<html><head><meta http-equiv="content-type" content="text/html; charset=UTF-8"/></head><body style="overflow-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;">Yes, you can use the metadata object without the PA API.<br id="lineBreakAtBeginningOfMessage"/><div><br/></div><div><br/><blockquote type="cite"><div>On 8 Feb 2024, at 20:01, Louis DeLosSantos <louis.delos@gmail.com> wrote:</div><br class="Apple-interchange-newline"/><div><div dir="auto">Thanks a ton for the info. </div><div dir="auto"><br/></div><div dir="auto">I dug at this for awhile and yes, I wound up just calling into the pulse audio api to switch sink inputs. </div><div dir="auto"><br/></div><div dir="auto">I dug enough to find that this file: <div><a href="https://gitlab.freedesktop.org/pipewire/pipewire/-/blob/master/src/modules/module-protocol-pulse/modules/module-stream-restore.c?ref_type=heads">https://gitlab.freedesktop.org/pipewire/pipewire/-/blob/master/src/modules/module-protocol-pulse/modules/module-stream-restore.c?ref_type=heads</a></div><div dir="auto"><br/></div><div dir="auto">Is writing to metadata. I kinda quit there, because I couldnt tell if the metadata it was writing was "stuck" in the pulse audio module or was made available to the pipewire api proper. </div><div dir="auto"><br/></div><div dir="auto">Sounds like from your response that the state that the pa stream restore module stashes on metadata is indeed available at the "default-metadata" object that I can retrieve on the registry? </div><div dir="auto"><br/></div><div dir="auto">If so, thats great, i can remove the call into pulse-audio library and just use wireplumber/pipewire. </div></div><div><br/><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Thu, Feb 8, 2024 at 3:46 PM George Kiagiadakis <<a href="mailto:mail@gkiagia.gr">mail@gkiagia.gr</a>> wrote:<br/></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;padding-left:1ex;border-left-color:rgb(204,204,204)">Hi,<br/>
<br/>
Yes, it is easy to re-link streams to different sinks, similar to pavucontrol.<br/>
<br/>
You can do this by setting the “target.object” property in the “default” metadata object. The value may be the “<a href="http://node.name/" rel="noreferrer" target="_blank">node.name</a>" or the “object.serial” of the target sink/source that you want to link your stream with.<br/>
<br/>
On the command line:<br/>
<br/>
pw-metadata -n default <ID of the stream> “target.object” “<name of the sink>” “Spa:String"<br/>
<br/>
For example:<br/>
<br/>
pw-metadata -n default 45 “target.object” “alsa_output.pci-0000_00_1f.3.analog-stereo” “Spa:String"<br/>
<br/>
Using the WirePlumber C API, you need to find the WpMetadata object first, using an object manager (use a constraint on “<a href="http://metadata.name/" rel="noreferrer" target="_blank">metadata.name</a>” to match “default”) and then set the value with:<br/>
<br/>
wp_metadata_set (metadata, stream_node_id, PW_KEY_TARGET_OBJECT, “Spa:String”, target_node_name);<br/>
<br/>
PS: If you set the “object.serial” instead of the name, then the type should be “Spa:Id” instead.<br/>
<br/>
This is the same mechanism that is used by existing tools like pavucontrol. You can also use pavucontrol to see this in action. Use “pw-metadata -n default” to print the existing metadata values for inspection.<br/>
<br/>
I hope this helps.<br/>
<br/>
Best regards,<br/>
George<br/>
<br/>
<br/>
> On 26 Jan 2024, at 18:09, Louis DeLosSantos <<a href="mailto:louis.delos@gmail.com" target="_blank">louis.delos@gmail.com</a>> wrote:<br/>
> <br/>
> Hey all,<br/>
> <br/>
> I'm writing a Linux desktop shell which will have a built in audio mixer.<br/>
> I'm trying to isolate the API usage to the WirePlumber C API.<br/>
> <br/>
> Is it currently possible to "re-link" input or output streams to a<br/>
> different sink/source via WirePlumber?<br/>
> <br/>
> Is anyone able to point me to examples of doing this? I'm a bit<br/>
> confused about whether I need to delete the existing link and create a<br/>
> new one, or if I can update the existing link with new input/output<br/>
> ports.<br/>
> <br/>
> Thanks a lot.<br/>
<br/>
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