 0 packs of type 0x89
|
||||
14 : 00 00 00 00 = 0 packs of types 0x8a to 0x8d
|
||||
18 : 06 = 6 packs of type 0x8e
|
||||
19 : 03 = 3 packs of type 0x8f
|
||||
20 : 2c = last sequence for block 0
|
||||
This matches the sequence number of the last text pack (0x2c = 44)
|
||||
21 : 00 00 00 00 00 00 00 = last sequence numbers for block 1..7 (none)
|
||||
28 : 09 = language code for block 0: English
|
||||
29 : 00 00 00 00 00 00 00 = language codes for block 1..7 (none)
|
||||
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
Overview of libburn API calls for CD-TEXT (see libburn/libburn.h for details):
|
||||
|
||||
libburn can retrieve the set of text packs from a CD:
|
||||
|
||||
int burn_disc_get_leadin_text(struct burn_drive *d,
|
||||
unsigned char **text_packs, int *num_packs,
|
||||
int flag);
|
||||
|
||||
|
||||
It can write a text pack set with a CD SAO session.
|
||||
|
||||
This set may be attached as array of readily formatted text packs by:
|
||||
|
||||
int burn_write_opts_set_leadin_text(struct burn_write_opts *opts,
|
||||
unsigned char *text_packs,
|
||||
int num_packs, int flag);
|
||||
|
||||
The array may be read from a file by
|
||||
|
||||
int burn_cdtext_from_packfile(char *path, unsigned char **text_packs,
|
||||
int *num_packs, int flag);
|
||||
|
||||
|
||||
Alternatively the pack set may be defined by attaching CD-TEXT attributes
|
||||
to burn_session and burn_track:
|
||||
|
||||
int burn_session_set_cdtext_par(struct burn_session *s,
|
||||
int char_codes[8], int copyrights[8],
|
||||
int languages[8], int flag);
|
||||
|
||||
int burn_session_set_cdtext(struct burn_session *s, int block,
|
||||
int pack_type, char *pack_type_name,
|
||||
unsigned char *payload, int length, int flag);
|
||||
|
||||
int burn_track_set_cdtext(struct burn_track *t, int block,
|
||||
int pack_type, char *pack_type_name,
|
||||
unsigned char *payload, int length, int flag);
|
||||
|
||||
Macros list the texts for genre and language codes:
|
||||
|
||||
BURN_CDTEXT_LANGUAGES_0X00
|
||||
BURN_CDTEXT_FILLER
|
||||
BURN_CDTEXT_LANGUAGES_0X45
|
||||
|
||||
BURN_CDTEXT_GENRE_LIST
|
||||
BURN_CDTEXT_NUM_GENRES
|
||||
|
||||
There is a reader for Sony Input Sheet Version 0.7T:
|
||||
|
||||
int burn_session_input_sheet_v07t(struct burn_session *session,
|
||||
char *path, int block, int flag);
|
||||
|
||||
CD-TEXT can be read from a CDRWIN cue sheet file which defines the tracks
|
||||
of a session
|
||||
|
||||
int burn_session_by_cue_file(struct burn_session *session,
|
||||
char *path, int fifo_size, struct burn_source **fifo,
|
||||
unsigned char **text_packs, int *num_packs, int flag);
|
||||
|
||||
|
||||
The session and track attributes can then be converted into an array of
|
||||
text packs by:
|
||||
|
||||
int burn_cdtext_from_session(struct burn_session *s,
|
||||
unsigned char **text_packs, int *num_packs,
|
||||
int flag);
|
||||
|
||||
or they can be written as array of text packs to CD when burning begins and
|
||||
no array of pre-formatted packs was attached to the write options by
|
||||
burn_write_opts_set_leadin_text().
|
||||
|
||||
There are calls for inspecting the attached attributes:
|
||||
|
||||
int burn_session_get_cdtext_par(struct burn_session *s,
|
||||
int char_codes[8], int copyrights[8],
|
||||
int block_languages[8], int flag);
|
||||
|
||||
int burn_session_get_cdtext(struct burn_session *s, int block,
|
||||
int pack_type, char *pack_type_name,
|
||||
unsigned char **payload, int *length, int flag);
|
||||
|
||||
int burn_track_get_cdtext(struct burn_track *t, int block,
|
||||
int pack_type, char *pack_type_name,
|
||||
unsigned char **payload, int *length, int flag);
|
||||
|
||||
and for removing attached attributes:
|
||||
|
||||
int burn_session_dispose_cdtext(struct burn_session *s, int block);
|
||||
|
||||
int burn_track_dispose_cdtext(struct burn_track *t, int block);
|
||||
|
||||
|
||||
UPC/EAN and ISRC not only affect CD-TEXT but also information that is written
|
||||
along with the tracks in Q sub-channel. These can be influenced by
|
||||
burn_session_input_sheet_v07t(), burn_session_by_cue_file() and by
|
||||
|
||||
void burn_write_opts_set_mediacatalog(struct burn_write_opts *opts,
|
||||
unsigned char mediacatalog[13]);
|
||||
|
||||
void burn_write_opts_set_has_mediacatalog(struct burn_write_opts *opts,
|
||||
int has_mediacatalog);
|
||||
|
||||
void burn_track_set_isrc(struct burn_track *t, char *country, char *owner,
|
||||
unsigned char year, unsigned int serial);
|
||||
|
||||
int burn_track_set_isrc_string(struct burn_track *t, char isrc[13],
|
||||
int flag);
|
||||
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
Sony Text File Format (Input Sheet Version 0.7T):
|
||||
|
||||
This text file format provides comprehensive means to define the text
|
||||
attributes of session and tracks for a single block. More than one
|
||||
such file has to be read to form an attribute set with multiple blocks.
