legacy/libburn/trunk/doc/cookbook.txt

-------------------------------------------------------------------------------
Note: This is about how libburn operates optical drives. Not about how to
      operate libburn. The libburn API is described in libburn/libburn.h
-------------------------------------------------------------------------------

libburnia-project.org Optical Media Rotisserie Recipes as of December 2011

Content:
- TAO Multi-Session CD Cookbook (CD-R, CD-RW)
- SAO CD Cookbook (CD-R, CD-RW, pure audio or pure data only)
- Overwriteable DVD Cookbook (DVD-RAM, DVD+RW, DVD-RW, BD-RE)
- Sequential DVD-R[W] Cookbook
- DVD+R[/DL] Cookbook
- BD-R Cookbook

-------------------------------------------------------------------------------
                         TAO Multi-Session CD Cookbook
-------------------------------------------------------------------------------
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-project.org by Thomas Schmitt <scdbackup@gmx.net>

-------------------------------------------------------------------------------

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


-------------------------------------------------------------------------------
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)


-------------------------------------------------------------------------------
Writing a session to CD in TAO mode :

The writing method for blank or appendable media is the same. A new session
will get created automatically by the first track when 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    Whether to keep appendable      00b = finalize
                                                  11b = keep appendable
 Copy             Whether to deny copying         1 = deny by SCMS , 0 = allow
 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
 Media Catalog Number  A property of the disc     0x80 if valid
                                                  13 decimal digits as ASCII
 ISRC             A property of the track         0x80 if valid
                                                  12 letters and digits, ASCII
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)

A track must at least contain 300 payload blocks: 4 seconds of audio or
600 KiB of data.
(mmc5r03c.pdf 6.3.3.1.2)

Up to december 2009 the track was 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 worked for my drives.
(mmc5r03c.pdf 6.3.3.1.2)
This is omitted since libburn-0.7.4, relying entirely on 35h SYNCHRONIZE CACHE.
First appeared a drive where CLOSE TRACK fails in simulation mode, later
another one produced error replies even with real burning.

After that, a new track may be written beginning with sending the mode page 05h
again. It is not tested whether 05h can be omitted if Track Mode and Data Block
Type are the same as with the previous track.
The new track will 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 whether the disc is finalized or stays appendable.
(mmc5r03c.pdf 6.3.3.1.3)


-------------------------------------------------------------------------------
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 )


-------------------------------------------------------------------------------
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:
If M is smaller than 90:  LBA = (M * 60 + S) * 75 + F - 150
Else                   :  LBA = (M * 60 + S) * 75 + F - 450150

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 whether POINT = B0h and 52h READ TRACK INFORMATION are always in
sync. libburn uses the info provided by 52h READ TRACK INFORMATION.


-------------------------------------------------------------------------------

-------------------------------------------------------------------------------
                                 SAO CD Cookbook
-------------------------------------------------------------------------------
Guided by reading     libburn/* from http://icculus.org/burn
backed by reading  mmc5r03c.pdf from http://www.t10.org/ftp/t10/drafts/mmc5/
backed by reading     scms.html from
                     http://www.barrel-of-monkeys.com/graphics/prod/dvdplayers/
and by experiments with drives  NEC ND-4570A, LG GSA-4082B, LITE-ON LTR48125S,
                                Optiarc BD RW BD-5300S, LG BDDVDRW GGC-H20L

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

-------------------------------------------------------------------------------

Recognition of media type and state (blank, appendable, finalized) is as
described in the TAO Multi-Session CD Cookbook. See there.

The MMC specs do not give much hint about the combination of SAO and
multi-session. My drives refused not only on a few experiments which i did
in libburn but also failed with cdrecord -sao on an appendable CD.
So for now only blank CD seem to be suitable for SAO writing.  

Different from TAO mode, the whole session layout is announced to the drive by
sending a Cue Sheet. This implies that the sizes of the tracks have to be known
in advance, which is a heavy drawback when dealing with track data sources like
stdin, named pipes or sockets.
Nevertheless, SAO seems to be best writing mode for audio purposes, as our
audio expert Lorenzo Taylor found out.

A SAO session in libburn may either consist entirely of audio tracks or
entirely of data tracks. For mixed sessions, only TAO is usable yet.

- Composing a SAO CD Cue Sheet (either audio or data, but not mixed)
- Writing the prepared SAO CD session
- What is known about mixed mode sessions


-------------------------------------------------------------------------------
Composing a Cue Sheet (either audio or data, but not mixed) :

The Cue Sheet will get submitted to the drive by 5Dh SEND CUE SHEET.
Each entry of the sheet is of 8 bytes size. Its fields are named
CTL|ADR, TNO, INDEX, DATA FORM, SCMS, MIN, SEC, FRAME .
(mmc5r03c.pdf 6.33)

CTL is comprised of four bits:
  bit4 = Pre-emphasis (audio only)
  bit5 = Digital copy permission:
         0 = prohibited (one-time copy is permitted if SCMS is 00h)
         1 = permitted (unlimited)                         
  bit6 = Data track indicator (bit4 and bit7 shall be 0)
  bit7 = 4-channel audio
Usually CTL is 40h for data and 00h for audio.
(mmc5r03c.pdf 6.33.3.4)
ADR is 01h for entries which define time points. It is 02h for media catalog
entries and it is 03h for track ISRC entries.
The bits of CTL and ADR are combined in the CTL|ADR byte.

TNO is the track number. The TNO of the first track may be chosen in the range
of 1 to 99. The TNO of following tracks must be the TNO of their predecessor
plus 1. The last track must not have a TNO larger than 99.

INDEX is a subaddress within tracks. INDEX 1 is mandatory and marks the start
of the payload area of a track. The range between INDEX 0 and 1 is called
pre-gap. It should contain zeros if it exists. Further cue sheet entries with
consecutive INDEX numbers mark ranges within the track. The range of the last
index may contain a post-gap with zeros.
(mmc5r03c.pdf 4.2.3.5.2)
A pre-gap of 2 seconds is mandatory only for the first track. Pre-gap and
post-gap may be needed with further tracks if they have neighbors with
different DATA FORM values. (Such mixing is not yet supported by libburn.)

