This change makes it possible to configure an arbitrary constant volume for a
volume element in the path configuration, which is applied when the path is
selected. Note: this is only useful when the exact hardware and driver are
known beforehand.
---
src/modules/alsa/alsa-mixer.c | 46 +++++++++++++++++++-
src/modules/alsa/alsa-mixer.h | 9 +++-
.../alsa/mixer/paths/analog-output.conf.common | 16 ++++---
3 files changed, 59 insertions(+), 12 deletions(-)
diff --git a/src/modules/alsa/alsa-mixer.c b/src/modules/alsa/alsa-mixer.c
index 3eef5f9..2893b47 100644
--- a/src/modules/alsa/alsa-mixer.c
+++ b/src/modules/alsa/alsa-mixer.c
@@ -1145,6 +1145,31 @@ static int element_zero_volume(pa_alsa_element *e, snd_mixer_t *m) {
return r;
}
+static int element_apply_constant_volume(pa_alsa_element *e, snd_mixer_t *m) {
+ snd_mixer_elem_t *me;
+ snd_mixer_selem_id_t *sid;
+ int r;
+
+ pa_assert(m);
+ pa_assert(e);
+
+ SELEM_INIT(sid, e->alsa_name);
+ if (!(me = snd_mixer_find_selem(m, sid))) {
+ pa_log_warn("Element %s seems to have disappeared.", e->alsa_name);
+ return -1;
+ }
+
+ if (e->direction == PA_ALSA_DIRECTION_OUTPUT)
+ r = snd_mixer_selem_set_playback_volume_all(me, e->constant_volume);
+ else
+ r = snd_mixer_selem_set_capture_volume_all(me, e->constant_volume);
+
+ if (r < 0)
+ pa_log_warn("Failed to set volume to %li of %s: %s", e->constant_volume, e->alsa_name, pa_alsa_strerror(errno));
+
+ return r;
+}
+
int pa_alsa_path_select(pa_alsa_path *p, snd_mixer_t *m) {
pa_alsa_element *e;
int r = 0;
@@ -1185,6 +1210,10 @@ int pa_alsa_path_select(pa_alsa_path *p, snd_mixer_t *m) {
r = element_zero_volume(e, m);
break;
+ case PA_ALSA_VOLUME_CONSTANT:
+ r = element_apply_constant_volume(e, m);
+ break;
+
case PA_ALSA_VOLUME_MERGE:
case PA_ALSA_VOLUME_IGNORE:
r = 0;
@@ -1368,6 +1397,12 @@ static int element_probe(pa_alsa_element *e, snd_mixer_t *m) {
pa_log_warn("Your kernel driver is broken: it reports a volume range from %li to %li which makes no sense.", e->min_volume, e->max_volume);
e->volume_use = PA_ALSA_VOLUME_IGNORE;
+ } else if (e->volume_use == PA_ALSA_VOLUME_CONSTANT &&
+ (e->min_volume > e->constant_volume || e->max_volume < e->constant_volume)) {
+ pa_log_warn("Constant volume %li configured for element %s, but the available range is from %li to %li.",
+ e->constant_volume, e->alsa_name, e->min_volume, e->max_volume);
+ e->volume_use = PA_ALSA_VOLUME_IGNORE;
+
} else {
pa_bool_t is_mono;
pa_channel_position_t p;
@@ -1685,8 +1720,15 @@ static int element_parse_volume(
else if (pa_streq(rvalue, "zero"))
e->volume_use = PA_ALSA_VOLUME_ZERO;
else {
- pa_log("[%s:%u] Volume invalid of '%s'", filename, line, section);
- return -1;
+ uint32_t constant;
+
+ if (pa_atou(rvalue, &constant) >= 0) {
+ e->volume_use = PA_ALSA_VOLUME_CONSTANT;
+ e->constant_volume = constant;
+ } else {
+ pa_log("[%s:%u] Volume invalid of '%s'", filename, line, section);
+ return -1;
+ }
}
return 0;
diff --git a/src/modules/alsa/alsa-mixer.h b/src/modules/alsa/alsa-mixer.h
index c24a896..a29aed1 100644
--- a/src/modules/alsa/alsa-mixer.h
+++ b/src/modules/alsa/alsa-mixer.h
@@ -62,9 +62,10 @@ typedef enum pa_alsa_switch_use {
typedef enum pa_alsa_volume_use {
PA_ALSA_VOLUME_IGNORE,
- PA_ALSA_VOLUME_MERGE, /* merge this volume slider into the global volume slider */
- PA_ALSA_VOLUME_OFF, /* set this volume to minimal unconditionally */
- PA_ALSA_VOLUME_ZERO /* set this volume to 0dB unconditionally */
+ PA_ALSA_VOLUME_MERGE, /* merge this volume slider into the global volume slider */
+ PA_ALSA_VOLUME_OFF, /* set this volume to minimal unconditionally */
+ PA_ALSA_VOLUME_ZERO, /* set this volume to 0dB unconditionally */
+ PA_ALSA_VOLUME_CONSTANT /* set this volume to a constant value unconditionally */
} pa_alsa_volume_use_t;
typedef enum pa_alsa_enumeration_use {
@@ -137,6 +138,8 @@ struct pa_alsa_element {
pa_alsa_required_t required_any;
pa_alsa_required_t required_absent;
+ long constant_volume;
+
pa_bool_t override_map:1;
pa_bool_t direction_try_other:1;
diff --git a/src/modules/alsa/mixer/paths/analog-output.conf.common b/src/modules/alsa/mixer/paths/analog-output.conf.common
index c7c4435..ccaa494 100644
--- a/src/modules/alsa/mixer/paths/analog-output.conf.common
+++ b/src/modules/alsa/mixer/paths/analog-output.conf.common
@@ -75,13 +75,15 @@
; required-absent = ignore | switch | volume # If set, require this element to not be of this kind and not
; # available, otherwise don't consider this path valid for the card
;
-; switch = ignore | mute | off | on | select # What to do with this switch: ignore it, make it follow mute status,
-; # always set it to off, always to on, or make it selectable as port.
-; # If set to 'select' you need to define an Option section for on
-; # and off
-; volume = ignore | merge | off | zero # What to do with this volume: ignore it, merge it into the device
-; # volume slider, always set it to the lowest value possible, or always
-; # set it to 0 dB (for whatever that means)
+; switch = ignore | mute | off | on | select # What to do with this switch: ignore it, make it follow mute status,
+; # always set it to off, always to on, or make it selectable as port.
+; # If set to 'select' you need to define an Option section for on
+; # and off
+; volume = ignore | merge | off | zero | <volume step> # What to do with this volume: ignore it, merge it into the device
+; # volume slider, always set it to the lowest value possible, or always
+; # set it to 0 dB (for whatever that means), or always set it to
+; # <volume step> (this only makes sense in path configurations where
+; # the exact hardware and driver are known beforehand).
; volume-limit = <volume step> # Limit the maximum volume by disabling the volume steps above <volume step>.
; enumeration = ignore | select # What to do with this enumeration, ignore it or make it selectable
; # via device ports. If set to 'select' you need to define an Option section
--
1.7.4.1
