linuxaudio.org

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Hi,=0A=0AI am trying to get my own ALSA plug-in to work with some real time=

 controls.=A0 ( Is this the right place to ask?)=0A=0AI am successful with =

the PCM part of it.=A0 What I mean is from:=0A=0Ahttp://www.alsa-project.or=

g/alsa-doc/alsa-lib/pcm_external_plugins.html=0AExternal Plugin: Filter-Typ=

e Plugin=0A=0Astatic snd_pcm_sframes_t=0Amyplg_transfer(snd_pcm_extplug_t *=

ext,=0A=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 const snd_pcm_channel_area_t *dst_are=

as,=0A=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 snd_pcm_uframes_t dst_offset,=0A=A0=A0=

=A0=A0=A0=A0=A0=A0=A0=A0 const snd_pcm_channel_area_t *src_areas,=0A=A0=A0=

=A0=A0=A0=A0=A0=A0=A0=A0 snd_pcm_uframes_t src_offset,=0A=A0=A0=A0=A0=A0=A0=

=A0=A0=A0=A0 snd_pcm_uframes_t size)=0A{=0A// my PCM processing works=0A// =

I want to add a control parameter that can be set in real time by an app=0A=

}=0A=0ASND_PCM_PLUGIN_DEFINE_FUNC(myplg)=0A{=0A// This all works for PCM pr=

ocessing just like the examples=0A...=0Aerr =3D snd_pcm_extplug_create(&mix=

->ext, name, root, sconf, stream, mode);=0A=A0=A0=A0 if (err < 0) {=0A=A0=

=A0=A0=A0=A0=A0=A0 free(mix);=0A=A0=A0=A0=A0=A0=A0=A0 return err;=0A=A0=A0=

=A0 }=0A...=0A}=0A=0ASND_PCM_PLUGIN_SYMBOL(myplg);=0A=0A=0ANow I want to ad=

d a simple real time adjustment, an integer value that can be sent by an ap=

plication to adjust the sound (PCM samples) in real time.=A0 I tried some w=

ays of doing it it but without success, I am not understanding the basics.=

=0A=0AI first looked at doing a ctl. I was able=A0 get separately (without =

PCM processing) get a control to work but that looks like ts only for hardw=

are control?=A0 I can't connect it to my PCM processing.=0A=0Ahttp://www.al=

sa-project.org/alsa-doc/alsa-lib/ctl_external_plugins.html=0A=0AI looked at=

 LADSPA but I'm not sure where that is going to take me.=0A=0AI am now look=

ing at=0A=0Ahttp://www.alsa-project.org/alsa-doc/alsa-lib/pcm_external_plug=

ins.html=0AExternal Plugin: I/O Plugin=0A=0ABut, I am confused because I al=

so see pcm type callbacks.=0A=0ASo, I do not have a specific coding questio=

n (yet) but I just need a general direction. ...=0A-Should I use ctl_extern=

al_plugins and figure out how to use it with my PCM?=0A-Should=A0 I use a L=

ADSPA example?=0A-Should I go wth External Plugin: I/O Plugin?=0A-Something=

 else?=0A=0AI hope I am clear enough about my question and thanks for any p=

ointers you can provide.=0A=0ABob

--0-1307444440-1312303594=:38499

Content-Type: text/html; charset=iso-8859-1

Content-Transfer-Encoding: quoted-printable
Hi,I am tryin=

g to get my own ALSA plug-in to work with some real time controls.  ( =

Is this the right place to ask?)I am successful with the PCM part o=

f it.  What I mean is from:http://www.alsa-project.org/alsa-do=

c/alsa-lib/pcm_external_plugins.htmlExternal Plugin: Filter-Type Plugin=

static snd_pcm_sframes_tmyplg_transfer(snd_pcm_extplug_t *ext,<=

br>           const snd_p=

cm_channel_area_t *dst_areas,       =

    snd_pcm_uframes_t dst_offset,   &nbsp=

;       const snd_pcm_channel_area_t *src_are=

as,           snd_pcm=

_uframes_t

 src_offset,         &nbsp=

; snd_pcm_uframes_t size){// my PCM processing works// I want t=

o add a control parameter that can be set in real time by an app}SND_PCM_PLUGIN_DEFINE_FUNC(myplg){// This all works for PCM proce=

ssing just like the examples...err =3D snd_pcm_extplug_create(&=

mix->ext, name, root, sconf, stream, mode);    if (er=

r < 0) {        free(mix);&nb=

sp;       return err;    }=

...}SND_PCM_PLUGIN_SYMBOL(myplg);Now I want to =

add a simple real time adjustment, an integer value that can be sent by an =

application to adjust the sound (PCM samples) in real time.  I tried s=

ome ways of doing it it but without success, I am not understanding the bas=

ics.I first looked at doing a ctl. I was able  get

 separately (without PCM processing) get a control to work but that looks l=

ike ts only for hardware control?  I can't connect it to my PCM proces=

sing.http://www.alsa-project.org/alsa-doc/alsa-lib/ctl_external_plu=

gins.htmlI looked at LADSPA but I'm not sure where that is going to=

 take me.I am now looking athttp://www.alsa-project.org/als=

a-doc/alsa-lib/pcm_external_plugins.htmlExternal Plugin: I/O Plugin=

But, I am confused because I also see pcm type callbacks.So, I =

do not have a specific coding question (yet) but I just need a general dire=

ction. ...-Should I use ctl_external_plugins and figure out how to use =

it with my PCM?-Should  I use a LADSPA example?-Should I go wt=

h External Plugin: I/O Plugin?-Something else?I hope I am clear=

 enough about my question and thanks for any pointers you can provide.<=

br>Bob

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