Re: [PATCH v3] audio/jack: add JACK client audiodev

[Geoffrey McRae]

On 2020-04-29 22:59, Eric Blake wrote:
> On 4/29/20 12:53 AM, Geoffrey McRae wrote:
> > This commit adds a new audiodev backend to allow QEMU to use JACK as
> > both an audio sink and source.
> >
> > Signed-off-by: Geoffrey McRae <address@hidden>
> > ---
> >   audio/Makefile.objs    |   5 +
> >   audio/audio.c          |   1 +
> >   audio/audio_template.h |   2 +
> >   audio/jackaudio.c      | 615 
> > +++++++++++++++++++++++++++++++++++++++++
> >   configure              |  17 ++
> >   qapi/audio.json        |  50 +++-
>
> Focusing just on UI:
>
> > +++ b/qapi/audio.json
> > @@ -152,6 +152,51 @@
> >       '*out':     'AudiodevPerDirectionOptions',
> >       '*latency': 'uint32' } }
> >   +##
> > +# @AudiodevJackPerDirectionOptions:
> > +#
> > +# Options of the JACK backend that are used for both playback and
> > +# recording.
> > +#
> > +# @server_name: select from among several possible concurrent server 
> > instances.
> > +# If unspecified, use "default" unless $JACK_DEFAULT_SERVER is 
> > defined in the
> > +# process environment.
>
> Our convention is to prefer '-' over '_' except in cases of
> pre-existing consistency.  This should be 'server-name' unless you
> have an example of what we have to be consistent with.

No reason at all just didn't think about it, I will correct it :)

> > +#
> > +# @client_name: the client name to use. The server will modify this 
> > name to
> > +# create a unique variant, if needed unless @exact_name is true.
> > +#
> > +# @start_server: set to true to start a jack server instance if one 
> > is not
> > +# present.
> > +#
> > +# @exact_name: use the exact name requested otherwise JACK 
> > automatically
> > +# generates a unique one, if needed.
>
> Ditto for these three.
>
> > +#
> > +# Since: 4.0
>
> The earliest this will be added is 5.1, not 4.0.

Yup, copy & paste error :)

> > +##
> > +{ 'struct': 'AudiodevJackPerDirectionOptions',
> > +  'base': 'AudiodevPerDirectionOptions',
> > +  'data': {
> > +    '*server_name':  'str',
> > +    '*client_name':  'str',
> > +    '*start_server': 'bool',
> > +    '*exact_name':   'bool' } }
> > +
> > +##
> > +# @AudiodevJackOptions:
> > +#
> > +# Options of the JACK audio backend.
> > +#
> > +# @in: options of the capture stream
> > +#
> > +# @out: options of the playback stream
> > +#
> > +# Since: 4.0
>
> 5.1
>
> > +##
> > +{ 'struct': 'AudiodevJackOptions',
> > +  'data': {
> > +    '*in':  'AudiodevJackPerDirectionOptions',
> > +    '*out': 'AudiodevJackPerDirectionOptions' } }
> > +
> >   ##
> >   # @AudiodevOssPerDirectionOptions:
> >   #
> > @@ -300,8 +345,8 @@
> >   # Since: 4.0
> >   ##
> >   { 'enum': 'AudiodevDriver',
> > -  'data': [ 'none', 'alsa', 'coreaudio', 'dsound', 'oss', 'pa', 
> > 'sdl',
> > -            'spice', 'wav' ] }
> > +  'data': [ 'none', 'alsa', 'coreaudio', 'dsound', 'jack', 'oss', 
> > 'pa',
> > +            'sdl', 'spice', 'wav' ] }
>
> It's worth adding a doc comment that @jack was added in 5.1 (I didn't
> check if audio.json has an example of adding to an enum, but other
> .json files do)

No worries, I will see if I can figure this out.

-Geoff