[jbetzer]

Hi there

First of all, let me say, I am a total linux beginner, so if you can help me with the following problem, please be as specific as possible

I've recently bought a Zotac ION 330, I have been using windows XBMC for quite some time now on my old HTPC, but since there is no support for GPU acceleration i had to change to linux (ubuntu).

With some help from my some of my linux experienced mates I was able to setup Ubuntu with XBMC and pretty much everything is running as it should

But I have run into a problem I havent been able to find a solution for on the forums nor on the wiki.

Problem:
When playing AC3/DTS content, once in a while (every 5 min or so) the SPDIF signal cuts for <0.5 seconds and then resumes as it should. It is not a lot, but it is enough for me to notice and therefore: be annoyed by it.

I havent been able to reproduce this problem on 2ch MP3 audio content(PCM). Its only on AC3/DTS

My system spec is as follows:
Hardware: Zotac ION N330, 1 GB ram
Linux Distrobution: Ubuntu 9.04 - 2.6.28-15 Generic 32 bit - Up to date as of 2009-10-04(from the "uname -a" command)
Architecture: i686
Install Method: PPA
SVN Revision: 23321 (I have also tried with 23281, where the problem still is present)
Nvidia driver: 185 (From nvidia.com)
Sound: Updated to version 1.0.21 using the ALSA update script

Besides that, I have tried removing Pulse-Audio as well as only enabling the External audio (Realtek ALC662) in bios.

Any help will be much appreciated, I am a bit lost atm

[chrisism]

Hi,
I've got the same problem. Dont know if it's only with ac3 or anything.
Also everytime I start a movie or music it takes some time (1 sec.) before the sound is turned on.
Doesn't matter if it goes over the hdmi or over the spdif?

Anyone yet?

[Ben8472]

i'm having the same issue since i upgraded my AMP, noticed it on dts movies, will try ac3 later. Every 75 seconds +-3

[frozenice]

yesterday i have the same problem while watching a 1080p Movie over HDMI.

Every ~5-10 Min. the Audio Signal lost and returns. (~1second)

Bug in Xbmc?


Thanks!

(HW: AsRock ION 330)

[Ben8472]

i reaquired my old AMP to see if the problem is there too, i will have time later today to test it out.

what AMP are you guys using?
mine is a yamaha 465, i read on the internet that it might have a bad error correction if the ac3/dts stream jitters during playback.

[frozenice]

Sony STR-DG820, but i dont think that can be a problem with the AMP because my HDX1000 and WDTV plays all stuff without these audio "lags".

I think that must be an Bug in Linux/Xbmc/Alsa I don't know.

Hope anybody can help us

[poserdonut]

I have the same problem on my Asrock ion 330.

[vikjon0]

I am not sure it fix this problem to 100% but you could try to use a .asoundrc file with dmixer. There is a sample in another thread discussing this problem.

I used that file to fix the problem with shutter/spikes when opening e.g. a dvd iso using spdif with passthrough to the amp. This problem was fixed.

[Ben8472]

@vikjon0: i tried to find the thread you are refering to, can you please point us at the right one?


one thing i found out, if playing a dts movie the @24p the sound drop occours every 115 seconds +-2

the sound drops on DTS is more noticeable (sound really gone for a fraction of second), on ac3 its even less fraction of a second so not as much noticeable.

can you confirm that?

[frozenice]

For me its very different, not every 115 seconds.

I try now the reproduce these Error and take a look in the xbmc.log file in the /home/<username>/.xbmc/temp/ directory.

What says your xbmc.log file, after the error comes up

[vikjon0]

I didnt find the thread with a quick google but it was ongoing on this issue just a few days ago.

Instead I found my own post with the file:
EDIT: try the second sample first. It is from toiva, that had the same problem as you. You could probably find the thread I am talking about by looking for his posts.

pcm.!default {
type plug
slave.pcm "dmixer"
}

pcm.dsp0 {
type plug
slave.pcm "dmixer"
}
pcm.dmixer {
type dmix
ipc_key 1024
slave {
pcm "hw:0,1"
period_time 0
period_size 1024
buffer_size 8192
#periods 128
rate 44100
}
bindings {
0 0
1 1
}
}
ctl.mixer0 {
type hw
card 0
}

and a variation from someone else:

pcm.dmixer {
type dmix
ipc_key 1024
ipc_key_add_uid false
ipc_perm 0660
slave {
pcm "hw:0,3"
rate 48000
channels 2
period_time 0
period_size 1024
buffer_time 0
buffer_size 4096
}
}

pcm.!default {
type plug
slave.pcm "dmixer"
}

[Ben8472]

EDIT: still having the issue with sound cuts, will try vikjon0's suggestion now. will report back after watching something.

it seems that i got a fix too, i reworked my xorg.conf, with my old amp i had a different installation.

so far the sound plays uninterrupted

edit: sound drop is not gone, i just didn't notice because they are more rare now or i missed em due to headache.

what i did:

i let nvidia-settings create a config file, detecting my flatscreen tv

Code:

Section "Monitor"
    Identifier     "Monitor0"
    VendorName     "Unknown"
    ModelName      "TSB TOSHIBA-TV"
    HorizSync       15.0 - 81.0
    VertRefresh     23.0 - 76.0
    Option         "DPMS"
    ModeLine "1920x1080@60p" 148.50 1920 2008 2052 2200 1080 1084 1089 1125 +hsync +vsync
    ModeLine "1920x1080@50p" 148.50 1920 2448 2492 2640 1080 1084 1089 1125 +hsync +vsync
    ModeLine "1920x1080@60i" 74.18 1920 2008 2052 2200 1080 1084 1094 1124 +hsync +vsync Interlace
    ModeLine "1920x1080@50i" 74.25 1920 2448 2492 2640 1080 1084 1094 1124 +hsync +vsync Interlace
    ModeLine "[email protected]" 74.175 1920 2558 2602 2750 1080 1084 1089 1125 +hsync +vsync
    ModeLine "1920x1080@24p" 74.16 1920 2558 2620 2750 1080 1084 1089 1125 +hsync +vsync
    ModeLine "1920x1080@25p" 74.25 1920 2448 2492 2640 1080 1084 1089 1125 +hsync +vsync

plus i added these modes to the Section "Screen"

Code:

Modes "1920x1080@60p" "1920x1080@24p" "1920x1080@25p" "1920x1080@50i" "1920x1080@50p" "1920x1080@60i" "[email protected]"

i know this seems like a long shot, but so far no more sound drops on the test movie (dts 1.5mbit rate)

what i GUESS is that the video/sound wasn't sync properly leading to those sound drops

[Ben8472]

ok i tested with putting the second config in my home folder

sound drops still present very noticeable in dts movies

[frozenice]

hmmm... for me i updated now to the latest SVN from xbmc. Testing now

[Ben8472]

this is what the debug log says at the sound cuts:

Code:

14:55:06 T:2811231120 M:1234935808   DEBUG: CDVDPlayerAudio:: Discontinuty - was:1409449579,114476, should be:1409459965,849701, error:10386,735225

Code:

14:57:03 T:2811231120 M:1235443712   DEBUG: CDVDPlayerAudio:: Discontinuty - was:1508818567,273438, should be:1527271874,995501, error:18453307,722063

i also have those errors

Code:

14:57:01 T:2842688400 M:1235283968 WARNING: Decode - avcodec_decode_video didn't consume the full packet. size: 13379, consumed: 0