Skip to main content


Please be aware that much of the software linked to or mentioned on this forum is niche and therefore infrequently downloaded. Lots of anti-virus scanners and so-called malware detectors like to flag infrequently downloaded software as bad until it is either downloaded enough times, or its developer actually bothers with getting each individual release allow listed by every single AV vendor. You can do many people a great favor when encountering such a "problem" example by submitting them to your AV vendor for examination. For almost everything on this forum, it is a false positive.
Topic: interpretting ripped CD text info (Read 483 times) previous topic - next topic
0 Members and 1 Guest are viewing this topic.

interpretting ripped CD text info

Ripped a bunch of CDs back in 2014 using cdparanoia and some other tools I unfortunately don't recall. At time I made vorbis lossy encoding but I want opus now, for quality with smaller file size for my phone.

I archived each CD rip as a single file along with a file called cdinfo.txt that I know was created with some tool at time of rip but I forget.

Anyway would like to reprocess those archived rips into lossy, but like an idiot I did not take any notes on my previous process and don't remember.

The cdinfo.txt file (among other things) has the following:

Code: [Select]
Disc mode is listed as: CD-DA
CD-ROM Track List (1 - 9)
  #: MSF       LSN    Type   Green? Copy? Channels Premphasis?
  1: 00:02:00  000000 audio  false  no    2        yes
  2: 05:22:40  024040 audio  false  no    2        yes
  3: 10:34:20  047420 audio  false  no    2        yes
  4: 15:40:42  070392 audio  false  no    2        yes
  5: 20:24:02  091652 audio  false  no    2        yes
  6: 24:47:50  111425 audio  false  no    2        yes
  7: 28:20:15  127365 audio  false  no    2        yes
  8: 32:00:20  143870 audio  false  no    2        yes
  9: 35:46:55  160855 audio  false  no    2        yes
170: 39:50:60  179160 leadout (401 MB raw, 401 MB formatted)

Looking at the MSF value in #2 and the MSF value in #1 and taking the difference I get 5:20 which is the length of the first track.
Can I assume that the MSF value then specifies the beginning of the track in the CD? e.g. first track starts 2 seconds in?

Can I assume that the AA:BB:CC is Minutes:Seconds:SixtiethOfSeconds ??

What is the LSN ??

This rip is Tom Petty - Southern Accents.

What I am doing with reprocessing is applying the deemph, then EBU R128 loudness normalize (via ffmpeg-normalize) - yes can use tags for that but a lot of players don't respect them. Then resample to 48/16 (ffmpeg-normalize leaves it at 192/16) via sox with dithering. Then split into individual wave files, then lossy encode.

But I need to know how to interpret the MSF and maybe LSN to get sox to split correctly.

I just didn't take notes on what those things mean, given that nothing in the : delimited fields are > 59 I assume they are scale of 60 but I have no idea what the LSN field is.

Thank you to anyone familiar with this format.

Re: interpretting ripped CD text info

Reply #1
Okay I found the shell script I used to process it before.
It looks like the last :NN is actually frames where 75 of them are second.

Re: interpretting ripped CD text info

Reply #2
Yes, the MSF value specifies the beginning of the track in the CD. It's typical for there to be 2 seconds of lead-in (with no audio) before the first track.

The MSF column is formatted in Minutes:Seconds:Frames, where there are 75 frames per second.

The LSN is the logical sector number. It's the same information as the MSF column, but in terms of frames (1/75th of a second) since the beginning of the audio.

Re: interpretting ripped CD text info

Reply #3
Got it all working beautifully. All the other CDs I ripped should be pretty easy now. Though my taste in music has changed, don't think I'll bother with a lot of them as I never listen to my existing vorbis for a lot of them ;)

SimplePortal 1.0.0 RC1 © 2008-2021