сб, 25 мая 2019 г. в 18:38, Tanu Kaskinen <tanuk@xxxxxx>: > > Hello, > > I nowadays use module-loopback on a daily basis, and I thought it would > be nice to provide a GUI (in pavucontrol) for configuring loopbacks. > For this I propose we create a new module: module-loopback-manager. The > purpose of that module is to provide a client interface for managing > loopbacks. Without such manager interface it's not possible to create > loopbacks that stay around after reboot. Well, one could add module- > loopback to default.pa, but that doesn't mesh well with dynamic > hardware, and that's not doable from pavucontrol anyway. The new module > would maintain a database of loopbacks, so that they can be recreated > after a reboot. > > The client interface would contain functionality for adding and > removing loopbacks, and changing the parameters of existing loopbacks. > > A loopback object would have the following attributes (to be shown in > "pactl list loopbacks"): > > Name: The identifier for the loopback. > > Description: A human-friendly description for UI labels. > > Source: The source name. Can also be unset, in which case the > loopback should follow the default source setting. > > Sink: The sink name. Can also be unset, in which case the loopback > should follow the default sink setting. > > Enabled: The user can temporarily disable a loopback without > removing it altogether. > > Running: A boolean that is true when the loopback is running, and > false when the loopback is stopped for whatever reason. The interface > should also provide a human-friendly string explaining why the loopback > is not running (the loopback could be disabled, the sink or source > might not be present at the moment, or the sink or source might be > suspended). > > Requested latency: The latency that has been requested by the user. > > Current latency: The current actual latency. Might be different > than the requested latency, because the requested latency may be too > low to work. > > Persistent: A boolean indicating whether the loopback will be > restored after restarting PulseAudio. My plan is that loopbacks that > are created through the manager interface are always persistent, and > non-persistent loopbacks are only for loopbacks that are created by > loading module-loopback. > > Source output index: When the loopback is running, it will have a > source output associated with it. > > Sink input index: When the loopback is running, it will have a sink > input associated with it. > > module-loopback index: When the loopback was created by loading > module-loopback, this is the module index. > > A maximum latency attribute could be added later, which would prevent > the loopback increasing the latency too much (at the cost of drop- > outs). > > The pactl interface could look like this: > > pactl loopback add [--description=<description>] [--enabled=<enabled>] [--latency-msec=<latency>] <name> <source> <sink> > pactl loopback remove <name> > pactl loopback set-description <name> <description> > pactl loopback set-source <name> <source> > pactl loopback set-sink <name> <sink> > pactl loopback set-enabled <name> <enabled>/toggle > pactl loopback set-latency-msec <name> <latency> > > Any thoughts? Would this kind of addition be welcome? If you think that > it's not worth having this feature, please say so, so that I don't > spend too much effort on this. I think it would be a useful exercise for you as a developer, even if there are very few users. At least, it is (AFAIK) the first attempt in PulseAudio to create something dynamically based on a policy stored in a persistent database. The experience gained through the exercise would likely be useful in other cases when one needs to deal with the "default.pa is too static and cannot configure hot-plugged things" problem. An obvious proposed addition to the API would be an ability to list persistent loopbacks, including those that refer to a source or a sink that doesn't exist at the moment. -- Alexander E. Patrakov _______________________________________________ pulseaudio-discuss mailing list pulseaudio-discuss@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/pulseaudio-discuss
