Re: [PATCH v3 06/15] jackaudio: use more jack audio buffers

[Volker Rümelin]

> On Dienstag, 1. März 2022 20:13:02 CET Volker Rümelin wrote:
> > The next patch reduces the effective qemu playback buffer size
> > by timer-period. Increase the number of jack audio buffers by
> > one to preserve the total effective buffer size. The size of one
> > jack audio buffer is 512 samples. With audio defaults that's
> > 512 samples / 44100 samples/s = 11.6 ms and only slightly larger
> > than the timer-period of 10 ms.
> >
> > The larger jack audio buffer increases audio dropout safety,
> > because the high priority jack-audio worker threads can provide
> > audio data for a longer period of time as with a smaller buffer
> > and more audio data in the mixing engine buffer that they can't
> > access.
> >
> > Signed-off-by: Volker Rümelin <vr_qemu@t-online.de>
> > ---
> I actually reviewed this patch already, but OK, then a 2nd time:
>
> Reviewed-by: Christian Schoenebeck <qemu_oss@crudebyte.com>

Oh, now that you write it, I remember this. Thank you.

With best regards,
Volker

> Best regards,
> Christian Schoenebeck
>
> >   audio/jackaudio.c | 4 ++--
> >   1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/audio/jackaudio.c b/audio/jackaudio.c
> > index 317009e936..26246c3a8b 100644
> > --- a/audio/jackaudio.c
> > +++ b/audio/jackaudio.c
> > @@ -483,8 +483,8 @@ static int qjack_client_init(QJackClient *c)
> >           c->buffersize = 512;
> >       }
> >
> > -    /* create a 2 period buffer */
> > -    qjack_buffer_create(&c->fifo, c->nchannels, c->buffersize * 2);
> > +    /* create a 3 period buffer */
> > +    qjack_buffer_create(&c->fifo, c->nchannels, c->buffersize * 3);
> >
> >       qjack_client_connect_ports(c);
> >       c->state = QJACK_STATE_RUNNING;