|
||||
|
||||
The information is given by text lines of the following form:
|
||||
purpose specifier [whitespace] = [whitespace] content text
|
||||
[whitespace] is zero or more ASCII 32 (space) or ASCII 9 (tab) characters.
|
||||
The purpose specifier tells the meaning of the content text.
|
||||
Empty content text does not cause a CD-TEXT attribute to be attached.
|
||||
|
||||
The following purpose specifiers apply to the session as a whole:
|
||||
Specifier = Meaning
|
||||
-------------------------------------------------------------------------
|
||||
Text Code = Character code for pack type 0x8f
|
||||
"ASCII", "8859"
|
||||
Language Code = One of the language names for pack type 0x8f
|
||||
Album Title = Content of pack type 0x80
|
||||
Artist Name = Content of pack type 0x81
|
||||
Songwriter = Content of pack type 0x82
|
||||
Composer = Content of pack type 0x83
|
||||
Arranger = Content of pack type 0x84
|
||||
Album Message = Content of pack type 0x85
|
||||
Catalog Number = Content of pack type 0x86
|
||||
Genre Code = One of the genre names for pack type 0x87
|
||||
Genre Information = Cleartext part of pack type 0x87
|
||||
Closed Information = Content of pack type 0x8d
|
||||
UPC / EAN = Content of pack type 0x8e
|
||||
Text Data Copy Protection = Copyright value for pack type 0x8f
|
||||
"ON" = 0x03, "OFF" = 0x00
|
||||
First Track Number = The lowest track number used in the file
|
||||
Last Track Number = The highest track number used in the file
|
||||
|
||||
The following purpose specifiers apply to particular tracks:
|
||||
Track NN Title = Content of pack type 0x80
|
||||
Track NN Artist = Content of pack type 0x81
|
||||
Track NN Songwriter = Content of pack type 0x82
|
||||
Track NN Composer = Content of pack type 0x83
|
||||
Track NN Arranger = Content of pack type 0x84
|
||||
Track NN Message = Content of pack type 0x85
|
||||
ISRC NN = Content of pack type 0x8e
|
||||
|
||||
The following purpose specifiers have no effect on CD-TEXT:
|
||||
Remarks = Comments with no influence on CD-TEXT
|
||||
Disc Information NN = Supplementary information for use by record companies.
|
||||
ISO-8859-1 encoded. NN ranges from 01 to 04.
|
||||
Input Sheet Version = "0.7T"
|
||||
|
||||
|
||||
libburn peculiarties:
|
||||
|
||||
libburn may read files of the described format by
|
||||
burn_session_input_sheet_v07t()
|
||||
after the burn_session has been establiched and all burn_track objects have
|
||||
been added.
|
||||
|
||||
The following purpose specifiers accept byte values of the form 0xXY.
|
||||
Text Code , Language Code , Genre Code , Text Data Copy Protection
|
||||
E.g. to indicate MS-JIS character code (of which the exact name is unknown):
|
||||
Text Code = 0x80
|
||||
Genre Code is settable by 0xXY or 0xXYZT or 0xXY 0xZT.
|
||||
Genre Code = 0x001b
|
||||
|
||||
Purpose specifiers which have the meaning "Content of pack type 0xXY"
|
||||
may be replaced by the pack type codes. E.g.:
|
||||
0x80 = Session content of pack type 0x80
|
||||
Track 02 0x80 = Track content of pack type 0x80 for track 2.
|
||||
Applicable are pack types 0x80 to 0x86, 0x8d, 0x8e.
|
||||
|
||||
Text Code may be specified only once. It gets speficied to "ISO-8850-1"
|
||||
automatically as soon as content is defined which depends on the text
|
||||
encoding of the block. I.e with pack types 0x80 to 0x85.
|
||||
|
||||
If a track attribute is set, but the corresponding session attribute is not
|
||||
defined or defined with empty text, then the session attribute gets attached
|
||||
as empty test. (Normally empty content is ignored.)
|
||||
|
||||
|
||||
Example cdrskin run with three tracks:
|
||||
|
||||
$ cdrskin dev=/dev/sr0 -v input_sheet_v07t=NIGHTCATS.TXT \
|
||||
-audio track_source_1 track_source_2 track_source_3
|
||||
|
||||
----------------------------------------------------------
|
||||
Content of file NIGHTCATS.TXT :
|
||||
----------------------------------------------------------
|
||||
Input Sheet Version = 0.7T
|
||||
Text Code = 8859
|
||||
Language Code = English
|
||||
Album Title = Joyful Nights
|
||||
Artist Name = United Cat Orchestra
|
||||
Songwriter = Various Songwriters
|
||||
Composer = Various Composers
|
||||
Arranger = Tom Cat
|
||||
Album Message = For all our fans
|
||||
Catalog Number = 1234567890
|
||||
Genre Code = Classical
|
||||
Genre Information = Feline classic music
|
||||
Closed Information = This is not to be shown by CD players
|
||||
UPC / EAN = 1234567890123
|
||||
Text Data Copy Protection = OFF
|
||||
First Track Number = 1
|
||||
Last Track Number = 3
|
||||
Track 01 Title = Song of Joy
|
||||
Track 01 Artist = Felix and The Purrs
|
||||
Track 01 Songwriter = Friedrich Schiller
|
||||
Track 01 Composer = Ludwig van Beethoven
|
||||
Track 01 Arranger = Tom Cat
|
||||
Track 01 Message = Fritz and Louie once were punks
|
||||
ISRC 01 = XYBLG1101234
|
||||
Track 02 Title = Humpty Dumpty
|
||||
Track 02 Artist = Catwalk Beauties
|
||||
Track 02 Songwriter = Mother Goose
|
||||
Track 02 Composer = unknown
|
||||
Track 02 Arranger = Tom Cat
|
||||
Track 02 Message = Pluck the goose
|
||||
ISRC 02 = XYBLG1100005
|
||||
Track 03 Title = Mee Owwww
|
||||
Track 03 Artist = Mia Kitten
|
||||
Track 03 Songwriter = Mia Kitten
|
||||
Track 03 Composer = Mia Kitten
|
||||
Track 03 Arranger = Mia Kitten
|
||||
Track 03 Message =
|
||||
ISRC 03 = XYBLG1100006
|
||||
----------------------------------------------------------
|
||||
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
CDRWIN cue sheet files:
|
||||
|
||||
A CDRWIN cue sheet file defines the track data source (FILE), various text
|
||||
attributes (CATALOG, TITLE, PERFORMER, SONGWRITER, ISRC), track block types
|
||||
(TRACK), track start addresses (INDEX).