DATA FORM is 00h for audio payload, 01h for audio pause, 10h for data,
41h for CD-TEXT in Lead-in. 
(mmc5r03c.pdf 6.33.3.11 CD-DA Data Form, 6.33.3.12 CD-ROM mode 1 Form)

SCMS value 80h in conjunction with bit5 of CTL is an indicator for exhausted
one-time-copy permission. If this permission is still intact, then SCMS is 00h.

MIN, SEC, FRAME give the MSF address where the described data entity starts.
LBA = frames - 150, 75 frames = 1 sec , 60 sec = 1 min.
This address must increase from entry to entry (or at least stay equal).


The first two entries in a Cue Sheet may describe the Media Catalog Number,
a string of 13 characters, also known with CD-TEXT as "UPC/EAN".
(02h, catalog characters 1 to 7)
(02h, catalog characters 8 to 13, 00h)
These two entries shall be omitted if no catalog number is given.

The next entry (eventually being the first one) describes the Lead-in.
Its content is 
(CTL|ADR ,00h,00h, DATA FORM ,00h,00h,00h,00h)
With the CTL|ADR for the first track: 41h for data, 01h for audio.
DATA FORM is 41h if CD-TEXT shall be stored in Lean-in. Else it is 01h.

The LBA for the first write is negative: -150. This corresponds to MSF address
00h:00h:00h. All addresses are to be given in MSF format.

Each track may be preceded by two entries describing an ISRC string of 12
characters.
(CTL | 03h, TNO, characters 1 to 6)
(CTL | 03h, TNO, characters 7 to 12)
These entries shall be omitted if no ISRC is given for the track.
CTL shall be the same as with the track.

The first information track on disc is preceded by a pause encoding or pre-gap
of at least 2 seconds:
(CTL|ADR,01h,00h, DATA FORM ,00h,00h,00h,00h) 
with DATA FORM = 00h for audio and 10h for data. By those 2 seconds the MSF
address increases to 00h:02h:00h = LBA 0. Optional further sectors may occupy
addresses larger than 0. This entry has to come after ISRC, if ISRC is given
for the track. INDEX has to be 0.

Each track is represented by one or more entries, with increasing index number.
At least the entry for INDEX 1 has to exist:
(CTL|ADR, TNO ,01h,DATA FORM,00h, MIN , SEC , FRAME)
TNO gives the track number. MIN, SEC, FRAME give the MSF address which becomes
the start address of the track. The MSF address is then increased by the size
of the track (to be used with next track or with lead-out).
There may be more entries with INDEX 2 to 99. Their MSF address tells the
sector where their range starts. This range ends at the MSF of the next entry
in the cue sheet. INDEX information is stored in the sub-channel of the sectors
but not in the Table-of-Content of the disc.

A track must at least contain 300 payload blocks: 4 seconds of audio or
600 KiB of data.
(mmc5r03c.pdf 6.33.3.6)

At the end of the session there is a lead-out entry
(CTL|ADR,AAh,01h,01h,00h,MIN,SEC,FRAME)
marking the end of the last track. (With libburn CTL is as of the last track.)


-------------------------------------------------------------------------------
Writing the prepared 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)

If CD-TEXT shall be written into Lead-in, then it is necessary to obtain the
Start Time of Lead-in by 43h READ TOC/PMA/ATIP Format 0100b. It is an MFS
address which varies from media manufacturer to media manufacturer.
Minute will be >= 90. Therefore this conversion applies:
  LBA = (M * 60 + S) * 75 + F - 450150

A Write Parameters mode page 05h has to be composed and transmitted via
55h MODE SELECT. This page describes the following 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              02h = SAO
 Multi-session    Whether to keep appendable      00b = finalize
                                                  11b = keep appendable
 Track Mode       Describes frame type            0 (is ignored)
 Data Block Type  Layout of payload blocks        0 (is ignored)
 Audio Pause Length                               150 = 2 seconds (ignored ?)
 Media Catalog Number                             0x80 if valid
                  See also Cue Sheet ADR 02h      13 decimal digits as ASCII
 (With SAO, ISRC is transmitted only by the Cue Sheet.)

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)

The Cue Sheet is submitted to the drive by 5Dh SEND CUE SHEET. Cue Sheet Size
is 8 times the number of entries.
(mmc5r03c.pdf 6.33)

Writing is performed by multiple 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)
Block addresses may be negative for areas before the normally readable
data. Data representation of addresses is 4-byte, big-endian, two's-complement.
E.g:  -150 = FFh FFh FFh 6Ah.
This is the natural form found with about any 32-bit processor, so only
the endianness has to be taken into respect when converting a 32-bit
integer into a LBA for command 2Ah WRITE.

If CD-TEXT shall be written into Lead-in, then writing begins at the start
address of Lead-in, which was obtained above.
The 18 bytes of each text pack have to be split up to 24 bytes with only the
lowest six bits used in each byte. E.g. text pack
   8F 00 2A     00 01 01     03 00 06     05 04 05     07 06 01     02 48 65
becomes
  23 30 00 2A  00 00 04 01  00 30 00 06  01 10 10 05  01 30 18 01  00 24 21 25
4 of these 24 byte packs form a block of DATA FORM 41h. I.e. only 96 bytes
payload per block. The whole range from Lead-in start to LBA -150 has to be
filled with blocks of this form. Therefore it is necessary to write the
list of given packs in repeated cycles.
A typical Lead-in start address is -11635 = FFh FFh D2h 8Dh.
A description of the CD-TEXT pack format is given in file  doc/cdtext.txt .

Writing without CD-TEXT begins at LBA -150 = FFh FFh FFh 6Ah.

In both cases, the mandatory pause preceding the first track has to be
written as 150 blocks of the matching sector size: 2048 for data,
2352 for audio. By this, the LBA increases from -150 to 0.

