Upconverting Stereo sound to Surround 5.1 or higher?

rabcor · 2013-10-29 04:45:09

Does something of the sort exist for linux? I'm just having a hard time living without the "CMSS-3D" feature of the windows soundblaster drivers. They also have an alternative called DTS:Connect which includes DTS:Neo PC (which i could use) and DTS:Interactive, is there any way to utilize those functions of my card?

Creative's Crystalizer and Sound Volume Management i can live without in fact i can live without everything except equalizer and Stereo to Surround conversion, it's the latter i'm having a hard time finding on linux, do you know any solution to this problem?

Last edited by rabcor (2013-11-03 17:18:41)

brebs · 2013-10-29 12:48:50

See ALSA config in my sig - "upmix_20to51"

Do you want an additional effect/distortion?

rabcor · 2013-10-29 17:04:30

That's one useful sig you've got there , Thanks!

Right now i'm just focusing on converting stereo sound into 5.1, i'll need to play a bit with the config file (since i have very rarely configured it) to test that function though so i don't know yet if i need any additional effects or distortion, but it would be nice to know about which ones are available, i quite like tweaking my sound to perfection, thats why i even have a soundblaster card to begin with.

Quoting Wikipedia on an effect that i do like to use (Crystalizer, but as i said before i don't think it's something really important to me)

Creative Labs states that the primary function of the Crystalizer is to "restore portions of the sound which were lost during compression". The "compression" that is meant here is not the digital file-size reduction achieved by digital audio data compression technologies like for example mp3. Rather, the idea is to reverse the effects of dynamic range compression, an analog technique that was and is used during the production of most 1990s and newer Audio CDs (with the exception of some classical music recordings) to make them sound louder at the same volume level setting, as it was found that subjectively louder CDs get more airplay and sell better. To achieve this loudness without introducing strong distortion, points in the signal where the volume reaches a maximum are compressed (which means in this case: reduced in volume), then the whole signal is multiplied by a factor so that the maximum volume is reached again. After this, the music as a whole is louder than it was before, but the maximum volume points (mostly transients) are not as pronounced as they were before. Since this whole process is done before the final Audio CD is recorded, its effect is equally present in uncompressed audio files created from such a CD, in lossless compressed audio made from the CD, as well as in lossy compressed audio from that same CD. Transients are typically found in percussive sounds, in plosive consonants of voice recordings, and during the first few milliseconds (the so called attack phase) of non-percussive instrument sounds. All these tend to be somewhat muffled by dynamic range compression.
To undo this effect, the Crystalizer uses a multiband compander (compressor/expander) with dynamically adjusted compression/expansion. Its main function is to detect transients and to increase their relative volume level. As a consequence of enabling the Crystalizer, the signal is altered, and whether the result improves upon the input audio is purely a matter of perception and can depend on the type of audio being played.

Last edited by rabcor (2013-10-29 21:37:47)

defears · 2013-10-29 23:15:10

Audacious is the only player I know that has a Crystalizer effect. If you install swh-plugins and ladspa plugins there are a lot of high/low pass and compression type effects also.

rabcor · 2013-11-03 05:37:44

Allright, i'm trying to understand what's going on in this config file, but me and asound.conf or .asoundrc just seem to hate each other, i'm terrible at configuring this specific file and struggle just to make options that work, making something for a specific purpose is a bit much of an undertaking for me at this point. Makes configuring my wireless network feel like it's a breeze! so i'd appreciate some guidance.

I'd like to just copy the config file from you Brebs, since it looks like you know what you're doing and from what i can understand it includes most of the stuff i would ever possibly need.

But how do i set the system to upmix all stereo sources to 5.1 and downmix all things higher than 5.1 down to 5.1 by default assuming i'm just using the config file provided in Brebs's sig?

Edit:

I figured out to change the default PCM to:

pcm.!default {
	type asym
	playback.pcm "upmix_20to51"
}

To get upmixing.

However

speaker-test -D upmix_20to51 -c 6

Gives me only sound from L&R speakers. How can i fix that?

pcm.!default {
	type plug
	slave.pcm "surround51"
	slave.channels 6
	route_policy duplicate
}

or my prettier modification...

pcm.!default {
	type plug
	slave.pcm "dmixed"
	route_policy duplicate
}

Works, but it's not exactly elegant as it has no filtering or anything...

Last edited by rabcor (2013-11-03 17:19:19)

rabcor · 2014-06-09 03:47:08

A bit of a late update, but the best upmixing I could find (and get working) was in brebs' alsa configuration file (ch51dup). Here's basically all you need to have in your config to get it:

pcm.!default {
	slave.pcm "surround51"
	slave.channels 6
	type route

	# Front and rear
	ttable.0.0 0.7
	ttable.1.1 0.7
	ttable.2.2 0.6
	ttable.3.3 0.6

	# Center and LFE
	ttable.4.4 1
	ttable.5.5 1

	# Front left/right to center
	ttable.0.4 0.5
	ttable.1.4 0.5

	# Front left/right to rear
	ttable.0.2 0.5
	ttable.1.3 0.5
}

If anyone knows of a higher quality method than this, I would be grateful to have it as I have not yet found anything that can hold a candle to Creative's CMSS-3D Surround upmixing.

Last edited by rabcor (2014-06-09 03:48:07)

brebs · 2014-06-09 07:46:25

The higher-quality method is the "upmix_20to51" which you've already seen, in the same file that I provide.

Arch Linux

#1 2013-10-29 04:45:09

Upconverting Stereo sound to Surround 5.1 or higher?

#2 2013-10-29 12:48:50

Re: Upconverting Stereo sound to Surround 5.1 or higher?

#3 2013-10-29 17:04:30

Re: Upconverting Stereo sound to Surround 5.1 or higher?

#4 2013-10-29 23:15:10

Re: Upconverting Stereo sound to Surround 5.1 or higher?

#5 2013-11-03 05:37:44

Re: Upconverting Stereo sound to Surround 5.1 or higher?

#6 2014-06-09 03:47:08

Re: Upconverting Stereo sound to Surround 5.1 or higher?

#7 2014-06-09 07:46:25

Re: Upconverting Stereo sound to Surround 5.1 or higher?

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