<div dir="ltr">Hi Tanu,<div><br></div><div style>Thanks for replying :-)</div><div style><br></div><div style>When upmixing is disabled, mono playback is silent but does not generate errors that I can see from pulseaudio -vvv or any notifications.</div>
<div style><br></div><div style>Here's a bit of output:</div><div style><br></div><div style><div><font face="courier new, monospace" size="1">I: [pulseaudio] source-output.c: Trying to change sample rate</font></div>
<div><font face="courier new, monospace" size="1">I: [pulseaudio] source-output.c: Resampling enabled to 44100 Hz</font></div><div><font face="courier new, monospace" size="1">D: [pulseaudio] module-suspend-on-idle.c: Sink alsa_output.pci-0000_01_00.1.hdmi-surround-extra1 becomes busy.</font></div>
<div><font face="courier new, monospace" size="1">D: [pulseaudio] resampler.c: Channel matrix:</font></div><div><font face="courier new, monospace" size="1">D: [pulseaudio] resampler.c: I00 I01 I02 I03 I04 I05 </font></div>
<div><font face="courier new, monospace" size="1">D: [pulseaudio] resampler.c: +------------------------------------</font></div><div><font face="courier new, monospace" size="1">D: [pulseaudio] resampler.c: O00 | 0.000 0.000 0.000 0.000 0.000 0.000</font></div>
<div><font face="courier new, monospace" size="1">I: [pulseaudio] remap.c: Using generic matrix remapping</font></div><div><font face="courier new, monospace" size="1">I: [pulseaudio] resampler.c: Using resampler 'peaks'</font></div>
<div><font face="courier new, monospace" size="1">I: [pulseaudio] resampler.c: Using float32le as working format.</font></div><div><font face="courier new, monospace" size="1">D: [pulseaudio] memblockq.c: memblockq requested: maxlength=33554432, tlength=0, base=12, prebuf=0, minreq=1 maxrewind=0</font></div>
<div><font face="courier new, monospace" size="1">D: [pulseaudio] memblockq.c: memblockq sanitized: maxlength=33554436, tlength=33554436, base=12, prebuf=0, minreq=12 maxrewind=0</font></div><div><font face="courier new, monospace" size="1">I: [pulseaudio] source-output.c: Created output 14 "Peak detect" on alsa_output.pci-0000_01_00.1.hdmi-surround-extra1.monitor with sample spec float32le 1ch 25Hz and channel map mono</font></div>
<div><br></div><div><br></div><div><br class="">This particular one is from a mono youtube video played in Chrome, the behaviour is the same in other applications too.</div><div><br></div><div style>For the plans comment, this is just a quote referring to fine-grained control over upmixing from this thread: <a href="http://lists.freedesktop.org/archives/pulseaudio-bugs/2009-December/003553.html">http://lists.freedesktop.org/archives/pulseaudio-bugs/2009-December/003553.html</a></div>
<div style><br></div><div style>That was several years ago though.</div><div style><br></div><div style>I think your option would be good, to make sure I understand it it would be:</div><div style><br></div><div style>- no upmixing of stereo sources (or any multichannel source) with the upmix module disabled</div>
<div style>- mono would still be upmixed (probably to all channels) regardless of the upmix module being active or not</div><div style><br></div><div style>Or something functionally equivalent to the above.</div><div style>
<br></div><div style>If I can help with testing I'm happy to try any patch on my system. </div><div style><br></div><div style>Cheers</div><div style>Carl</div><div style><br></div><div style><br></div><div><br></div>
<div><br></div></div></div><div class="gmail_extra"><br><br><div class="gmail_quote">On 21 March 2013 07:58, Tanu Kaskinen <span dir="ltr"><<a href="mailto:tanuk@iki.fi" target="_blank">tanuk@iki.fi</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div class="im">On Wed, 2013-03-20 at 10:34 +0000, Carl Gridley wrote:<br>
> Hi folks,<br>
><br>
> I have found some old messages on this, but wondered if anything had<br>
> changed or anyone had any bright ideas on it now :-)<br>
><br>
> I have PA 2.1 running on Kubutu 12.10.<br>
><br>
> It is connected via HDMI to my AV receiver and so I have 5.1 PCM output.<br>
><br>
> I've got two music speakers, and the surround speakers are much smaller, so<br>
> I turn 5.1 upmixing off. I also turn off LFE mixing as the receiver does a<br>
> good job and can set a crossover per channel.<br>
><br>
> Everything sounds great, but mono sounds don't work as they can't get<br>
> upmixed to stereo. If I re-enable upmixing, mono works, but then all stereo<br>
> sources get upmixed which I'd prefer not to.<br>
<br>
</div>I haven't bothered to try this myself: how do mono streams behave when<br>
upmixing is disabled? Does the stream fail to connect to the device, or<br>
does it connect but is silent, or something else?<br>
<div class="im"><br>
> I know from the previous notes there were no plans to allow more control<br>
> over upmixing, has this changed at all?<br>
<br>
</div>No plans in what sense? Patches for enabling sensible use cases will be<br>
accepted, and this use case definitely is sensible. If you mean "no<br>
plans" as in "nobody has promised to do the work", then you're right,<br>
and nothing has changed.<br>
<div class="im"><br>
> An option just to enable mono<br>
> upmixing only would be fantastic :-)<br>
><br>
> Or even map mono to the centre channel if one is reported.<br>
<br>
</div>I'm not sure there is need to have any new options. If mono streams<br>
don't work at all in case upmixing is disabled, I don't see why anyone<br>
would want to keep the current behavior. We could have a special case<br>
for mono-only streams so that such streams would always be upmixed to<br>
all channels (or some smart selection of a subset of the available<br>
channels, but all channels is easier to implement).<br>
<br>
I looked at the remixing code to determine what it would take to<br>
implement this, and it seems simple enough that I'll write a patch<br>
myself.<br>
<span class="HOEnZb"><font color="#888888"><br>
--<br>
Tanu<br>
<br>
</font></span></blockquote></div><br></div>