Many years ago (around 2003 I think) I burned a CD with mp3 files on them as a data disk. Every mp3 file is perfectly readable, however every song ends with the last few seconds of the previous song on the CD. Other file types (JPG, m3u, nfo and sfv files) on the CD aren't readable or corrupt. So somehow the file 'boundaries' seem shifted.

Does this sound familiar to anyone? And could it be fixed?

  • Files don't have "boundaries" like your saying.. Either the files system's fat tables are corrupted or the file system is, the fact anything works is frankly amazing. Since CDs are read only I don't know how you could fix it, make an iso and compare it bit by bit to a good CD perhaps then hex edit the bad image to "straighten" out the files? BTW, I've never heard of this exact issue... – acejavelin Jan 15 '17 at 21:54
  • Speculation: the audio tracks were cross-faded. The 'boundary' had to be somewhere, it it was put at the start of the cross-fade. – Tetsujin Jan 16 '17 at 7:17
  • Well I think that the file system is corrupt. I know that mp3 files are always readable, in the times of Napster when I downloaded an mp3 file, it was always listenable no matter how much I had downloaded of that track. Could it be possible to 'hand craft' a file system that fixes the 'offset' as I would call it? The files on the CD are data, no conventional audio tracks, so the crossfade option can be striked out. – THiCE Jan 17 '17 at 9:03

My suspicion is that this is a mechanical problem occurring because of differences between your old CD-writer with your new CD-reader. Either that or your old CD software was slightly buggy. Try the CD on another computer; maybe you have a friend with a fairly old system. If it works there, save the contents to a USB thumb drive, bring it home, and generate a new CD.

It is technically possible that the problem is with your new system, and the CD is fine. If this were the case, you probably would have had other problems before now, though. Another possibility is that the CD has gotten corrupted with age. However, the fact that every song exhibits the same problem makes random bit degradation an unlikely cause.

As a last-ditch fix, copy the files onto your own disk. They will contain extra data at the end, which you should be able to crop using an MP-3 editor. Using Google, I see that there are free programs and even online utilities which should do the trick. Once you have corrected all your files, you can burn another CD with them.

IIRC the CD "file system" is a kludge on top of a system primarily designed to play consecutive music files. Part of what happens while burning files is that first an "ISO image" of the data is built. It contains what is to be written, pretending to have the kind of disk sectors and tracks a normal r/w file system uses. The CD is actually writing spirally outward from the center, and it lacks physical tracks and sectors. A mismatch between physical reality and ISO pretense could be a contributing cause, or the ISO-image portion was poorly written.

Speculation: Imagine if the ISO spec requires that files be 0-filled to the end of a whole sector boundary (512 or even 2048 bytes, say). But the buggy old software you had in 2003 failed to do this. Buffers were re-used, and non-cleared data from the old song still remained in the final sector buffer of each new song. Your old software was smart enough to use a file-size byte-count to denote end of file. Now imagine your new software reads entire sectors and expects to stop at either the end of the final file sector or until it starts seeing 0s. The mismatch between how your old software and new software detect end-of-file could explain this problem. It would be a weird case of complementary bugs, but that kind of stuff does happen.

  • I'm not sure if the previous song is cut off at the end. If that's the case, your assumption about re-using buffers could be right! I'll check that later this week. Another thing I might try is to create an ISO file of the CD and edit its CDFS afterwards, probably with tools like cdfs.com or so. – THiCE Jan 17 '17 at 9:07

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