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Normal CD datatype (DAO or SAO) ?

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Normal CD datatype (DAO or SAO) ?

Postby webbertrix on Fri Jun 27, 2003 10:55 am

Hello,

As far i understand over Alcohol 120% :

(The Disc At Once method always allow the writing of RAW 2353 byte sectors with some subcode channels variations) :


1) RAW (DAO) : where the 96 bytes of associated P-W subcode channels are ALWAYS generated by the HARDWARE recorder.

2) RAW DAO-16 : where the 16 bytes of associated P-Q subcode channels are generated by SOFTWARE (but R-S-T-U-V-W by HARDWARE).

3)*RAW DAO-96 : where the 96 bytes of associated P-W subcode channels are ALWAYS generated by SOFTWARE.


*N.B : Best CD-R DAO write mode is #3 since :

(It allows writing of all subchannel information, including Digital Signatures, CD-Text, ISRC, Catalog Numbers, CD+G, CD+Midi, Gaps, Indices, TOC, etc.)


I beleive the setting in Alcohol "Write Method" = DAO/SAO is using DAO write mode #1.

But i dont understand what's SAO has to do into this..


Finally,

DAO always write in RAW but have some subchannel variations.
(SAO is another story.)


Someone could tell me which write method between DAO or SAO is actually used when burning a CD in "Normal CD" datatype.


My burner have some big problems reading back DAO RAW-96.
But, my burner could read back the CD'R if it was previously burned over DAO/SAO

I would like to confirm it could read back DAO (RAW). (And not SAO)


Thanks.
webbertrix
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Postby Inertia on Fri Jun 27, 2003 1:32 pm

DAO is the process in which a single session is written without turning the laser off and the disc is closed.

SAO is a subset of DAO, and is a multisession mode primarily used for CD-Extra. The CD-Extra format writes audio tracks without turning off the laser during the first session and turns off the laser at session end. A second session containing CD-ROM XA Mode 2 data is then written and the disc closed. SAO is essentially like DAO except the disc doesn't have to be closed after the first session.

The term SAO as used with programs that defeat copy protection usually refers to SAO RAW, which is not a MMC standard and is not the same process as defined in the paragraph above. SAO RAW is a software trick used to write data as if it were audio, using the full 2,352 bytes for data without any error correction. Since there is no error correction, this preserves the orginal errors from the source disc which are part of the copy protection scheme.

DAO is the method of burning a "normal CD" and not SAO. True SAO is rarely used except for CD-Extra. RAW DAO-96 should not be used unless there is a specific reason to use it, or it is the only method that will work. For all normal burning DAO is the best mode
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Postby webbertrix on Fri Jun 27, 2003 2:14 pm

I already understand what was the difference between DAO and SAO.
Thanks for the recap!

What i wish to know is if Alcohol is using DAO or SAO when you
are burning a CD with : Write Method selected to DAO/SAO.


Since it can't be both at the same time. Right ?
So which one is really used ?

I'm trying to figure out this problem :
http://www.cdrlabs.com/phpBB/viewtopic. ... highlight=


Regards,
webbertrix
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Postby Inertia on Fri Jun 27, 2003 10:45 pm

webbertrix wrote:What i wish to know is if Alcohol is using DAO or SAO when you
are burning a CD with : Write Method selected to DAO/SAO.


Since it can't be both at the same time. Right ?
So which one is really used ?


If the checkbox "Don't close the last session of current disc" is checked, the process is SAO. If the box is unchecked, the burn process is DAO.

As I explained earlier, if a single session has the laser turned on throughout the burn and is finalized at the conclusion of the session, the process is DAO.

DAO is not the same as RAW DAO. DAO corrects errors and is the normal mode for copying unprotected audio and data discs. The RAW modes copy everything "as is" without error correction.
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Postby webbertrix on Sat Jun 28, 2003 12:54 am

Ok cool....

