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Peter and David:<br>
<br>
<blockquote type="cite">
<pre wrap="">This amplification will likely not work with HDMI audio, or you may have
to change some settings to get it to work.
In my experience, HDMI audio is digital and volume controls either in
mythtv or in Linux have no effect on volume. If you are seeing [ and ]
having an effect you may have something set up wrongly.
Some suggestions -
- Run alsamixer before starting mythtv and make sure your volume is set
to maximum on all devices shown.</pre>
</blockquote>
Verified at 100%/maximum<br>
<blockquote type="cite">
<pre wrap="">- use raspi-config to force HDMI audio</pre>
</blockquote>
Found the utility; didn't see anything to configure audio. In
Preferences there is an Audio Device Settings option (a few above
the Raspberry Pi Configuration option) and it has a Sound Card
selection, of which the only option is "bcm2835 ALSA (Alsa mixer)
(Default)" All options turned on and set to 100%.<br>
<br>
(Please note not trying to be a 'smart-rump': I've got Ubuntu
computers here which one will have an option and another will not
and they were configured from the same ISO.)<br>
<br>
<blockquote type="cite">
<pre wrap="">- try the digital audio with ALSA instructions, see
<a class="moz-txt-link-freetext" href="https://www.mythtv.org/wiki/Raspberry_Pi">https://www.mythtv.org/wiki/Raspberry_Pi</a>
</pre>
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<br>
This reference was very helpful! <br>
<br>
<blockquote type="cite">
<pre wrap="">I can't test it right now to give the exact instructions, but
somewhere in the MythTV audio setup, there is an option for software
volume control. When that is enabled and the output audio is digital,
MythTV will decode the audio, adjust the volume in software and then
re-encode the audio before sending it out. Now, this requires some
level of CPU power to do this, but I believe most current CPUs,
including the RPi, should be able to do it.</pre>
</blockquote>
<br>
What I found out is both you you were right, depending on the
configuration in Setup > Audio. If (page 1) Audio Output Device
is set for "ALSA:sysdefault:CARD=ALSA" and (page 2) "Use internal
volume controls" is ticked and 'Mixer device' is set to
'ALSA:default" then the [ and ] keys will control the volume, which
is handy as the monitor does not have a volume control.<br>
<br>
If I set to (page 1) to 'ALSA:pluhw:CARD=ALSA,DEV=0' or 'DEV=1' then
I loose the keyboard control.<br>
<br>
Also experimented with the OpenMAX options; didn't seem to make any
difference and the webpage indicated ALSA was better on the RPi
experimented more with the ALSA.<br>
<br>
So I guess unless we can figure how to increase above 100% (and no
distortion!) I'll leave things as-is.<br>
<br>
Thanks for the assistance!<br>
<br>
Barry<br>
<br>
<br>
<br>
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