URL:
Http://forums.Afterdawn.com/thread_view.cfm/23595
Translation Date: September 29, 2004 Translator Note: I don't understand so many disc engraved terms, just translated by experience, wrong, please correctly correct it in time, To avoid misunderstandings.
Before reading this post you must know that when you extract an image from a CD (useful in order to do a 'true copy' of the CD, whose layout is made up by 'sectors', 74 min = 330,000 sectors) you can extract Data In Many Ways: Before reading this post, you must know when you make an image to a disc (generally used for "complete replication" disc, the disc is composed of one "sector", 74 minutes = 330,000 Sector), the data reads the disc has several ways: 1) 'Cooked' (2048 bytes / sector); 1) Usually: 2048 bytes / sector; (Note: This 2048 bytes should be Normal data stored in CD) 2) RAW (2352 BYTES / SECTOR) 2) Original mode RAW: 2352 byte / sector (Note: 2352 bytes In addition to the normal data of 2048 bytes, you should also include verification data 3) RAW SUB (2352 bytes 96 Bytes for Subchannel Data PW = 2448 BYTES) 3) The original mode RAW sub-channel SUB: 2352 bytes 96 bytes of PW sub-channel data = 2448 bytes. (Translator Note: I don't understand the so-called sub-channel and PW. In short, it is an additional data attached to a sector on the disc.) Sub Data Are Sometimes Used for Storing CD-text, CD-G Some Protection Methods. Subchannel data is sometimes used to store CD-TEXT, CD-G (karaoke), and disc anti-copy data.
Well, WHEN YOU BAN BAK The Extracted Info On A CD-R You Can Choose Between 5 Different Burning Modes: Ok, when you burn a disc image, you can choose 5 different burn modes. (Not all burning software support these five modes):
1) TAO (Track-At-ONCE). Disposable Track burning You Burn on the cd-r all Data (2048 of 2352) But Recalculate - Thereby Changing Them - All Correction Codes. On Multiple TRACKS CDS, The Laser Pauses Between THEM (THIS mean you cannot RECORD LIVIO CDS WITHOUT GAPS) Burning 2048 bytes in the 2352 byte but recalculates (therefore also changed) check data. On the multi-track disc, the laser head will be paused between each track (this means you can't use this way to burn no gap music disc). 2) DAO / SAO (DISC-AT-ONCE, SESSION-AT-ONCE). (Total Disposable Segmentation) AS Tao, But The Laser Does Not Pause Between Tracks. This Way You will not add extra Pauses Between Tracks. You Can Record Live Audio CDS WITHOUT GAPS. (Sao Is Smilar To DAO, But Dao Closes The Last Session) is similar to TAO mode, but the laser head will not be paused between the rails (Translator Note Refer to those below, this mode is still 2048 bytes first, but also recalculates the check data. (SAO mode is similar to DAO mode, the difference is that DAO will end the entire light, while Sao is only the final segment)
3) RAW SAO (Sometimes Simply Called 'Raw Write'). The original SAO (sometimes simple, called "original burning"). You burn all 2352 bytes you extrcatced on the CD Since you do not recalculate ECC / EDC, you end up with an 1:.. 1 copy of the sector Please note that since the error correction codes are not recalculated, the chance of burning incorrect Data is higher. Avoid Burning At Very High Speed. Direct burn 2352 bytes, since the ECC / EDC (check data) is not recalculated, this way is 1: 1 to replicate the entire sector. Note: Since the check data is not recalculated, the chance to burn an error will greatly increase, so avoid burning at a higher speed.
4) Raw Sao 16 (Sometimes Called Dao 16). (Sometimes called Dao 16) As Raw Sao, But You'll ALSO WRITE P and Q Subchannel Data (8 Bytes Each). You NEED An Image Complete with .sub Info To DO That (clonecd, for instance ;.bin / .cue format is no good for That Since Only Stores The 2352 Part). You'll End Up with An 1.1 Copy of The Sector Plus The Pq Subchanenes. Similar to Raw Sao, but P and Q sub-channel data (8 bytes per sub-channel, two additions are 16 bytes, so called DAO 16). This mode requires that the image file is saved with .sub data (such as clonecd, .bin / .cue only saves 2352 bytes of data, so it is not suitable for this mode). This way you burn a 1: 1 copy sector plus the disc of the P-Q sub-channel data. 5) Raw Dao (Sometimes Called Dao 96). (Sometimes the Dao 96) AS ABOVE, But You'll Also Write P - W Subchannel Data. As Above, You NEED An Image Complete with .sub info to do what. You 'LL End Up with a' Perfect 'Copy (1.1 Copy Of The Sector Plus The Pw Subchannels). Similar to the above, the PW sub-channel data (96 bytes) will be written. This method also needs your image file to include .sub data. Using this mode You can "perfect" copy a disc (1: 1 copy sector plus P-W sub-channel data).
Translator Note: In summary, all 1: 1 replica burn mode, such as RAW SAO, DAO 16, DAO 96, can not be burned at too high speed, because the check data is not recalculated.