Next the tracks' payload is sent. For each track exactly the number of blocks
has to be transmitted as is announced in the Cue Sheet by the difference
of the track's own start address and the start address of the next entry in
the Cue Sheet. After each write the LBA for the next write has to be increased
by the number of blocks transmitted. Just like with TAO writing.

There is no separator between the tracks of a pure mode SAO session.
(If the session was mixed mode, there would be extended Pre-gaps and Post-gaps
between data mode tracks and audio mode tracks.)
(libburn sends its own buffer to the drive at the end of each track but does
not sync the drive's chache. It is unclear whether this separation of tracks
on the level of 2Ah WRITE is necessary with a pure mode session. It does not
harm in any case and would probably be unavoidable if audio and data tracks
were mixed.)

When writing of all tracks is done, it is mandatory to force the drive's buffer
to media by 35h SYNCHRONIZE CACHE.
(mmc5r03c.pdf, 6.41)

No further finalization is necessary. (I.e. no 5Bh CLOSE TRACK SESSION.)


-------------------------------------------------------------------------------
Obtaining CD-TEXT from Lead-in :

Audio CDs may contain CD-TEXT information in their Lead-in. It is gained by
43h READ TOC/PMA/ATIP, Format 0101b. The reply consists of 4 bytes header,
of which the first two bytes give the number of following bytes as big-endian
16 bit number. The other two bytes are 0.
Following are text packs of 18 bytes each.
(mmc5r03c.pdf 6.26.3.7.1 table 495)


A description of CD-TEXT packs and of the applicable libburn API calls is
given in file doc/cdtext.txt .


----------------------------------------------------------------------------
What is known about mixed mode sessions :

For now, SAO sessions with a mix of data and audio are not supported in
libburn. Here are the reasons why.

Obviously the code of http://icculus.org/burn is incomplete in this aspect.
In mmc5r03c.pdf comparison of table 555 and 6.33.3.18 seems self-contradicting.
(The second Pre-gap in table 555 does not match any of the criteria of
6.33.3.18. Also, there is no Post-gap shown in table 555 although 6.33.3.19
would prescribe some.)

If a data track follows an audio track then the data track gets a preceding
extended Pre-gap:
(CTL|ADR, TNO ,01h,DATA FORM,00h, MIN , SEC , FRAME)
with TNO already the number of the data track. The MSF address is to be
increased by 3 seconds. The first second of the extended Pre-gap needs to be
written in the audio track's mode and the other 2 seconds are to be written
in the data track's mode.
(libburn compares DATA FORM rather than burn_track.mode . Wrong ?)
(libburn currently does only 2 seconds and the second part of Pre-gap. There is
an issue with burn_track.pregap1 about this. Seems libburn mistakes the pause
preceding track 1 for a part 2 of an extended Pre-gap.)

If a data track is followed by an audio track then it gets a Post-gap of at
least two seconds.
No example of Post-gap is given for Cue Sheet. Maybe it is to be added to the
track, or maybe it gets an own Cue Sheet entry ... who knows ?
(libburn contains write code for pregap1, pregap2 and postgap. But only
pregap2 ever gets activated. Once hackingly for the first 2 second pause, once
incompletely for a change of DATA FORM.)

Seems nobody ever tested this. Libburnia simply knows no use case where the
correctness of Pre-gap and Post-gap would become evident.


-------------------------------------------------------------------------------

-------------------------------------------------------------------------------
                           Overwriteable DVD Cookbook
-------------------------------------------------------------------------------
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/
by own experiments with drives NEC ND-4570A, LG GSA-4082B, PHILIPS SPD3300L,
LG GGW H20L, and by BD-RE experiments done by Giulio Orsero on LG BE06LU10.

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

-------------------------------------------------------------------------------

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
BD-RE                          0043h

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, DVD-RW, BD-RE
- Unformatted DVD+RW
- Partly formatted DVD+RW
- Unformatted DVD-RW
- Partly formatted DVD-RW
- Intermediate state DVD-RW
- DVD-RAM and BD-RE formatting
- DVD-RAM and BD-RE speed tuning

Slightly off topic are
- ISO 9660 multi-session emulation on overwriteable media
- ISO 9660 based TOC emulation on overwriteable media

-------------------------------------------------------------------------------
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, DVD+RW, BD-RE 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.


-------------------------------------------------------------------------------
DVD-RAM, fully formatted DVD+RW, DVD-RW, BD-RE :

Full format is the natural state of DVD-RAM.

BD-RE are sold unformatted and need to be fully formatted first.
See paragraph about DVD-RAM and BD-RE formatting below.

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.)


-------------------------------------------------------------------------------
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.


-------------------------------------------------------------------------------
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.


-------------------------------------------------------------------------------
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)
Experiments on my drives indicate that only Blanking Type 000b "Blank the disc"
achieves neat media. Media blanked via type 001b offer no feature 0021h and
stall cdrecord or libburn already when those media get examined. growisofs can
burn them - but only via DAO (feature 002Fh which prescribes Write Type 2).
(mmc5r03c.pdf 5.3.11, 5.3.25)

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.


-------------------------------------------------------------------------------
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)


-------------------------------------------------------------------------------
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)


-------------------------------------------------------------------------------
DVD-RAM and BD-RE formatting :

Although DVD-RAM usually are sold formatted, there may still arise the wish
to adjust formatting.
BD-RE are sold unformatted and need to be formatted prior to usage.

