CDR Mystery
- Thread starter ellucidate
- Start date
Have you been able to replicate the pop-up?
Trying to think what could be placed in a single session... (and doing a "show CD properties" from most writer programs should confirm that it is single session).
1. Fields such as the Title, Artist etc. - it's possible that Soundforge may place something here, but it's not a file, and I know of no simple means of triggering it to be displayed.
2. "Don't play track 1" - if it has a track 1 that will not play as audio, or is just noise if it does, then it's a "Mixed mode" data plus audio.
3. Data in pregap - I don't know how to produce these, but this involved a longer than normal pregap, containing data - on some audio CD's, this is used for a hidden audio track that can only be backspaced into.
4. CD-Text (in TOC subchannels) or CD-G (in track subchannels)
Without grossly violating specifications, and with no standard method of retrieval, I cannot see what else could exist in single session.
A mono tape played through a stereo transfer, may have experienced slight channel skew, this may give rise to a diversity effect.
The questions are many:
Are you suspecting malicious interference with the transfer, or merely misguided attampts to clean it up.
Are you considering that it may have included tampering with the master tapes, or is the issue the authenticity of those tapes in the first place.
Some recorders do put RIN codes on as an anti-piracy measure (traceable to that recorder), bur again, I have absolutely no idea what would be capable of displaying them.
Trying to think what could be placed in a single session... (and doing a "show CD properties" from most writer programs should confirm that it is single session).
1. Fields such as the Title, Artist etc. - it's possible that Soundforge may place something here, but it's not a file, and I know of no simple means of triggering it to be displayed.
2. "Don't play track 1" - if it has a track 1 that will not play as audio, or is just noise if it does, then it's a "Mixed mode" data plus audio.
3. Data in pregap - I don't know how to produce these, but this involved a longer than normal pregap, containing data - on some audio CD's, this is used for a hidden audio track that can only be backspaced into.
4. CD-Text (in TOC subchannels) or CD-G (in track subchannels)
Without grossly violating specifications, and with no standard method of retrieval, I cannot see what else could exist in single session.
A mono tape played through a stereo transfer, may have experienced slight channel skew, this may give rise to a diversity effect.
The questions are many:
Are you suspecting malicious interference with the transfer, or merely misguided attampts to clean it up.
Are you considering that it may have included tampering with the master tapes, or is the issue the authenticity of those tapes in the first place.
Some recorders do put RIN codes on as an anti-piracy measure (traceable to that recorder), bur again, I have absolutely no idea what would be capable of displaying them.
Duracell said:a CD-Extra or Mixed-Mode CD wouldn't be a one session CD?)
NO, not neccessarily so. A mixed mode CD or CD-extra consists of several audio tracks, and one data track (which includes all small data files). Under the book definition, all tracks should be burned in the same session, but nevertheless many burning programs burn one session including all the audio tracks, and a second session which includes the data track. I have no idea which way this standalone buurner operates, but since it claims "red book compatibility" I might assume that it burns all the tracks in the same session.
Simplest way should be the one mentioned by Chickenman: use ISOBuster, spot the single data track and extract it's contents to harddisk.
ellucidate
New member
I have now tried CD/DVD Inspector, IsoBuster and CDRWin and none will apparently read outside of the audio tracks other than CD/DVD Inspector which produces a disc utilisation map showing 'extra data'.ChickenMan said:
Taking one of my CDs for example with two audio tracks on it, the audio sectors are number 1 - 104357. However CD/DVD Inspector reveals sectors 104550 - 104559, 104680 - 104689, 104750 - 104759, 104760 - 104769 (the latter two sets being apparently one group of data). Surely the information I am looking for could easily be amongst those blocks?
As said above these 'outside the audio tracks sectors' are simply inaccessible. Obviously the RIN code that I saw must be in there somewhere.
ellucidate
New member
They are definately one session discs.Duracell said:a CD-Extra or Mixed-Mode CD wouldn't be a one session CD?
@ ellucidate: How about providing us some screen shots?
i would like to see the TOC of this CD and where you recognize the "small files";
I have attached two screen shots as requested. You can see the small data files at the bottom of the disc utilisation map. If I click on that it identifies the sectors in the left hand pane.
Edited reason:- changed the images from BMP to JPG for smaller file size quicker to download/display >>>VIPER_1069 <<<<
Attachments
ellucidate
New member
LTR12101B - thanks for your replyLTR12101B said:
No, I have not been able to replicate the pop-up.
