All times are UTC - 5 hours [ DST ]




Post new topic Reply to topic  [ 24 posts ]  Go to page Previous  1, 2
Author Message
 Post subject: Re: Data Recovery Digitech Jamman Stereo (guitar pedal)
PostPosted: August 9th, 2019, 20:00 
Offline
User avatar

Joined: September 8th, 2009, 18:21
Posts: 11717
Location: Australia
Could we see an example of a header and footer from phrase.wav ?

BTW, here is your broken URL:

http://www.at91.com/viewtopic.php?f=9&t=29088

_________________
A backup a day keeps DR away.


Top
 Profile  
 
 Post subject: Re: Data Recovery Digitech Jamman Stereo (guitar pedal)
PostPosted: August 9th, 2019, 22:55 
Offline
User avatar

Joined: September 8th, 2009, 18:21
Posts: 11717
Location: Australia
framp wrote:
Just an update for everybody facing a similar issue: I managed to login into the looper via UART. The looper is runnign QNX, a posix compliant Unix. I was able to dump the NAND data and a tool called etfsctl.

How did you dump the NAND?

Did you dd the NAND "drive" to an SD card?

Did you copy (cat) individual files to your SD card?

You say you scanned your dump for RIFF headers. Do the unplayable WAVs correspond to deleted loop data that were discovered by the scan?

_________________
A backup a day keeps DR away.


Top
 Profile  
 
 Post subject: Re: Data Recovery Digitech Jamman Stereo (guitar pedal)
PostPosted: August 9th, 2019, 23:22 
Offline
User avatar

Joined: December 4th, 2012, 1:35
Posts: 3372
Location: Adelaide, Australia
duplicate post


Last edited by HaQue on August 9th, 2019, 23:25, edited 1 time in total.

Top
 Profile  
 
 Post subject: Re: Data Recovery Digitech Jamman Stereo (guitar pedal)
PostPosted: August 9th, 2019, 23:24 
Offline
User avatar

Joined: December 4th, 2012, 1:35
Posts: 3372
Location: Adelaide, Australia
I haven't been following the thread, but saw recent posts about first dumping a NAND, then issues playing files.

I think Franc may be alluding to this, but there is a few possible reasons:

1) the format could be different than straight .wav
2) post processing done by decoder to not use all of the .wav spec or in a different manner than intended
3) your dump included information such as SA bytes or ECC or something that further needs to be stripped out
4) files are not stored in a totally concurrent fashion... I have seen recently while hacking some games consoles that ROM files for example have a block of DATA and if the ROM is bigger than this, the next block is stored somewhere else, not straight after.
5) your dump might be ok, but not ECC corrected, so bit errors are present. (Linux systems that use NAND should have this built in though at a driver level)
6) may be some binary to ascii conversion happening, but I would think files would be totally screwed up if this were the case (thinking like specifying BINARY option in some rudimentary older protocals)

kudos or getting this far. I remember when I first got a prompt from a Microvax 3400 after a friend came across 2 complete but disassembled systems. right at the start of accessable internet, searching was in infancy, and I had help from a Tafe college lecturer that correctly identified the plug that looked like a LAN port as a terminal adapter port. not knowing anything about unix, terminals etc. this opened up a whole new world


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 24 posts ]  Go to page Previous  1, 2

All times are UTC - 5 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 7 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group