|
||||
The rules for CDRWIN cue sheet files are described at
|
||||
http://digitalx.org/cue-sheet/syntax/
|
||||
There are three more text attributes mentioned in man cdrecord for defining
|
||||
the corresponding CD-TEXT attributes: ARRANGER, COMPOSER, MESSAGE.
|
||||
|
||||
|
||||
--------------------------------------------------------
|
||||
Example of a CDRWIN cue sheet file named NIGHTCATS.CUE :
|
||||
--------------------------------------------------------
|
||||
|
||||
CATALOG 1234567890123
|
||||
FILE "audiodata.bin" BINARY
|
||||
TITLE "Joyful Nights"
|
||||
TRACK 01 AUDIO
|
||||
FLAGS DCP
|
||||
TITLE "Song of Joy"
|
||||
PERFORMER "Felix and The Purrs"
|
||||
SONGWRITER "Friedrich Schiller"
|
||||
ISRC XYBLG1101234
|
||||
INDEX 01 00:00:00
|
||||
TRACK 02 AUDIO
|
||||
FLAGS DCP
|
||||
TITLE "Humpty Dumpty"
|
||||
PERFORMER "Catwalk Beauties"
|
||||
SONGWRITER "Mother Goose"
|
||||
ISRC XYBLG1100005
|
||||
INDEX 01 08:20:12
|
||||
TRACK 03 AUDIO
|
||||
FLAGS DCP
|
||||
TITLE "Mee Owwww"
|
||||
PERFORMER "Mia Kitten"
|
||||
SONGWRITER "Mia Kitten"
|
||||
ISRC XYBLG1100006
|
||||
INDEX 01 13:20:33
|
||||
|
||||
By
|
||||
|
||||
$ cdrskin -v dev=/dev/sr0 -text cuefile=NIGHTCATS.CUE
|
||||
|
||||
this yields as text packs:
|
||||
|
||||
0 : 80 00 00 00 J o y f u l N i g h t f0 f7
|
||||
1 : 80 00 01 0c s 00 S o n g o f J o 43 1c
|
||||
2 : 80 01 02 0a y 00 H u m p t y D u m 43 f9
|
||||
3 : 80 02 03 0a p t y 00 M e e O w w w 24 72
|
||||
4 : 80 03 04 08 w 00 00 00 00 00 00 00 00 00 00 00 6e af
|
||||
5 : 81 00 05 00 00 F e l i x a n d T 4d 51
|
||||
6 : 81 01 06 0b h e P u r r s 00 C a t a7 40
|
||||
7 : 81 02 07 03 w a l k B e a u t i e 59 80
|
||||
8 : 81 02 08 0f s 00 M i a K i t t e n 30 c9
|
||||
9 : 81 03 09 0a 00 00 00 00 00 00 00 00 00 00 00 00 ad 19
|
||||
10 : 82 00 0a 00 00 F r i e d r i c h S 70 8f
|
||||
11 : 82 01 0b 0b c h i l l e r 00 M o t h 33 43
|
||||
12 : 82 02 0c 04 e r G o o s e 00 M i a d6 f5
|
||||
13 : 82 03 0d 03 K i t t e n 00 00 00 00 00 f5 83
|
||||
14 : 8e 00 0e 00 1 2 3 4 5 6 7 8 9 0 1 2 92 3e
|
||||
15 : 8e 00 0f 0c 3 00 X Y B L G 1 1 0 1 2 c0 2b
|
||||
16 : 8e 01 10 0a 3 4 00 X Y B L G 1 1 0 0 bb b3
|
||||
17 : 8e 02 11 09 0 0 5 00 X Y B L G 1 1 0 f3 bf
|
||||
18 : 8e 03 12 08 0 0 0 6 00 00 00 00 00 00 00 00 5b 5c
|
||||
19 : 8f 00 13 00 00 01 03 00 05 05 04 00 00 00 00 00 9b fe
|
||||
20 : 8f 01 14 00 00 00 00 00 00 00 05 03 15 00 00 00 11 0b
|
||||
21 : 8f 02 15 00 00 00 00 00 09 00 00 00 00 00 00 00 da 77
|
||||
|
||||
--------------------------------------
|
||||
|
||||
Some restrictions apply in the libburn call burn_session_by_cue_file():
|
||||
|
||||
Only FILE types BINARY, MOTOROLA, WAVE are allowed.
|
||||
Only TRACK datatypes AUDIO, MODE1/2048 are allowed. They may not be mixed in
|
||||
the same session.
|
||||
|
||||
On the other hand, ARRANGER, COMPOSER, MESSAGE are supported unconditionally.
|
||||
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
This text is copyright 2011 - 2012 Thomas Schmitt <scdbackup@gmx.net>.
|
||||
Permission is granted to copy, modify, and distribute it, as long as the
|
||||
references to the original information sources are maintained.
|
||||
There is NO WARRANTY, to the extent permitted by law.
