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<blockquote class="gmail_quote" style="PADDING-LEFT: 1ex; MARGIN: 0px 0px 0px 0.8ex; BORDER-LEFT: #ccc 1px solid">On Sep 22, 2006, at 5:31 AM, Thomas B�rkel wrote:<br><br>> HI!<br>><br>> Scott wrote:<br>><br>
>> Audio output device:<br>>> ALSA:iec958:CARD=0,AES0=0x6,AES1=0x82,AES2=0x0,AES3=0x2<br>>> Passthrough output device: Default<br>>> Enable AC3 to SPDIF passthrough: [checked]<br>>> Enable DTS to SPDIF passthrough: [checked]
<br>>> Aggressive Sound card Buffering: [not checked]<br>>> Use internal volume controls: [not checked]<br>><br>> It is funny, that this actually works, because with these setting,<br>> MythTV uses the "Default" device for AC3, not the one with the hex
<br>> codes.<br><br>Yes. But, my understanding of the "Passthrough output device" is that<br>if it is set to "Default" (case sensitive) then it simply refers to<br>the device defined by "Audio output device". This can be confirmed by
<br>running with mythtvfrontend -v audio > audio.debug.txt and looking at<br>the device MythTV opens with ALSA.<br><br>So you're correct that mythtv uses the "Passthrough output device"<br>when AC3/DTS passthrough is enabled. However, setting "Passthrough
<br>output device" to "Default" is a special case that tells MythTV to<br>use the "Audio output device". Using the HOWTO asoundrc file the<br>following alternative setup should work as well:<br><br>
Audio output device: ALSA:digital-dmix<br>Passthrough output device:<br>ALSA:iec958:CARD=0,AES0=0x6,AES1=0x82,AES2=0x0,AES3=0x2<br>Enable AC3 to SPDIF passthrough: [checked]<br>Enable DTS to SPDIF passthrough: [checked]<br>
Aggressive Sound card Buffering: [not checked]<br>Use internal volume controls: [not checked]<br><br>This config would be useful if MythTV was able to detect and route<br>AC3/DTS sound through the "Passthrough output device" only as needed.
<br>For example, if in MythMusic sound would not be 48kHz AC3 format and<br>get routed via the "Audio output device". During OTA ATSC playback<br>where AC3 formats are present MythTV would route sound via the<br>
"Passthrough output device" instead.<br><br>Of course, I have no idea if MythTV actually works this way. I'm just<br>saying, based on the definition of the two fields that it would be<br>nice if it MythTV could work this way! :)
<br><br>--<br>Scott</blockquote>
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<div>Wow! Scott, Thank you!</div>
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<div>I use optical as well for all of my sound out of my myth frontend and for over the past year with .18, .19, and now .20 I have never been able to pass through DD or DTS properly to the receiver. </div>
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<div>The receiver would switch to DD mode when I tried different settings and played an OTA HD recording, but I would get no sound. Then If I played something recorded from my PVR-250 it would switch back to PCM and play fine. Going to an OTA HD recording again would send the receiver back to DD mode but silent.
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<div>I have tried probly 7 or 8 times over the past year to try to get this work with every different .asoundrc config file possible without success. </div>
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<div>I have an Intel HD on MOBO sound chip as well, however my aplay -l reports CMIXXXX instead of ALCXXXX (sorry not at home so I don't have everything exactly).</div>
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<div>So just for kicks last night I started tinkering with it again with no success and found this discussion. I deleted my /etc/asound.conf and made sure I didn't have a ~/.asoundrc file and used the one from the Wiki to start fresh. And I still couldn't get it to work.
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<div>On a whim and last resort last night I tried your string of <font size="2">ALSA:iec958:CARD=0,AES0=0x6,AES1=0x82,AES2=0x0,AES3=0x2 in the passthrough device and HD recordings played perfectly in DD! For the first time EVER!
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<div><font size="2">So the settings I have are:</font></div>
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<div><font size="2"><font size="2">Audio output device: ALSA:default<br>Passthrough output device: <font size="2">ALSA:iec958:CARD=0,AES0=0x6,AES1=0x82,AES2=0x0,AES3=0x2 </font><br>Enable AC3 to SPDIF passthrough: [checked]
<br>Enable DTS to SPDIF passthrough: [checked] <br>Aggressive Sound card Buffering: [not checked] <br>Use internal volume controls: [not checked] </font></font></div>
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<div><font size="2">This way PCM sound (from my PVR-250) plays using the default Alsa device and DD is passed through to the string.</font></div>
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<div><font size="2">I can't believe after all of this I get true DD now from HD. It is like I just started using Myth again... I am that giddy!</font></div>
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<div><font size="2">Also upgraded the backend and frontend from .20 to .20.2 and it fixed alot of the other misc issues I was having. (Preview on recording list was incorrect colors, fast forward and rewind would freeze after 5 secs or so and then it would jump back to the original starting point, etc)
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<div><font size="2">Overall .20 is a great improvement!</font></div>
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<div><font size="2">Thanks everyone!</font></div>
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<div><font size="2">Jason</font></div>
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