From: Jyri Sarha <jyri.sarha@xxxxxxxxx> The first patch in the set gives sink implementor a possibility to synchronize HW and SW volume usage in IO-thread. The remaining patches implement the synchronization for the alsa-sink and add the necessary module parameters and defaults for them in daemon configuration. This code has been tested on Nokia's ARM based Meego platform, on i686 laptop and on amd64 desktop. Tanu Kaskinen has also reviewed the code. To check what this set of patches does, please try following: 1. play white noise in background on low volume: # pacat --fix-rate --volume=10000 < /dev/urandom 2. play a short transient stream with high volume while the noise plays in background: # dd if=/dev/zero count=200 | pacat --fix-rate --volume=65536 Without these patches on most hardware you hear an annoying snap either in the beginning or the end (sometimes both) of the transient stream. After applying the patch the snap should be gone or at least less audible. With a little fiddling of the parameters it should be possible to get rid of the snap on all hardware. The default parameters work well at least on my Lenovo T60 running Debian Squeeze and they should be good, maybe a bit conservative, for most HW out there. This patch is pretty much mandatory for proper usage of flat volume especially on less powerful HW. Cheers, Jyri ps. This is my second attempt to try to get this functionality in. This second version the patches is improved from the earlier and there is no need locks anymore. I can't think of any more improvements to it, so please let me know if I should still do something to get this integrated. Jyri Sarha (5): core: Add infrastructure for synchronizing HW and SW volume changes alsa: Take syncronized HW volume infra into use for alsa-sink udev-detect: Add sync_volume parameter daemon-conf: Add sync volume parameters to daemon-conf man: sync_volume parameters to manual page man/pulse-daemon.conf.5.xml.in | 26 ++++ src/daemon/daemon-conf.c | 9 + src/daemon/daemon-conf.h | 5 +- src/daemon/daemon.conf.in | 4 + src/daemon/main.c | 3 + src/modules/alsa/alsa-mixer.c | 117 ++++++++++++++- src/modules/alsa/alsa-mixer.h | 9 +- src/modules/alsa/alsa-sink.c | 128 ++++++++++++++-- src/modules/alsa/alsa-source.c | 2 +- src/modules/alsa/module-alsa-card.c | 4 +- src/modules/alsa/module-alsa-sink.c | 10 +- src/modules/module-udev-detect.c | 18 ++- src/pulse/def.h | 7 +- src/pulsecore/core.c | 4 + src/pulsecore/core.h | 3 + src/pulsecore/sink.c | 281 +++++++++++++++++++++++++++++++++-- src/pulsecore/sink.h | 97 ++++++++++-- 17 files changed, 672 insertions(+), 55 deletions(-)
