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handle xrun if xfers are not frame-aligned

This commit is contained in:
Alexandre Ratchov 2014-02-13 15:11:33 +01:00
parent 9fc928011a
commit 05c5ae3c6a
1 changed files with 27 additions and 15 deletions
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42
libsndio/sio_alsa.c
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@ -466,24 +466,36 @@ sio_alsa_stop(struct sio_hdl *sh)
static int
sio_alsa_xrun(struct sio_alsa_hdl *hdl)
{
long long wpos, rpos;
int rdiff;
int clk;
int wsil, rdrop, cmove;
int rbpf, rround;
int wbpf, wround;
DPRINTFN(2, "sio_alsa_xrun:\n");
if (_sndio_debug >= 2)
_sio_printpos(&hdl->sio);
rpos = (hdl->sio.mode & SIO_REC) ?
hdl->sio.cpos - hdl->sio.rused / hdl->ibpf : hdl->sio.cpos;
wpos = (hdl->sio.mode & SIO_PLAY) ?
hdl->sio.cpos + hdl->sio.wused / hdl->obpf : hdl->sio.cpos;
/*
* we assume rused/wused are zero if rec/play modes are not
* selected. This allows us to keep the same formula for all
* modes, provided we set rbpf/wbpf to 1 to avoid division by
* zero.
*
* to understand the formula, draw a picture :)
*/
rbpf = (hdl->sio.mode & SIO_REC) ?
hdl->sio.par.bps * hdl->sio.par.rchan : 1;
rround = hdl->sio.par.round * rbpf;
wbpf = (hdl->sio.mode & SIO_PLAY) ?
hdl->sio.par.bps * hdl->sio.par.pchan : 1;
wround = hdl->sio.par.round * wbpf;
rdiff = rpos % hdl->par.round;
wsil = rdiff + wpos - rpos;
rdrop = rdiff;
cmove = -(rdiff + hdl->sio.cpos - rpos);
clk = hdl->sio.cpos % hdl->sio.par.round;
rdrop = (clk * rbpf - hdl->sio.rused) % rround;
if (rdrop < 0)
rdrop += rround;
cmove = (rdrop + hdl->sio.rused) / rbpf;
wsil = cmove * wbpf + hdl->sio.wused;
DPRINTFN(2, "wsil = %d, cmove = %d, rdrop = %d\n", wsil, cmove, rdrop);
@ -492,12 +504,12 @@ sio_alsa_xrun(struct sio_alsa_hdl *hdl)
if (!sio_alsa_start(&hdl->sio))
return 0;
if (hdl->sio.mode & SIO_PLAY) {
hdl->odelta += cmove;
hdl->sio.wsil += wsil * hdl->obpf;
hdl->odelta -= cmove;
hdl->sio.wsil = wsil;
}
if (hdl->sio.mode & SIO_REC) {
hdl->idelta += cmove;
hdl->sio.rdrop += rdrop * hdl->ibpf;
hdl->idelta -= cmove;
hdl->sio.rdrop = rdrop;
}
DPRINTFN(2, "xrun: corrected\n");
DPRINTFN(2, "wsil = %d, rdrop = %d, odelta = %d, idelta = %d\n",