|
||||
-------------------------------------------------------------------------------
|
||||
|
119
libburn/branches/1.3.0.pl01/doc/comments
Normal file
119
libburn/branches/1.3.0.pl01/doc/comments
Normal file
@ -0,0 +1,119 @@
|
||||
/**
|
||||
@author Mario Danic, Thomas Schmitt
|
||||
|
||||
@mainpage Libburn Documentation Index
|
||||
|
||||
@section intro Introduction
|
||||
|
||||
Libburnia is an open-source project for reading, mastering and writing
|
||||
optical discs. This page is about its capability to handle optical media.
|
||||
For now this means CD-R, CD-RW, DVD-RAM, DVD+RW, DVD+R, DVD+R/DL, DVD-RW,
|
||||
DVD-R, DVD-R/DL, BD-R, BD-RE.
|
||||
|
||||
Our scope is currently Linux 2.4 and 2.6, or FreeBSD, or Solaris . For ports
|
||||
to other systems we would need : login on a development machine resp.
|
||||
an OS ithat is installable on an AMD 64-bit PC, advise from a system person
|
||||
about the equivalent of Linux sg or FreeBSD CAM, volunteers for testing of
|
||||
realistic use cases.
|
||||
|
||||
libburn is the library by which preformatted data get onto optical media.
|
||||
Its code is independent of cdrecord. Its DVD capabilities are learned from
|
||||
studying the code of dvd+rw-tools and MMC-5 specs. No code but only the pure
|
||||
SCSI knowledge has been taken from dvd+rw-tools, though.
|
||||
|
||||
cdrskin is a limited cdrecord compatibility wrapper for libburn.
|
||||
cdrecord is a powerful GPL'ed burn program included in Joerg Schilling's
|
||||
cdrtools. cdrskin strives to be a second source for the services traditionally
|
||||
provided by cdrecord. Additionally it provides libburn's DVD/BD capabilities,
|
||||
where only -sao is compatible with cdrecord.
|
||||
cdrskin does not contain any bytes copied from cdrecord's sources.
|
||||
Many bytes have been copied from the message output of cdrecord runs, though.
|
||||
See cdrskin/README for more.
|
||||
|
||||
The burn API example of libburn is named test/libburner.c . The API for media
|
||||
information inquiry is demonstrated in test/telltoc.c .
|
||||
Explore these examples if you look for inspiration.
|
||||
|
||||
SONAME:
|
||||
libburn.so.4 (since 0.3.4, March 2007),
|
||||
|
||||
|
||||
@section using Using libburn
|
||||
|
||||
Our build system is based on autotools.
|
||||
User experience tells us that you will need at least autotools version 1.7.
|
||||
|
||||
To build libburn and its companion applications go into its toplevel directory
|
||||
and execute
|
||||
|
||||
- ./bootstrap (needed if you downloaded from SVN)
|
||||
|
||||
- ./configure
|
||||
|
||||
- make
|
||||
|
||||
To make the libraries accessible for running resp. developing applications
|
||||
|
||||
- make install
|
||||
|
||||
|
||||
@section libburner Libburner
|
||||
|
||||
libburner is a minimal demo application for the library libburn
|
||||
(see: libburn/libburn.h) as provided on http://libburnia-project.org .
|
||||
It can list the available devices, can burn to recordable CD, DVD, or BD,
|
||||
can blank a CD-RW or DVD-RW, and can format unformatted DVD-RW, BD-R, or BD-RE.
|
||||
|
||||
It's main purpose, nevertheless, is to show you how to use libburn and also
|
||||
to serve the libburnia team as reference application. libburner does indeed
|
||||
define the standard way how above gestures can be implemented and stay upward
|
||||
compatible for a good while.
|
||||
|
||||
@subsection libburner-help Libburner --help
|
||||
<pre>
|
||||
Usage: test/libburner
|
||||
[--drive address|driveno|"-"] [--audio]
|
||||
[--blank_fast|--blank_full|--format] [--try_to_simulate]
|
||||
[--multi] [one or more imagefiles|"-"]
|
||||
Examples
|
||||
A bus scan (needs rw-permissions to see a drive):
|
||||
test/libburner --drive -
|
||||
Burn a file to drive chosen by number, leave appendable:
|
||||
test/libburner --drive 0 --multi my_image_file
|
||||
Burn a file to drive chosen by persistent address, close:
|
||||
test/libburner --drive /dev/hdc my_image_file
|
||||
Blank a used CD-RW (is combinable with burning in one run):
|
||||
test/libburner --drive /dev/hdc --blank_fast
|
||||
Blank a used DVD-RW (is combinable with burning in one run):
|
||||
test/libburner --drive /dev/hdc --blank_full
|
||||
Format a DVD-RW, BD-RE or BD-R:
|
||||
test/libburner --drive /dev/hdc --format
|
||||
Burn two audio tracks (to CD only):
|
||||
lame --decode -t /path/to/track1.mp3 track1.cd
|
||||
test/dewav /path/to/track2.wav -o track2.cd
|
||||
test/libburner --drive /dev/hdc --audio track1.cd track2.cd
|
||||
Burn a compressed afio archive on-the-fly:
|
||||
( cd my_directory ; find . -print | afio -oZ - ) | \
|
||||
test/libburner --drive /dev/hdc -
|
||||
To be read from *not mounted* media via: afio -tvZ /dev/hdc
|
||||
</pre>
|
||||
libburner has two companions, telltoc and dewav, which help to perform some
|
||||
peripheral tasks of burning.
|
||||
|
||||
telltoc prints a table of content (sessions, tracks and leadouts), it tells
|
||||
about type and state of media, and also is able to provide the necessary
|
||||
multi-session information for program mkisofs option -C. Especially helpful
|
||||
are its predictions with "Write multi" and "Write modes" where availability
|
||||
of "TAO" indicates that tracks of unpredicted length can be written.
|
||||
See: test/telltoc --help.
