legacy/libburn/trunk/doc/cookbook.txt

libburnia.pykix.org Optical Media Rotisserie Recipes as of January 2007

Content:
- TAO Multi-Session CD Cookbook (CD-R, CD-RW)
- Overwriteable DVD Cookbook (DVD-RAM, DVD+RW, DVD-RW)


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                         TAO Multi-Session CD Cookbook
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Guided by reading mmc-r10a.pdf , O.8 "Write a Track"
                               from http://www.t10.org/ftp/t10/drafts/mmc/
backed by reading mmc5r03c.pdf from http://www.t10.org/ftp/t10/drafts/mmc5/
by reading        spc3r23.pdf  from http://www.t10.org/ftp/t10/drafts/spc3/
by reading        libburn/*    from http://icculus.org/burn
and by experiments with drives NEC ND-4570A, LG GSA-4082B, LITE-ON LTR48125S
which used in part code from http://icculus.org/burn.

For libburnia.pykix.org by Thomas Schmitt <scdbackup@gmx.net>

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Media type can be recognized by Current Profile from 46h GET CONFIGURATION.
(mmc5r03c.pdf 6.6.2.1)

CD-R                           0009h
CD-RW                          000ah

The following topics are covered in this text:
- About blank, appendable and finalized CD media
- Writing a session to CD in TAO mode
- Obtaining CD multi-session info for extending ISO-9660 filesystems
- Obtaining a Table Of Content from CD


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About blank, appendable and finalized CD media :

CD media have to be blank or appendable in order to be writeable in TAO mode.
The according status may be inquired by 51h READ DISC INFORMATION requesting
Data Type 000b Standard Disc Information, where reply value Disc Status
indicates:
00b   blank
01b   appendable
10b   finalized
11b   others (unsuitable for this recipe)
(mmc5r03c.pdf 6.22.3.1.4)

CD-RW which are finalized or appendable may be blanked by command A1h BLANK
with blanking types 000b "Blank the disc" or 001b "Minimally blank the disc".
The Start Address/Track Number will be ignored so it may well be 0.
Because the operation is long running it is advised to set the Immed bit and to
watch the progress by commands 00h TEST UNIT READY and 03h REQUEST SENSE
with DESC bit set to 0 for fixed format reply.
It is done when 00h succeeds and 03h reports 0 in PROGRESS INDICATION 
(byte 1+2 in Table 22 = byte 16+17 SENSE KEY SPECIFIC in table 26).
(mmc5r03c.pdf 6.2 BLANK)
(spc3r23.pdf 4.5.2.4.4 table 22, 4.5.3 table 26,
             6.27 REQUEST SENSE, 6.33 TEST UNIT READY)


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Writing a session to CD in TAO mode :

The writing method for blank or appendable media is the same. A new session
will get automatically by the first track ehen it is written. If the media is
blank then the new session will be the first and only one in the table of
content. If the media is appendable then a new session will be appended to
the existing sessions. In any case the new track will be the first one in
the new session.

Speed may be set by BBh SET CD SPEED parameter Drive Write Speed. Note that
kbytes/sec means 1000 bytes/sec and not 1024/sec. Rotational control should
be set to 00b. 1x CD speed is 176.4 kbytes/sec. Speed is usually set to the
next lower possible value by the drive. So it is helpful to add a few 
kbytes/sec just in case the drive has rounding problems.
(mmc5r03c.pdf 6.37)

Before writing can occur, a Write Parameters mode page 05h has to be composed
and transmitted via 55h MODE SELECT. Mode page 05h describes several burn
parameters:
 BUFE             Buffer Underrun protection      0=off, 1=on
 Test Write       -dummy mode for writing         0=off, 1=on
 Write Type       Packet/TAO/SAO/RAW              01h = TAO
 Multi-session    Wether to keep appendable       00b = finalize
                                                  11b = keep appendable
 Track Mode       Describes frame type            4 for data , 0 for audio
 Data Block Type  Layout of payload blocks        8 for 2048 byte data blocks
                                                  0 for 2352 byte audio blocks
 Audio Pause Length                               150 = 2 seconds
Any other parameters may be set to 0.
Mode page data as of MMC-5 table 644 are preceded by a Mode Parameter Header
as of SPC-3 table 240. This 8-byte header may be filled with zeros.
(mmc5r03c.pdf 7.5.4 The Mode Page, 4.2.3.4 Table 17 CONTROL = Track Mode)
(spc3r23.pdf 6.8 MODE SELECT, 7.4.3 Mode parameter header formats)


