On Mon, Jan 24, 2011 at 10:07:45PM +0100, Gerd Hoffmann wrote:
> 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 <kra...@redhat.com>
> ---
> audio/paaudio.c | 12 +++++++++++-
> 1 files changed, 11 insertions(+), 1 deletions(-)
>
> diff --git a/audio/paaudio.c b/audio/paaudio.c
> index 858ca81..75e3ea0 100644
> --- a/audio/paaudio.c
> +++ b/audio/paaudio.c
> @@ -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;
> +
What's the default buffer size? Is there any reason to query this on startup
somewhere instead of hard coding it?
> 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) {
> --
> 1.7.1
>
>