|
||||
|
||||
dewav extracts raw byte-swapped audio data from files of format .wav (MS WAVE)
|
||||
or .au (SUN Audio). See example in libburner --help.
|
||||
|
||||
@subsection libburner-source Sourceode of libburner
|
||||
|
||||
Click on blue names of functions, structures, variables, etc in oder to
|
||||
get to the according specs of libburn API or libburner sourcecode.
|
||||
|
||||
@include libburner.c
|
||||
*/
|
1519
libburn/branches/1.3.0.pl01/doc/cookbook.txt
Normal file
1519
libburn/branches/1.3.0.pl01/doc/cookbook.txt
Normal file
File diff suppressed because it is too large
Load Diff
388
libburn/branches/1.3.0.pl01/doc/ddlp.txt
Normal file
388
libburn/branches/1.3.0.pl01/doc/ddlp.txt
Normal file
@ -0,0 +1,388 @@
|
||||
-------------------------------------------------------------------------------
|
||||
|
||||
Users of modern desktop Linux installations report misburns with CD/DVD
|
||||
recording due to concurrency problems.
|
||||
|
||||
This text describes two locking protocols which have been developed by our
|
||||
best possible effort. But finally they rather serve as repelling example of
|
||||
what would be needed in user space to achieve an insufficient partial solution.
|
||||
|
||||
Ted Ts'o was so friendly to help as critic with his own use cases. It turned
|
||||
out that we cannot imagine a way in user space how to cover reliably the needs
|
||||
of callers of libblkid and the needs of our burn programs.
|
||||
|
||||
-------------------------------------------------------------------------------
|
||||
Content:
|
||||
|
||||
The "Delicate Device Locking Protocol" shall demonstrate our sincere
|
||||
consideration of the problem.
|
||||
|
||||
"What are the Stumble Stones ?" lists reasons why the effort finally failed.
|
||||
|
||||
-----------------------------------------------------------------------------
|
||||
|
||||
|
||||
Delicate Device Locking Protocol
|
||||
(a joint sub project of cdrkit and libburnia)
|
||||
(contact: scdbackup@gmx.net )
|
||||
|
||||
Our projects provide programs which allow recording of data on CD or DVD.
|
||||
We encounter an increasing number of bug reports about spoiled burn runs and
|
||||
wasted media which obviously have one common cause: interference by other
|
||||
programs which access the drive's device files.
|
||||
There is some riddling about which gestures exactly are dangerous for
|
||||
ongoing recordings or can cause weirdly misformatted drive replies to MMC
|
||||
commands.
|
||||
We do know, nevertheless, that these effects do not occur if no other program
|
||||
accesses a device file of the drive while our programs use it.
|
||||
|
||||
DDLP shall help to avoid collisions between programs in the process of
|
||||
recording to a CD or DVD drive and other programs which access that drive.
|
||||
The protocol intends to provide advisory locking. So any good-willing program
|
||||
has to take some extra precautions to participate.
|
||||
|
||||
If a program does not feel vulnerable to disturbance, then the precautions
|
||||
impose much less effort than if the program feels the need for protection.
|
||||
|
||||
Two locking strategies are specified:
|
||||
DDLP-A operates on device files only. It is very Linux specific.
|
||||
DDLP-B adds proxy lock files, inspired by FHS /var/lock standard.
|
||||
|
||||
|
||||
DDLP-A
|
||||
|
||||
This protocol relies on the hardly documented feature open(O_EXCL | O_RDWR)
|
||||
with Linux device files and on POSIX compliant fcntl(F_SETLK).
|
||||
|
||||
Other than the original meaning of O_EXCL with creating regular files, the
|
||||
effect on device files is mutual exclusion of access. I.e. if one
|
||||
filedescriptor is open on that combination of major-minor device number, then
|
||||
no other open(O_EXCL) will succeed. But open() without O_EXCL would succeed.
|
||||
So this is advisory and exclusive locking.
|
||||
With kernel 2.6 it seems to work on all device drivers which might get used
|
||||
to access a CD/DVD drive.
|
||||
|
||||
The vulnerable programs shall not start their operation before they occupied a
|
||||
wide collection of drive representations.
|
||||
Non-vulnerable programs shall take care to detect the occupation of _one_ such
|
||||
representation.
|
||||
|
||||
So for Friendly Programs
|
||||
|
||||
A program which does not feel vulnerable to disturbance is urged to access
|
||||
CD/DVD drives by opening a file descriptor which will uphold the lock
|
||||
as long as it does not get closed. There are two alternative ways to achieve
|
||||
this.
|
||||
Very reliable is
|
||||
|
||||
open( some_path , O_EXCL | ...)
|
||||
|
||||
But O_EXCL imposes restrictions and interferences:
|
||||
- O_EXCL | O_RDONLY does not succeed with /dev/sg* !
|
||||
- O_EXCL cannot provide shared locks for programs which only want to lock
|
||||
against burn programs but not against their own peers.
|
||||
- O_EXCL keeps from obtaining information by harmless activities.
|
||||
- O_EXCL already has a meaning with devices which are mounted as filesystems.
|
||||
This priority meaning is more liberal than the one needed for CD/DV recording
|
||||
protection.
|
||||
|
||||
So it may be necessary to use a cautious open() without O_EXCL and to aquire
|
||||
a POSIX lock via fcntl(). "Cautious" means to add O_NDELAY to the flags of
|
||||
open(), because this is declared to avoid side effects within open().
|
||||
|
||||
With this gesture it is important to use the paths expected by our burn
|
||||
programs: /dev/sr[0..255] /dev/scd[0..255] /dev/sg[0..255] /dev/hd[a..z]
|
||||
because fcntl(F_SETLK) does not lock the device but only a device-inode.
