AC3 Problems
#16
I completely understand that i am outputting stereo audio

if downmixing is happening its not through XBMC because the option is unchecked

AAC 5.1 plays fine without downmixing enabled (im guessing its handled by Apple's Core audio http://developer.apple.com/technologies/...video.html)

AC3 isn't handled by Apples core audio

so what i really want to know is, if there a way of telling XBMC which codecs to downmix and which to leave alone so it doesnt downmix every 5.1 source, only the ones Apple's Core Audio doesn't

i hope you understand what i'm asking now
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#17
There is no way to do what you want XBMC uses its own libraries to process decoding and ignore other OS features entirely including core audio

It would help if you tell me which version of XBMC you are on.
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#18
I'm using Camelot

although i've used the most recent build (28256 from the XBMC website) i reverted back because my skin works better on Camelot

XBMC cant completely ignore the os features because Mac users can hear AAC 5.1 fine without downmixing whereas windows users seem to have difficulty
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#19
Not my intention to muddy the waters so to speak, but the posts intrigued me due to a problem I had yesterday. I have an Onkyo digital receiver that supports all the formats. Yesterday I backed up a hddvd copy of batman begins using eac3 audio format. When I play through XBMC (digital, hdmi on my revo) all I hear is background sounds. However when I mix to AC3 using Hdbrstreamextractor it plays fine. This is not a comprehensive test by no means, but it appears that eac3 does not work. Would be interested to know if this is the same audio format that others are having problems with.
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#20
mungki Wrote:I'm using Camelot

although i've used the most recent build (28256 from the XBMC website) i reverted back because my skin works better on Camelot

XBMC cant completely ignore the os features because Mac users can hear AAC 5.1 fine without downmixing whereas windows users seem to have difficulty

I have XBMC on a windows PC playing fine AAC 5.1 downmixed to stereo with build 28256

As such you can actually play AC3 files so indeed you have no problem playing those, the issue you have is with AAC downmix, as far as I remember that was only working properly through HDMI and not through optical/spdif
I would suggest you to try with the 28256 as the core audio within XBMC has completely been rewritten and set it to analogue audio, I have this configuration exactly like yours and AAC 5.1 play just fine though a bit low volume overall
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#21
Galactus Wrote:Not my intention to muddy the waters so to speak, but the posts intrigued me due to a problem I had yesterday. I have an Onkyo digital receiver that supports all the formats. Yesterday I backed up a hddvd copy of batman begins using eac3 audio format. When I play through XBMC (digital, hdmi on my revo) all I hear is background sounds. However when I mix to AC3 using Hdbrstreamextractor it plays fine. This is not a comprehensive test by no means, but it appears that eac3 does not work. Would be interested to know if this is the same audio format that others are having problems with.

XBMC should support dolby digital plus eac3 but I do not have a compatible decoder so I do not how to help you
Do you connect with optical or HDMI?
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#22
You Don't seem to be listening to me

mungki Wrote:although i've used the most recent build (28256 from the XBMC website)
interceptor121 Wrote:I would suggest you to try with the 28256
and again...
mungki Wrote:Mac users can hear AAC 5.1 fine without downmixing
interceptor121 Wrote:I have XBMC on a windows PC playing fine AAC 5.1 downmixed to stereo
and again...
interceptor121 Wrote:AAC 5.1 play just fine though a bit low volume overall
mungki Wrote:when downmixing is on the levels are are terrible on AAC 5.1 films you can hardly hear whats being said

I Just wanted to know if you could only downmix AC3 and nothing else
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#23
I replied already NO that is not possible

You seem not to understand that one way or another you are already downmixing because obviously you have two speakers not 6
Furthermore you do not understand as well that XBMC is playing fine AC3 in what should be your normal set up (analogue or digital downmixed (PCM)) and is actually not playing correctly AAC in the same set up as it does with AC3

So in short:
1. there is no possibility to do what you ask because those are system settings that are driven by the receiver capability - in your case NONE as you have analogue jack and a TV
2. You are looking into the wrong place for the solution of your problem because AC3 works
3. There are other people that play fine AAC,AC3,DTS with your same set up you seem to be obliviant to suggestions
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#24
I have a similar issue. I have a 5.1 setup using a receiver and connecting my htpc to my receiver through HDMI. In xbmc I set to Digital output but what I am noticing that sounds effects appear to be louder than vocals in action scenes and it doesnt seem to be balanced.

I have already played around with my speaker levels and that doesnt seem to help so I am starting to think its the way XBMC is handling the stream or a setting that I am missing.
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#25
I read through the many posts this morning and it appears I am not the only one having problems with surround sound playback in XBMC. It could be my lack of knowledge with the correct set-up as some claim they have no problems. I would really appreciate some positive feedback or assistance. I am not here for controversy but for assistance from positive people. I did not enjoy reading through the argument by two individuals on this thread.

