Unexplained CD restarts

DLE

Estimable
Jul 22, 2014
7
0
4,510
This is really strange. I have burned BurnAware Free) 20 or 30 CDs (Sony CD-R, 700 MB discs) of 50s & 6os Rock and Roll in mp3 format for listening in my car (2011 Toyota Highlander). All have worked fine except one! I have a single CD that gets to a particular point and starts over. The original disc had 697 MB and 342 files (songs). This is about normal for what I have burned. The "restart" occurs around the 254th file. I have re-burned the disc. I have removed files in the +/- area of 254 with the same outcome. I have replaced the files in the +/- area of 254 with different files with the same outcome. The original disc and the modified discs all play fine from my desk top hard drive, and from my desk top CD drive.
 
Very interesting.

Are you playing the files sequentially: I.e., 1 - 253, then the restart at 254?

What happens if the CD is played randomly (if you have that feature) - will all 342 files eventually play or does it restart whenever file/song "254" is selected? Even if "254" happens to be the first to play.

Probably would take a lot of listening to see if "random" makes a difference within your car player.

Can you replicate the problem via a CD-RW disc?

Then overwrite the "area files" with other songs but using the same .mp3 file names.

Wish I could provide a direct answer per se. Still quite intrigued and thinking out loud a bit.....

What make and model is the CD player in your Highlander?

254 = 11111110 binary.

Perhaps there is some unique sequence of bits being sent via the CD to the player causing the restart to be setup and execute.

E.g. with respect to a Sony Remote....

http://www.armory.com/~spcecdt/remote/sony.html

No "254" code listed per se. But the idea is to see if some such pattern is unique to and present on the problem CD that in turn affects your car CD player. If you can find the codes for your CD player that might be a key.

Depending on how much time you have and really wish to spend on figuring it out. :)

 

DLE

Estimable
Jul 22, 2014
7
0
4,510
 
You are welcome.

Have somewhat now convinced myself is that what is happening is that one of the recorded songs has a "code" in it that your CD player firmware recognizes. First there is some pattern distinguishing a coming command (versus "music") and then the command itself plus some parameters with respect to that command.

E.g., code to the CD player: "If you play 254 songs then there are no more songs. Start over".

The code is probably some unique sequence of bits where 254 = FE(hex) which could be the song count or just a "start over" code. Since you have swapped out the songs around 254th file that suggests that it is not a "start over" in embedded in one of those songs.

The source of that code may be some early attempt at copyright protection embedded in the songs. Just something old that just impacts the Highlander's generic model CD player. Only its firmware recognizes the sequence of "bits" involved. And rightly or wrongly restarts at song/file 254.

Anyway - that is my thinking for the moment.

If you are interested here is a link that will provide further insight:

http://www.request.com/downloads/Integration%20-%20ReQuest%20Communication%20Protocol%20Guide%20v220.pdf

If you take a look starting around page 6 and a few pages further you will probably get a sense of the command codes and how some string of bytes involving 254/FEh, somewhere on the CD, could be causing the problem.

 

DLE

Estimable
Jul 22, 2014
7
0
4,510


 

DLE

Estimable
Jul 22, 2014
7
0
4,510
That had crossed my mind. While the "in's and out's" are probably beyond me, I did run 2 tests.

First, using the original disc, I jumped forward to #252 and let it play. It reset.

Second, I used the disc with different #251 through #257 and did the same thing. It reset.

Granted, the simple act of inserting the disc may have read something on the disc (first 250 tracks?).

I am now trying to devise a plan of attack to "save" the material.

 
A hex editor may come in handy. E.g.:

http://www.eassos.com/how-to/hex-editor.php

Or any such tool that you find - just google hex editor.

Copy the music CD to to CD-RW as the original CD is RO (Read Only). Make sure that the CD-RW will play.

Then you can explore the CD-RW disc and perhaps tinker with "some logically applied editing". Meaning try something and see what happens..... :)

Look for patterns that may indicate that there is a command(s) coming for the CD player. And it may be early on and read during insertion as you have alread surmised.

Worst case the CD-RW gets messed up. Reformat, copy the files to it again, and tinker away.

 

DLE

Estimable
Jul 22, 2014
7
0
4,510
I finally got around to checking the CD in my wife's car. Same year. My Highlander vs her RAV4. Different player models (at least externally). The results were a little different but close enough to validate your idea of a file setting some sort of code.

I her car, when the CD got around the "H's", it jumped to the "Y's" (on mine it started over).

My problem now is to figure out what is "good" and what is not, so I "save" the "good".