Two format types are relevant for DVD-RAM : 00h and 01h.
00h offers the default size format and usually a maximum payload size format.
Even with that maximum size payload there is hardware defect management.
(mmc5r03c.pdf 6.5.4.2.1.2)
01h allows to convert payload capacity into spare blocks for defect
managment. There is no way to increase payload capacity by format 01h.
(mmc5r03c.pdf 6.5.4.2.2.1)

With BD-RE there are three format types : 00h, 30h and 31h.
00h offers the default size format. This may be the only fast formatting
mode that is offered by the drive.
Feature 0023h tells whether format 31h and certain 30h subtypes are available.
(mmc5r03c.pdf 5.3.13)
30h offers several sizes with defect management. Usually there are three
sizes given: #1: default size, #2: maximum spare area, #3: minimal spare.
One may demand any spare size between maximum and minimum. There may be quick
certification and full certification. See feature 0023h.
31h offers a single size and disables defect management. This has the side
effect to speed up writing to nominal speed.
(mmc5r03c.pdf 6.5.4.2.15, 6.24.3.3, Table 472)

Only format sizes from the list of format descriptors are permissible
for DVD-RAM. The format list can be obtained by 23h READ FORMAT CAPACITIES.
It also includes a description of the current formatting state.
(mmc5r03c.pdf 6.24, 6.24.3.2, 6.24.3.3)

Formatting is done by command 04h FORMAT UNIT. Its data payload consists
of a Format List Header and a Format Descriptor. It is advisable to set
the Immed bit and the FOV bit in header byte number 1. The descriptor should
be a copy of a descriptor from 23h READ FORMAT CAPACITIES.
(mmc5r03c.pdf 6.5, 6.5.3.2, 6.5.3.3)
With nearly all formats Sub-type should be set to 0. But with BD-RE formats
30h and 31h the Sub-type selects the certification mode.
Usable with 30h seem 10b Full Certification and 11b Quick Certification.
Usable with 31h seem also 00b Quick Reformat and 01b No Certification.
(mmc5r03c.pdf 6.5.4.2.15.1)

Other format types have their certification intensity controlled by
a pair of bits: CmpList and DCRT.
CmpList resides in CDB byte 1 as bit 3. DCRT resides in the payload byte 1
as bit 5. Both together should request a quick size change without lengthy
certification but maintaining the list of known defects.
(mmc5r03c.pdf 6.5, table 249, 6.5.3.2)
With DVD-RAM on my PHILIPS SPD3300L drive they prevent any format size
change though. The TSSTcorp SH-S203B works properly.
With BD-RE format 00h, the default is specified to be Quick Reformat,
and with 00h in general certification can only be disabled not enabled.
(mmc5r03c.pdf 6.5.4.2.1.7)


-------------------------------------------------------------------------------
DVD-RAM and BD-RE tuning :

A special aspect of DVD-RAM and BD-RE is their low speed with write operations,
which usually is only half than the nominal speed of media and drive.
This is blamed to the automatic checkreading which happens for managing
eventual defects. 

Defect management of BD-RE can be disabled by format type 31h. See above.
There is no drive known yet which would apply command 2Ah WRITE10 to DVD-RAM
with full speed.

The only known way to get full speed from DVD-RAM or BD-RE with enabled defect
management is the use of AAh WRITE12 with Streaming Bit set to 1.
(mmc5r03c.pdf 6.45)
With some DVD-RAM drives this fails if a write buffer is not full 32 kB.
With the tested BD-RE one must write full 64 kB buffers, or else writing
might not get into effect at all.

Although it seems not optimal, this is specified not only to disable the
cumbersome checkread but also to ignore known defects and to write data
to these defective addresses.
(mmc5r03c.pdf 4.8.5)
So the speed-up is only advisable as long as the media are free of
incorrectable errors.

Caveat:
MMC-5 does not guarantee AAh WRITE12 to work on DVD-RAM or BD-RE at all.
None of the features of profiles 0012h and 0043h promises the existence of
AAh WRITE12.
(mmc5r03c.pdf 5.4.13, 6.45)
Nevertheless it worked on all tested drives if proper alignment and block
size was observed.


-------------------------------------------------------------------------------
ISO 9660 multi-session emulation on overwriteable media :

Overwriteable media provide a single overwriteable track which may grow up to
the full media capacity. There is no builtin table-of-content which records
the history of write sessions.
mount -t iso9660 will use sbsector=0 as default.
The term "superblock" shall depict the first 64 KiB after the sbsector address.

ISO 9660 multi-session depends on typical TOC information in two ways:
It needs the superblock address MSC1 of the most recently recorded session and
it needs the Next Writeable Address NWA for which to prepare the adress offset.

The following is learned from growisofs and from ECMA-119:
http://www.ecma-international.org/publications/files/ECMA-ST/Ecma-119.pdf

ISO 9660 filesystems provide information about the number of sectors which
is also the lowest unused block address and thus a suitable NWA.
This block address is stored in the Primary Volume Descriptor which is supposed
to be stored in block 16 (eventually relative to MSC1).
The bytes 0 to 5 of a PVD block are 
   0x01 'C' 'D' '0' '0' '1'
The sector count can then be read from byte 80 to 83
   sectors= pvd[80] | (pvd[81] << 8) | (pvd[82] << 16) | (pvd[83] << 24);
(Ecma-119.pdf 8.4)
To support CD, DVD and BD media alike, it is advisable to round the NWA
to the next multiple of 32 (= 64 KiB).

So one can use 0 as MSC1 and prepare a new ISO session for the computed NWA.
After writing the session it is necessary to patch the PVD at LBA 16.
The minimal change would be to update the number of image sectors.
It is stored in both notations LSB and MSB:
   for(i= 0; i < 4; i++)
     pvd[87 - i]= pvd[80 + i]= (sectors >> (8 * i)) & 0xff;

cdrskin --grow_overwriteable_iso not only patches the sector fields of the
PVD block but also the blocks up to LBA 31 which begin with
   0xff 'C' 'D' '0' '0' '1'
libisoburn submits 64 KiB data buffer to libisofs before image generation and
afterwards writes these 64 KiB as new superblock to LBA 0.


-------------------------------------------------------------------------------
ISO 9660 based TOC emulation on overwriteable media :

Above method of multi-session emulation yields a single session image after
each add-on session. No reliable session history can be read because the
sector size of the existing session gets overwritten by the new one.
A TOC with session history is nevertheless desirable with incremental backups
in order to access older backup states by mounting older superblocks at the
start addresses of older sessions.

