softvol, ao_pulse: prefer ao_pulse volume control by default

--softvol is enabled by default. For most audio outputs, this is a good
thing, as they have either their own (bad) soft volume implementation,
or control the system mixer. With ao_pulse, the situation is a bit
different: it supports per-application volume (i.e. volume control is
not really global). More importantly, ao_pulse uses a rather large audio
buffer, and changing the volume with mplayer's volume filter has a large
delay. With the native ao_pulse volume control, it's instant, because
PulseAudio's audio filtering happens at a later stage in its processing
pipeline (inaccessible for mplayer).

This means native volume control should really be allowed for ao_pulse,
while it's the reverse for other audio outputs. Make --softvol a choice
option, and add a new "auto" choice. This is default and will use PA's
volume control with ao_pulse, and mplayer's volume filter otherwise
(i.e. the old softvol behavior).

1 files changed, 6 insertions, 1 deletions

diff --git a/mixer.c b/mixer.c
index d01cab8b71..8b52145d62 100644
--- a/mixer.c
+++ b/mixer.c
@@ -32,10 +32,15 @@ static void checkvolume(struct mixer *mixer)
     if (!mixer->ao)
         return;
 
+    if (mixer->softvol == SOFTVOL_AUTO) {
+        mixer->softvol = mixer->ao->per_application_mixer
+                         ? SOFTVOL_NO : SOFTVOL_YES;
+    }
+
     ao_control_vol_t vol;
     if (mixer->softvol || CONTROL_OK != ao_control(mixer->ao,
                                                 AOCONTROL_GET_VOLUME, &vol)) {
-        mixer->softvol = true;
+        mixer->softvol = SOFTVOL_YES;
         if (!mixer->afilter)
             return;
         float db_vals[AF_NCH];