I didn't have this problem, but I got the ALSA:front tip from the myth how-to (<a href="http://www.mythtv.org/wiki/Installing_MythTV_on_Fedora">http://www.mythtv.org/wiki/Installing_MythTV_on_Fedora</a>) - see the last line in the guide. It also mentioned changing the mixer setting to master from PCM. Worth a try - I'm not too experienced with this stuff so I'm grasping. Hopefully someone will have more insight.<br>
<br><div class="gmail_quote">On Fri, Jan 22, 2010 at 7:47 PM, steve <span dir="ltr"><<a href="mailto:networks1@cox.net">networks1@cox.net</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
<div lang="EN-US" link="blue" vlink="purple">
<div>
<p class="MsoNormal"><span style="color:#1F497D">></span>Now that I have
playback audio working on my system, I notice there is terrible audio
quality. This is hard to describe, but it’s “gravely,”
like there are very frequent short drop-outs. This happens not <span style="color:#1F497D">></span>only when I play back via Mythtv, but also
when I play the mpeg via the Totem movie player in Gnome.</p>
<p class="MsoNormal"><span style="color:#1F497D">></span> </p>
<p class="MsoNormal"><span style="color:#1F497D">></span>To rule out the
possibility that the capture device (HDPVR) is defective, I copied the mpeg
file onto a windoze machine and played it, and the audio sounds fine. To
rule out some problem with the <span style="color:#1F497D">></span>audio
hardware on the linux box I played a CD, which also sounds fine.</p>
<p class="MsoNormal"><span style="color:#1F497D">></span> </p>
<p class="MsoNormal"><span style="color:#1F497D">></span>So somehow the
problem only occurs when playing the audio from mpeg files. Mythtv is
configured to use ALSA:front for output (ALSA:default wouldn’t
work). I don’t know if Totem uses that too. </p>
<p class="MsoNormal"><span style="color:#1F497D">></span> </p>
<p class="MsoNormal"><span style="color:#1F497D">></span>I realize this
appears not to be a mythtv-specific problem (I also posted on the fedora list)
but I was wondering if any other mythtv users have had this problem, and if so
how they fixed it.</p>
<p class="MsoNormal"><span style="color:#1F497D"> </span></p>
<p class="MsoNormal"><span style="color:#1F497D">Well I checked the frontend log
and found additional information (below). This explains the intermittent
dropouts of audio. BTW the subject should have been “graveley”
(though the situation is grave). Other posts describe this sound as “crackely”
or “stuttering.”</span></p>
<p class="MsoNormal"><span style="color:#1F497D"> </span></p>
<p class="MsoNormal"><span style="color:#1F497D">Checking some other posts/wiki
entries suggested that pulse audio might be the problem but when I uninstalled
alsa-plugins-pulseaudio the audio quit altogether, so I reinstalled it. </span></p>
<p class="MsoNormal"><span style="color:#1F497D"> </span></p>
<p class="MsoNormal"><span style="color:#1F497D">Tried “aggressive buffering”
option. No help so I turned it off.</span></p>
<p class="MsoNormal"><span style="color:#1F497D"> </span></p>
<p class="MsoNormal"><span style="color:#1F497D">Not sure where to go from here.</span></p>
<p class="MsoNormal"><span style="color:#1F497D"> </span></p>
<p class="MsoNormal"><span style="color:#1F497D">Steve</span></p>
<p class="MsoNormal"><span style="color:#1F497D"> </span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt;font-family:"Courier New"">2010-01-22 17:22:02.861 TV: Attempting to change
from None to Watching WatchingPreRecorded</span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt;font-family:"Courier New"">2010-01-22 17:22:02.921 TV: StartPlayer(0, Watching
WatchingPreRecorded, main) -- begin</span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt;font-family:"Courier New"">2010-01-22 17:22:03.241 AFD: Opened codec 0x3223cc0,
id(H264) type(Video)</span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt;font-family:"Courier New"">2010-01-22 17:22:03.242 AFD: codec AAC has 2
channels</span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt;font-family:"Courier New"">2010-01-22 17:22:03.242 AFD: Opened codec 0x32244b0,
id(AAC) type(Audio)</span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt;font-family:"Courier New"">2010-01-22 17:22:03.243 Opening audio device
'front'. ch 2(2) sr 48000</span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt;font-family:"Courier New"">2010-01-22 17:22:03.244 Opening ALSA audio device
