[Fergus]

Description of Fault

Playing 5.1 Dolby Digital media with AC3 Passthrough enabled results in no audio. The amplifier emits a brief burst of static and incorrectly displays "[Dolby Digital 2/0]" on its front panel, but does not then emit any further sound. Manually switching the amplifier to another source and then back to the Apple TV optical input (whilst the media is already playing) results in the amplifier panel correctly displaying "[Dolby Digital 3/2]", but again does not emit any sound.

I'm guessing that TRAC isn't open to ATV2 tickets just yet, so I've captured as much relevant info as I can think of below. Give me a shout if there's anything else I can add/try to assist troubleshooting this one.

Environment

Platform : Apple TV 2
iOS Version : 4.2.1
Build Version : XBMC PRE-10.0 Git:cee5417 (compiled : Feb 7 2011)
Install Method : apt-get update && apt-get install org.xbmc.xbmc-atv2
Amplifier : Sony STR-DB930
Audio Connection : ATV Optical to Amplifier Optical

XBMC Config

Audio Output : Optical/Coax
Speaker Configration : 5.1
Boost volume level on downmix : On
Dolby Digital (AC3) capable... : On
DTS Capable Receiver : On
Audio Output Device : Default Output Device
Guisettings.xml : http://fergus.pastebin.com/PcfhanRQ

Logs

MediaInfo : http://fergus.pastebin.com/uFENmpKT
Debug Log : http://fergus.pastebin.com/ukFMtGyy


Finally, I really should say just how much I appreciate all the work that's been done to date by the team. Even without my 5.1 sound, it's phenomenal to see my tiny ATV2 running XBMC. Thank you!

[keith]

Description of Fault

Playing 5.1 Dolby Digital media with AC3 Passthrough enabled results in no audio. The amplifier emits a brief burst of static and incorrectly displays "[Dolby Digital 2/0]" on its front panel, but does not then emit any further sound. Manually switching the amplifier to another source and then back to the Apple TV optical input (whilst the media is already playing) results in the amplifier panel correctly displaying "[Dolby Digital 3/2]", but again does not emit any sound.

I'm guessing that TRAC isn't open to ATV2 tickets just yet, so I've captured as much relevant info as I can think of below. Give me a shout if there's anything else I can add/try to assist troubleshooting this one.

I'm not sure about trac, but I'll ask. Thank you for the detailed report! I wish I knew why. I will try to bring this post up to someones attention and see if anyone has any ideas.

Just out of curiousity, do you have Extract Thumbnails under System > Video > File Lists disabled?

and try this:
http://forum.xbmc.org/showpost.php?p=714...stcount=92

[Fergus]

Meshuga - Thanks for your help on this, really do appreciate the efforts of everyone who's helping here!

Just out of curiousity, do you have Extract Thumbnails under System > Video > File Lists disabled?

I have experimented with this, but can't be 100% that I left the setting 'disabled' when capturing the logs yesterday. I'll double-check this evening and post back.

and try this:
http://forum.xbmc.org/showpost.php?p=714...stcount=92

I have tried that previously without success;

http://forum.xbmc.org/showpost.php?p=715...tcount=104

Again, many thanks!

[Fergus]

I have experimented with this, but can't be 100% that I left the setting 'disabled' when capturing the logs yesterday. I'll double-check this evening and post back.

Thumb extraction was indeed enabled in the original xbmc.log, so I ran through the test again this evening with the setting disabled.

The AC3 problem still exists, exactly as before. For completeness, I've attached a fresh log to show the behaviour with thumb extraction disabled;

http://fergus.pastebin.com/V8BduMMn

[keith]

Thumb extraction was indeed enabled in the original xbmc.log, so I ran through the test again this evening with the setting disabled.

The AC3 problem still exists, exactly as before. For completeness, I've attached a fresh log to show the behaviour with thumb extraction disabled;

http://fergus.pastebin.com/V8BduMMn

Someone mentioned having a problem with FrontRow being set to 'On' for digital audio instead of 'Auto'.

[Fergus]

Someone mentioned having a problem with FrontRow being set to 'On' for digital audio instead of 'Auto'.

Didn't recognise you by your new name at first there Keith! Thanks for the tip, I'll give that one a go this evening and report back my findings.

[Fergus]

Sneaked home at lunch time, and found that FrontRow already had Digital Audio set to 'Auto'. I toggled it back and forth between 'Auto' and 'On', but neither setting made a difference to the behaviour witnessed to date.

[keith]

Have you verified audio works fine under FrontRow with optical?

[Fergus]

Have you verified audio works fine under FrontRow with optical?

Fair shout, but no joy yet!

I tried playing the Holophone 5.1 podcast through FrontRow, and found that it was downmixing. I changed the FrontRow DigitalAudio option from "Auto" to "On", and then found that the Podcast played properly with 5.1 pass through; the led read "[Dolby Digital 3/2]" and the big blue light on the front of my amp lit right up!

I then went back into XBMC (with AC3 capabable Amp enabled) and received the silent treatment and incorrect "[Dolby Digital 2/0] display on the led when I replayed the film from the debug and media info example.

[andersaloof]

Just wanna bump this thread as I recently experienced this myself. Did you have any luck with this Fergus?

I just moved my ATV2 with a nighly Eden build from the end of november to my theater room where I have a Sony STR-DB920 receiver (the previous version of the DB930 receiver with fewer digital audio inputs) and I have the exact same problem.

When using the same settings in XBMCs audio setup as you described, I get the [Dolby Digital 2/0] display and no audio. If I disable AC3 support, the audio is downmixed to 2.0 stereo and played. It does not matter if I go to the ATV2 setup and switch between 16bit and auto etc, as I've seen suggested elsewhere on the forum.

I did find a related post on the Plex forums (http://forums.plexapp.com/index.php/topi...t__p__6808) suggesting it's the lack of a bitstream flag in the audio stream that causes older receivers not to recognize the signal.

As a sidenote, DTS audio works flawless.

[mgc_bb]

Hi guys,

Plus one for this issue please.
My amp is on old Sony STR-DB940 receiver from around 2003

DTS plays perfectly but AC3 is silent, the strange thing is the amp does actually show DD5.1 on the display so something is getting through, just no sound at all.
Been using this amp for a long time now, not had any issues before, worked fine with my pc based xbmc setup (gone nas now).

Read all posts regarding the fault and tried removing the audio output part of the setting xml file and re entering to coax 5.1 tick tick etc but no joy. Set to 16bit in atv settings.

Got two ATV2's and neither work on the amp, yet as I say DTS is perfect.

Would love to resolve this as a lot of the old movies do not a DTS soundtrack.

[Ned Scott]

always. read. the FAQ first.

http://wiki.xbmc.org/index.php?title=XBM...AQ#NoSound

[mgc_bb]

Hi Ned, yeah did check it out and none of it solved the problem.

This is the only thing I cant get working myself.

Everything else is running nicely, no buffering issues, mysql using three profiles with remote thumbnails no problems, just cant get the AC3 working.

I guess it just must may be my amp then?

[andersaloof]

This is my experience also. I've searched the forums, read the FAQ and tried every suggestion I see, but with no luck. Seems to be related to the Sony receivers as we all have variations of the same receiver.

But still, if I try to play a movie which fails to play AC3 sound on ATV2, with XBMC on my HTPC instead, connected to the same receiver (through coax instead of optical) I get full AC3 sound.

Is there any other media players I can install on the ATV2 to test AC3 with?

[Ned Scott]

I'll search around and see if "virigin" atv2s are also having this issue. If so, it might provide some ideas for work arounds.