oysteikt/mpd
0
0
Fork 0
Code Issues Pull Requests Releases Activity

Merge tag 'v0.22.10'

Browse Source 
release v0.22.10
This commit is contained in:
Max Kellermann
2021-08-06 18:21:59 +02:00
parent a74b07728e 64c39af556
commit bd893e6336
17 changed files with 177 additions and 30 deletions
Download Patch File Download Diff File Expand all files Collapse all files

79
src/mixer/plugins/AlsaMixerPlugin.cxx
View File

@@ -83,6 +83,24 @@ class AlsaMixer final : public Mixer {
AlsaMixerMonitor *monitor;
/**
* These fields are our workaround for rounding errors when
* the resolution of a mixer knob isn't fine enough to
* represent all 101 possible values (0..100).
*
* "desired_volume" is the percent value passed to
* SetVolume(), and "resulting_volume" is the volume which was
* actually set, and would be returned by the next
* GetPercentVolume() call.
*
* When GetVolume() is called, we compare the
* "resulting_volume" with the value returned by
* GetPercentVolume(), and if it's the same, we're still on
* the same value that was previously set (but may have been
* rounded down or up).
*/
int desired_volume, resulting_volume;
public:
AlsaMixer(EventLoop &_event_loop, MixerListener &_listener)
:Mixer(alsa_mixer_plugin, _listener),
@@ -101,6 +119,27 @@ public:
void Close() noexcept override;
int GetVolume() override;
void SetVolume(unsigned volume) override;
private:
[[gnu::const]]
static unsigned NormalizedToPercent(double normalized) noexcept {
return lround(100 * normalized);
}
[[gnu::pure]]
double GetNormalizedVolume() const noexcept {
return get_normalized_playback_volume(elem,
SND_MIXER_SCHN_FRONT_LEFT);
}
[[gnu::pure]]
unsigned GetPercentVolume() const noexcept {
return NormalizedToPercent(GetNormalizedVolume());
}
static int ElemCallback(snd_mixer_elem_t *elem,
unsigned mask) noexcept;
};
static constexpr Domain alsa_mixer_domain("alsa_mixer");
@@ -144,18 +183,26 @@ AlsaMixerMonitor::DispatchSockets() noexcept
*
*/
static int
alsa_mixer_elem_callback(snd_mixer_elem_t *elem, unsigned mask)
int
AlsaMixer::ElemCallback(snd_mixer_elem_t *elem, unsigned mask) noexcept
{
AlsaMixer &mixer = *(AlsaMixer *)
snd_mixer_elem_get_callback_private(elem);
if (mask & SND_CTL_EVENT_MASK_VALUE) {
try {
int volume = mixer.GetVolume();
mixer.listener.OnMixerVolumeChanged(mixer, volume);
} catch (...) {
}
int volume = mixer.GetPercentVolume();
if (mixer.resulting_volume >= 0 &&
volume == mixer.resulting_volume)
/* still the same volume (this might be a
callback caused by SetVolume()) - switch to
desired_volume */
volume = mixer.desired_volume;
else
/* flush */
mixer.desired_volume = mixer.resulting_volume = -1;
mixer.listener.OnMixerVolumeChanged(mixer, volume);
}
return 0;
@@ -233,7 +280,7 @@ AlsaMixer::Setup()
throw FormatRuntimeError("no such mixer control: %s", control);
snd_mixer_elem_set_callback_private(elem, this);
snd_mixer_elem_set_callback(elem, alsa_mixer_elem_callback);
snd_mixer_elem_set_callback(elem, ElemCallback);
monitor = new AlsaMixerMonitor(event_loop, handle);
}
@@ -241,6 +288,8 @@ AlsaMixer::Setup()
void
AlsaMixer::Open()
{
desired_volume = resulting_volume = -1;
int err;
err = snd_mixer_open(&handle, 0);
@@ -279,7 +328,12 @@ AlsaMixer::GetVolume()
throw FormatRuntimeError("snd_mixer_handle_events() failed: %s",
snd_strerror(err));
return lround(100 * get_normalized_playback_volume(elem, SND_MIXER_SCHN_FRONT_LEFT));
int volume = GetPercentVolume();
if (resulting_volume >= 0 && volume == resulting_volume)
/* we're still on the value passed to SetVolume() */
volume = desired_volume;
return volume;
}
void
@@ -287,12 +341,13 @@ AlsaMixer::SetVolume(unsigned volume)
{
assert(handle != nullptr);
double cur = get_normalized_playback_volume(elem, SND_MIXER_SCHN_FRONT_LEFT);
int delta = volume - lround(100.*cur);
int err = set_normalized_playback_volume(elem, cur + 0.01*delta, delta);
int err = set_normalized_playback_volume(elem, 0.01*volume, 1);
if (err < 0)
throw FormatRuntimeError("failed to set ALSA volume: %s",
snd_strerror(err));
desired_volume = volume;
resulting_volume = GetPercentVolume();
}
const MixerPlugin alsa_mixer_plugin = {