cant get downmix 5.1 source into stereo (1 Viewer)

[lanceuppercu]

MediaPortal Version: 1.2 beta
MediaPortal Skin: StreamedMP 1.6.6.2799 Beta
Windows Version: XP SP3
CPU Type: Intel Atom Dual Core 330 1.6GHz
HDD: Kingston 16Gb SSD
Memory: 2Gb
Video Card: NVidia ION
Video Card Driver: v195.62
Sound Card: NVidia ION
Sound Card AC3: ac3filter
Sound Card Driver: 1.00.00.59
MPEG2 Video Codec: ffdshow tryout beta7
MPEG2 Audio Codec: ffdshow tryout beta7
h.264 Video Codec: CoreAVC
TV: LG 47LF7700
TV - HTPC Connection: HDMI

building a htpc for my mate, same setup as i have except i go via a amp (5.1) but his goes straight to the tv, so only stereo.

anything with a stereo sources seem to play fine in MP, but anything 5.1, the center channel is really quiet like its not downmixing the audio to work in 2.0, it used to work before, cant find what im missing to make this work again.

however the same movie in MPC-HC or WMP11 plays (/downmixes) with out any issue. what am i missing here?

 

[Sarlan19]

Up.

I have the same problem here.

Did u manage to make it work ??

Sarlan19

 

[mm1352000]

Hi Sarlan19

What format is the audio in - AAC, AC3, MPEG???

mm

 

[Sarlan19]

Hi,

sorry for the long reply had to work.... It's a shame

My audio format is usually DTS 5.1 or DD 5.1. I'm decoding it with ffdshow and I manage last night to have some control via the "mixer" option in the ffdshow audio configuration but I can't seem to find decent settings that will keep voice nice and clear and the surround (action sequence, music) not so loud.

My soundcard goes to a stereo amp (not an AV) Music is great, but volume are all over the place in movies. I guess I'll need an AV and 5.1 speakers and a didicated room for Media to get rid of the problem

Sarlan19

 

[mm1352000]

Hi again Sarlan19

In 5.1, most of the voice will be in the center channel, so I recommend you do the matrix like this:

stereo left = 5.1 center + 5.1 left [front] + 5.1 left side
stereo right = 5.1 center + 5.1 right [front] + 5.1 right side

mm

 

[Owlsroost]

A couple bits of info re. the FFDShow mixer matrix - the numbers are floating point, and can be negative (this inverts the phase of the signal, which can be useful for modifying stereo image width etc - anti-phase L/R crosstalk widens it, in-phase crosstalk narrows it)

Tony

 

[Sarlan19]

Thanks for the replies guys !

That matrix in FFdshow is way over my league floating point ? I understand that crosstalk is when sound for the right speaker bleeds to the left or vice versa, am I right ?

so how do I setup that matrix so that it downmix like mm1352000 suggest ??

thanks again, I'm new to that whole forum stuff and I find it amazing !

Sarlan

 

[Owlsroost]

See the attached image (which should handle 7.1 as well)

Tony

 

[mm1352000]

...and just to answer the questions...

floating point ?

It is just a number with a decimal point like 0.123. Tony has shown you an example using only 1.0 as the values - the columns are the inputs and the rows are the outputs. Each 1 means that the input channel (the column) is mixed into the output channel (the row) at full volume. If you wanted to have less of the surround channels then you might do something like the attached matrix. You have complete control over the mixture that way.

I understand that crosstalk is when sound for the right speaker bleeds to the left or vice versa, am I right ?

Yes.

mm

 

[Sarlan19]

Thanks Guys,

I will fiddle around with those info as soon as i can take back control of my htpc ( friends are staying over)....
But at least now I understand.... which is a great feeling ;-)

The images were a great help

I'll report back