Re: [Qemu-devel] [PATCH] Nowadays alsa and pulseaudio are most often the default soundsystem. When the headerfiles are found, enable the build of the alsa and pulseaudio audio driver for the default targetos.

[Sander Eikelenboom]

Thursday, May 1, 2014, 3:06:27 PM, you wrote:

> On 1 May 2014 13:56, Sander Eikelenboom <address@hidden> wrote:
>> Thursday, May 1, 2014, 1:06:35 PM, you wrote:
>>> This is a lower-quality duplicate of the code we already
>>> have in configure for probing whether an audio backend
>>> is present (for instance it doesn't allow for the possibility
>>> that the headers have been installed elsewhere). It would
>>> be better to update the existing probe code to distinguish
>>> between "must be present", "don't use" and "use if present"
>>> for each audio driver, in the same way we do for other
>>> features. Then we could just set the default list here
>>> to "maybe-pa maybe-alsa oss" (syntax off the top of my
>>> head, feel free to have a better idea).
>>
>> How bad would it be for the generic targetos case to start with:
>>
>> audio_drv_list == audio_possible_drivers = "oss alsa sdl esd pa"
>>
>> or just add the probably most used two:
>> audio_drv_list = "oss alsa pa"
>>
>> and just let the auto probing do it's business ?

> At the moment if you put something in audio_drv_list
> then configure will stop with an error if that driver
> can't be probed. So putting 'pa' or 'alsa' in the
> default list is a bad idea, because people whose setups
> worked fine for building qemu will suddenly find they
> stop working.

Those thoughts only occur to me a few milliseconds after hitting the send 
button 

I think a "probe-" prefix would be more clear then the "maybe-" prefix.

so "alsa" would require alsa and fail/exit the configure if the headers are not 
present
"probe-alsa" would do the audio probe but not fail/exit the configure but just 
not select it for build. 

I will try brew something :-)

> We need both behaviours -- distributions want to be able
> to say "build with pulseaudio" and have the build fail
> if their pulseaudio dependencies aren't set up correctly
> rather than silently produce a package which won't work
> in their distro. But the average person building QEMU
> for their own use generally would prefer "probe for the
> features but if they're not present then just don't
> build the code that uses them".

> thanks
> -- PMM