2011-01-26, 11:15
Hey guys,
I was wondering if someone more knowledgeable than me could enlighten me on what happens inside XBMC when multi-channel audio is getting down-mixed.
My situation is the following, I have a pretty high-end headphone system, which consist of a digital to analog converter (DAC), a headphone amplifier and a pair of headphone, the "problem" is that this setup is obviously stereo only, so there's no way for me to decode Dolby Digital or DTS. I saw that XBMC has the option to specify if the user owns a receiver capable of decoding digital format and If so I guess XBMC would just bitstream the audio track and let the receiver handling the decoding.
I messed a bit with the setup options, it seems the only thing working is to select the output as "analog" and set the speakers to 2.0 channel, in that case I get 2 channels LPCM, there's obviously a down-mix happening when XBMC is decoding the audio track, otherwise I would only hear right/left channel but I do get the whole multi-channel audio track, with dialogues (center channel) and surround effects.
So my question what is happening inside XBMC when it's down-mixing 7.1/5.1 audio track to a 2.0 stereo track, is it a proprietary codec? is purely channel mapping and the missing channels are simply redirected to left or right? Or is there some kind of algorithm running in the background that's simulating multi-channel audio on a stereo setups using crossfeeds, delays and such?
Any inputs would be greatly appreciated.
Cheers
I was wondering if someone more knowledgeable than me could enlighten me on what happens inside XBMC when multi-channel audio is getting down-mixed.
My situation is the following, I have a pretty high-end headphone system, which consist of a digital to analog converter (DAC), a headphone amplifier and a pair of headphone, the "problem" is that this setup is obviously stereo only, so there's no way for me to decode Dolby Digital or DTS. I saw that XBMC has the option to specify if the user owns a receiver capable of decoding digital format and If so I guess XBMC would just bitstream the audio track and let the receiver handling the decoding.
I messed a bit with the setup options, it seems the only thing working is to select the output as "analog" and set the speakers to 2.0 channel, in that case I get 2 channels LPCM, there's obviously a down-mix happening when XBMC is decoding the audio track, otherwise I would only hear right/left channel but I do get the whole multi-channel audio track, with dialogues (center channel) and surround effects.
So my question what is happening inside XBMC when it's down-mixing 7.1/5.1 audio track to a 2.0 stereo track, is it a proprietary codec? is purely channel mapping and the missing channels are simply redirected to left or right? Or is there some kind of algorithm running in the background that's simulating multi-channel audio on a stereo setups using crossfeeds, delays and such?
Any inputs would be greatly appreciated.
Cheers
