[pulseaudio-discuss] Routing of audio to loudspeakers or headphones
gmane at colin.guthr.ie
Tue Sep 14 07:00:56 PDT 2010
'Twas brillig, and Kim Therkelsen at 14/09/10 10:48 did gyre and gimble:
> Based on the advice from Colin Guthrie I am now trying to modify the
> module-ladspa-sink module so that it takes a "master_port" argument and
> only creates the virtual sink when the master sink's port matches the
> argument value (and unload it when it changes). I think it should be
> possible to leave the master_port argument out and let the functionality
> fall back to the original functionality to ensure backward compatibility.
Yes, backwards compatibility is a good plan.
> Furthermore I have updated module-ladspa-sink to support multiple audio
> channels based on:
Oh dear, that's been there an awful long time :(
I guess it's been missed due to general Trac weirdness :(
> Unfortunately I can not find much information about how to handle these
> "ports" in the source code.
> I can see that pavucontrol can switch between the ports and from the
> "info" command in pulseaudio I get:
> 1 sink(s) available.
> * index: 0
> name: <alsa_output.pci-0000_00_1b.0.analog-stereo>
> driver: <module-alsa-card.c>
> flags: HARDWARE HW_MUTE_CTRL HW_VOLUME_CTRL DECIBEL_VOLUME LATENCY
> analog-output: Analog Output (priority 9900)
> analog-output-speaker: Analog Speakers (priority 10000)
> analog-output-headphones: Analog Headphones (priority 9000)
> active port: <analog-output-headphones>
> But how do I update int pa__init(pa_module*m) to perform the port check?
> Which command should I use to ask PA which port is active?
In the pa__init() function, you'll need to read and store the
master_port argument first of all.
In the userdata struct there is a pa_sink* sink element.
When this is populated, you'll see from looking at pulsecore/sink.h that
it is just a struct.
In that struct you will see "pa_device_port *active_port" member.
This is where you can find the active port of the sink you are attaching to.
Hope that's the info you need.
Tribalogic Limited [http://www.tribalogic.net/]
Mandriva Linux Contributor [http://www.mandriva.com/]
PulseAudio Hacker [http://www.pulseaudio.org/]
Trac Hacker [http://trac.edgewall.org/]
More information about the pulseaudio-discuss