Displaying 20 results from an estimated 34 matches for "decorrelate".
2009 Jan 30
1
echo_cancellation_api
Please,
I'm looking at speex rc1 echo_cancellation API docs and I
found there is now a funcion for doing decorrelation:
void speex_decorrelate(
SpeexDecorrState * st,
const spx_int16_t * in,
spx_int16_t * out,
int strength)
How does it fit to the speex_echo_cancellation function ?
When removing echo from multiple channels I need to
decorrelate the input mic first and then put the
decorrelation output in the rec paramet...
2006 Oct 09
2
understanding decorrelation
Hi FLACers
I'm studying music production and am currently doing an analysis of the FLAC format. If anyone has the knowledge and a minute to explain i would greatly appreciate any help. One thing that i cannot make sense from in the FLAC documentation (a thing that is hard to find info on in general) is how the decorrelation fase works exactly. I understand that the two channels in a stereo
2008 Oct 30
3
Multichannel echo cancellation
...ve been searching documentation about that but I could not find it
Where it is? If it doesn't exist? Could you add a short example showing
how do you think it should work?
or It's "just" necessary to:
init the multichannel echo cancellation state,
init the decorrelation state
decorrelate the far-end signal
apply cancellation (the same way it is applied to a single channel)
destroy the decorrelation state
destroy the multichannel echo canceller state,
Best regards
David
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.xiph.org...
2006 Oct 09
0
understanding decorrelation
--- Ulrik Nissen <obbarius@rediffmail.com> wrote:
>
> Hi FLACers
>
> I'm studying music production and am currently doing an analysis of
> the FLAC format. If anyone has the knowledge and a minute to explain
> i would greatly appreciate any help. One thing that i cannot make
> sense from in the FLAC documentation (a thing that is hard to find
> info on in
2013 Jun 19
0
Simple example of variables decorrelation using the Cholesky decomposition
...ations of 2 variables, 100% correlated
obs=matrix(nrow=2,ncol=4)
obs[1,]=seq(from=1, to=4, by=1)
obs[2,]=obs[1,]
# Plot
plot( obs[1,], obs[2,],pch=16)
# Correlation matrix
corr=matrix(nrow=2,ncol=2)
corr[1,2]=0.95
corr[2,1]=0.95
corr[1,1]=1
corr[2,2]=1
# Cholesky decomposition
choM=chol(corr)
# Decorrelated observation
decObs=matrix(nrow=2,ncol=4)
for( i in 1:4 ) decObs[,i]=choM%*%obs[,i]
# Other possibility
#decObs=solve(choM,obs)
# Plot
plot(decObs[1,], decObs[2,],pch=16)
###########################################
Does anyone have an idea?
Thanks,
regards,
Xavier
--
*----------------------...
2004 Sep 10
2
multi-channel / ambisonics
when i encode i multi channel file, does flac encode every channel
seperatly or does is look for similarities between channels?
the documentation says:
INTER-CHANNEL DECORRELATION
In the case of stereo input, once the data is blocked it is optionally
passed through an inter-channel decorrelation stage. The left and right
channels are converted to center and side channels through the following
2007 Jan 02
3
Decoding Type=Independent
On 1/2/07, Josh Coalson <xflac@yahoo.com> wrote:
> I'm not sure I understand... I think the INDEPENDENT you are referring
> to means the interchannel decorrelation method. this stage is before
> and independent of LPC analysis.
Correct.
> I'm not sure why "independent" frames would not decode correctly
> though. more info on exactly how it is not working
2007 Jan 01
2
Decoding Type=Independent
Hello, I am new to the list, to FLAC and to FLAC development but I am
having a problem in trying to make FLAC work with MediaMVP based the
mvpmc project (ref. http://www.wvpmc.org) that hopefully someone can
help me with. This device is possibly minimum spec. for a FLAC
decoder.
In any case, I have had some success cross-compiling libFLAC (without
the ogg or metadata modules).for the embedded
2009 Apr 14
3
technical questions about FLAC
Hey everyone,
I have a few questions about FLAC that aren't answered in the FAQ or the documentation. Maybe someone knows about these details.
