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<th align="right" nowrap="nowrap" valign="baseline">Subject: </th>
<td>Using JACK for Audio</td>
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<th align="right" nowrap="nowrap" valign="baseline">Date: </th>
<td>Mon, 07 Jan 2008 01:03:45 -0800</td>
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<th align="right" nowrap="nowrap" valign="baseline">From: </th>
<td>Martin Lynch <a class="moz-txt-link-rfc2396E" href="mailto:martin.lynch@shaw.ca"><martin.lynch@shaw.ca></a></td>
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<th align="right" nowrap="nowrap" valign="baseline">Reply-To: </th>
<td><a class="moz-txt-link-abbreviated" href="mailto:martin.lynch@shaw.ca">martin.lynch@shaw.ca</a></td>
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<th align="right" nowrap="nowrap" valign="baseline">To: </th>
<td><a class="moz-txt-link-abbreviated" href="mailto:mythtv-users@mythtv.org">mythtv-users@mythtv.org</a></td>
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<font size="+1"><font face="sans-serif">Has anyone successfully used
JACK to output audio from MythTV? I start qjackctl, select JACK from
the front end settings in Myth, then tune in a channel. The connection
shows ever so briefly in qjackctl's connections box but then
disappears. I use JACK successfully day in and day out for music
recording projects (with Ardour) without any problems whatsoever, so I
don't think it's on JACK's end. I also tried selecting various sample
rates (by default I use 96K but tried it with 44.1K and 48K) and with
and without real time priorities, all to no avail.</font></font><font
size="+1"><font face="sans-serif"> I scoured the web with no
luck; also all my old archives of this list and the only matches I got
were in the context of "I don't know jack about..." - nothing relating
to JACK...</font></font><font size="+1"><font face="sans-serif"> Anyone
have any suggestions?<br>
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<font size="+1"><font face="sans-serif">_______________<br>
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Few things I had to do to get JACK to work:<br>
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- In the General section of Setup in the frontend, I had to change
"JACK:output" to "JACK:" This finally allowed me to connect to JACK,
but the audio was horrible - slow and distorted and goofy.<br>
- I changed some settings in JACK: changed sample rate to 44.1 (from
96) and changed the frames/period to 256 (from 64). Periods/buffer
remained at 3. The latency, which I ordinarily keep at 2ms for music
projects went up to 17.4ms (ie. (256 X 3)/44,100). Real time checkbox
remains checked in JACK, and I'm using "Extra Audio Sound" in Myth.<br>
<br>
This works great and has eliminated audio choppiness on HD channels
which had recently developed and which slowed down playback.<br>
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