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      <base href="https://bugs.freedesktop.org/">
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    <body><table border="1" cellspacing="0" cellpadding="8">
        <tr>
          <th>Bug ID</th>
          <td><a class="bz_bug_link 
          bz_status_NEW "
   title="NEW - module-combine fails to set best sample rate"
   href="https://bugs.freedesktop.org/show_bug.cgi?id=99437">99437</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>module-combine fails to set best sample rate
          </td>
        </tr>

        <tr>
          <th>Product</th>
          <td>PulseAudio
          </td>
        </tr>

        <tr>
          <th>Version</th>
          <td>unspecified
          </td>
        </tr>

        <tr>
          <th>Hardware</th>
          <td>All
          </td>
        </tr>

        <tr>
          <th>OS</th>
          <td>Linux (All)
          </td>
        </tr>

        <tr>
          <th>Status</th>
          <td>NEW
          </td>
        </tr>

        <tr>
          <th>Severity</th>
          <td>normal
          </td>
        </tr>

        <tr>
          <th>Priority</th>
          <td>medium
          </td>
        </tr>

        <tr>
          <th>Component</th>
          <td>modules
          </td>
        </tr>

        <tr>
          <th>Assignee</th>
          <td>pulseaudio-bugs@lists.freedesktop.org
          </td>
        </tr>

        <tr>
          <th>Reporter</th>
          <td>julianhughes@gmail.com
          </td>
        </tr>

        <tr>
          <th>QA Contact</th>
          <td>pulseaudio-bugs@lists.freedesktop.org
          </td>
        </tr>

        <tr>
          <th>CC</th>
          <td>lennart@poettering.net
          </td>
        </tr></table>
      <p>
        <div>
        <pre>$ pulseaudio --version
pulseaudio 5.0

$ uname -a
Linux pi 4.4.0-1-rpi #1 Debian 4.4.6-1+rpi14 (2016-05-05) armv6l GNU/Linux

I'm successfully using module-combine as follows (from my
/etc/pulse/default.pa):

"load-module module-alsa-sink device="hw:0,0" sink_name=dac0
load-module module-alsa-sink device="hw:1,0" sink_name=dac1
load-module module-combine sink_name=combo slaves=dac0,dac1
set-default-sink combo"

(each DAC outputs the same 2 channel audio to a different amplifier). 

Both USB DACs are identical and support the following rates:
96000, 88200, 48000, 44100, 32000.
My /etc/pulse/daemon.conf is the Debian package default so default sample rate
is 44100 and the alternative is 48000.

If I use just one dac with an unmodified /etc/pulse/default.pa then the sample
rate is successfully switched between 44100 and 48000 where appropriate and
possible.

When I use module-combine and two dacs the virtual sink/device only uses the
default rate set in /etc/pulse/daemon.conf.  If uncomment the default and
alternative rates and set them to different supported values and restart
pulseaudio then this new default rate is used, but the virtual/combined device
only ever uses the specified default.

This issue came up in 2009, see
<a href="https://lists.freedesktop.org/archives/pulseaudio-discuss/2009-March/003232.html">https://lists.freedesktop.org/archives/pulseaudio-discuss/2009-March/003232.html</a>
but the submitted patch was problematic and nothing came of it.  However the
following was stated:

"Otherwise file a feature request bug and I
will look into it eventually.

Lennart

-- 
Lennart Poettering "

Would now be eventually? :-)

I couldn't find any reference to this bug ever being fixed in newer versions.

Hope you can fix this, thanks!</pre>
        </div>
      </p>


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