[LAU] Stereo-to-5.1 converter (was Re: ANN: New Quicktoot)

[Joel Roth]

PM +1000, Patrick Shirkey wrote:
> We are please to announce a new Quick Toot.
> 
> The AC3 Test Suite for ALSA
> 
> http://quicktoots.linux-audio.com

FWIW, here is a Nama script to create Patrick's stereo-to-5.1 converter
configuration.

channel 1 - Left Front : left input
channel 2 - Right Front : right input
channel 3 - Center : left + right + (bandpass 200hz-16000hz) + (amplify 71%)
channel 4 - LFE : left + right + (low pass 200hz) + (amplify 71%)
channel 5 - Left Rear: inverse left + right  + (amplify 50%) + 20ms delay
channel 6 - Right Rear: inverse channel 5

These are the commands:

add_tracks Stereo L_front R_front Center Subwoofer L_inverted Right R-L L_rear R_rear
add_bunch all Stereo L_front R_front Center Subwoofer L_inverted Right R-L L_rear R_rear

# no recording to disk, remove volume and pan controls
for all; rec_defeat; remove_fader_effect vol; remove_fader_effect pan

# create a bus for summing (inverted L) + R
add_sub_bus R-L

# we'll do our own routing for these tracks
Stereo move_to_bus null
R-L    move_to_bus null

# connect six tracks to the stereo source
for L_front R_front Center Subwoofer L_inverted Right; source track Stereo

# prepare sources for R-L (Note: 'afx' is an abbreviation for 'add_effect')
L_inverted afx chmute 2; afx ea -100
Right afx chmute 1

# feed these two tracks to R-L
for L_inverted Right; move_to_bus R-L

# sum R-L source channels to mono
R-L afx chmix 1

# Center: sum R+L to mono, bandpass, output at channel 3
Center afx chmix 3; afx efh 200; afx efl 16000; afx ea 70

# Subwoofer: sum R+L to mono, bandpass, output at channel 4
Subwoofer afx chmix 4; afx efl 200 ; afx ea 70

# L_rear and R_rear get input from R-L 
for L_rear R_rear; source track R-L

# Output L_rear, R_rear at channels 5,6
L_rear afx chmove 1 5
R_rear afx ea -100;afx chmove 1 6

Patrick's original script:
  
#!/bin/bash

ecasound -z:mixmode,sum -f:s16_le,2,48000 \
-a:1,2,3,4,5,6 -i $1 \
-a:1 -chmute:2 \
-a:2 -chmute:1 \
-a:3 -chmix:3 -efh:200 -efl:16000 -ea:70 \
-a:4 -chmix:4 -efl:200 -ea:70 \
-a:5 -chmute:2 -ea:-100 \
-a:6 -chmute:1 \
-a:5,6 -o loop,1 \
-a:7 -i loop,1 \
-a:7 -efh:200 -efl:16000 -etd:20,0,1,100,100 -ea:50 -o loop,2 \
-a:8,9 -i loop,2 \
-a:8 -chmix:5 \
-a:9 -chmix:6 -ea:-100 \
-a:1,2,3,4,8,9 -f:s16_le,6,48000 -o $2

Regards,

Joel


-- 
Joel Roth