Problems with passthrough EAC3 Audio
#1
Hi,

i have problems getting eac3/dd+ passthrough form HD-DVDs to work.

My setup:

xbmc 9.11 beta
ubuntu 9.10

Intel OnBoard Audio (Bios set to HDMI) -> spidf -> nvidia GeForce 9500 -> HDMI -> AVR DENON 1910

Settings: Digitial Audio, AVR supports DTS and DD, Stereo downmix off, passthrough on.

Devices:
I can select between HDMI and iec958. When i select HDMI i always get the warning that the audi device could not be opened - and i get no sound.

When i select iec958 and play DTS or DD my AVR displays DTS or DD and i get nice 5.1 sound.

If i try to play DD+ (eac3 640kbit says eac3to) the avr displays stereo and i can listen to the effect channels (no speach etc.)

When i select stereo downmix i get a nice and clean stereo downmix.

aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: Intel [HDA Intel], device 0: ALC1200 Analog [ALC1200 Analog]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 0: Intel [HDA Intel], device 1: ALC1200 Digital [ALC1200 Digital]
Subdevices: 1/1
Subdevice #0: subdevice #0

Is the spidf connection the problem? I connected the onboard 2-wire cable directly to the GeForce.

Thx for any help

Martin
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#2
Could this be introduced with one of the latest xbmc versions?

How can i revert back to an old one to test this?

Martin
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#3
mbosner,

Linux does not have the ability to bitstream Dolby Digital +, Dolby TrueHD, or any of the DTS-HD flavors. As a result of Linux being unable to bitstream these "HD" audio codecs XBMC is unable to do so as well. XBMC can decode some HD audio streams but they will then have to be passed to your receiver as a Multi-Channel LPCM stream. However, this is not possible without an INTEGRATED Nvidia Video Card. If you are interested in learning more about this check out this thread http://forum.xbmc.org/showthread.php?tid=59877

Sincerely,
Will
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#4
Hi Bahndit,

that doesnt seem to be the problem. In fact one of the movies worked fine 3 weeks ago (i just recognized that - OCEAN´s 11 was the movie). I am not talking about DD HD or DTS HD - but just plain DD+ which is, in my case, a pretty simple 640kbit 5.1 eac3 stream.

With one of the later alphas or beta it seems to stop working.

Only system changes were regular ubuntu-9.10 updates and xbmc updates.

thx
Martin
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#5
Bahndit Wrote:mbosner,
Linux does not have the ability to bitstream Dolby Digital + ...
http://forum.xbmc.org/images/icons/icon9.gif
---However, this is not possible without an INTEGRATED Nvidia Video Card. If you are interested in learning more about this check out this thread http://forum.xbmc.org/showthread.php?tid=59877

I bought a GeForce 210 just to figure out that its not yet supported.

Shouldnt Linux be able to passthrough a 640kbit eac3 audio stream via any spidf ? It does work fine with my 640kbit ac3 audio streams - and i am pretty sure that it worked 3 weeks ago.

Martin
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#6
This is expected behaviour - you can't pass DD+ over spdif.
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#7
prae5 Wrote:This is expected behaviour - you can't pass DD+ over spdif.

Even if i set spidf mode in BIOS to HDMI?

I read all the other threads about this - and most are about LPCM etc.

May i ask why that doesnt work? Remember my spidf is connected to my GeForce.

I thought as long as the bitrate is below 1512kbit it should be possible.

---------

Okay i have reread http://en.wikipedia.org/wiki/Dolby_Digital_Plus

Is it possible to remix it on the fly to something else then 2.0 Stereo?

Martin
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#8
It makes no difference if it is connected to your graphics card - it is still passing it via spdif - your graphics card then passes the signal via hdmi. In essence though, you are using spdif and are limited to its capabilities.

You need to transcode the stream (as per your link). There is no (easy) way i know of doing this.

You might be able to setup something with alsa.
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#9
Thanks for the fast answers.


Okay so i need a new GeForce with onboard full hdmi support. I already have a GeForce 9500GT and it doesnt seem to support that. Any suggestions for such a card?

Martin
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#10
You will need something like a G210 which has a built in audio chip. However, drivers for these were a little flakey last time i looked at them - suspect this has been resolved by now though.
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#11
Okay i will look for a solution for this - any start points?

All known threads i am aware of do not have any solutions :/
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