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Posts: 2,853 | Thanked: 968 times | Joined on Nov 2005
#4
THE RESULTS SO FAR :

Oblomow was the first to confirm that standard h-e-n procedure to activate USB Host was enough to support external sound devices (in his case, a recorder).

Installing h-e-n also means installing a custom Linux kernel (the Power Kernel also used for overclocking), which packs a lot of stuff that was missing in the stock Maemo distribution.
Activating host mode detects the external equipment and automatically creates the corresponding ALSA device. Streaming to/from this device is supported by the kernel.
So that's two major hurdles in one jump, without even trying :-)

Oblomow verified this by playing a sound file from the command line in xterm, using mplayer with the ALSA device as a parameter.

This proof of concept was a very manual process, but it was a great moment when the sound came out from the DAC/amp :-)

Using GUI media players (like Maemo's, or Rockbox) requires redirecting the default sound output (managed by PulseAudio) to the ALSA device above.
Sounds simple in principle, but unfortunately has proved intractable up to now :-)

Then kirillkk chimed in with another solution : use MOC (mocp), a full-featured media player that happens to run in text mode, in the xterm console.
The output device can be specified in its configuration file, so it's start and play...

kirillkk provided his own build of MOC for Maemo, with some useful hints on how to install it.
After a few fumbles I got it to work, it is truly very usable !
I do have a few questions for him when he comes back, though :-)

So thanks to them and the h-e-n team and the Power kernel hackers, we have something working that I thought was impossible just a fortnight ago...

What remains, mostly, is to make it fluid and user-friendly for day-to-day use.

EDIT: I forgot to add another solution that was suggested later on, thanks to Estel for remiding me about it.
smplayer is a full GUI for mplayer, available from the repositories, which is more user-friendly (lets you choose ALSA output from a list, amongst other things).
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Last edited by fpp; 2012-11-03 at 17:58.
 

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