Quantize for CD Audio -Sound Forge - PC - MAGIX Community Forums Archive

Subject:Quantize for CD Audio Posted by: a1star1 Date:3/9/2002 2:11:14 PM When chopping a large wavefile into pieces for transfer to CD, how do you quantize the markers so that they are on a multiple of 2352 Bytes to provide compatibility with CD Red Book Audio data grouping.
Subject:RE: Quantize for CD Audio Reply by: HowhiMZ3 Date:3/9/2002 2:48:34 PM From the Ahead (Nero) site: Block Often, instead of Block the description Sector is also used. However the description Block, has become established, which is what is used here as well. A Block is the smallest addressable unit on a CD. It is identified by a time given in minutes and seconds and in the case of data through an additional identification character, whereby a Block corresponds to one seventy-fifth of a second. On a CD there is a fixed number of blocks. A Block consists of 98 Frames and consists of 3234 Bytes. As a frame contains two times 4 EDC/ECC Bytes respectively and 1 control byte respectively, there are a maximum of 2352 Bytes of further useable data available. For audio CDs (CD-DA) these are fully utilized, for data a further large number of Bytes are lost: Synchronisation bytes Header further EDC/ECC Bytes for additional security Data format Useable data per Block CD-DA (Audio CD) 2352 CD-ROM Mode 1 2048 CD-ROM Mode 2 2336 CD-ROM Mode 2, XA Form 1/CD-I 2048 CD-ROM Mode 2, XA Form 2/CD-I 2324 The key here is that a block is so small, ie, 1/75 sec, that you could not hear the truncation that your CDR burning software uses to burn a CD that complies with Red Book specs. Regards
Subject:RE: Quantize for CD Audio Reply by: a1star1 Date:3/9/2002 5:00:08 PM I didn't realize that CD burning software automatically truncated files to an even block. Thanks for the help.

From the Ahead (Nero) site:

Block
Often, instead of Block the description Sector is also used. However the description Block, has become established, which is what is used here as well.

A Block is the smallest addressable unit on a CD. It is identified by a time given in minutes and seconds and in the case of data through an additional identification character, whereby a Block corresponds to one seventy-fifth of a second.

On a CD there is a fixed number of blocks. A Block consists of 98 Frames and consists of 3234 Bytes. As a frame contains two times 4 EDC/ECC Bytes respectively and 1 control byte respectively, there are a maximum of 2352 Bytes of further useable data available. For audio CDs (CD-DA) these are fully utilized, for data a further large number of Bytes are lost:

Synchronisation bytes
Header
further EDC/ECC Bytes for additional security

Data format
Useable data per Block

CD-DA (Audio CD)
2352

CD-ROM Mode 1
2048

CD-ROM Mode 2
2336

CD-ROM Mode 2, XA Form 1/CD-I
2048

CD-ROM Mode 2, XA Form 2/CD-I
2324

The key here is that a block is so small, ie, 1/75 sec, that you could not hear the truncation that your CDR burning software uses to burn a CD that complies with Red Book specs.

Regards