The trigger flag adds an extra dependency on the node so that it does
not automatically get scheduled. A manual scheduling is required with,
for example pw_stream_trigger_process().
This can be used to create an artificial dependency between a sink
stream and a source stream, like when using loopback or filter-chain.
Normally those streams are not linked in the graph but they have an
internal dependency. Without any such dependency, the source part of the
chain will be scheduled first and then the sink part and we get a
cycle of delay (with possible quantum change etc).
With this patch, the sink part will be scheduled first and its process
function will trigger the 'downstream' source stream explicitly. The
sink and source stream will stay in sync and will use the same quantum.
This reduces the latency and glitches because of quantum changes.
Fixes#1873
The node.link-group property marks streams that are internally linked
together in some way. It is used to relate the input and output streams
of some of the module streams.
This also brings the advantage that all tools, examples, modules, components
can also be compiled standalone out-of-tree using libpipewire from the system
Just like the real free() we should just ignore a NULL pointer, makes the
caller code easier for those instances where properties are optional.
Patch generated with concinelle with a few manual fixes.
SPA_MEMBER is misleading, all we're doing here is pointer+offset and a
type-casting the result. Rename to SPA_PTROFF which is more expressive (and
has the same number of characters so we don't need to re-indent).
Make it possible to specify different channels and positions
per stream so that we can do remapping as well.
Make sure we only copy available input channels and set the remaining
channels empty.
Handle error when loading and fix leaks.
Mark streams as virtual if nothing else is specified.
Try to reuse an existing core connection if possible.
unload the module when the core is in error or when it is destroyed.
