Re: [Qemu-devel] [PULL 07/15] audio: audiodev= parameters no longer optional when -audiodev present

[Zoltán Kővágó]

On 2019-08-26 00:15, Maxim Levitsky wrote:
> On Sun, 2019-08-25 at 20:05 +0200, Zoltán Kővágó wrote:
>> On 2019-08-25 11:44, Maxim Levitsky wrote:
>>> On Wed, 2019-08-21 at 10:41 +0200, Gerd Hoffmann wrote:
>>>> From: Kővágó, Zoltán <address@hidden>
>>>>
>>>> This means you should probably stop using -soundhw (as it doesn't allow
>>>> you to specify any options) and add the device manually with -device.
>>>> The exception is pcspk, it's currently not possible to manually add it.
>>>> To use it with audiodev, use something like this:
>>>>
>>>>     -audiodev id=foo,... -global isa-pcspk.audiodev=foo -soundhw pcspk
>>>
>>> Hi!
>>
>> Hi,
>>
>>> There is one corner case this breaks.
>>> In qemu 4.1.0, there is no way to specify audiodev for a sound device, 
>>> specifying it
>>> fails with error.
>>> So some of my machines have audiodev (which is miles better that using old 
>>> env variables)
>>> but also have sound devices without audiodev reference since this wasn't 
>>> supported.
>>>
>>>
>>> In what will be qemu 4.2, you must specify it, thus this kind of breaks 
>>> backward compatibility.
>>> Maybe we can have audiodev reference optional for a version or two?
>>>
>>> This is just a minor itch, as otherwise the sound improvements are really 
>>> good. The days
>>> of installing that old realtek driver are finally gone :-)
>>
>> Hmm, this is what happens when you split a patch series.  We could
>> either revert this patch, or alternatively turn the error messages into
>> warnings about using deprecated behavior.
> Warning would be great in this case!
>>
>>> Another thing I noted, that there is no way for pulseaudio audiodev to 
>>> specify the 'client name',
>>> it always shows up in pavucontrl as the socket path to the server. 
>>> Thus if I added two PA audiodevs, I can't really distinguish between them.
>>> The in|out.name= seems to specify the pulseaudio source/sink to connect to, 
>>> which is not the same.
>>
>> We currently supply the constant "qemu" as a name to pa_stream_new.
>> While it's still not ideal, shouldn't this end up as a client name in
>> pulseaudio instead of a socket path?
> 
> Actually it seems that pulseaudio has two names supplied for each stream
> Maybe stream name and application name?
> 
> This is how chromium playback looks versus qemu in pavucontrol and in gnome 
> volume control.
> 
> https://imgur.com/a/I8HZhgx
> 
> I do notice that 'qemu' now, in pavucontrol though.

I see.  We currently pass the server socket to pa_context_new instead of
the client name.  I'll prepare a patch soon, thanks for the report!

Regards,
Zoltan