|
||||
|
||||
std_path = one of the standard device files:
|
||||
/dev/sr[0..255] /dev/scd[0..255] /dev/sg[0..255] /dev/hd[a..z]
|
||||
or a symbolic link pointing to one of them.
|
||||
open( std_path , ... | O_NDELAY)
|
||||
fcntl(F_SETLK) and close() on failure
|
||||
... eventually disable O_NDELAY by fcntl(F_SETFL) ...
|
||||
|
||||
There is a pitfall mentioned in man 2 fcntl :
|
||||
"locks are automatically released [...] if it closes any file descriptor
|
||||
referring to a file on which locks are held. This is bad [...]"
|
||||
So you may have to re-lock after some temporary fd got closed.
|
||||
|
||||
|
||||
Vulnerable Programs
|
||||
|
||||
For programs which do feel vulnerable, O_EXCL would suffice for the /dev/hd*
|
||||
device file family and their driver. But USB and SATA recorders appear with
|
||||
at least two different major-minor combinations simultaneously.
|
||||
One as /dev/sr* alias /dev/scd*, the other as /dev/sg*.
|
||||
The same is true for ide-scsi or recorders attached to SCSI controllers.
|
||||
|
||||
So, in order to lock any access to the recorder, one has to open(O_EXCL)
|
||||
not only the device file that is intended for accessing the recorder but also
|
||||
a device file of any other major-minor representation of the recorder.
|
||||
This is done via the SCSI address parameter vector (Host,Channel,Id,Lun)
|
||||
and a search on standard device file paths /dev/sr* /dev/scd* /dev/sg*.
|
||||
In this text the alternative device representations are called "siblings".
|
||||
|
||||
For finding them, it is necessary to apply open() to many device files which
|
||||
might be occupied by delicate operations. On the other hand it is very
|
||||
important to occupy all reasonable representations of the drive.
|
||||
So the reading of the (Host,Channel,Id,Lun) parameters demands an
|
||||
open(O_RDONLY | O_NDELAY) _without_ fcntl() in order to find the outmost
|
||||
number of representations among the standard device files. Only ioctls
|
||||
SCSI_IOCTL_GET_IDLUN and SCSI_IOCTL_GET_BUS_NUMBER are applied.
|
||||
Hopefully this gesture is unable to cause harmful side effects on kernel 2.6.
|
||||
|
||||
At least one file of each class sr, scd and sg should be found to regard
|
||||
the occupation as satisfying. Thus corresponding sr-scd-sg triplets should have
|
||||
matching ownerships and access permissions.
|
||||
One will have to help the sysadmins to find those triplets.
|
||||
|
||||
A spicy detail is that sr and scd may be distinct device files for the same
|
||||
major-minor combination. In this case fcntl() locks on both are needed
|
||||
but O_EXCL can only be applied to one of them.
|
||||
|
||||
|
||||
An open and free implementation ddlpa.[ch] is provided as
|
||||
http://libburnia.pykix.org/browser/libburn/trunk/libburn/ddlpa.h?format=txt
|
||||
http://libburnia.pykix.org/browser/libburn/trunk/libburn/ddlpa.c?format=txt
|
||||
The current version of this text is
|
||||
http://libburnia.pykix.org/browser/libburn/trunk/doc/ddlp.txt?format=txt
|
||||
|
||||
Put ddlpa.h and ddlpa.c into the same directory and compile as test program by
|
||||
cc -g -Wall -DDDLPA_C_STANDALONE -o ddlpa ddlpa.c
|
||||
|
||||
Use it to occupy a drive's representations for a given number of seconds
|
||||
./ddlpa /dev/sr0 300
|
||||
|
||||
It should do no harm to any of your running activities.
|
||||
If it does: Please, please alert us.
|
||||
|
||||
Your own programs should not be able to circumvent the occupation if they
|
||||
obey above rules for Friendly Programs.
|
||||
Of course ./ddlpa should be unable to circumvent itself.
|
||||
|
||||
A successfull occupation looks like
|
||||
DDLPA_DEBUG: ddlpa_std_by_rdev("/dev/scd0") = "/dev/sr0"
|
||||
DDLPA_DEBUG: ddlpa_collect_siblings() found "/dev/sr0"
|
||||
DDLPA_DEBUG: ddlpa_collect_siblings() found "/dev/scd0"
|
||||
DDLPA_DEBUG: ddlpa_collect_siblings() found "/dev/sg0"
|
||||
DDLPA_DEBUG: ddlpa_occupy() : '/dev/scd0'
|
||||
DDLPA_DEBUG: ddlpa_occupy() O_EXCL : '/dev/sg0'
|
||||
DDLPA_DEBUG: ddlpa_occupy() O_EXCL : '/dev/sr0'
|
||||
---------------------------------------------- Lock gained
|
||||
ddlpa: opened /dev/sr0
|
||||
ddlpa: opened siblings: /dev/scd0 /dev/sg0
|
||||
slept 1 seconds of 300
|
||||
|
||||
Now an attempt via device file alias /dev/NEC must fail:
|
||||
DDLPA_DEBUG: ddlpa_std_by_rdev("/dev/NEC") = "/dev/sg0"
|
||||
DDLPA_DEBUG: ddlpa_collect_siblings() found "/dev/sr0"
|
||||
DDLPA_DEBUG: ddlpa_collect_siblings() found "/dev/scd0"
|
||||
DDLPA_DEBUG: ddlpa_collect_siblings() found "/dev/sg0"
|
||||
Cannot exclusively open '/dev/sg0'
|
||||
Reason given : Failed to open O_RDWR | O_NDELAY | O_EXCL : '/dev/sr0'
|
||||
Error condition : 16 'Device or resource busy'
|
||||
|
||||
With hdc, of course, things are trivial
|
||||
DDLPA_DEBUG: ddlpa_std_by_rdev("/dev/hdc") = "/dev/hdc"
|
||||
DDLPA_DEBUG: ddlpa_occupy() O_EXCL : '/dev/hdc'
|
||||
---------------------------------------------- Lock gained
|
||||
ddlpa: opened /dev/hdc
|
||||
slept 1 seconds of 1
|
||||
|
||||
|
||||
Ted Ts'o provided program open-cd-excl which allows to explore open(2) on
|
||||
device files with combinations of read-write, O_EXCL, and fcntl().