All usual ISO 9660 formatter programs write a complete superblock to the
start of each session.
With a uniform NWA rounding rule it is possible to compute the address of
superblock N+1 as the NWA after session N. The only problem is N=1
because it gets overwritten by later sessions.

libisoburn preserves the information of session 1 by writing the first session
to LBA 32 rather than LBA 0. Afterwards it writes the overall superblock to
LBA 0 (up to 31).
So with all further add-on sessions the superblock at LBA 0 will enclose the
overall image, while the superblocks of the sessions form a chain beginning
at LBA 32. Each session superblock points to the next one by its sector count
rounded up to 32. The chain end is marked by the overall image size.
This chain gives the start addresses of sessions. The sector count minus start
address gives the size of a particular session. ECMA-119 explains how to
retrieve more info from the PVD (e.g. the volume id).

See also the multi-session example in libisofs/doc/checksums.txt.


-------------------------------------------------------------------------------

-------------------------------------------------------------------------------
                        Sequential DVD-R[W] Cookbook
-------------------------------------------------------------------------------
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-project.org by Thomas Schmitt <scdbackup@gmx.net>

-------------------------------------------------------------------------------

Media type can be recognized by Current Profile from 46h GET CONFIGURATION.
(mmc5r03c.pdf 6.6.2.1)
DVD-R                          0011h
DVD-RW Restricted Overwrite    0013h
DVD-RW Sequential Recording    0014h
DVD-R/DL Sequential Recording  0015h (can only do single-session)

There are two approaches for writing to sequential DVD-R[W]: DAO and
Incremental. Not all media and drives offer Incremental which allows 
multi-session as with CD media and does not demand a predicted track size.
DAO seems to be the older method. It allows only one single session and
track and it demands an exactly predicted track size.

- About overwriteable, blank, appendable and finalized DVD-R[W] media
- Incremental writing
- DAO writing
- Obtaining DVD-R[W] multi-session info for extending ISO-9660 filesystems
- Obtaining a Table Of Content from DVD-R[W]
- Hearsay about DVD-R/DL (Dual Layer)


-------------------------------------------------------------------------------
About overwriteable, blank, appendable and finalized DVD-R[W] media :

DVD-RW can be either in formatted state Restricted Overwrite or in unformatted
state Sequential Recording. Sequential media can be either blank, appendable
or finalized.

Only blank and appendable media are sequentially writeable. For overwriteable
DVD-RW see the Overwriteable DVD Cookbook.

Overwriteable DVD-RW can be detected by their profile number 0013h in contrast
to profile number 0014h for sequential DVD-RW.
The status of sequential media can be inquired like with CD 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)

Finalized, appendable or overwriteable DVD-RW can be brought into blank
sequential state by command A1h BLANK with blanking type 000b "Blank the disc".
See TAO Multi-Session CD Cookbook for details about blanking.

After minimal blanking (type 001b) DVD-RW my two drives do not offer the
Incremental Streaming feature 0021h the media any more. Full blanking (000b)
brings back this feature.
(mmc5r03c.pdf 6.2)


-------------------------------------------------------------------------------
Incremental writing :

Incremental writing allows to produce multi-session DVDs. It is indicated
by feature 0021h being marked current in the reply of 46h GET CONFIGURATION.
growisofs inquires 0021h by setting Starting Feature Number to 0x21 and
Allocation Length to 16 in order to get only this one. The feature descriptor
begins at byte 8 of the reply. Its availability is indicated by the Current
Bit. libburn obtains the full feature list for this and other info.
(mmc5r03c.pdf 5.2.2. Feature Descriptor format, 5.3.11 Feature 0021h,
 6.2 46h GET CONFIGURATION, )
In mode page 05h this method is selected by Write Type 00h. 

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)	

growisofs fetches a mode page 05h template by MODE SENSE and inserts its own
parameters.  It sets Multi-session to 11b, unless dvd_compat is nonzero.
libburn composes its mode page 05h from zero and allows control of
Multi-Session by the application.
 BUFE             Buffer Underrun protection      0=off, 1=on
 LS_V             Link size valid                 1=true
 Test Write       -dummy mode for writing         0=off, 1=on
 Write Type       Packet/TAO/SAO/RAW              00h = Incremental (Packet)
 Multi-session    Whether to keep appendable      00b = finalize
                                                  11b = keep appendable
 Track Mode       Describes frame type            5  [*1]
 Data Block Type  Layout of payload blocks        8  [*2]
 Link Size        ???                             16 [*3]
 FP               Fixed Packet Size Bit           1
 Packet Size                                      16 [*4]  
(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)
[*1:]
growisofs takes the Track Mode from 52h READ TRACK INFORMATION, Address/Number
Type 1, Track 1, Track Information Block byte 5 & 0xf.
(mmc5r03.pdf 6.27)
The specs predict that this will be Track Mode 4 (6.27.3.8) and also state that
default is 5 (7.5.4.12). 4 means: uninterrupted, do not copy. 5 means
increment, do not copy.
[*2:]
8 means: 2048 byte data blocks. growisofs sets this value if Data Mode from
above 52h READ TRACK INFORMATION is 1 or Fh, which is predicted by the specs
to be always true.
(mmc5r03.pdf 6.27.3.10)
[*3:]
growisofs (transport.hxx) sets Link Size to 16 for profiles 0011h and 0014h.
libburn now records the first link size from feature 0021h in its burn_drive
structure. If another link size item is 16, then 16 is used.
[*4:]
growisofs takes Packet Size from 52h. Specs predict it will be 16 (= 32 kiB).
(mmc5r03.pdf 7.5.4.16)

The writing process is much like in "Writing a session to CD in TAO mode" :
Next Writeable Address is fetched from the reply of 52h READ TRACK INFORMATION.
libburn writes full 32 kiB buffers via 2Ah WRITE.
(mmc5r03c.pdf, 6.27 READ TRACK INFORMATION, 6.44 WRITE)
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.
growisofs uses the logical track number for that and not FFh like libburn
does with TAO CD. So libburn obtains the Last Track Number in Last Session
from the reply of  51h READ DISC INFORMATION requesting Data Type 000b
"Standard Disc Information".
(mmc5r03c.pdf 6.3.3.2.2 CLOSE TRACK, 6.22.3.1.)

