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Topic: A newbie needs clarifications about TOC reports (Read 1366 times) previous topic - next topic
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A newbie needs clarifications about TOC reports

Hi, first post here.
I recently learned about EAC and started using it.
Ripped a bunch of CDs, obviously after configuring AR and the drive.
Everything went smooth until checking logs, the TOC section to be exactly.
According to AR the tracks were ripped accurately (with high confidence); even CTDB plugin reported high accuracy.
As I said earlier the problem lies with the TOC; it turns out that EAC, CTDB and MusicBrainz all reports different TOC value (especially Starting Sector).
Almost all my logs report 0 as Starting Sector while CTDB and MB reports 150 in every CD i checked.
For this reason almost all tracks have different crc between my rips and CTDB/MB due to different TOC positions.
My main questions are:
Why 3 different values for the same CD?
Who should I trust for accuracy?
Does it matters if AR reports no errors and high confidence?

Thanks

Re: A newbie needs clarifications about TOC reports

Reply #1 –
Quote from: CarloSadarusa on
Why 3 different values for the same CD?
You can use this tool to look up the musicbrainz disc id and freedb id from an EAC/XLD log. If it exists in those databases then you at least know the version/edition you have and should also be able to verify your rip. Obviously this isn't something you'll want to do with 100s of CDs as it'll be quite time consuming.

Some CDs can show "shifted" &/or "drift" TOCs.

Re: A newbie needs clarifications about TOC reports

Reply #2 –
Quote from: CarloSadarusa on
Almost all my logs report 0 as Starting Sector while CTDB and MB reports 150 in every CD i checked.
An audio CD has a 2 second (150 sector) Lead-In followed by the program area. The Lead-In is where the TOC is stored. ref: https://en.wikipedia.org/wiki/Compact_Disc_Digital_Audio#Data_structure
The EAC extraction log TOC excludes the 150 sector Lead-In and starts at the beginning of the program area.
The CT and MB databases show from the beginning of the CD (which includes the 150 sector Lead-In).

Quote
Does it matters if AR reports no errors and high confidence?
The AccurateRip and CUETools databases only use the audio in the program area to calculate checksums used for verification.
korth

Re: A newbie needs clarifications about TOC reports

Reply #3 –
Quote from: jaybeee on
Quote from: CarloSadarusa on
Why 3 different values for the same CD?
You can use this tool to look up the musicbrainz disc id and freedb id from an EAC/XLD log. If it exists in those databases then you at least know the version/edition you have and should also be able to verify your rip. Obviously this isn't something you'll want to do with 100s of CDs as it'll be quite time consuming.

Some CDs can show "shifted" &/or "drift" TOCs.

Thanks for the help/clarification and the link.
I used directly this: http://db.cuetools.net/?tocid= by adding the tocid contained in the log to check.
That way I was sure that the CD is the same that I have.
From here I have discovered that the TOC is different from EAC to CT and MB.
Sometimes even the tracks duration time differers by a few between log and what is reported here.

Quote from: korth on
Quote from: CarloSadarusa on
Almost all my logs report 0 as Starting Sector while CTDB and MB reports 150 in every CD i checked.
An audio CD has a 2 second (150 sector) Lead-In followed by the program area. The Lead-In is where the TOC is stored. ref: https://en.wikipedia.org/wiki/Compact_Disc_Digital_Audio#Data_structure
The EAC extraction log TOC excludes the 150 sector Lead-In and starts at the beginning of the program area.
The CT and MB databases show from the beginning of the CD (which includes the 150 sector Lead-In).

Quote
Does it matters if AR reports no errors and high confidence?
The AccurateRip and CUETools databases only use the audio in the program area to calculate checksums used for verification.


Thanks for the clarification.
So I guess everything is fine since both says "Accurately Ripped" (with high number of confidence)

Re: A newbie needs clarifications about TOC reports

Reply #4 –
Quote from: korth on
An audio CD has a 2 second (150 sector) Lead-In followed by the program area. The Lead-In is where the TOC is stored.
Where does the assumption come from that a disc "starts" 150 sectors before the beginning of the program area, rather than at the beginning of the program area itself? That's definitely not how the standard defines it, and the lead-in is much, much bigger than 150 sectors long.

Re: A newbie needs clarifications about TOC reports

Reply #5 –
I was replying to:

Quote from: CarloSadarusa on
Almost all my logs report 0 as Starting Sector while CTDB and MB reports 150 in every CD i checked.

The positions read from the CD's TOC start at the begining of the program area so the CD won't start playing before LBA 150 (0 relative to the start of the program area) but if the CD player doesn't "start" reading the CD at LBA 0, how does it read the TOC?

Here's the MusicBrainz explanation of how their CD-DA DISC ID is calculated:
https://wiki.musicbrainz.org/Disc_ID_Calculation

The reserved lead-in area of a CD-R is much bigger than 150 sectors (6750 I believe) until the actual lead-in is written to the CD but that's not what's being discussed.
korth
 

Re: A newbie needs clarifications about TOC reports

Reply #6 –
Here's another reference in a forum post by spoon: https://forum.dbpoweramp.com/forum/dbpoweramp/cd-ripper/15186-proposed-cd-toc-storage-standard

Quote
Here is where it gets complex, 2 seconds in (MSF) really is 150 LBA (if you take the disc start into account), the reason CD drives return 0 LBA, is for a valid audio CD it has to have 2 seconds of lead-in, anything less is not valid, so everything is referenced from 0 LBA, not 150 LBA.

Many metadata providers use 150 as the starting point when calculating the database identifier...
korth

Re: A newbie needs clarifications about TOC reports

Reply #7 –
2 seconds is the minimum for the spec, it can be longer.

Re: A newbie needs clarifications about TOC reports

Reply #8 –
Anything beyond 2 seconds will appear in the TOC of EAC.
EAC may show the start sector of track 1 as 75 in the extraction TOC where MusicBrainz and CUETools DB will show as 225 (150+75).
korth