Writing has to begin at the address returned by 52h READ TRACK INFORMATION
with Address/Number Type set to 01b and Logical Block Address/Track/Session
Number set to FFh. The Next Writeable Address as of table 500 is the number
to start writing with.
(mmc5r03c.pdf 6.27 )

Writing is performed by one or more 2Ah WRITE transactions with the Logical
Block Address counted up from the initial number in sync with the number of
blocks written. I.e the Transfer Length of the previous 2Ah WRITE has to be
added to the Logical Block Address for the next 2Ah WRITE. Only full blocks
can be written.
(mmc5r03c.pdf, 6.44)
When writing is done, it is mandatory to force the drive's buffer to media by
35h SYNCHRONIZE CACHE.
(mmc5r03c.pdf, 6.41)

The track has to be closed by 5Bh CLOSE TRACK SESSION Close Function 001b.
Older MMC specifies a valid Logical Track Number FFh to depict the open track.
MMC-5 is quite silent about this. FFh works for my drives.
(mmc5r03c.pdf 6.3.3.1.2)

After that, a new track may be written beginning with sending the mode page 05h
again (it is not tested wether 05h can be omitted). The track will then be
added to the session which was opened by the first track.

After the last track of a session, 5Bh CLOSE TRACK SESSION Close Function 010b
with Logical Track Number 0 closes the session. It depends on the Multi-Session
value in mode page 05h wether the disc is finalized or stays appendable.
(mmc5r03c.pdf 6.3.3.1.3)


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Obtaining CD multi-session info for extending ISO-9660 filesystems :

Program mkisofs expects two numbers with its option -C which describe the
situation on an appendable CD which already contains a ISO-9660 filesystem
in the first track of the last session.

The first number is the Logical Block Address of that track containing the
existing ISO-9660 filesystem image. This number is needed for mkisofs option
-M to connect to the existing image. The new image will refer to files in
the previously existing image. mkisofs option -M needs read access to the
CD or a blockwise copy of it on hard disk. 
The number is gained by 43h READ TOC/PMA/ATIP.
(mmc5r03c.pdf 6.26)
Untested is Format 0001b which in table 478 promises quick access via
Start Address Of First Track In Last Session.
(mmc5r03c.pdf 6.26.2.5 table 478, 6.26.3.3.1)
libburn gets the number from its Table Of Content model which is obtained
by 43h READ TOC/PMA/ATIP, Format 0010b. See below.

The second number is an exact prediction of the Logical Block Address of the
new track which will contain the newly generated ISO-9660 image.
Even without mkisofs option -M this second number is still needed to make the
inner block address pointers of the image match the Logical Block Addresses
on CD. For that one may inquire 52h READ TRACK INFORMATION with
Address/Number Type set to 01b and Logical Block Address/Track/Session
Number set to FFh. The Next Writeable Address as of table 500 is the number
to use.
(mmc5r03c.pdf 6.27 )


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Obtaining a Table Of Content from CD :

The structure of a CD is comprised of sessions. Each session contains one or
more tracks and is followed by a lead-out. A track has an address and a length.

Table of content information is gained by 43h READ TOC/PMA/ATIP, Format 0010b.
(mmc5r03c.pdf 6.26.2.5 table 478)

The number of sessions is given by Last Complete Session Number.
The number of TOC Track descriptors is: (TOC Data Length - 2)/11 . 

Each TOC Track Descriptor contains a Session Number.

If POINT is >= 1 and <= 99 (63h) then the descriptor is about the track of
which POINT tells the number.
The start address of this track can be read from PMIN, PSEC, PFRAME where
it is encoded in MSF format:
blocks = frames - 150, 75 frames = 1 sec , 60 sec = 1 min.
The length of the track is given by MIN,SEC,FRAME in the same format.