Your No 1 - Whatever triggered Sound Forge was a gift. Maybe it cannot be repeated, but it surely put me on the right lines. I believe there was editing of my audiotapes and I have now got a fair idea of how it was done, but if I could repeat the launch of that Sound Forge window I would have some solid evidence of editing (notwithstanding we probably can prove analogue mono converted back to stereo). I can live without it though. But it will be a shame if it cannot be dug out of the CDs.
Your No 2 - Don't misunderstand me - everything plays, that is not a problem.
Your No 3 - That's simply beyond my knowledge. I am not an expert.
Your No 4 - Again, I only half get the gist of what you'r saying. Later this week I have arranged to take my audio cassettes to an audio/music restoration expert. If, as we suspect editing of the tapes occurred, the digital file must have been played back to analogue, speaker to mic. The person who is going to look at them thinks that should be determinable by examination of the quantization sampling rates.
Yes, the issue is the authenticity of the tapes in the first place.
Yes, it does seem strange that RIN codes can be put on a disc but there is no way of retrieving them!
ellucidate
New member
See my reply to Duracell scarecrow and the file attachments. You will see that CD/DVD Inspector HAS found data outside of the audiotracks. There is obviously data on audio CDs beyond the tracks, the RIN code etc. Just because a programme cannot or will not read it does not mean it isn't there. As I understand it a track is 300+ sectors, so it seems to me that small amounts of ancilliary data are not going to pass the threshold to be recognised as being a 'track'.scarecrow said:
The three programmes I have used thus far simply wll not read the sectors beyond or outside of the the audiotracks.
Try to extract that data file with Isobuster,and examine it with a hex editor...
ellucidate
New member
Its not possible roadworker, I have tried. What happens is that when you insert sector numbers larger that the audio component values IsoBuster indicates the end address contains an illegal number.roadworker said:
Duracell
1
first of all thanks for the screenshots;ellucidate said:
however, i don't think there is data contained, although Inspector shows "colored blocks"; your second pic says clearly there are only 2 audio tracks declared in the discs TOC;
if no data track is registered in the discs TOC, then no PC CD drive and no Windows will be able to read/execute anything beside the audio tracks, even if there would exist hidden data in gaps or anywhere;
ellucidate
New member
If I click on the coloured data blocks their numbers are displayed in the left hand pane. They are smaller than 300 blocks and therefore less than track size, so perhaps that is why they are not read. But again data is there or else where did the RIN code that launched come from that one time?Duracell said:first of all thanks for the screenshots;
however, i don't think there is data contained, although Inspector shows "colored blocks"; your second pic says clearly there are only 2 audio tracks declared in the discs TOC;
if no data track is registered in the discs TOC, then no PC CD drive and no Windows will be able to read/execute anything beside the audio tracks, even if there would exist hidden data in gaps or anywhere;
The data and unidentified blocks appear in the address region of the leadout.
I assume the software would detect an open multisession (one way that some extra blocks may be associated with the leadout - if a CD-RW and writer software sees the CD as still writeable or "open", that would also indicate an anomaly that isn't a properly finished audio CD.
Do other written CD-R (data or audio) show similar junk in the leadout when analysed?
As I understand it, the writer is sent one command to write leadout, and it writes 90 seconds of whatever counts as leadout - maybe that composition varies between writers, but I don't believe there is any way to influence it.
I assume the software would detect an open multisession (one way that some extra blocks may be associated with the leadout - if a CD-RW and writer software sees the CD as still writeable or "open", that would also indicate an anomaly that isn't a properly finished audio CD.
Do other written CD-R (data or audio) show similar junk in the leadout when analysed?
As I understand it, the writer is sent one command to write leadout, and it writes 90 seconds of whatever counts as leadout - maybe that composition varies between writers, but I don't believe there is any way to influence it.
ellucidate
New member
I have examined a number of other audio CDs for data blocks. Commercial music, home-made albums purchased from iTunes and home made compilations from internet downloads. The first two categories have data blocks present whilst my internet compilations do not. I should add that all of the CDs examined have red unexplained blocks.LTR12101B said:
Of my three CDs, the two suspected as being made from edited analogue tape have data blocks, whilst the one where no editing is suspected has no data blocks, in the same way as my home made internet compilations.
The three programmes that I have used to read and gain access to the data blocks will not apparently allow reading. This is however disputed by Peter Van Hove who is the author of the IsoBuster programme. He believes it is my drive that is refusing to read the sectors, but that doesn't explain why CD/DVD Inspector apparently can, at least in one of its facilities. I have contacted Infinadyne, the maker of CD/DVD Inspector, for their comments, but they have not yet replied.