| Message ID | 1491287418-11297-1-git-send-email-sutar.mounesh@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, 04 Apr 2017 08:30:18 +0200, sutar.mounesh@gmail.com wrote: > > From: Timo Wischer <twischer@de.adit-jv.com> > > Distorted sound is heard if the capture device of an ioplug plugin is used, > which is accessed through any ALSA plugin (like copy, linear, ...) via MMAP access. > E.g. aplay -> loop -> copy -> arecord -M -> aplay -> hw:0 > As mentioned in the ALSA API (see pcm/pcm.c:942): > The function #snd_pcm_avail_update() have to be called > before any mmap begin+commit operation. > > Signed-off-by: Timo Wischer <twischer@de.adit-jv.com> > Signed-off-by: Mounesh Sutar <sutar.mounesh@gmail.com> Applied this one, too. Thanks. Takashi > > diff --git a/src/pcm/pcm_plugin.c b/src/pcm/pcm_plugin.c > index aaea2ab..ec57f6e 100644 > --- a/src/pcm/pcm_plugin.c > +++ b/src/pcm/pcm_plugin.c > @@ -490,7 +490,14 @@ static snd_pcm_sframes_t snd_pcm_plugin_avail_update(snd_pcm_t *pcm) > snd_pcm_uframes_t slave_offset; > snd_pcm_uframes_t slave_frames = ULONG_MAX; > snd_pcm_sframes_t result; > - > + /* As mentioned in the ALSA API (see pcm/pcm.c:942): > + * The function #snd_pcm_avail_update() > + * have to be called before any mmap begin+commit operation. > + * Otherwise the snd_pcm_areas_copy will not called a second time. > + * But this is needed, if the ring buffer wrap is reached and > + * there is more data available. > + */ > + slave_size = snd_pcm_avail_update(slave); > result = snd_pcm_mmap_begin(slave, &slave_areas, &slave_offset, &slave_frames); > if (result < 0) { > err = result; > -- > 2.7.4 >
diff --git a/src/pcm/pcm_plugin.c b/src/pcm/pcm_plugin.c index aaea2ab..ec57f6e 100644 --- a/src/pcm/pcm_plugin.c +++ b/src/pcm/pcm_plugin.c @@ -490,7 +490,14 @@ static snd_pcm_sframes_t snd_pcm_plugin_avail_update(snd_pcm_t *pcm) snd_pcm_uframes_t slave_offset; snd_pcm_uframes_t slave_frames = ULONG_MAX; snd_pcm_sframes_t result; - + /* As mentioned in the ALSA API (see pcm/pcm.c:942): + * The function #snd_pcm_avail_update() + * have to be called before any mmap begin+commit operation. + * Otherwise the snd_pcm_areas_copy will not called a second time. + * But this is needed, if the ring buffer wrap is reached and + * there is more data available. + */ + slave_size = snd_pcm_avail_update(slave); result = snd_pcm_mmap_begin(slave, &slave_areas, &slave_offset, &slave_frames); if (result < 0) { err = result;