If POINT = A0h then the descriptor tells in PMIN the first track number of its
session.
POINT = A1h tells in PMIN the last track number of its session.
POINT = A2h describes in PMIN, PSEC, PFRAME the lead-out of a session, i.e the
first address after the session's end. (Next writeable address typically is
lead-out + 11400 after the first session, lead-out + 6900 after further
sessions.)
POINT = B0h tells in MIN,SEC,FRAME this next writeable address or FFh,FFh,FFh
for finalized disc.
(mmc5r03c.pdf 6.26.3.4 table 489, 4.2.3.7 Mode-1 Q, Mode-5 Q)


In libburn the address of the first track in the last session is obtained from
the last session's POINT = A0h and from the track descriptor with the POINT
value matching the PMIN value of the A0h descriptor.
Untested is wether POINT = B0h and 52h READ TRACK INFORMATION are always in
sync. libburn uses the info provided by 52h READ TRACK INFORMATION.


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                           Overwriteable DVD Cookbook
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Inspired by Andy Polyakov's http://fy.chalmers.se/~appro/linux/DVD+RW/tools ,
backed by reading mmc5r03c.pdf from http://www.t10.org/ftp/t10/drafts/mmc5/
and by experiments with drives NEC ND-4570A and LG GSA-4082B.

For libburnia.pykix.org by Thomas Schmitt <scdbackup@gmx.net>

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Media type can be recognized by Current Profile from 46h GET CONFIGURATION.
(mmc5r03c.pdf 6.6.2.1)

DVD-RAM                        0012h
DVD-RW Restricted Overwrite    0013h
DVD-RW Sequential Recording    0014h (i.e. unformatted)
DVD+RW                         001Ah

A short compilation of the write model:
- Overwriting in general

The recipes described here are depending on formatting state:
- DVD-RAM, fully formatted DVD+RW or DVD-RW
- Unformatted DVD+RW
- Partly formatted DVD+RW
- Unformatted DVD-RW
- Partly formatted DVD-RW
- Intermediate state DVD-RW


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Overwriting in general :

Depending on media type, some kind of formatting has to have happened before
data can be written. Formatting may happen separately from writing or
simultaneously. See the particular recipes below.

No Write Parameters mode page 05h is to be sent. Speed can be influenced by
B6h SET STREAMING , speed capabilities can be inquired by ACh GET PERFORMANCE.
It is advised to set only speeds and sizes which are returned by ACh.
(mmc5r03c.pdf 6.39 SET STREAMING, 6.8 GET PERFORMANCE)
Optimal performance is promised without any speed setting. But my experiments
showed that SET STREAMING values persist after media change.

In the formatted area of the media, coarse random access is possible.
For DVD-RAM and DVD+RW write addresses and data size need to be aligned
to 2 KiB. For DVD-RW alignment has to be 32 KiB. Within these limitations
the write address is at the discretion of the sending program.
Just use 2Ah WRITE to send data.
(mmc5r03c.pdf, 6.44)
When writing is done, it is mandatory to force the drive's buffer to media by
35h SYNCHRONIZE CACHE.
(mmc5r03c.pdf, 6.41)

The size of the formatted area can be inquired by 23h READ FORMAT CAPACITIES.
The Number Of Blocks value in the Current/Maximum Capacity Descriptor gives
this size in 2 KiB blocks. But this is true only if Descriptor Type is 10b
("Formatted Media").
(mmc5r03c.pdf, 6.24.3.2.1, 6.24.3.2.3)

Not yet formatted areas may be completely forbidden or they may be allowed for
sequential writing (DVD-RW Intermediate state) or they may be allowed for
random access only after the necessary waiting time for formatting to reach
the desired address (DVD+RW with background formatting active).

Already written areas can be overwritten without special precaution.
Blanking a DVD-RW actually destroys its formatting.


Most of the concepts usually expressed in Write Parameters mode page 05h do not
apply to the recipes here: Test-Write, Buffer Underrun protection,
Multi-session, Write Type, Block Type, Track Mode, ...
There are hints for multi-session formats with DVD-RW but both of my drives
do not offer "Add Session" Format Types 12h or 14h.
(mmc5r03c.pdf 6.5.4.2.7 , 6.5.4.2.9)


Caution: Drive and media compatibility seems still to be quite an adventure.
If you experience problems, especially problems with readability, then try
different drives and media brands. Failure does not necessarily mean that the
software did anything wrong.


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DVD-RAM, fully formatted DVD+RW or DVD-RW :

Full format is the natural state of DVD-RAM. 

