5.1 to Dolby Surround with foobar2000?

2004-04-19 12:19:51

foobar2000 has a dsp-effect called "Convert 5.1 to stereo". But is there any way to downmix 5.1 to dolby surround or pro-logic II?

5.1 to Dolby Surround with foobar2000?

Reply #1 – 2004-04-19 18:45:56

I don't know enough about Dolby Surround or ProLogic to do this, sorry. 5.1->2 is rather straightforward.

5.1 to Dolby Surround with foobar2000?

Reply #2 – 2004-04-19 19:12:03

OK, thank you.
But how downmixes the "Convert 5.1 to stero"-Function? I'm right to think it downmixes the lfe-, center- and surround-channels into the front channels or does it just "deletes" them?

5.1 to Dolby Surround with foobar2000?

Reply #3 – 2004-04-19 20:02:55

down - 5.1 channels to something lower
mix - mixing of channels into others

hence.. 5.1 downmix to stereo will combine all the channels to get the stereo output!

5.1 to Dolby Surround with foobar2000?

Reply #4 – 2004-04-19 20:58:11

For DS/PL:
L'=L + LFE - SL - SR + C/sqrt(2)
R'=R + LFE + SL + SR+ C/sqrt(2)

For DPL2:
L'=L + LFE + C/sqrt(2) - SL*sqrt(3)/2 - SR/2
R'=R + LFE + C/sqrt(2) + SL/2 + SR*sqrt(3)/2

Hope this helps.

5.1 to Dolby Surround with foobar2000?

Reply #5 – 2004-04-19 23:11:10

OK, but my question was: does the "convert 5.1 to stereo"-function (it isn't named "downmix 5.1 to stero" at least) make a real downmix or does it just "deletes" the other 4 channels?

5.1 to Dolby Surround with foobar2000?

Reply #6 – 2004-04-20 07:26:37

It does a full downmix (not deleting anything).

5.1 to Dolby Surround with foobar2000?

Reply #7 – 2004-04-20 07:27:48

Quote

Hope this helps.

Thanks very much!

5.1 to Dolby Surround with foobar2000?

Reply #8 – 2004-04-20 08:36:30

Please test

http://sjeng.org/ftp/fb2k/foo_dsp_extra.dll

5.1 to Dolby Surround with foobar2000?

Reply #9 – 2004-04-20 10:54:02

Thank you!
I can't test it, 'cos my soundcard is broken (i use the 2ch-soundchip atm). But i hope there's another one who tests it, and tell us about it's functionality.

But there's another question:
Is it possible to disable the build-in AC3 decoder and configure foobar to use the AC3Filter0.70b, 'cos it has an build-in-option to downmix to dolby surround/pro logic?

Btw: If the foo_dsp_extra.dll works like it should, don't take notice of the last question.

5.1 to Dolby Surround with foobar2000?

Reply #10 – 2004-04-20 11:02:46

Why does always people request 5.1 sound, and noone requests 6.1 and 7.1 :S

5.1 to Dolby Surround with foobar2000?

Reply #11 – 2004-04-20 11:11:58

I never had a 6.1 or 7.1-Audio until now and i think the most user's had the same, so it maybe not so necessary atm.

5.1 to Dolby Surround with foobar2000?

Reply #12 – 2004-04-20 11:37:52

wonder why someone hasn't made a 2.1 to 5.1/6.1/7.1 upmixing plugin...

5.1 to Dolby Surround with foobar2000?

Reply #13 – 2004-04-20 11:41:58

@SafirXP
That should have been my next question 
A Plugin which upmixes 2ch (or 2.1/DS/DPL) to 5.1ch would make foobar2000 to the allroundtool i've ever searched for.

Btw: If there is any possibility to use the AC3Filter0.70b, then there would be an upmix-function for AC3-2.0 to 5.1 available...

5.1 to Dolby Surround with foobar2000?

Reply #14 – 2004-04-20 18:13:25

Upmixing (that gives a good effect and doesn't just duplicate channels) is very hard to do well.

A simple upmixer would be easy, there's already stereo to 4 channels for example.

5.1 to Dolby Surround with foobar2000?

Reply #15 – 2004-04-21 02:59:59

Upmixing is simply the process of decoding DS or DPL2, downmixing is encoding to DS or DPL2. You can google around for the decoding routine, or you can invert the matrix yourself to get the transform. Apply a LPF to C to get LFE. I think you need to add a delay to SL and SR too.

5.1 to Dolby Surround with foobar2000?

Reply #16 – 2004-04-21 03:12:30

since its that easy to make... why can't anyone take on this project?  i would if i could... but don't know jack about it!

5.1 to Dolby Surround with foobar2000?

Reply #17 – 2004-04-21 08:15:24

I'll see what I can do.

5.1 to Dolby Surround with foobar2000?

Reply #18 – 2004-04-21 12:11:43

@Garf
I think you made a good job with the foo_dsp_extra.dll 
I converted a 5.1-AC3 to Dolby Surround-HE-AAC and played it with the MPC and Matrix Mixer ('cos it shows the splitting of the channels). It isn't recognized as Dolby Surround, but if i upmixed it to 5.1, the channels were separated properly (other than stereo sources).
But notice: It is just according to the level meters of Matrix Mixer. I can't test it with my own ears because of my broken soundcard...
Now i'm very curious about an (maybe yours?) upmix-plugin

5.1 to Dolby Surround with foobar2000?

Reply #19 – 2004-04-27 12:17:46

I am seeking for a way, and I hope that it will be become possible soon (humble feature request) that I can burn with foobar DTS and/or AC3 cd's; witch i can play at my reciever downstairs. Sofar as i know there is not any program wich support this - at a simple manner anway.

It should not be that difficult because:
1. foobar can play ac3 (and other) files already.
2. It has multiple diskwriter, audiocd and nero/burn support.
3. if it has to be - aid can be called uppon besweet/besure (doom9)
4. but foobar has already dll to downsample and so forth already.
5. If I am not mistaken: ac3-files (-->DD-wav?) burn 'as is' onto cd.

In short is my question:
Is it already and how then, possible to burn digital surround cd's with foobar? (DolbyDigital and or DTS)

If not: please consider this as a humble  feature request.