AAC 5.1 downmix to stereo
#1
While playing movies...

Downmixing from AC3 to analog stereo is working fine for me. But from AAC, I get background sounds and VERY low volume dialogs. I tested it using mplayer by itself and it works fine. The problem seem to be when XBMC calls mplayer.

I appreciate any help you can give me.
Regards.

Ubuntu 10.04
xbmc installed last friday from stable ppa.
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#2
Please read: http://forum.xbmc.org/showthread.php?tid=34655
Thanks.
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#3
I read the link and this is a rewriting of my last message.

I have 2 movies coded with AAC 5.1 that are played fine using mplayer by itself. That is: both are downmixed correctly to analog stereo, so you can hear dialogs clearly. However, when playing those movies inside XBMC, just ambiance sound are reproduced, and dialog are either at a VERY low volume (almost inaudible), or just not able to hear them at all.

This behavior is reproduced every time I tested it.

First movie (1080)
This is the mediainfo: http://pastebin.com/K1s9vwQA
This is the mplayer log: http://pastebin.com/Pe2Siz05
This is the XBMC log: http://pastebin.com/VNkkNrED

Second movie (1440)
This is the mediainfo: http://pastebin.com/de8iz8CD
This is the mplayer log: http://pastebin.com/d1Hmjjr6
This is the XBMC log: http://pastebin.com/0W34GuCd

After a simple check of the logs, my UNeducated guess is that XBMC is failing in open libfaad (from xbmc.log):

>DEBUG: FactoryCodec - Audio: passthrough - Failed
>DEBUG: FactoryCodec - Audio: libfaad - Opening
>DEBUG: Loading: libfaad.so.0
>ERROR: Unable to load libfaad.so.0, reason: libfaad.so.0: cannot open shared object file: No such file or directory
>DEBUG: Dll libfaad.so.0 was not found in path
>DEBUG: FactoryCodec - Audio: libfaad - Failed

While mplayer by other hand seems to have no problem to open it (from mplayer log):

>==========================================================================
>Opening audio decoder: [faad] AAC (MPEG2/4 Advanced Audio Coding)
>AUDIO: 48000 Hz, 2 ch, s16le, 128.0 kbit/8.33% (ratio: 16000->192000)
>Selected audio codec: [faad] afm: faad (FAAD AAC (MPEG-2/MPEG-4 Audio))
>==========================================================================
>AO: [pulse] 48000Hz 2ch s16le (2 bytes per sample)

Additional information:

Hardware
Dell Dimension E520
Pentium D (2 cores), 4Gb RAM.
Geforce 9500 GT 1Gb internal RAM

OS and drivers
Ubuntu Desktop Edition 10.04 (i386)
last update: 8/20/2010
$ uname -a
Linux vaughan 2.6.32-24-generic-pae #41-Ubuntu SMP Thu Aug 19 02:43:57 UTC 2010 i686 GNU/Linux
Nvidia driver 195.36.24

XBMC
$ dpkg -l xbmc
ii xbmc 1:9.11-lucid3 XBMC Media Center (full metapackage)

XBMC 9.11 R26018 (compiled: Aug 19 2010)
Installed from ppa:team-xbmc, following instructions from xbmc wiki.
Skin: Confluence (no other skin installed).
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#4
Well, seems ubuntu doesn't carry that version of libfaad anymore, and the 9.11 release doesn't downmix when using ffmpeg.

You can upgrade to the dharma branch or you can set up a custom alsa device that does the downmixing for you.
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#5
check out the thread about getting hdmi audio

http://forum.xbmc.org/showthread.php?p=5...post587495

I was having similar problem with AAC and now I have it working like a dream

it was the two wget lines of code that did it for me



-=Jason=-
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#6
@bobo1on1:
Quote:...set up a custom alsa device...
Do you mean one of those custom asound.conf files?
Quote:...upgrade to the dharma branch...
Is that the ppa:team-xbmc-svn ?

@Flomaster: I'm reading that thread (30+ pages!)

Thanks in advance.
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#7
The svn ppa currently contains Dharma builds, you can use that.
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#8
It took me sometime to research this issue. Let me see if I understand.

The xbmc package version 1:9.11-lucid3 that is available at ppa:team-xbmc, was created especially for Ubuntu 10.04 Lucid Lynx (thus the name).

But according to the logs presented before, it was built using libfaad0. However, this library is not part of Lucid. Ubuntu 10.04 uses libfaad2.

Am I correct? If so, my conclusion is that the package 1:9.11-lucid3 has not been properly built.

Am I missing something?
Regards.

BTW, libfaad0 is a library found in previous versions of Ubuntu like 9.04 Jaunty, and 9.10 Karmic.
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