DVD+RW reaches this state if Background Formatting is allowed to finish without
being stopped by 5Bh CLOSE TRACK SESSION.
(mmc5r03c.pdf, 6.5 FORMAT UNIT, 6.5.4.2.14 Format Type = 26h)
The formatting state of a DVD+RW may be inquired by 51h READ DISC INFORMATION
requesting Data Type 000b "Standard Disc Information". In the reply,
BG Format 3 indicates fully formatted media.
(mmc5r03c.pdf 6.22.3.1.13)

DVD-RW reaches this state either by Format Type 00h (or 10h) with maximum
size given as Number Of Blocks, or by writing sequentially until the disc is
completely full into an intermediate session opened by format 15h resp. 13h.
(mmc5r03c.pdf, 6.5 FORMAT UNIT, 6.5.4.2.1, 6.5.4.2.10, 6.5.4.2.8)
A fully formatted DVD-RW can be recognized by 23h READ FORMAT CAPACITIES. The
Descriptor Type of the Current/Maximum Capacity Descriptor is 10b ("Formatted
Media") and 0 blocks are offered with Format Types 13h or 11h.
(mmc5r03c.pdf, 6.24.3.2.1, 6.24.3.3)
See also discussion of unformatted or partially formatted DVD-RW below.


In fully formatted state there is no need for any formatting before writing nor
for any finalizing other than forcing the drive's buffer to media by
35h SYNCHRONIZE CACHE (which is mandatory for writing, anyway).
(mmc5r03c.pdf, 6.41)

(It seems to do no harm to send to DVD+RW or DVD-RW a 5Bh CLOSE TRACK SESSION
with Close Function 010b despite there is no session open in this scenario.)


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Unformatted DVD+RW

This is the state of previously unused DVD+RW media.

The formatting state of a DVD+RW may be inquired by 51h READ DISC INFORMATION
requiring Data Type 000b "Standard Disc Information".
In the reply, BG Format 0 indicates unformatted media (or unsuitable media).
(mmc5r03c.pdf 6.22.3.1.13)

Formatting has to be started by command 04h FORMAT UNIT, Format Type 26h.
Different from other format types, 26h allows to send a fantasy size of
0xffffffff blocks and does not require the caller to know the exact maximum
size offered with that format.
(mmc5r03c.pdf, 6.5 FORMAT UNIT, 6.5.4.2.14 Format Type = 26h)

As its name suggests, one has not to wait for background formatting to end
but may very soon start writing as on formatted media. Random access to
yet unformatted areas can last long, though.

If backup formatting has been started at the beginning of the session, then
it may get stopped after the final cache sync by 5Bh CLOSE TRACK SESSION
with Close Function 010b. 
(mmc5r03c.pdf 6.3.3.6)

Formatting of DVD+RW is called "de-icing" because unformatted areas offer
no hold for random access addressing and are thus slippery like ice. One can
also see a color change from shiny unformatted to more dull formatted media.


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Partly formatted DVD+RW :

This state is achieved by stopping background formatting before the media
was completely formmatted. 

The formatting state of a DVD+RW is obtained by 51h READ DISC INFORMATION
requiring Data Type 000b "Standard Disc Information".
In the reply, BG Format 1 indicates partly formatted media.
(mmc5r03c.pdf 6.22.3.1.13)

If the data of the session surely fit into the formatted area, then it would
be unnecessary to restart background formatting.
But in order to make the DVD+RW surely accept its maximum number of bytes,
formatting may be restarted by command 04h FORMAT UNIT, Format Type 26h,
with the Restart bit set and Number of Blocks set to 0xffffffff.
(mmc5r03c.pdf, 6.5 FORMAT UNIT, 6.5.4.2.14 Format Type = 26h)

From then on, the same rules apply as for previously unformatted DVD+RW.


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Unformatted DVD-RW (media profile is 0014h) :

This state is present with previously unused media. It is also present with
media blanked by programs cdrecord, wodim or dvd+rw-format and with media which
were sequentially written from blank state.
Profile transition from formatted 0013h to unformatted 0014h is done by
A1h BLANK.
(mmc5r03c.pdf, 6.2)

For becoming overwriteable such media need to be treated by command 04h FORMAT
UNIT.
(mmc5r03c.pdf, 6.5)
The Format Type has to be chosen from the list replied by 23h READ FORMAT
CAPACITIES. Suitable are Format Types 00h, 10h, 15h.
(mmc5r03c.pdf 6.24)

