otg media keeps getting corrupted

[konakona]

Hi, I have a somewhat complicated isssue which may not be caused by GMMP per se, but I am hoping to get some ideas here to avoid it. I know, it is quite a longshot 

My setup:
nexus 7 tablet with auto-suspend (if no power is supplied to the otg y-cable, it goes into firm sleep in a preset amount of time)
USB 2.0 hub - not self-powered (has provisions for but unplugged atm)
USB 2.0 USB-A extension cable
USB-A sd card reader
128gb sd card <= all my music resides here

When it works as intended, shutting the car down cuts music off (GMMP goes out of audio focus, car amp turns off, etc.) gracefully without any adverse effects. The trouble is, the sdcard gets randomly corrupted, or at least that's what the android tablet thinks. Curiously, the same sd card in the same sd card reader plugged into a Windows 10 machine nets no errors whatsoever with a disk scan. All files on it are accessible just fine in Windows. Take it back to the tablet, still getting the dreaded corrupted sd card message. Weirder yet, the exact nature of the 'corruption' seems a bit random - there are times I can still access and play music off the sdcard just fine despite the corrupted sd card notification, other times the whole shebang is inaccessible/invisible from any file manager app altogether.

I had suspected this has something to do with power being lost while the sd card is still being accessed, so I attmpted using tasker to stop music before the suspend timeout kicks in - sadly to no avail. My rudimentary understanding is that a storage device would only corrupt when a write operation gets interrupted, not a read-only op (please correct me if I am wrong). Does GMMP ever write anything back to the storage medium when a music track is accessed for playback? Is there anything I could do within/outside GMMP to minimize the chances of this corruption happening? Thanks!

[GoneMAD]

Wrong forum section. This is for quasi tv

edit: moved to the right section

[GoneMAD]

okay so GMMP only writes to your storage when manually editing the tags or changing the rating of a song. Its read only otherwise. Files for playback are opened read-only. If the write permissions to the sdcard are revoked GMMP would still function normally (except for being unable to edit tags / write ratings to disk)

corruption can happen tons of different ways, not necessarily just writing. If corruption happened while writing i would expect it to be also corrupted when you are viewing / reading the data on windows 10. It sounds like an issue with the nexus 7 or perhaps something happened with the partition table that windows is able to read but android is not.

While i dont think its related to gmmp at all.. if you want to be positive you could stop/pause playback and then force kill GMMP just to be certain before power off

[konakona]

Yep, come to think of it, I did have force kill (root) GMMP by tasker in my previous setup and haven't had corruption problems for a while. Merely stopping the playback alone appears to be inadequate. Think I will go back to killing the app then.

If I resort to killing the GMMP just before suspending, I want it to be auto-loaded and ready to use on the next resume. Ideally, I want to a specific playlist and activate the shuffle mode. Is there an intent or something along that line to enable shuffle when loading a playlist? Tasker autoinput could probably do it, just wondering if it could be done by GMMP internally. Thanks again!

[GoneMAD]

gonemad.gmmp.command.SHUFFLE_QUEUE

you can play anything with the standard view intent android.intent.action.VIEW and point it to the m3u playlist

[konakona]

strange... sending the above intent works at first, but the moment I alt tab into GMMP from another vizualizer app (which is also launched 300ms later), it goes right back to normal (i.e. no shuffling) mode.

[GoneMAD]

Not sure about that one. Gmmp only changes shuffle mode when told or when an album artist genre etc is selected to play