Okay, having said that here is some back-story. I am running the latest ATVFlash on AppleTV and using XBMC within that environment. Everything is up to date and I am running the latest AppleTV, latest ATVFlash and latest XBMC. I have installed a Crystal HD graphics card and am enjoying 720p and 1080p playback on my AppleTV through XBMC finally. I realize the 1080p files are scaled to 720p currently but playback is good and quality is excellent. I've found the XBMC members to be very responsive and helpful to date, and I have given a donation in recognition of the help they have provided me. I am an average person needing some help. I am not an engineer.

My AppleTV is connected to a Yamaha receiver via HDMI. Movies with surround sound of any kind will play fine through Sapphire or Nito TV on my Apple TV but when I go to the XBMC environment the surround sound will not usually play. DTS surround seems to be the exception and I get proper surround playback.

Recently a member asked me to read the manual and I did go through the manual and believe that I am setting the audio environment correctly. I have experimented with various settings first starting in Nito TV or Sapphire with a file to confirm the audio is playing all surround tracks. I then Move to XBMC to discover that I only have stereo audio. I enter the system audio area and have tried the following:

Setting the output to digital out and selecting the various receiver outs one at a time in hopes I can find the output which matches my movie files. I receive either no sound or stereo depending on which format I select. I have tried analog out as I do have analog cables running to my receiver as well as a back-up. I thought maybe my receiver could decode the information from the stereo pair through pro logic or something. I have also tried mixing audio down to two channels.

I have tried turning on all possible digital modes out and then I get crazy noise on the output, obviously this is the wrong choice. Anyway, it's obvious I could use some assistance with this as the audio is resident in the files but I simply do not understand how to set up XBMC to extract these audio channels properly. I want to use XBMC because it's the only application capable of playing my 720 and 1080 HQ files without stuttering.

Positive help appreciated.

Thanks,

Jack Tunnicliffe
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#26
I just opened the movie files in question on my Mac and here's how they look in QT Player. The stereo audio channels are AAC. If you go into movie properties the Dolby channels show up in the inspector as Dolby AC3 files. The AAC files are checked and the dolby AC3 channels are not checked yet the surround plays in Nito TV and Sapphire but no XBMC. Do these other applications override the QT checks? I tried checking AC3 in properties and closing the movie but QT wants to re-write the entire file to save this property change and eventually freezes up.

The MKV files have DTS and do play the surround through in XBMC on AppleTV. Again when checking their properties on a Mac laptop and not on AppleTV the DTS is checked or turned on in QT. So, have I discovered something useful for the developers or am I just missing something in XBMC?

Thanks, hope this additional information helps.

Jack Tunnicliffe
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#27
Videos encoded for appletv should have a default two channel AAC track and a second AC3 track (the ATV does not support DTS only XBMC does)
When you play those files the ATV will select the AAC track or AC3 depending on the receiver detected on the digital output
To hear AC3 in XBMC you will need to call the OSD and select audio and from there select the second track otherwise XBMC will only play two channels AAC
In any case the two channel AAC is usually a Dolby Pro Logic so you still hear all the channels with a compatible decoder
The reason why quicktimes are encoded like this is so that they can be played on any Apple device even without a dolby digital decoder
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#28
Interceptor... this is excellent information. I noticed the OSD when reading through the manual recently and wondered if there wasn't some functionality that I was missing. I have never seen the OSD so just went to the manual again and it says it is available as part of the PM3.HD skin, so I'm going to go looking to see if I can find that skin. Hopefully I will find it and find the OSD. Thanks again.

Jack
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#29
Interceptor... many thanks. After literally months of not being able to resolve this or get it to work my surround sound is now working perfectly. Here's the odd thing. I could see the OSD in the manual but couldn't figure out how to access it. I looked through the manual but couldn't see how to get it to show. I have XBMC configured for the AppleTV remote so I should be able to get it there. I tried ever combination of controls and then finally I did a google search and found the info where someone else had the exact same question. The answer for anyone else following this thread is to hold down the pause/play key for a few seconds and the OSD appears. Now I can select my audio channels get into the video adjustments and finally turn subtitles on and off without leaving the movie. Fantastic! Thanks again.
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#30
Okay, the only thing I don't seem to be able to deal with now is AAC 5.1 files. I do not seem to be able to find a setting to play these in XBMC. Nito TV will only play the stereo channels and not surround.

I tried re-encoding through handbrake moving the AAC audio to AC3 but this didn't work, either. I ended up with an AC3 stereo pair of audio channels. Anyone with any thoughts on this?
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