Rockbox Technical Forums

Third Party => Other Utilities => Topic started by: rubbedlung on January 20, 2015, 02:43:22 PM

Title: Ipod 7th Gen Classic with Android Head Unit
Post by: rubbedlung on January 20, 2015, 02:43:22 PM
Ive installed Rockbox on my 7th gen and Im trying to get my head-unit to recognize my Izod in a usable way. I have doubletwist installed on my Android Head unit. It recognizes that its connected however, I can't access any of the songs much less have the preferred organized layout. Does anyone have any suggestions?
Title: Re: Ipod 7th Gen Classic with Android Head Unit
Post by: saratoga on January 20, 2015, 06:04:17 PM
Does your head unit successfully mount the ipod as an MSC device?  Assuming it does, is your software able to find and parse the files on an MSC device? 
Title: Re: Ipod 7th Gen Classic with Android Head Unit
Post by: rubbedlung on January 20, 2015, 06:30:15 PM
Yeah it mounts USB storage. And it recognizes that the Ipod is connected because it shows the name that I have for it in the que. But I can't find any of the songs etc.
Title: Re: Ipod 7th Gen Classic with Android Head Unit
Post by: saratoga on January 20, 2015, 06:48:56 PM
So it sounds like the tablet is working correctly, but that your software doesn't know what to do.  Is the software able to read any MSC mounted external storage at all? 
Title: Re: Ipod 7th Gen Classic with Android Head Unit
Post by: rubbedlung on January 20, 2015, 07:28:07 PM
So it sounds like the tablet is working correctly, but that your software doesn't know what to do.  Is the software able to read any MSC mounted external storage at all?

Youre talking about the Android Head Unit right? Its running KitKat 4.4 right now and it can run a microsd and a USB stick but doesn't play  music from my Ipod for some reason. Have you heard of this thing happening before with Ipods Classics and what is essentially a tablet?
Title: Re: Ipod 7th Gen Classic with Android Head Unit
Post by: saratoga on January 20, 2015, 07:39:10 PM
So it is able to play music from a USB stick (not sure if I'm parsing your reply correctly)?  The ipod is also basically a USB stick, but maybe the software expects the iPod to have some specific folder structure or something.  Have you tried asking them? 
Title: Re: Ipod 7th Gen Classic with Android Head Unit
Post by: rubbedlung on January 20, 2015, 08:11:49 PM
So it is able to play music from a USB stick (not sure if I'm parsing your reply correctly)?  The ipod is also basically a USB stick, but maybe the software expects the iPod to have some specific folder structure or something.  Have you tried asking them?

I havent asked Android. I just came here because I wasn't sure if this was a common problem with Ipod/Rockbox users when using android head units in their car.
Title: Re: Ipod 7th Gen Classic with Android Head Unit
Post by: [Saint] on January 21, 2015, 06:29:51 PM
As saratoga stated, this should "Just Work".

At this point (with Rockbox installed), the device (the iPod) is essentially just generic removable storage, which modern Android devices with USB-OTG can make use of quite readily.

If it works with standard generic USB flash media, but doesn't work with the iPod, one possible explanation is that it is recognising the USB VID/PID (vendor and product IDs) to recognise the hardware as an iPod and attempting to treat it as such, and then it freaks out when it can't find literally any of the expected database structure or even a single solitary shred of the original firmware.

For any of the other Rockbox-supported iPod devices this is not an issue, because we leave the original firmware largely intact by default, as well as the device's file system and directory and database structures, and we don't remove the firmware partition. On the iPod 6/7G, none of those things are true - it is somewhat of a special creature in this regard.

Fortunately, we do not need to speculate about whether or not this is the issue. With the magic of science, we can test this issue, by way of telling the host (the Android head unit) that the device is in fact not an iPod. In this binary (http://caudec.net/rockbox/latest/rockbox-ipod6g-usbid_0x123A_0x456B.zip)*, a patch (http://pastebin.com/4P2PFevk) has been applied to the source prior to compilation that changes the defined USB VID/PID to unassigned values.

The take-away from all that jargon is that with that binary installed the device will deliberately misrepresent itself, and if all goes to plan, the Android head unit should then be happy to treat the iPod as a generic removable storage volume.

If this is the case we then know that the head unit is attempting to be "smart" and treat the iPod as an iPod, instead of a generic storage volume.

If this is not the case and installing the linked binary does not have any effect, then I suspect you would want to talk to the OEM (Original Equipment Manufacturer), and not Google (whom I believe you were referring to when you stated 'I haven't asked Android'). Google's oversight of the Android operating system is probably not as tight nor as ruthless as one might imagine, it is quite likely that Google is entirely unaware that this hardware even exists.

If the issue does rest with the head unit, and it cannot be solved by tricking it into thinking that it isn't dealing with an iPod, it is incredibly unlikely to ever be fixed. Many OEMs are incredibly unwilling to push any updates that do not fix either exploits or critical vulnerabilities, even for widely supported and adopted devices with always-on style mobile radios, let alone car audio systems. This has multiple facets, but the obvious ones are:

1 - Any time and effort spent fixing, updating, or upgrading the previous platform is time that isn't spent working on the next iteration of the platform.
2 - If you have ready access to operating system updates you are far less likely to upgrade the hardware in order to receive the latest operating system updates.


[Saint]

*This binary is generated by a third party, and like the official Rockbox binaries, comes with absolutely no warranty or guarantee of functionality - either express or implied. This binary is modified, but only for the sole purpose of reporting fake USB vendor and product IDs for the sake of testing and/or complying with overzealous hardware and/or software.
Title: Re: Ipod 7th Gen Classic with Android Head Unit
Post by: rubbedlung on January 21, 2015, 07:10:46 PM
Thanks for your detailed response. So in reference to the bin. Should i throw it in the root directory?
Title: Re: Ipod 7th Gen Classic with Android Head Unit
Post by: [Saint] on January 24, 2015, 01:35:24 AM
Thanks for your detailed response. So in reference to the bin. Should i throw it in the root directory?

That shouldn't change anything at all.

What actually would help, is taking the time to install the binary I provided in my previous post and reporting back either success or failure. That would help immensely.


[Saint]