[mythtv-users] .24 Audio results: mixed
Douglas_Peale at comcast.net
Fri Jun 18 06:48:10 UTC 2010
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On 06/17/2010 10:56 PM, Jean-Yves Avenard wrote:
> On 18 June 2010 15:34, Douglas Peale <Douglas_Peale at comcast.net> wrote:
>> In .23, I was using Alsa:default 5.1 with digital pass through enabled for Dolby digital and AC3. This was working with the
>> exception of always having to toggle the mute button in the mixer app off then on nearly every time I started the myth front end.
> but what did you have in your digital passthrough settings, certainly
> not ALSA:default.
> So choose in the list what is available. don't type it manually,
> select the actual device.
> If you output via SPDIF, you will have an entry ALSA:iec859
> if it's via HDMI, it will be ALSA:hdmi etc..
But ALSA:default WAS in the list in .23, and it did not get changed when I upgraded to .24. I changed it to PulseAudio:default,
and that caused the front end to hang when attempting to view LiveTV, so I set it back the way it was, even if I had to manually
type it in.
>> I tried setting it back to alsa:default, but alsa:default is no longer listed as one of the options. I manually typed in
>> Oh, this is strange, it is now working. My receiver reports Dolby Digital.
>> Tried changing to 7.1, got silence. switched back to 5.1 and still have silence. Brought up the mixer app, toggled the mute
>> button off & on and got sound back.
> It could be an issue in the alsa driver, the mute buttons is with the
> mixer , you are disabling the output and reenable it.
> Select 7.1 if you have 7.1 system attached to it, and note that this
> is not possible if you output audio via digital other than hdmi
> When you select 7.1, you give mythtv a hint of what system you have,
> so it knows what kind of upsampling or downsampling will be required.
> When actually opening the audio card, the new audio code now actually
> queries the audio card to find out how many channels are supported by
> that device.
> ALSA:default, or spdif , will report 2 channels only as only stereo
> PCM can be sent over (AC3 and DTS are sent over a stereo PCM stream).
> If you select 7.1, but at run time it sees that your system only
> supports stereo and you haven't checked AC3 passthrough, it will only
> send out stereo audio.
> If you have AC3 and DTS checked, then it will know it needs to encode
> the audio out as AC3
>> I guess I'm back where I was with flaky sound.
>> I'm going to hold off on the ticket for a bit to see if I can pin down the flakiness a bit.
> Showing the output is always going to show what's going on, being
> invalid or not , it will help.
> I guess I can make the logs a bit more verbose, like if you select
> 7.1, but your system only reports stereo at run time , I could display
> a message in the log..
> My original ideas was to actually fill the speaker configuration in
> the settings based on what your audio card reports.
> Like if the audio output shows stereo only, I display AC3 and DTS, if
> you check those, 5.1 is also showed.
> If the audio card report 2, 6 and 8, that's what I would show
> But the amount of work required, and my lack of knowledge with the Qt
> interface, in particular with dynamic field meant that I left this
> idea in the air, hoping that people will select the right config.
> Because at the end of the day, you can't know for sure, from the
> software point of view, what you have actually connected
> The other thing that made it difficult, is that ALSA reports the
> number of channels that are supported, not the speaker configurations.
> So 4 could be L+F+C+LFE or L+F+RR+RL etc...
Why not ask the user what they set up, they should know, they wired the speakers.
> Hope that makes sense.
> mythtv-users mailing list
> mythtv-users at mythtv.org
Audio setting are a real problem. Even though I know what I have physically connected, I do not have a clue as to what that
means in terms of the chipsets listed in any of the menus.
For example, On my system, my motherboard has 7.1 analog outputs, optical & coax SPDIF outputs, my video card has an HDMI port
that can support HDMI audio.
If I look at the hardware section of sound preferences, it shows 3 devices:
Cx23880/1/2/3 PCI Video and Audio Decoder [Audio Port]. I THINK this is an ATI HDTV Wonder for which I have never gotten the
analog portion to work.
HD48x0 audio. I think this is my ATI HD 4850 video card
Internal Audio. I'm pretty sure this is the motherboard audio
I'm pretty sure you can get all this information with your software, but from this can you tell what hardware is actually
connected? There is certainly no place for me to enter that data.
Even if I tell you that I have a receiver connected to the coax SPDIF audio port on the motherboard, that really does not tell
Even if I tell you that it is a Denon AVR3801, you have no idea how many speakers I have connected to it.
The reality is that I have 7 full range speakers connected, but no sub-woofer.
Even if I know all of this, I have no idea the correct way to set up sound on my system. I spent 2 hours yesterday trying to get
an analog microphone to work (I even went so far as to boot up an old windows 2000 computer just to prove the microphone was
functional). The microphone suddenly started working after going back to some settings that did not previously work.
I have 7 speakers hooked up, therefore if I see an option for 7.1, that is the one I will select.
I know that ALSA is being depreciated in Ubuntu and being replaced by PulseAudio, so if I see PulseAudio in the list, I assume
that is what I should choose. All the variants of PulseAudio or ALSA are random strings of characters to me IEC958? what the
hell is that? I see "default" that makes more sense. I know my reciever handles DTS, DTSes, PCM, and Dolby Digital, it says so,
right on the front, so those are selected.
Hell, I'm an electronics engineer with more than 20 years of experience, and I can't tell by looking at the menu options what
the optimal way to set up audio on my system, or in MythTV. Imagine what it is like for non-technical people.
Perhaps the menus should be:
How did you hook up your audio: (only show options that exist for this system)
SPDIF (optical or coax)
How many speakers do you have?
(if SPDIF was selected enable these check boxes)
What does your receiver support?
And please have a TEST button so I don't have to navigate 20 menus every time I get it wrong!
I might be able to correctly set that up.
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