Multiple tracks are permissible in a single session. After all of them have
been written, 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 whether the disc is finalized or stays appendable.
(mmc5r03c.pdf 6.3.3.2.3)


-------------------------------------------------------------------------------
DAO writing :

DAO is the mode described by feature 002Fh. This feature also gives information
about capabilities for Burnfree (BUF), Test Write and DVD-RW.
(mmc5r03c.pdf 5.3.25)
Experiments with growisofs showed that the track size needs to be predicted
and may not be exceeded during the write process. (growisofs ran into SCSI
errors with piped non-ISO-9660 images and with piped ISO-9660 which have
trailing data.)

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)	

The mode page 05h to be sent :
 BUFE             Buffer Underrun protection      0=off, 1=on
 LS_V             Link size valid                 0=false [*3]
 Test Write       -dummy mode for writing         0=off, 1=on
 Write Type       Packet/TAO/SAO/RAW              02h = DAO (same code as SAO)
 Multi-session    Whether to keep appendable      00b = finalize
 Track Mode       Describes frame type            5  [*1]
 Data Block Type  Layout of payload blocks        8  [*2]
 Link Size        ???                             0 [*3]
 FP               Fixed Packet Size Bit           0 [*3]
 Packet Size                                      0 [*3]  
(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)
[*1:]
growisofs takes the Track Mode from 52h READ TRACK INFORMATION, Address/Number
Type 1, Track 1, Track Information Block byte 5 & 0xf.
(mmc5r03.pdf 6.27)
[*2:]
8 means: 2048 byte data blocks. growisofs sets this value if Data Mode from
above 52h READ TRACK INFORMATION is 1 or Fh, which is predicted by the specs
to be always true. (If not: growisofs aborts.)
(mmc5r03.pdf 6.27.3.10)
[*3:]
Link Size, Packet Size and their companions only apply to Write Type 00h.

The session layout must be described by 53h RESERVE TRACK, RMZ=ARSV=0.
Reservation size should better already be aligned to 32 KiB. It has not been
tested yet, what happens if not enough data get written.
(mmc5r03c.pdf 6.31)

Next Writeable Address is fetched from the reply of 52h READ TRACK INFORMATION.
The reply is supposed to be 0. libburn writes full 32 kiB buffers via
2Ah WRITE.
(mmc5r03c.pdf, 6.27 READ TRACK INFORMATION, 6.44 WRITE)
If the track source delivers less than the announced size then libburn pads up
by zeros.
When writing is done, it is mandatory to force the drive's buffer to media by
35h SYNCHRONIZE CACHE.
(mmc5r03c.pdf, 6.41)

No further finalization is necessary. (I.e. no 5Bh CLOSE TRACK SESSION.)


-------------------------------------------------------------------------------
Obtaining DVD-R[W] multi-session info for extending ISO-9660 filesystems :
(valid for DVD+R too)

Like with CD it is necessary to obtain the two numbers for mkisofs option -C
in order to prepare a ISO-9660 filesystem image which by its inner pointers
matches the block addresses of the future location on media.
These are the start address of the first track in the last complete session
and the predicted start address of the track which will host the new image.
See TAO Multi-Session CD Cookbook for some more info about mkisofs aspects.


The first number may be gained by 43h READ TOC/PMA/ATIP 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)
Regrettably the MMC-5 specs still define a useless reply for non-CD media
which obviously stems from MMC-3 times when no multi-session was possible
with non-CD.
(mmc5r03c.pdf 6.26.3.3.3)
Both my drives do give a useful reply with the correct number for appendable
DVD-RW. But not being backed by the specs this method appears unappealing .

Another approach would be a formatted Table of Content, obtained by 43h READ
TOC/PMA/ATIP Format 0000b. The specs do not totally outrule that this returns
useful data with non-CD but they define a crippled TOC for multi-session.
(mmc5r03c.pdf 6.26.3.2.4)
My LG drive returns a more detailed TOC, my NEC drive stays with the rather
suboptimal specs. So one would get different TOCs on different drives.
Nevertheless, the MMC-5 compliant TOC would return the desired number in
the Track Start address of the track with the highest number before AAh.

Most stable seems the approach to obtain the desired number from the reply
of 52h READ TRACK INFORMATION, Address/Number Type 01b. The field Logical Block
Address/Track/Session has to bear the track number of the first track in the
last complete session. To determine this number one has to determine the
number of the last session and the number of the last track from 51h READ DISC
INFORMATION and to iterate over the tracknumber by 52h READ TRACK INFORMATION
until the first track with the desired session number appears and reveils
its start address. 
(mmc5r03c.pdf 6.22 51h DISC, 6.27 52h TRACK)
This method is very near to fabricating an own TOC. So libburn does this 
when inspecting the media. If the first number for -C is needed, libburn
inquires its TOC model for the address of the first track in the last
complete session. See below for a detailed description of TOC fabrication.


The second -C number is the exact prediction of future track start address. It
is gained like with CD by 52h READ TRACK INFORMATION Type 01b. Different from
CD one may not use track number FFh but has to use the Last Track in Last
Session from 51h READ DISC INFORMATION. 
(mmc5r03c.pdf 6.22 51h DISC, 6.27 52h TRACK)


-------------------------------------------------------------------------------
Obtaining a Table Of Content from DVD-R[W]:
(valid for DVD+R too)

The raw TOC entries from 43h READ TOC/PMA/ATIP Format 0010b as described with
CD media are not available with non-CD.
There is a Format 0000b "Formatted TOC" but this is with non-CD a fictional
information much at the discretion of the drive. Two drives with the same disc
may well return different Formatted TOC. They are supposed to be consistent
only about the last complete session and even there the MMC-5 specification
6.26.3.2.5 seems to prescribe a structure which does not match the true
structure of incremental writing to sequential DVD-R[W].
(mmc5r03c.pdf 6.26.3.2)
So i prefer not to use this method of getting a TOC.


