[Libmtp-discuss] GSoC Proposal v2: Amarok MTP Collection rewrite with emphasis on Android device support

[Philip Langdale]

On Mon, 29 Apr 2013 11:30:06 +0200
Linus Walleij <linus.ml.walleij at gmail.com> wrote:

> 2013/4/29 Matěj Laitl <matej at laitl.cz>:
> 
> > One question may come to attentive reader's mind: why the
> > implementation doesn't involve kio-mtp?[6] It is because kio-mtp
> > doesn't use the track libmtp API (rather it uses the file API) -
> > with track API we can query metadata like sample rate or artist
> > without having to download the file at all.
> 
> Actually I've been wondering how the Android MTP stack and the
> Samsung MTP stack handles metadata.
> 
> It seems to me like you can indeed in most cases query tracks for
> metadata over MTP, but when sending metadata it seems to be
> ignored on some devices, and the proper way to get that in place
> is to have tags in the files.

This isn't too surprising. From an implementation point of view, the
stack has a media scanner that runs through all the files and does
things like tag extraction. I'd actually be more surprised if it paid
any attention to metadata sent to the device.

I've thought about reading track metadata in gvfs-mtp and setting it
as GFile metadata but I couldn't find any standardised attribute names
for it.

--phil