pulseaudio: setup buffer attrs

Request reasonable buffer sizes from pulseaudio.  Without this
pa_simple_write() can block quite long and lead to dropouts,
especially with guests which use small audio ring buffers.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: malc <av1474@comtv.ru>
This commit is contained in:
Gerd Hoffmann 2011-01-24 22:07:45 +01:00 committed by malc
parent 6315633b25
commit e6d16fa439

View file

@ -289,6 +289,7 @@ static int qpa_init_out (HWVoiceOut *hw, struct audsettings *as)
{
int error;
static pa_sample_spec ss;
static pa_buffer_attr ba;
struct audsettings obt_as = *as;
PAVoiceOut *pa = (PAVoiceOut *) hw;
@ -296,6 +297,15 @@ static int qpa_init_out (HWVoiceOut *hw, struct audsettings *as)
ss.channels = as->nchannels;
ss.rate = as->freq;
/*
* qemu audio tick runs at 250 Hz (by default), so processing
* data chunks worth 4 ms of sound should be a good fit.
*/
ba.tlength = pa_usec_to_bytes (4 * 1000, &ss);
ba.minreq = pa_usec_to_bytes (2 * 1000, &ss);
ba.maxlength = -1;
ba.prebuf = -1;
obt_as.fmt = pa_to_audfmt (ss.format, &obt_as.endianness);
pa->s = pa_simple_new (
@ -306,7 +316,7 @@ static int qpa_init_out (HWVoiceOut *hw, struct audsettings *as)
"pcm.playback",
&ss,
NULL, /* channel map */
NULL, /* buffering attributes */
&ba, /* buffering attributes */
&error
);
if (!pa->s) {