The alternative is to produce an own TOC from information gained by 51h READ
DISC INFORMATION and by 52h READ TRACK INFORMATION which reveil a CD-like
structure of sessions and 1:n related tracks.

51h READ DISC INFORMATION Data Type 000b, fields Number of Sessions (Least
Significant Byte) and Number of Sessions (Most Significant Byte) give the
number of sessions. The last complete session number of an appendable disc
is one less because there is an incomplete session at its end. libburn only
records complete sessions in its TOC model.
libburn uses Last Track in Last Session as a hint for the range of track
numbers.
(mmc5r03c.pdf 6.22)

Next step is to iterate from 1 up to the last track number and to obtain
the according track info by 52h READ TRACK INFORMATION. Each track tells its
Session Number (LSB at byte 2, MSB at 33), its Logical Track Start Address,
its Logical Track Size, and much more which is not needed for a fake CD TOC.
One may analyze the track info more finely but for this special purpose
it is enough to discard the tracks which do not belong to complete sessions.
(mmc5r03c.pdf 6.27)

At the end of each session libburn inserts fake leadout entries into its TOC
model. Their start address is computed from the start and size of the last
track of the session.


-------------------------------------------------------------------------------
Hearsay about DVD-R/DL (Dual Layer) :

Meanwhile confirmed by one user:

DVD-R/DL can assume profile 0015h DVD-R Dual Layer Sequential which is supposed
to behave like DVD-R or 0016h DVD-R Dual Layer Jump which has no counterpart
with DVD-R.

A half-sentence in mmc5r03c.pdf 6.3.3.3.3 indicates that closing a session
by 5Bh CLOSE TRACK SESSION Close Function 010b overrides the multi-session bits
in mode page 05h.
growisofs applies this function in case of not DAO, though. A comment in
growisofs_mmc.cpp states: "// DVD-R DL Seq has no notion of multi-session".
I am not reading this from the specs - but not explicitely the contrary either.

For now libburn will close the session but there is a macro prepared in
libburn/write.c Libburn_dvd_r_dl_multi_no_close_sessioN which will suppress
close session if multi-session is demanded.


-------------------------------------------------------------------------------

-------------------------------------------------------------------------------
                             DVD+R[/DL] Cookbook
-------------------------------------------------------------------------------
Inspired by reading mmc5r03c.pdf from http://www.t10.org/ftp/t10/drafts/mmc5/
backed by Andy Polyakov's http://fy.chalmers.se/~appro/linux/DVD+RW/tools ,

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

-------------------------------------------------------------------------------

Media type can be recognized by Current Profile from 46h GET CONFIGURATION.
(mmc5r03c.pdf 6.6.2.1)
DVD+R                          001bh
DVD+R/DL                       002bh

- About empty, appendable and finalized DVD+R
- Writing a Pseudo Session to DVD+R
- DVD+R/DL (Dual Layer

The following two chapters of the Sequential DVD-R[W] Cookbook are valid for
DVD+R media too:
- Obtaining DVD-R[W] multi-session info for extending ISO-9660 filesystems
- Obtaining a Table Of Content from DVD-R[W]

-------------------------------------------------------------------------------
About blank, appendable and finalized DVD+R :

In the beginning a DVD+R holds an empty session and the Incomplete Fragment.
From these one may spawn reserved fragments or one may write directly to
the incomplete fragment. As soon as this is done the empty session becomes the
open session which finally needs to get closed. By closing fragments and
session a new empty session with empty Incomplete Fragment gets spawned.
So the disc stays appendable.

A DVD+R may hold 153 closed sessions with a single track each.
The open session may hold up to 15 open fragments. But on closure of the
session those fragments together form a single logical track.  So one will
usually only use a single fragment for sequential writing. 
(mmc5r03c.pdf 4.3.6.2)

The disc may get finalized by another close command so that no more data can
be written.
(mmc5r03c.pdf 6.3.3.4.4) 


-------------------------------------------------------------------------------
Writing a Pseudo Session to DVD+R :

Session writing has to be pseudo because only one logical track per session
can be distinguished. So actually there have to be written multiple sessions
to mark multiple tracks. The pseudo session cannot get marked on disc and thus
the tracks of a pseudo session cannot be grouped accordingly in a TOC.

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)	

No mode page 05h is to be sent.
growisofs sends a page but the specs clearly state that one shall not do.
(mmc5r03c.pdf 7.5.3)

It is optional whether a track size is reserved in advance or not. Eventually
this is done by 53h RESERVE TRACK, RMZ=ARSV=0. Reservation size should better
already be aligned to 32 KiB.
(mmc5r03c.pdf 6.31)
The specs promise to pad up the track if not enough data get written.
(mmc5r03c.pdf 6.3.3.4.2)

Next Writeable Address is fetched from the reply of 52h READ TRACK INFORMATION
with track number FFh.
(mmc5r03c.pdf 6.27)
Since the fixely set write type is 16-block packet, full 32 kiB buffers have
to be transmitted via 2Ah WRITE.
(mmc5r03c.pdf 4.3.6.2.2)

When writing is done, it is mandatory to force the drive's buffer to media by
35h SYNCHRONIZE CACHE.
(mmc5r03c.pdf 6.41)

The written fragment (i.e. track-to-be) has to be closed by 5Bh CLOSE TRACK
SESSION Close Function 001b.
(mmc5r03c.pdf 6.3.3.4.2)
libburn obtains the necessary logical track number from Last Track Number in
Last Session from the reply of 51h READ DISC INFORMATION requesting
Data Type 000b.
(mmc5r03c.pdf 6.22) 

After each track 5Bh CLOSE TRACK SESSION Close Function 010b with Logical Track
Number 0 closes the DVD+R session but keeps the media appendable.
(mmc5r03c.pdf 6.3.3.4.3)
If the media shall not stay appendable then the last DVD+R session is to be
closed by Close Function 101b rather than 010b. This finalizes the media
"with minimal radius".
(mmc5r03c.pdf 6.3.3.4.4) 

Note: growisofs has code for that gesture but explicitly avoids to use it, if
the media was appendable before writing began. Instead it recommends to fill
up the media with zeros. This gesture nevertheless caused error replies from
the drives in my own experiments.
The reason given by Andy Polyakov is that some DVD-ROM drives get mislead by
the lead-out information of (formerly) appendable media unless the media is
fully written.
(http://fy.chalmers.se/~appro/linux/DVD+RW/ , "Compatibility: caveat lector")

Own experiments showed no such problems with PC attached PATA DVD-ROM drives.
For best DVD-ROM compatibility one should avoid appendable media at all
by closing them already after the first session.


