See the last message for the fix -- using ALSA:hw:0,4 in place of /dev/dsp in the sound device settings.

I'm having a bit of a problem using AC3 passthru with my fresh, shiny R5F27 install. I have everything working pretty much perfectly (THANKS, guys!) but for this one little issue.

The problem is, about 50-80% of the time I play back an HD recording (with AC3), my SPDIF output carries this horrible digital "noise" instead of the audio. It's a sound that definitely gets your attention when you start a playback! If I exit the playback and start it again (sometime several times), I can get it to play correctly.

I have tried all combinations of playback decoders (standard, ffmpeg, xvmc, etc) and all work the same. I have monkeyed with various alternative settings in the configuration of the sound, but I can find nothing that eliminates the problem, save disabling AC3 passthru which fixes the problem for all time. But I want my AC3 with its rumbling LFE channel and surround goodness! (Sing along with me... I want my, I want my AC3!)

My system is based on an Abit AS8 m/b with a Pentium 4 531 processor (Prescott core, 3.0GHz). It has onboard Realtek sound of some vintage. It worked perfectly on earlier releases, but I never tried it on R5F1.

Joe

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Could it be your receiver or prepro? On mine I can set my to autodetect or only read from the Analog or Digital inputs. I generally force mine to always pick the digital input since I never want the analog signal.

AFAIK myth always sends the data out both the analog and digital output at the same time, so if there is a slight momentary pause in the beginning the prepro might decide that there is no digital signal coming in so it just gets the data from the analog line (which is why you get that horrible scratchy sound which is basically the AC3 signal converted to analog form).

On my setup I only have the digital optical hooked up -- no analog signals at all. (That's how much I like it, my AC3....) When I uncheck the AC3 Passthru option, it still uses the digital output but passes normal dolby stereo (not 5 channel) to the optical out.

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Are these new recordings, or recordings that were made prior to the upgrade? Do you have the same sound problem when watching live TV?

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LinHES 8.3, 1 BE, 3 FE

Joe,
I have an Abit AS8 based frontend that works perfectly well with digital audio on HDTV recordings using the standard decoder. With Xine, that's another story. You can see my complete configuration from the link in my signature. It's FE#2. Here are my settings that work for me. These are the values from my DB. Sorry, I'm not in front of the box:


I do not use MythTV's internal volume controls.

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Mike
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Thanks for your settings, Mike. I'll try those. The old AS8 has been super-reliable for me until this last issue. It's not a huge disaster if I am forced to get a new motherboard for this (grin) but I'm just trying to squeeze the last "bit" out of this one first.

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Thanks again Mike -- this made ALL the difference! I can use full AC-3 passthru AND it avoids some nasty audio glitching I was getting. Excellent tip!

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Happy to help!

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Mike
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I tried that setting and didn't see to help me. I just get a buzz out of my onboard digital coax jack but if I replace it with a chiantech card and use the opitcal out and don't change any setting it works just fine. My onboard sound work up until a couple versions of KM ago. It is a Nvidia Nforce430 based motherboard. I have downloaded newer versions of the alsa driver and tried them but no luck. Has anyone else had this problem?


Thanks

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Marty

Long live Myth and Knoppmyth!!!!!

Hi~

I'm ok with everything (videos, recorded TV, mythstream) except mythmusic.
Running mythfrontend from a command prompt returns "unable to open" error snd_pcm_output(hw:0,2)

currently using /dev/adsp in General\Audio -- but nothing I input to the output device field seems to be able to change the 'hw:0,2' value to get mythmusic playing. Selecting a song does nothing except produce the error.

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R5F27 | M2NPV-VM | 4600+ 65W AM2X2 | CORSAIR TWIN2X1024A-6400 | 2x HD-5000 |
DVI to HP LC3700N

Post the output of this command (this can be done as mythtv or root, doesn't matter):

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Mike
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sorry for the delay in response- was on vacation for a couple of weeks... came home to a nice full hard drive though! Thanks for the assist
~F

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R5F27 | M2NPV-VM | 4600+ 65W AM2X2 | CORSAIR TWIN2X1024A-6400 | 2x HD-5000 |
DVI to HP LC3700N

Try

0 = card #0
1 = device #1

You don't have a device #2 as evidenced by the output of aplay -l

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Mike
My Hardware Profile

Good work guys. I've added a link to this thread in the R5F27 Hints as Known Change #7.7

that's the thing that is driving me nuts- no matter what I put into the field, I always get that same ""unable to open" error snd_pcm_output(hw:0,2) "

I've even put (literally) XXXX just to see what happens and it always returns that "unable to open" error snd_pcm_output(hw:0,2)

Is there a way to force it via mysql?

thanks for the speedy reply BTW!

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R5F27 | M2NPV-VM | 4600+ 65W AM2X2 | CORSAIR TWIN2X1024A-6400 | 2x HD-5000 |
DVI to HP LC3700N