|
||||
(This does not mean that Ted endorsed our project yet. He helps exploring.)
|
||||
|
||||
Friendly in the sense of DDLP-A would be any run which uses at least one of
|
||||
the options -e (i.e. O_EXCL) or -f (i.e. F_SETLK, applied to a file
|
||||
descriptor which was obtained from a standard device file path).
|
||||
The code is available under GPL at
|
||||
http://libburnia.pykix.org/browser/libburn/trunk/test/open-cd-excl.c?format=txt
|
||||
To be compiled by
|
||||
cc -g -Wall -o open-cd-excl open-cd-excl.c
|
||||
|
||||
Options:
|
||||
-e : open O_EXCL
|
||||
-f : aquire lock by fcntl(F_SETLK) after sucessful open
|
||||
-i : do not wait in case of success but exit 0 immediately
|
||||
-r : open O_RDONLY , with -f use F_RDLCK
|
||||
-w : open O_RDWR , with -f use F_WRLCK
|
||||
plus the path of the devce file to open.
|
||||
|
||||
Friendly Programs would use gestures like:
|
||||
./open-cd-excl -e -r /dev/sr0
|
||||
./open-cd-excl -e -w /dev/sg1
|
||||
./open-cd-excl -e -w /dev/black-drive
|
||||
./open-cd-excl -f -r /dev/sg1
|
||||
./open-cd-excl -e -f -w /dev/sr0
|
||||
|
||||
Ignorant programs would use and cause potential trouble by:
|
||||
./open-cd-excl -r /dev/sr0
|
||||
./open-cd-excl -w /dev/sg1
|
||||
./open-cd-excl -f -w /dev/black-drive
|
||||
where "/dev/black-drive" is _not_ a symbolic link to
|
||||
any of /dev/sr* /dev/scd* /dev/sg* /dev/hd*, but has an own inode.
|
||||
|
||||
Prone to failure without further reason is:
|
||||
./open-cd-excl -e -r /dev/sg1
|
||||
|
||||
|
||||
----------------------------------------------------------------------------
|
||||
|
||||
DDLP-B
|
||||
|
||||
This protocol relies on proxy lock files in some filesystem directory. It can
|
||||
be embedded into DDLP-A or it can be used be used standalone, outside DDLP-A.
|
||||
|
||||
DDLP-A shall be kept by DDLP-B from trying to access any device file which
|
||||
might already be in use. There is a problematic gesture in DDLP-A when SCSI
|
||||
address parameters are to be retrieved. For now this gesture seems to be
|
||||
harmless. But one never knows.
|
||||
Vice versa DDLP-B may get from DDLP-A the service to search for SCSI device
|
||||
file siblings. So they are best as a couple.
|
||||
|
||||
But they are not perfect. Not even as couple. fcntl() locking is flawed.
|
||||
|
||||
|
||||
There is a proxy file locking protocol described in FHS:
|
||||
http://www.pathname.com/fhs/pub/fhs-2.3.html#VARLOCKLOCKFILES
|
||||
|
||||
But it has shortcommings (see below). Decisive obstacle for its usage are the
|
||||
possibility for stale locks and the lack of shared locks.
|
||||
|
||||
DDLP-B rather defines a "path prefix" which is advised to be
|
||||
/tmp/ddlpb-lock-
|
||||
This prefix will get appended "device specific suffixes" and then form the path
|
||||
of a "lockfile".
|
||||
Not the existence of a lockfile but its occupation by an fcntl(F_SETLK) will
|
||||
constitute a lock. Lockfiles may get prepared by the sysadmin in directories
|
||||
where normal users are not allowed to create new files. Their rw-permissions
|
||||
then act as additional access restriction to the device files.
|
||||
The use of fcntl(F_SETLK) will prevent any stale locks after the process ended.
|
||||
It will also allow to obtain shared locks as well as exclusive locks.
|
||||
|
||||
There are two classes of device specific suffixes:
|
||||
|
||||
- Device file path suffix. Absolute paths only. "/" gets replaced by "_-".
|
||||
Eventual "_-" in path gets replaced by "_-_-". The leading group of "_-"
|
||||
is always interpreted as a group of "/", though. E.g.:
|
||||
/dev/sr0 <-> "_-dev_-sr0"
|
||||
/mydevs/burner/nec <-> "_-mydevs_-burners_-nec"
|
||||
/dev/rare_-name <-> "_-dev_-rare_-_-name"
|
||||
///strange/dev/x <-> "_-_-_-strange_-dev_-x"
|
||||
|
||||
- st_rdev suffix. A hex representation of struct stat.st_rdev. Capital letters.
|
||||
The number of characters is pare with at most one leading 0. I.e. bytewise
|
||||
printf("%2.2X") beginning with the highest order byte that is not zero.
|
||||
E.g. : "0B01", "2200", "01000000000004001"
|
||||
|
||||
If a lockfile does not exist and cannot be created then this shall not keep
|
||||
a program from working on a device. But if a lockfile exists and if permissions
|
||||
or locking state do not allow to obtain a lock of the appropirate type, then
|
||||
this shall prevent any opening of device file in question resp. shall cause
|
||||
immediate close(2) of an already opened device file.
|
||||
|
||||
The vulnerable programs shall not start their operation before they locked a
|
||||
wide collection of drive representations.