-------------------------------------------------------------------------------
DVD+R/DL (Dual Layer) :

libburn treats DL media just like their single layer equivalents.
This seems to work fine for DVD+R/DL, according to a report by nightmorph
in http://libburnia-project.org/ticket/13 .

-------------------------------------------------------------------------------

-------------------------------------------------------------------------------
                              BD-R Cookbook
-------------------------------------------------------------------------------
Inspired by reading mmc5r03c.pdf from http://www.t10.org/ftp/t10/drafts/mmc5/
backed by experiments iwith drive LG GGW H20L.

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

-------------------------------------------------------------------------------
Media type can be recognized by Current Profile from 46h GET CONFIGURATION.
(mmc5r03c.pdf 6.6.2.1)
BD-R                           0042h

There are two basic recording modes defined: Sequential Recording Mode SRM and
Random Recording Mode RRM. The latter is optional and for now not topic of this
text.
(mmc5r03c.pdf 4.5.3.5)


- SRM Formatting
- Writing a session in SRM-POW
(- Pseudo-OverWrite SRM+POW)


-------------------------------------------------------------------------------
SRM Formatting:

Despite being write-once media BD-R can optionally carry some formatting.

SRM has a disc structure model with tracks and sessions.
Several tracks may be open at the same time, each having its own NWA.
(mmc5r03c.pdf 4.5.3.5.2.2)
This structure is formatted onto blank media automatically as soon as the
first serious write attempt occurs.
(mmc5r03c.pdf 4.5.3.5)
Before such a write attempt, blank media may be explicitely formatted with
spares, which provide defect management.
(mmc5r03c.pdf 4.5.3.5.3)
Tracks get created from other tracks via RESERVE TRACK splitting.
(mmc5r03c.pdf 4.5.3.5.2.5)

On top of defect management there may be Pseudo-OverWrite SRM+POW, a costly
way to write several times to the same LBA. See below.
Fully sequential states are called SRM-POW.
(mmc5r03c.pdf 4.5.3.5.4)

Explicite formatting is done by 04h FORMAT UNIT. Its data payload consists
of a Format List Header and a Format Descriptor. It is advisable to set
the Immed bit and the FOV bit in header byte number 1. The descriptor should
be a copy of a descriptor from 23h READ FORMAT CAPACITIES but the size may be
adjusted within a certain range.
(mmc5r03c.pdf 6.5, 6.5.3.2, 6.5.3.3)

Format type 00h creates SRM layouts with a default number of spares (or
eventually RRM) chosen by the format sub-type:
  00b = SRM with support for POW
  01b = SRM without POW (but with some spares for defect management)
  10b = (RRM)
(mmc5r03c.pdf 6.5.4.2.1.6)

Format type 32h uses the same sub-types but allows to allocate non-default
amounts of spares. Similar to BD-RE format 31h, three format descriptors are
offered: #1: default size, #2: maximum spare area, #3: minimal spare.
The size may be chosen within that range.

The sense behind the Type Dependent Parameters is obscure
to me. Best will be to set ISA_V and TDMA_V to 0.
(mmc5r03c.pdf 6.5.4.2.1.17)


-------------------------------------------------------------------------------
Writing a session in SRM:

The procedure and constraints for writing BD-R SRM-POW are very similar to
DVD+R. libburn flatly re-uses its DVD+R code except the Close Function for
finalizing a disc.

In short:
If all written sessions are closed, then there is exactly one NWA.
In the beginning there is an empty session and track. A new track can be
written either with pre-announced size (by RESERVE TRACK) or open-end by
simply starting to write to the NWA. When done the track gets closed by
close function 001b. Then either session or disc gets closed depending on
the Close Function used:
- Close Function 010b closes the session and keeps the media appendable
  (same as with DVD+R)
- Close Function 110b finalizes the media and makes it read-only.
  (differs from libburn DVD+R procedure which uses 101b)

-------------------------------------------------------------------------------
Pseudo-OverWrite POW: (no used yet by libburn)

This enhancement of SRM emulates overwriting of existing data blocks.
(mmc5r03c.pdf 4.5.3.5.4)

POW establishes a virtual vLBA space on top of the real address space rLBA.
All read and write commands deal with vLBA. It seems that track NWAs are
assumed to be identical in vLBA space and in rLBA space.
It is not clear whether one may write to vLBA blocks which are neither written
yet nor at one of the track NWAs. Probably not, or else one could make NWAs run
into vLBAs which are associated with older rLBAs.

Replacing invalidated blocks consumes addresses in rLBA space at the NWA of
some track. I.e. no spares are consumed by POW. Nevertheless it is costly by
a special map called Orphanage. It covers rLBA which have been consumed
by differing vLBAs. It never shrinks and can grow with each write to remapped
addresses.
To avoid heavy Orphanage growth it is advised to write mostly to vLBA which
still coincide with their rLBA. E.g. those addresses which have neither been
written as rLBA nor as vLBA yet. So one should begin the vLBA of new sessions
at the NWA of a sufficiently sized track.
(mmc5r03c.pdf 4.5.3.5.4.2 , 4.5.3.6.9)


-------------------------------------------------------------------------------
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.
-------------------------------------------------------------------------------