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How can I decode AAC/ADTS files ripped by a Chrysler MyGig car system?, Was: Need help access AAC files. At my wits end.....
misterconnell
post Jan 23 2012, 07:48
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Ok, I have 5 AAC/ADTS files that I am trying to playback and/or convert.
Here they be:
http://www.northwoodrecords.com/dmdaac/

I have tried every encoder, decoder, player, and trick I can come up with... I am an audio engineer by trade, but I'm more of a studio guy who rarely deals with much outside the realm of wav, aiff, and plain old mp3.

long story short, this is my only remaining copy of these songs, and I am desperate to access them. they were ripped from wave file on cdr directly to and by my car stereo, a chrysler/harman becker "mygig" harddrive car system. I had been listening to these songs for a year in my car just fine, original CD got lost, and I went to the dealer and had the files extracted from my car to a usb drive. now i cant play them, or load them back on my car.

from what i know the car system runs a QNX RTOS, and encodes audio as some form of aac.

Can any experts out there make these work????????
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bug80
post Jan 23 2012, 09:41
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I tried to open the first file in foobar2000, VLC and ffmpeg (all on Linux), without any luck so far sad.gif
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Kohlrabi
post Jan 23 2012, 09:45
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The files don't seem to be valid, I wasn't able to mux them into MP4, nor does MediaInfo show any information for the files.


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hlloyge
post Jan 23 2012, 11:28
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Could they be encrypted? Check the manual of your car radio on how are they stored.
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misterconnell
post Jan 25 2012, 21:23
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The manual doesnt say much about the way it encodes files at all. I had to go to the dealer in the first place to get the files off the car(they have to hook it up to their computer and put the stereo in "service mode" to do this.) I thought everything was golden once i had the files on disc, but now nothing under the sun can open them. Info on the internet claimes that the stereo encodes as wma, but every file it rips (that isnt given a gracenote title, ie anything after 2008 or anything obscure) gets a simple track number with a .aac extension. The dealer know virtually nothing about this stuff, i actually had to perform the function myself after they put it in service mode, and the manufacturer makes this type of stereo exclusively for chrysler and redirects any customer service inquiries to the dealer.

This is my only copy left in existence of a recording i would really like to retrieve but I am getting nothing but dead ends. If i hadnt gotten them removed by the dealer(the function of doing so also wipes the car hard drive) I could have at least ripped open my stereo and simply tapped into the R/L wires and re-recorded the output audio, but now i cant even do that...

headbang.gif
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Kohlrabi
post Jan 26 2012, 00:10
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Try to contact the manufacturer of the stereo rather than the car dealer. They might help you, maybe you can send in your files for repairing/decrypting? I tried running TrID on your files, but nothing came up at all.


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DVDdoug
post Jan 26 2012, 01:58
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QUOTE
I could have at least ripped open my stereo and simply tapped into the R/L wires and re-recorded the output audio, but now i cant even do that...
That's what I was thinking, as a last resort... Did the "service mode" have an option of restoring the files from the USB?

I tried several tools on your files and everything totally failed. sad.gif (Most of the tools I was playing with probably use FFMPEG.)
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Mix3dmessagez
post Jan 28 2012, 19:05
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Honestly you could probably download the songs off the internet, I mean, you had access to the CD originally so the artists already have your money so in this one controlled small instance I'm sure it's understandable, especially for songs you really like.

This post has been edited by db1989: Jan 31 2012, 15:42
Reason for edit: deleting pointless full quote of first post. Also, do you /ever/ actually read things before spouting something in response?
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misterconnell
post Jan 31 2012, 15:27
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No, when i said 'only copy in existence' i meant it. these are songs by a band i recorded in my recording studio, and the cd was never released. the band lost their provided copies and these were the only copies left alive.

