[xamindar]

My setup is the following: PC plugged into my 7.1 receiver via HDMI, which then of course goes to the TV.

I updated XBMC to the latest version in Arch Linux's repository today. Looks like it was compiled today as well. Now DTSHD and TRUEHD are no longer being passed through to my receiver. This is my main desktop pc while not using xbmc so I am using pulseaudio as well. With exception of the second issue which I will talk about below, the HD codecs were being passed through to my receiver just fine before this update. I checked in settings and passthrough is still selected for these codecs. Is this a pulseaudio thing? Does anyone know what went wrong or how to possible fix it?


The second issue is something I have been wanting to ask for a long time. With XBMC using pulseaudio, every video that contains audio that is passed through directly to the receiver (ac3, dts, whatever), starts out playing very slow and choppy with no audio. I have to wait a couple of seconds and then skip or rewind a little and then audio will start playing (receiver detects the audio stream and starts decoding) and video is smooth again. It's as if audio output is blocked until i seek in the video file. I have seen other mention of this issue but no one seems to have an answer.

I'm a little disappointed in the current state of Linux audio. Without pulseaudio, many programs are unable to output sound, let alone at the same time. But with pulseaudio, XBMC seems to have lots of issues. And I am having a terrible time finding any usefull documentation on pulseaudio. There has got to be someone out there who knows how to get audio working properly.

Any help would be greatly appreciated.

[DaVu]

IIRC the gotham nightlies support pulseaudio. So maybe try one of these and look if it's fixed.

[fritsch]

Read here: http://wiki.xbmc.org/index.php?title=PulseAudio

and provide a debug log.

As of gotham, xbmc can use pulseaudio for multi channel out or for AC3, DTS, EAC3. Other bitstream formats pulseaudio does not support.

[jjd-uk]

Pulseaudio does not support passthrough of DTS-HD and TRUEHD for decoding on an AVR, only ALSA can do that as XBMC needs exclusive access to the audio device for DTS-HD and TRUEHD.

You must decide which is more important, use as a desktop or use as a HTPC.

If HTPC use is more important for passthrough, then you need to either remove Pulseaudio and use ASLA, or I believe you maybe able to launch XBMC with an environment variable to use ALSA.

[xamindar]

Thanks fritsch, I'll provide a debug log when I get home tonight.

[xamindar]

Pulseaudio does not support passthrough of DTS-HD and TRUEHD for decoding on an AVR, only ALSA can do that as XBMC needs exclusive access to the audio device for DTS-HD and TRUEHD.

You must decide which is more important, use as a desktop or use as a HTPC.

If HTPC use is more important for passthrough, then you need to either remove Pulseaudio and use ASLA, or I believe you maybe able to launch XBMC with an environment variable to use ALSA.

If pulse doesn't support truehd and dtshd passthrough then why was it working before i updated xbmc? Pulseaudio has been configured in xbmc as the output audio device for some time now.

Being able to launch xbmc to bypass pulseaudio may be the perfect option if this is possible. When I'm using xbmc I am not using any other desktop function so I don't care about other apps using audio. Just as long as steam big picture can still be launched and work with xbmc closed. Thanks for the idea, I'll look in to this.

[wsnipex]

HD audio passthrough has _never_ worked with pulse, it simply does not support it. If at all, you might have had it de/transcoded.

to run xbmc with alsa instead:
AE_SINK=ALSA xbmc

but you must make sure that pulse is either stopped or at least doesn't hog the audio device.

[fritsch]

I think he used plain ALSA before. We need to make sure to communicate this for the final release.

"People, you installed pulseaudio - so xbmc will use it!"

[xamindar]

HD audio passthrough has _never_ worked with pulse, it simply does not support it. If at all, you might have had it de/transcoded.

to run xbmc with alsa instead:
AE_SINK=ALSA xbmc

but you must make sure that pulse is either stopped or at least doesn't hog the audio device.

If pulseaudio doesn't support passthrough then why are there options for it in pulseaudio's config tool?

Or if you mean xbmc doesn't support passthrough with pulseaudio, could that be the cause of my second issue? Is xbmc trying pulseaudio and failing and then when I seek a little it switches over to alsa and works?

So after all these years and advances in linux, we are still stuck having to make a choice in having audio work in some applications and not the other?

[fritsch]

You don't have DTS-HD nor TrueHD config options in pulseaudio. You only have AC3, DTS or EAC3 which it does perfectly.

And for your last question: Because of people invest most time into whining then starting to hack and improve pulseaudio.

[jjd-uk]

So after all these years and advances in linux, we are still stuck having to make a choice in having audio work in some applications and not the other?

No your choice is between a desktop centric environment where Pulseaudio makes sense, or a media playback centric environment where Pulseaudio makes no sense so ALSA should be used.

[wojeda]

Whoaaa! I am sooooo confused now guys.

I came looking for a solution to my problem and now I feel my understanding on this subject has degraded by 75%.
I hear what jjd and wsnipex are saying but, this is what I know because I have been battling this monkey for two full weeks.
Pulseaudio DOES pass DTS-HD through.

On my Kubuntu 13.04 rig, 3.11 Kernel, I had pulseaudio configured properly via pavucontrol.
I installed nightly Gotham and was just having problems with DTS-HD. Everything else worked fine.

After an upgrade of nvidia drivers to 331.20 and reconfigure, Gotham picked up my pulseaudio server and turned on all the goodies. Left the HDMI 2.0 setting on. Pulseaudio Server selected for both, output and pass-through. I then played Flyboys and my Denon receiver lit up the DTS-HD Master logo immediately. Video played flawless, but audio was choppy.

Several days and many many forums later. I decided Gotham was not ready for prime time just yet, audio-wise, so I removed and went back to Frodo 12.3. With my right hand raised up in the air, I swear pulseaudio is passing through onto my Denon 3313ci and decoding DTS-HD Master Audio as it's displayed in the LCD. Flawless video. Audio is incredible! minus a very small glitch.

The audio stream gets interrupted for 1/2 a second. The LCD flashes out the DTS-HD Master for that same split second but it keeps playing great again afterwards. This keeps happening in 10-15 second intervals. Some times it can go for up to a full minute and it does not do it.

So I am not sure what they mean when they say pulseaudio does not work with DTS-HD.

Trying to fix my stream blip problem and truly believing pulseaudio was at fault I purged pulseaudio last night and configured ALSA from scratch. Frodo 12.3 still has the same audio glitch. Nothing changed. Same audio stream interruption for a split second. Only with DTS-HD Master though. No other format seems to be affected. So I really don't think this is related to AE anymore. Now I feel like going back to Gotham again. I wish I knew what the problem is. It is driving me crazy!

[fritsch]

Debug Log

Whenever you see DTS-HD Master logo on your AVR, you can be 100% sure, that it is not pulseaudio but ALSA. I know that 100% exact, as I have written that code and I only check for EAC3, AC3 and DTS - as PA does not support anything else.

[wojeda]

I don't doubt what you are saying fritch. So, can you please explain what is going on here? Is it a glitch that makes the AVR falsely detect?
Is xbmc lying and not using pulseaudio even with the pulseaudio server, HDMI, Denon #1 is selected and uses ALSA in the background? Is it software decoding 8 channels even though I have only 2.0 channels enabled? If pulse does not handle DTS-HD, why is xbmc lighting all the HD options when pulseserver is selected?

Does it matter that I didn't even have ALSA configured at all while pulse was active? In fact, I had to PPA a whole bunch of ALSA stuff before I could even get any sound after purging pulse.

...understanding degradation to 80%

[fritsch]

I already explained it to you now three times!

Debug Log <- now