[pulseaudio-discuss] PulseAudio on Android kernel, for Ubuntu phone

[David Henningsson]

On 05/28/2013 08:10 AM, Thomas Martitz wrote:
> Am 28. Mai 2013 04:54:52 schrieb Arun Raghavan
> <arun.raghavan at collabora.co.uk>:
>
>> >   - For setting up the mixer, I'll try to talk to the Android HAL
>> layer.
>> > Mixer controls vary a lot between hardware, so making a bridge to >
>> Android here would likely save us work in the long run. (This is the >
>> most
>> uncertain part.)
>>
>> IMO, this is good for short-term porting effort, but not that great in
>> the longer term. The Android HAL is an abstraction on top of another
>> abstraction (UCM/XML config). To my mind, it makes more sense to use UCM
>> here. Or if the UCM folks prefer the newer XML format, we could look at
>> that as well.
>
> I think the android Hal isn't stable at all so possibly you end up with
> code for each major android version or even each vendor / custom ROM
> (phone specific).
>
> Another question, is the Hal API defined somewhere or does it require
> reverse engineering?

I think Android is quite fluid in the sense that things can indeed vary 
between devices or versions of Android. OTOH, vendors are unlikely to 
change this without a good reason as this would mean additional coding 
efforts. Hence we would rely on de-facto standard, which is this [1]. As 
you can see, source is available, so there is no need to reverse 
engineer it.

This is what I think; but I don't have the wide hardware experience that 
would be good to have at this point.

-- 
David Henningsson, Canonical Ltd.
https://launchpad.net/~diwic

[1] 
https://github.com/CyanogenMod/android_hardware_libhardware/tree/jellybean/include/hardware