Removing background music from driver level

Audio software developers forum.

If you require help using Audacity, please post on the forum board relevant to your operating system:
Windows
Mac OS X
GNU/Linux and Unix-like

Re: Removing background music from driver level

Permanent link to this post Posted by kozikowski » Mon Jun 13, 2016 6:51 pm

left and right are reduced by a mere 6 dB.

I was admiring the flowers and clouds and semi-thinking about this. 6dB is a piffle compared to the full range of sounds and production, but it is half. Half the voltage in the presentation signal just vanished. Could you not use that as the cue for further processing? Sense the parts of the show that dip 6dB and assume they are the ones that need further processing?

Or is that what you're already doing and I'm late to the ball.

Koz
kozikowski
Forum Staff
 
Posts: 37710
Joined: Thu Aug 02, 2007 5:57 pm
Location: Los Angeles
Operating System: OS X 10.9 Mavericks

Re: Removing background music from driver level

Permanent link to this post Posted by Robert J. H. » Mon Jun 13, 2016 9:42 pm

kozikowski wrote:
left and right are reduced by a mere 6 dB.

I was admiring the flowers and clouds and semi-thinking about this. 6dB is a piffle compared to the full range of sounds and production, but it is half. Half the voltage in the presentation signal just vanished. Could you not use that as the cue for further processing? Sense the parts of the show that dip 6dB and assume they are the ones that need further processing?

Or is that what you're already doing and I'm late to the ball.

Koz

Indeed, I'm just doing that:
The audio is first transformed into side (L-R) and mid (L+R).
In the Short Fourier transform, the side is divided by the mid signal (magnitudes)--for all of the 4096 frequency bands.
The resulting array of values is then remapped to make a weighting for the mid channel, which is multiplied by those, still bin by bin.
The reconstructed mid channel is now indeed the center with a magnitude proportional to the distance from the center-panned position.
Subtracting the center from L and R respectively gives the stereo audio without center.
Robert
Robert J. H.
 
Posts: 1813
Joined: Thu May 31, 2012 8:33 am
Operating System: Windows 7

Previous

Return to General Audio Programming



Who is online

Users browsing this forum: Yahoo [Bot] and 3 guests