'front'.</span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt;font-family:"Courier New"">2010-01-22 17:22:03.324 Mixer unable to find control
PCM</span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt;font-family:"Courier New"">2010-01-22 17:22:03.324 Mixer unable to find control
PCM</span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt;font-family:"Courier New"">2010-01-22 17:22:03.324 Mixer unable to find control
PCM</span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt;font-family:"Courier New"">2010-01-22 17:22:03.324 Mixer unable to find control
PCM</span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt;font-family:"Courier New"">2010-01-22 17:22:03.325 Mixer unable to find control
PCM</span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt;font-family:"Courier New"">2010-01-22 17:22:03.325 Mixer unable to find control
PCM</span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt;font-family:"Courier New"">2010-01-22 17:22:03.325 Mixer unable to find control
PCM</span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt;font-family:"Courier New"">2010-01-22 17:22:03.325 Mixer unable to find control
PCM</span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt;font-family:"Courier New"">2010-01-22 17:22:03.325 Mixer unable to find control
PCM</span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt;font-family:"Courier New"">2010-01-22 17:22:03.940 OSD Theme Dimensions W: 1280
H: 720</span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt;font-family:"Courier New"">2010-01-22 17:22:04.694 TV: StartPlayer(0, Watching
WatchingPreRecorded, main) -- end ok</span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt;font-family:"Courier New"">2010-01-22 17:22:04.695 TV: Changing from None to
Watching WatchingPreRecorded</span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt;font-family:"Courier New"">2010-01-22 17:22:04.695 New DB connection, total: 3</span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt;font-family:"Courier New"">2010-01-22 17:22:04.698 Connected to database
'mythconverg' at host: mythtv</span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt;font-family:"Courier New"">2010-01-22 17:22:04.700 Realtime priority would
require SUID as root.</span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt;font-family:"Courier New"">2010-01-22 17:22:04.701 Video timing method: USleep
with busy wait</span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt;font-family:"Courier New"">2010-01-22 17:22:04.719 ScreenSaverX11Private: DPMS
Deactivated 1</span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt;font-family:"Courier New"">2010-01-22 17:22:05.014 WriteAudio: buffer underrun</span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt;font-family:"Courier New"">2010-01-22 17:22:06.391 NVP(0): prebuffering pause</span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt;font-family:"Courier New"">2010-01-22 17:22:06.419 NVP(0): prebuffering pause</span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt;font-family:"Courier New"">2010-01-22 17:22:06.456 NVP(0): prebuffering pause</span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt;font-family:"Courier New"">2010-01-22 17:22:06.476 NVP(0): prebuffering pause</span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt;font-family:"Courier New"">2010-01-22 17:22:06.528 NVP(0): prebuffering pause</span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt;font-family:"Courier New"">2010-01-22 17:22:06.568 NVP(0): prebuffering pause</span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt;font-family:"Courier New"">2010-01-22 17:22:06.605 NVP(0): prebuffering pause</span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt;font-family:"Courier New"">2010-01-22 17:22:06.647 NVP(0): prebuffering pause</span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt;font-family:"Courier New"">2010-01-22 17:22:06.698 NVP(0): prebuffering pause</span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt;font-family:"Courier New"">2010-01-22 17:22:06.733 NVP(0): prebuffering pause</span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt;font-family:"Courier New"">2010-01-22 17:22:06.772 NVP(0): prebuffering pause</span></p>
<p class="MsoNormal"><span style="color:#1F497D">[continues like this till I
escape playback]</span></p>
<p class="MsoNormal"><span style="color:#1F497D"> </span></p>
<p class="MsoNormal"><span style="color:#1F497D"> </span></p>
</div>
</div>
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<br></blockquote></div><br>