Format Types 00h and 10h provide a writeable area of a size given by Number of
Blocks. Type 00h seems to be the most traditional and complete one. It needs
no closing of a session at the end of writing.
The Number Of Blocks may be at most the value reported by 23h READ FORMAT
CAPACITIES in the entry for the desired format type. Full format is achieved
by sending exactly the reported value.
(mmc5r03c.pdf, 6.5.4.2.1 Format Type = 00h, 6.5.4.2.5 Format Type = 10h)

Format Type 15h provides a writeable area of given size too, but this area can
be expanded by sequential writing and afterwards marked as overwriteable by
closing the session. It is even allowed to format with size 0 and to leave
the size claim entirely to a sequential write process beginning at LBA 0.
(mmc5r03c.pdf, 6.5.4.2.10 Format Type = 15h)
When writing is done and cache is synced, one should send 5Bh CLOSE TRACK
SESSION with Close Function 010b in order to bring the session out of
Intermediate state. 
(mmc5r03c.pdf 6.3.3.2.3)
If not written up to the last 32 KiB block, the DVD-RW is only partly formatted
after that.


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Partly formatted DVD-RW (media profile is 0013h) :

This state is achieved by formatting a DVD-RW with a number of blocks which
is less than offered for the Format Type by the drive's reply to 23h READ
FORMAT CAPACITIES. If the media was most recently formatted by Format Types
015h or 013h then it must have got written some bytes and afterwards treated
by 5Bh CLOSE TRACK SESSION, 010b in order to be partly formatted.
(mmc5r03c.pdf 6.3.3.2.3 CLOSE TRACK SESSION 010b, 6.24 READ FORMAT CAPACITIES)
Elsewise the media is in Intermediate state. See below.

A partly formatted DVD-RW can be recognized by 23h READ FORMAT CAPACITIES. The
Descriptor Type of the Current/Maximum Capacity Descriptor is 10b ("Formatted
Media") and the Number Of Blocks with formats 00h, 10h or 15h is larger than the
currently formatted size, resp. more than 0 blocks are offered with Format
Types 13h or 11h.
(mmc5r03c.pdf, 6.24.3.2.1, 6.24.3.3)

If the data of the session surely fit into the formatted area, then it would
be unnecessary to do any further formatting.
But in order to make the DVD-RW surely accept its maximum number of bytes,
partial formatting may be expanded by command 04h FORMAT UNIT, Format Type 13h,
which is supposed to be offered by the drive in this state. This brings the
session again into Intermediate state and thus allows expansion by sequential
writing. As with Format Type 15h it is ok to set Number Of Blocks to 0, so that
no fixed size formatting work is done and writing can begin soon after.
(mmc5r03c.pdf, 6.5.4.2.8 Format Type = 13h)

When writing is done and cache is synced, one should send 5Bh CLOSE TRACK
SESSION with Close Function 010b in order to bring the session out of
Intermediate state. 
(mmc5r03c.pdf 6.3.3.2.3)
If not written up to the last 32 KiB block, the DVD-RW is only partly formatted
after that.

Format Type 13h has been tested only with expanding sessions formatted by 15h.
Nevertheless it is offered with sessions from 00h and 10h, too.
According to the specs, Format Type 11h would expand a session by a fixed
size. This has not been tested yet because it is less appealing than 13h.
(mmc5r03c.pdf, 6.5.4.2.6 Format Type = 11h)


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Intermediate state DVD-RW (media profile is 0013h) :

This state is achieved by formatting a DVD-RW with Format Type 15h or 13h
without subsequentially writing data and sending 5Bh CLOSE TRACK SESSION
with Close Function 010b.
Such media behave very unpleasing with my DVD-ROM drive under Linux 2.4 ide-cd.
One should therefore better avoid to release media in this state.

This state can be recognized by 23h READ FORMAT CAPACITIES. The Descriptor Type
of the Current/Maximum Capacity Descriptor is 11b ("Unknown Capacity") and
no formats 13h or 11h are offered.
(mmc5r03c.pdf, 6.24.3.2.1, 6.24.3.3)

One may treat such media as if Format Type 15h or 13h had been freshly applied.
I.e. sequential writing from LBA 0. After cache sync bring the session out
of Intermediate state by 5Bh CLOSE TRACK SESSION with Close Function 010b.
(mmc5r03c.pdf 6.3.3.2.3)


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