Re: [alsa-devel] parameter for pulse device?

Dear Takashi,

I tested your patch, after commenting some lines in my ~/.asoundrc, and I can confirm that it works. I can now specify a pulse device to 'ecasound':

ecasound -o alsa,pulse:music -i song.wav

and when I do it with no "DEVICE" argument, then it outputs to the sink defined by "pacmd set-default-sink":

ecasound -o alsa,pulse -i song.wav

I guess this only exercises one of the cases in your patch where the empty string is recognized as NULL:

+ } else if (!*device) { + device = NULL;

Let me know if you want me to do more testing, and apologies for the long delay in my reply.

Thanks,

Frederick

On Fri, Sep 20, 2019 at 09:44:19AM +0200, Takashi Iwai wrote:

On Fri, 20 Sep 2019 09:35:59 +0200, Tanu Kaskinen wrote:

...

On Thu, 2019-09-19 at 14:12 -0700, frederik@ofb.net wrote:

...

Thank you for the tips.

I don't know if my input is still needed, but I figured out from looking at some of the syntax you linked to that I can put this in ~/.asoundrc and it does the job (this is what I had had in mind when I asked about "magic with macros", it is somewhat advanced for me):

pcm.!pulse {
    @args [ DEV ]
    @args.DEV {
        type string
        default "default"
    }
    type pulse;
    device $DEV
}

Now I can set up a filter like this:

ecasound -i alsa,pulse:mic -o alsa,pulse:monitor

Is something like this going into the alsa-plugins repo?

I'm sure something like this will be accepted if you submit a patch. I got the impression that Takashi isn't willing to write the patch himself, and nor am I, so you're in the best position to make this happen.

I have a test patch but had no chance to test the stuff at all currently as I am (and will be for the next few weeks) traveling.

...

Note that

        default "default"

doesn't do the intended thing with the current pcm_pulse.c code. With the current code the plugin will request PulseAudio to use a device named "default", which most likely won't exist and playback or recording will fail. The plugin code needs to pass NULL as the device name to pa_stream_connect_playback() and pa_stream_connect_record() when it detects that the default device is requested, so you'll need to modify pcm_pulse.c in order to make this work. Instead of "default" as the special string in the configuration, I suggested using "".

Below is the totally untested patch (even not build-tested!) If anyone interested, feel free to cook it.

thanks,

Takashi

---

diff --git a/pulse/50-pulseaudio.conf b/pulse/50-pulseaudio.conf index 62da207af9ca..916258d942af 100644 --- a/pulse/50-pulseaudio.conf +++ b/pulse/50-pulseaudio.conf @@ -1,7 +1,13 @@ # Add a specific named PulseAudio pcm and ctl (typically useful for testing)

pcm.pulse {

• @args [ DEVICE ]
• @args.DEVICE {

• type string
  

• default ""
  

• } type pulse
• device $DEVICE hint { show { @func refer

diff --git a/pulse/ctl_pulse.c b/pulse/ctl_pulse.c index fbb6eae2ec76..9b820fd04b15 100644 --- a/pulse/ctl_pulse.c +++ b/pulse/ctl_pulse.c @@ -664,6 +664,8 @@ SND_CTL_PLUGIN_DEFINE_FUNC(pulse) if (snd_config_get_string(n, &server) < 0) { SNDERR("Invalid type for %s", id); return -EINVAL;

• 	} else if (!*server) {
  

• 		server = NULL;
  }
  continue;
  

  }

@@ -671,6 +673,8 @@ SND_CTL_PLUGIN_DEFINE_FUNC(pulse) if (snd_config_get_string(n, &device) < 0) { SNDERR("Invalid type for %s", id); return -EINVAL;

• 	} else if (!*device) {
  

• 		device = NULL;
  }
  continue;
  

  }

@@ -678,6 +682,8 @@ SND_CTL_PLUGIN_DEFINE_FUNC(pulse) if (snd_config_get_string(n, &source) < 0) { SNDERR("Invalid type for %s", id); return -EINVAL;

• 	} else if (!*source) {
  

• 		source = NULL;
  }
  continue;
  

  }

@@ -685,6 +691,8 @@ SND_CTL_PLUGIN_DEFINE_FUNC(pulse) if (snd_config_get_string(n, &sink) < 0) { SNDERR("Invalid type for %s", id); return -EINVAL;

• 	} else if (!*sink) {
  

• 		sink = NULL;
  }
  continue;
  

  }

diff --git a/pulse/pcm_pulse.c b/pulse/pcm_pulse.c index 283174357e8b..869c9b674c6b 100644 --- a/pulse/pcm_pulse.c +++ b/pulse/pcm_pulse.c @@ -1069,6 +1069,8 @@ SND_PCM_PLUGIN_DEFINE_FUNC(pulse) if (snd_config_get_string(n, &server) < 0) { SNDERR("Invalid type for %s", id); return -EINVAL;

• 	} else if (!*server) {
  

• 		server = NULL;
  }
  continue;
  

  }

@@ -1076,6 +1078,8 @@ SND_PCM_PLUGIN_DEFINE_FUNC(pulse) if (snd_config_get_string(n, &device) < 0) { SNDERR("Invalid type for %s", id); return -EINVAL;

• 	} else if (!*device) {
  

• 		device = NULL;
  }
  continue;
  

  }

@@ -1091,6 +1095,8 @@ SND_PCM_PLUGIN_DEFINE_FUNC(pulse) if (snd_config_get_string(n, &fallback_name) < 0) { SNDERR("Invalid value for %s", id); return -EINVAL;

• 	} else if (!*fallback_name) {
  

• 		fallback_name = NULL;
  }
  continue;
  

  }