Kodi Community Forum

Pre post note :
This post has been first written on an unsituated thread.
Then I copy/past it here.
@Forum moderator, please delete : http://forum.xbmc.org/showthread.php?tid...pid1675204
and move Fritsch's answer (http://forum.xbmc.org/showthread.php?tid...pid1675272) here.

--

Hi all,

I am building a new HPTC (replacing my 4 years hardware) using :
Motherboard : http://www.asrock.com/server/overview.as...l=C2550D4I
Graphic Card : GeForce GT 630 fanless (PCIe 8x)
CEC adapter
Denon Ceol Piccolo : sound go through HDMI out of Graphic card, then go OUT of the TV through optic fiber to the Piccolo's input

First of all, I can confirm that this configuration works pretty well with "mplayer -vo vdpau My_Holidays_movie.mkv" :
Stable picture, no sound crackling or stuttering for more than one hour test.

Important software versions I use :
- Debian Jessie
- Latest Linux 3.14.0 ('cause / is BTRFS type and I want latest improvements of it)
- Nvidia proprietary drivers NVIDIA-Linux-x86_64-334.21 (with "kernel/nv-linux.h:#include <linux/acpi.h>" modified for 3.14.0 compatibility)
mplayer Debian's version : mplayer2 2.0-701-gd4c5b7f-2

Now, the XBMC part :
I'm using 13.0-BETA4 Git:20140405-ca6c289, built on my own with :
./configure --prefix=/usr/local --enable-vdpau --disable-pulse --disable-airplay --disable-airtunes --enable-mysql --disable-optical-drive --enable-libbluray --enable-libcec

Xbmc is launched from a .xinitrc file containing only :
export XBMC_HOME=/usr/local/share/xbmc
/usr/local/bin/xbmc-standalone

Entering Xbmc, all is running fine, menu sounds too.
When playing a video first 2 or 5 seconds are good, then audio stuttering happens
When playing old Xvid files silences last for less than one second, and I can expect to have 5 or 6 "incidents" in 40/45 minutes.
But, when playing a 1080p AC3 file (same as mplayer's test), stuttering happens so much time that it is impossible to listen to.
During the recording of the xbmc.log file, links residing a the end of this post, first seconds begin to stutter, then after 2 or 3 silences no more sound output ...

I worked on this issue all the week-end, but cannot find what happens.
I definitely validated my hardware and software setup because of the successful mplayer test.

I will be pleased to give a try to Dharma release (same issue ?) but I must get my hands on the VDPAU patch needed for latest Nvidia driver version that is hanging somewhere on my hard disk ...

Thanks for your help/attention, I will be please to received hints and test what ever proposed solutions but I will be away from home for the week

Logs of a test can be found here :
http://stargate.enneade.fdn.org/xbmc/xbmc.log2send

--

---

Answering to Fritsch (http://forum.xbmc.org/showthread.php?tid...pid1675272):

I will have to play around with audio configuration, you are right, but I am not very confident that will solve the issue ... (I'll do that this week-end).
For Piccolo and pass-through :
I don't use pass-through, because TV only support AC3, and as I am using CEC adapter it's really a mess when there is a DTS stream (you must use another remote for sound volume on passthrough, this is very confusing for my wife ...).
By the way, I will try enabling AC3 pass-through to wee what happens ... this could be interesting.
And again, with the exact same hardware configuration it's working well with mplayer, so this most likely a problem in my Xbmc configuration than hardware one.

I will spend time the incoming week-end (according to my wife ... the hardest part of the problem ), to try out the actual stable Xbmc version in spit of playing around with Gotham beta.

Read again, what I told concerning mplayer ... it just sends 2 channels not 5.1

Yes don't worry I read it well

Update :
2 days of research and tries learned me a lot.

I tried the following :
- 2 channels in Gotham : stuttering
- 2 channels in Frodo : stuttering
- mplayer : stuttering too (even if I think, the first time, it was ok, stuttering appears after 4 or 5 minutes)
- Flac file (audio only then) in Gotham : stuttering (!!!)
- Flac file (audio only then) in Frodo : stuttering (!!!)
- mp3 : same result
- tried Pulse with all tests done before : same result (not a surprise because it relies on alsa too)

What the hell ?
So, NVidia binary driver seems not responsible of the issue, only the audio part, so one (at least) of the following is guilty :
- Nvidia chipset
- card manufacturer : Asus
- Alsa driver : Intel HDA

I am on the way to enable alsa debug mode in kernel to see if I can grab more info, because right now I have near to nothing to show except Xbmc logs.
Did some body already "played" with Alsa module options or have an idea of what I could tweak ?
I saw there is also a lot of possible configuration in /etc/asound.conf, but I don't really know what to do with ...

I will try to post my issue on NVidia forum, just to see if somebody got the same issue and have a solution.

Any help/hint will be appreciated !

boot OpenElec or Xbmcbuntu 13beta from USB stick and see if it works there.

Good idea, I'll do.

Workaround found (sadly).

Well, I tried Xbmcbuntu : same result

Then the idea of a bad configured Graphic card comes up in my mind.
There were known problems with first implementation of PowerMizer (Nvidia way to reduce heat and power consumption by dynamically adapt frequencies to load) that flooded the system with IRQ signals and leaded to stuttering (video and audio).
So, I also tried to disable PowerMizer, issue not resolves, then fix frequencies, no good results too.

I was near to suicide (well ... almost ), when I found, in a forgotten drawer, an old usb sound dongle.
It was well recognized by the system, and first try "workaround" the problem : no stuttering (but bad and noisy analogue sound)

Seems problem is one of :
- Alsa
- Graphic Card
- Debian Jessie (mmm ... not convinced of this after Xbmcbuntu try)

I will try post my issue on Nvidia forums, and make regular tries on software updates, but right now I am on the way to put 60€ in an USB Creative Labs sound card with optical output and stop worry about HDMI sound.
(just because I am stuck with the Graphic Card as PCIe 8x are difficult to find)

I will try to update this post from time to time or if magic happens.

---

Forgot to mention I updated Nvidia drivers with latest stable and Beta (official support of Linux 3.14) : same result

sounds like I'm getting the same issue.
My logs are full of the CDVDPlayerAudio:: Discontinuity1 - was:635646.479000, should be:96000.000000, error:-539646.479000
and only when I enable passthrough.

My hardware however, is completely different.
Zotac HD-ID41
nVidia ION2

also running latest graphic drivers from ppa:mamarley/nvidia

I had xbmcbuntu 12 running fine without issue, it was only after testing xbmcbuntu13 that I started getting these errors.

UPDATE - My issue was solved by removing .asoundrc from the xbmc home folder.