On Fri, 2011-05-20 at 09:50 +0100, Colin Guthrie wrote: > Hello, > > As some of you know I've been working on restoring a little more > symmetry to our API to allow the adjustment of source output (capture > stream) volumes. This is really nice to have - thanks! > In the past, when stream volumes were added to sink inputs, it was > thought that this feature wouldn't be overly useful for capture streams > and while this argument still holds true, there is one feature that has > since been added to PA that would make it useful - flat volumes. > > Flat volumes allow for multiple streams to be connected to the same > device and when they differ in stream volume, the maximum one is chosen > and the h/w is set to that, with the difference in volume between the > streams applied in software. This in theory allows for optimum power > efficiency where the software stays out of the loop whenever possible. > > With flat volumes, adding per-stream volumes to capture streams makes sense. > > It does also simplify client code when they want to adjust their own > volumes, they don't have to implement their own asymmetry to deal with ours. > > > So I am proud to announce my work to try and achieve this. There are no > doubt still bugs, so a thorough review is very much appreciated. [...] I've not been able to test things extensively yet, but some comments: I've pushed a couple of patches on top of your tree, one trivial, one adds a set-source-output-volume to pactl at http://cgit.collabora.com/git/user/arun/pulseaudio.git/log/?h=master-source-volume 29cd2d78 capture: Add the passthrough format negitiation to capture streams. * There's typo in the commit message * Just in case I forget, the fix we were discussion for ownwership of the formats idxset in pa_sink_input_new_data_set_formats() needs to be added to pa_source_output_new_data_set_formats() as well * This is tangential to your work, but maybe we should just break compatibility with versions older than 0.9.20? (protocol version < 17) It'll make the code easier to read. o94d2b5 capture: Implement per-stream volume control for capture streams. * I don't see the source output changes actually show up in the samples (I'm opening two gnome-volume-recorder instances, doing a pactl set-source-output-volume on one, but the levels are identical before and after). Is there a missing pa_volume_memchunk in pa_source_output_push() or am I just doing something stupid? * module-echo-cancel.c - there's an s->volume inside #if 0 * [Not actually from your changes] pa_source_process_msg() - does it matter that the order of detach and set state within thread inverted compared to sink-input? * Again, this is for later, but we should eventually stop suspending monitors and change the source format dynamically. Will do some more extensive testing and port pulsesrc when I get some time as well. Cheers, Arun