If the datatype is set to Normal CD;

"Don't close the last session of current disc" is unchecked, so the burn process is DAO. This look like DAO (and not SAO) is the default!

=======

Next thing,

I was under the impression DAO was only working in RAW mode.

(The Disc At Once method always allow the writing of RAW 2353 byte sectors with (3) subcode channels variations) :

Where Mode #1 (see below) is usually the "Default DAO".

1) RAW (DAO) : where the 96 bytes of associated P-W subcode channels are ALWAYS generated by the HARDWARE recorder.
(So there's some sort hardware error correction into this mode)


2) RAW DAO-16 : where the 16 bytes of associated P-Q subcode channels are generated by SOFTWARE (but R-S-T-U-V-W by HARDWARE).


3)RAW DAO-96 : where the 96 bytes of associated P-W subcode channels are ALWAYS generated by SOFTWARE.
(No hardware correction at all here.. But software might do somes)


So reflecting that representation into Alcohol :
-----------------------------------------------------

A) If, Write Mode = DAO/SAO with last session unchecked
=> Mode #1, always with hardware error correction.

Example of string output :
(Method/Speed Recording - DAO / SAO - 16X (2400 KB/Sec)

====

B) If, Write Mode = RAW DAO WITHOUT rectify sub channel data checked
=> Mode #3, without software error correction.

Example of string output :
(Method/Speed Recording - RAW DAO - 4X (600 KB/Sec)
(RAW DAO Write Mode- RAW-PW(96))



C) If, Write Mode = RAW DAO WITH rectify sub channel data checked
=> Mode #3, WITH software error correction. (not hardware)


Regards,
webbertrix
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Postby Inertia on Sat Jun 28, 2003 5:13 am

If you haven't already, you can download the Alcohol User Manual.

Alcohol User Manual wrote:Write Method: Includes DAO/SAO (default), RAW SAO, RAW SAO+ SUB, and RAW DAO. Most CD/DVD recorders support DAO/SAO writing mode, but not every CD/DVD recorder supports RAW writing mode. You can check which writing modes your CD/DVD recorder supports in “System Info” in the above window.

DAO/SAO writing mode is used to backup normal CD/DVD discs. In contrast, RAW writing mode is used to backup raw data of CD/DVD discs (mainly for special CD/DVD formats).
Inertia
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Re: Normal CD datatype (DAO or SAO) ?

Postby kaikow on Fri Aug 08, 2003 8:38 pm

SEctors are 2352, not 2353, bytes.

webbertrix wrote:Hello,

As far i understand over Alcohol 120% :

(The Disc At Once method always allow the writing of RAW 2353 byte sectors with some subcode channels variations) :


1) RAW (DAO) : where the 96 bytes of associated P-W subcode channels are ALWAYS generated by the HARDWARE recorder.

2) RAW DAO-16 : where the 16 bytes of associated P-Q subcode channels are generated by SOFTWARE (but R-S-T-U-V-W by HARDWARE).

3)*RAW DAO-96 : where the 96 bytes of associated P-W subcode channels are ALWAYS generated by SOFTWARE.


*N.B : Best CD-R DAO write mode is #3 since :

(It allows writing of all subchannel information, including Digital Signatures, CD-Text, ISRC, Catalog Numbers, CD+G, CD+Midi, Gaps, Indices, TOC, etc.)


I beleive the setting in Alcohol "Write Method" = DAO/SAO is using DAO write mode #1.

But i dont understand what's SAO has to do into this..


Finally,

DAO always write in RAW but have some subchannel variations.
(SAO is another story.)


Someone could tell me which write method between DAO or SAO is actually used when burning a CD in "Normal CD" datatype.


My burner have some big problems reading back DAO RAW-96.
But, my burner could read back the CD'R if it was previously burned over DAO/SAO

I would like to confirm it could read back DAO (RAW). (And not SAO)


Thanks.
kaikow
CD-RW Player
 
Posts: 123
Joined: Thu Jul 03, 2003 4:05 pm


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