This post has been edited by db1989: Jan 31 2012, 15:37
Reason for edit: deleting pointless full quote of above post
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saratoga
post Jan 31 2012, 19:04
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I see a ton of stuff about that stereo online. Have you searched through it all? Its possible someone else has already figured out how it works.
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Rotareneg
post Jan 31 2012, 20:53
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Stupid question perhaps, but have you tried loading them back onto the MyGig to see if they'll play?
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db1989
post Jan 31 2012, 22:34
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QUOTE (misterconnell @ Jan 23 2012, 06:48) *
I went to the dealer and had the files extracted from my car to a usb drive. now i cant play them, or load them back on my car.
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Kohlrabi
post Feb 1 2012, 09:56
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In the end, this all adds up to a cautionary tale about not using (solely) optical media for backup, and additionally using more than one medium as backup storage. I must really question how you and the band valued their recordings if the only known copy in existence was a (lossy!) CD-R rip on a car stereo. Make a habit of instantly creating lossless (WAV,AIFF,FLAC) copies and/or save and the project files themselves. And back up the data to multiple media (CD-R, USB thumb drives, Hard disks, ...). This is not only a service to you but also to your customers!

I still do hope you can find a solution to retrieve the audio files. Any luck contacting the manufacturer of the stereo or rummaging through the online resources saratoga mentioned?


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misterconnell
post Mar 4 2012, 20:25
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I agree entirely, fact is, I did not terrible value the recording, and they band in question was very careless. I delivered 2 master copies to the band 2 years ago on CD, which is my standard delivery for all the artists I record. They broke up, never got it manufactured, never made a single copy, never ripped it to computer or anything like that. 2 years later they have reformed, have lost their masters and are looking to me for help. I am trying my best to help them and these AAC files are my only thread to pull on. So far it is looking like they are out of luck. sad.gif

And yes to above as well, I have scoured the internet and read everything I can possibly find on the net, to no avail so far...
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.alexander.
post Mar 5 2012, 08:01
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Hey, could you upload the files to http://www.northwoodrecords.com/dmdaac/ again?
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misterconnell
post May 7 2012, 21:10
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QUOTE (.alexander. @ Mar 5 2012, 09:01) *
Hey, could you upload the files to http://www.northwoodrecords.com/dmdaac/ again?


Late to reply but just saw this, files can be found here: http://13dogs.com/dmdaac
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psycho
post May 8 2012, 19:03
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I tried everything I could think of... Nothing works...

The furthest I got was with Winamp, which reports:

CODE
Payload Size: 2911940 bytes
Format: AAC
Header found at: 40 bytes

MPEG-4 AAC
Length: 105 seconds

CBR 224 kbps
Profile: LC

7350Hz Stereo

CRC: No


Strange... 7350 Hz?


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mixminus1
post May 8 2012, 19:11
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Hmm...7350 * 6 = 44100

Now I'm curious as to how the sample rate is written in an ADTS header...

This post has been edited by mixminus1: May 8 2012, 19:11


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.alexander.
post May 8 2012, 20:25
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first bytes do not correspond to ADTS or MP4. In case it's raw AAC use mp4box or faad2 to convert to ATDS trying all possible sample rates. It can also be broken ADTS then just replace all bytes before first synchroword 0xFFF and try to decode it
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LCtheDJ
post Aug 6 2012, 21:19
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My own research on Mygig shows that they play mp3 and wma files; aac or m4a or mp4 is not mentioned in the owner's manual.

One place stated that when copying a CD, the files saved are mp3.

If I take your files and change the extension to mp3, foobar 2000 will show properties on them but they still don't make music.

Maybe someone here can do more with your files working with them as mp3's.

Good luck.
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3mm
post Sep 12 2013, 07:23
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Do you still have access to the Mygig hard drive? You can take it out, install QNX or use live cd, with access to that hard drive (or you can make an image out of it and attach it to a virtual machine) and then look at the files. I'm not sure what that dealers' maintenance mode is, maybe it modifies the files somehow. Or maybe Mygig encrypts the mp3 data when you rip audio cd's. I read that only newer models of Mygig can play aac, so yours is not that.

My point is, you may see perfectly fine mp3's in there. If you do see .aac, then you have two options. First is to contact Mygig and ask them if they can decrypt/reassemble the audio tracks. They might need your hard drive if each one uses different, locally generated keys for encryption. Your second option is to look around the QNX filesystems you see on that disk, and try to find binary that is used to playback files. Or they might use one to decrypt the file and another one to play it back. Obviusly you need to be technically capable when it comes to UNIX type system.

And lastly, see if a thing like lockpick for mybox can have an audio output (I think it does), then play the songs from your car, and connect to output ton something that can record it.

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