|
||||
|
||||
Non-vulnerable programs shall take care to lock the suffix resulting from the
|
||||
path they will be using and the suffix from the st_rdev from that path.
|
||||
The latter is to be obtained by call stat(2).
|
||||
|
||||
Locks get upheld as long as their file descriptor is not closed or no other
|
||||
incident as described in man 2 fcntl releases the lock.
|
||||
|
||||
So with shared locks there are no imandatory further activities after they
|
||||
have been obtained.
|
||||
|
||||
In case of exclusive locks, the file has to have been opened for writing and
|
||||
must be truncated to 0 bytes length immediately after obtaining the lock.
|
||||
When releasing an exclusive lock it is a nice gesture to
|
||||
already do this truncation.
|
||||
Then a /var/lock/ compatible first line has to be written.
|
||||
E.g. by: printf("%10u\n",(unsigned) getpid()) yielding " 1230\n".
|
||||
|
||||
Any further lines are optional. They shall have the form Name=Value and must
|
||||
be printable cleartext. If such further lines exist, then the last one must
|
||||
have the name "endmark".
|
||||
Defined Names are:
|
||||
hostid =hostname of the machine where the process number of line 1 is valid
|
||||
start =start time of lock in seconds since 1970. E.g: 1177147634.592410
|
||||
program =self chosen name of the program which obtained the lock
|
||||
argv0 =argv[0] of that program
|
||||
mainpath =device file path which will be used for operations by that program
|
||||
path =device file path which lead to the lock
|
||||
st_rdev =st_rdev suffix which is associated with path
|
||||
scsi_hcil=eventual SCSI parameters Host,Channel,Id,Lun
|
||||
scsi_bus =eventual SCSI parameter Bus
|
||||
endmark =declares the info as complete.
|
||||
Any undefined name or a line without "=" shall be handled as comment.
|
||||
"=" in the value is allowed. Any line beginning with an "=" character is an
|
||||
extension of the previous value.
|
||||
|
||||
If programs encounter an exclusive lock, they are invited to read the content
|
||||
of the lockfile anyway. But they should be aware that the info might be in the
|
||||
progress of emerging. There is a race condition possible in the short time
|
||||
between obtaining the exclusive lock and erasing the file content.
|
||||
If it is not crucial to obtain most accurate info then one may take the newline
|
||||
of the first line as indicator of a valid process number and the "endmark"
|
||||
name as indicator that the preceding lines are valid.
|
||||
Very cautious readers should obtain the info twice with a decent waiting period
|
||||
inbetween. Only if both results are identical they should be considered valid.
|
||||
|
||||
|
||||
There is no implementation of DDLP-B yet.
|
||||
|
||||
|
||||
|
||||
----------------------------------------------------------------------------
|
||||
What are the Stumble Stones ?
|
||||
----------------------------------------------------------------------------
|
||||
|
||||
Any of the considered locking mechanisms has decisive shortcommings
|
||||
which keeps it from being the solution to all known legitimate use cases.
|
||||
|
||||
The attempt has failed to compose a waterproof locking mechanism from means of
|
||||
POSIX, FHS and from hardly documented Linux open(O_EXCL) on device files.
|
||||
The resulting mechanisms would need about 1000 lines of code and still do
|
||||
not close all gaps resp. cover the well motivated use cases.
|
||||
This attempt you see above: DDLP-A and DDLP-B.
|
||||
|
||||
|
||||
Summary of the reasons why the established locking mechanisms do not suffice:
|
||||
|
||||
None of the mechanisms can take care of the double device driver identity
|
||||
sr versus sg. To deduce the one device file from the other involves the need
|
||||
to open many other (possibly unrelated) device files with the risk to disturb
|
||||
them.
|
||||
This hard to solve problem is aggravated by the following facts.
|
||||
|
||||
Shortcommings of Linux specific open(O_EXCL) :
|
||||
|
||||
- O_EXCL | O_RDONLY does not succeed with /dev/sg*
|
||||
- O_EXCL cannot provide shared locks for programs which only want to lock
|
||||
against burn programs but not against their own peers.
|
||||
- O_EXCL keeps from obtaining information by harmless activities.
|
||||
- O_EXCL already has a meaning with devices which are mounted as filesystems.
|
||||
This priority meaning is more liberal than the one needed for CD/DV recording
|
||||
protection.
|
||||
|
||||
Shortcommings of POSIX fcntl(F_SETLK) :
|
||||
|
||||
- fcntl() demands an open file descriptor. open(2) might have side effects.
|
||||
- fcntl() locks can be released inadvertedly by submodules which just open and
|
||||
close the same file (inode ?) without refering to fcntl locks in any way.
|
||||
See man 2 fcntl "This is bad:".
|
||||
Stacking of software modules is a widely used design pattern. But fcntl()
|
||||
cannot cope with that.
|
||||
|
||||
Shortcommings of FHS /var/lock/ :
|
||||
|
||||
- Stale locks are possible.
|
||||
- It is necessary to create a file (using the _old_ meaning of O_EXCL flag ?)
|
||||
but /var/lock/ might not be available early during system start and it often
|
||||
has restrictive permission settings.
|
||||
- There is no way to indicate a difference between exclusive and shared locks.
|
||||
- The FHS prescription relies entirely on the basename of the device file path.
|
||||
|
1294
libburn/branches/1.3.0.pl01/doc/doxygen.conf.in
Normal file
1294
libburn/branches/1.3.0.pl01/doc/doxygen.conf.in
Normal file
File diff suppressed because it is too large
Load Diff
1212
libburn/branches/1.3.0.pl01/doc/mediainfo.txt
Normal file
1212
libburn/branches/1.3.0.pl01/doc/mediainfo.txt
Normal file
File diff suppressed because it is too large
Load Diff
Reference in New Issue
Block a user