1. What exactly is meant by "reference encoder"?
2. Concerning interchannel decorrelation, what is the point of creating separate signals, why not just keep the channels you have? For example, you might create "mid" and
2004 Sep 10
3
Non-audio applications
Hi,
I work for a company which makes meteor and wind radar
(http://www.gsoft.com.au).
On occasion (ie during meteor showers such as the Leonids) we configure
the system to save raw data as it comes out of the acquisition system,
the data rate for this varies (depends on acquisition parameters and
number of coherent integrations etc), but usually it is around
600kb/sec.
The data consists of 16
2004 Sep 10
4
Compressing sound fonts with FLAC
Josh Coalson wrote:
> yeah, flac doesn't have a 'gzip' fallback method
> so any non-audio data will probably get stored
> verbatim. I'm kind of reluctant to add a generic
> compressor. If you wan't, you could come up with a
> FLAC metadata block to store a gzip'ed chunk and I
> could add that to the format.
>
I had the same thought when I was
2008 Jul 24
0
Speex 1.2rc1 is out, status update
Hi everyone,
I've just released Speex 1.2rc1. This adds support for acoustic echo
cancellation with multiple microphones and multiple loudspeakers. It
also adds an API to decorrelate loudspeaker signals to improve
multi-channel performance. In the bugfix department, there are fixes for
a few bugs in the echo canceller, jitter buffer and preprocessor. At
this point, the API for 1.2 should be stable and only a few very minor
additions are planned. The mirrors haven't updated...
2009 Feb 05
0
AEC in live performance
Hi,
I plan to use AEC for a live performance, storytelling for very young
children (and their parents!) in a mongolian yourte . Actually the
storyteller can make vocal loops, there is an omnidirectional microphone
in the center of the yourte, 5 loudspeakers in a circle along the
yourte's wall and Pure Data in a linux box. And now she wants to make
vocal loops over music and loops over
2004 Sep 10
0
Compressing sound fonts with FLAC
> > the best thing would be to try and set the
> blocksize
> > to match the length of the individual 'sample'.
> if
> > each sample is much shorter than the blocksize
> then
> > the encoder may not be able to generate an
> efficient
> > model of the signal. if the samples within the
> > soundfont vary greatly in length that also makes
>
2004 Sep 10
1
FLAC and Surround
Hello,
I'm new to this list, and I would like to know about the current status of
FLAC and surround formats (5.1, 7.1). I know it is possible to compress
interleaved multichannel files with FLAC, but does it in any way have any
multichannel matrix, that collects common information from all channels and
use this when compressing?
If not, wouldn't it be a great idea to have this feature!!!
2007 Jan 02
0
Decoding Type=Independent
--- MVallevand <mvallevand@gmail.com> wrote:
> Hello, I am new to the list, to FLAC and to FLAC development but I am
> having a problem in trying to make FLAC work with MediaMVP based the
> mvpmc project (ref. http://www.wvpmc.org) that hopefully someone can
> help me with. This device is possibly minimum spec. for a FLAC
> decoder.
>
> In any case, I have had some
2007 Jan 02
0
Decoding Type=Independent
--- MVallevand <mvallevand@gmail.com> wrote:
> On 1/2/07, Josh Coalson <xflac@yahoo.com> wrote:
> > I'm not sure I understand... I think the INDEPENDENT you are
> referring
> > to means the interchannel decorrelation method. this stage is
> before
> > and independent of LPC analysis.
>
> Correct.
>
> > I'm not sure why
2012 Jun 17
0
flac -- exhaustive model search vs. -A <*>?
Martin Leese wrote:
>
> At:
> http://flac.sourceforge.net/documentation_tools_flac.html#flac_options_exhaustive_model_search
>
> it states, "If the max LPC order is high this
> can significantly increase the encode time."
> This suggest that if the max LPC order is low
> then using -e will not be slow.
>
----
That brings up another question then... What
2012 Jun 19
2
flac -- exhaustive model search vs. -A <*>?
Linda Walsh <flac at tlinx.org> wrote:
...
> That brings up another question then... What is 'hi' (v. low?)...
Zero, or close to zero, is low. 12 is high.
...
> What's a subset stream?
This is explained at:
http://flac.sourceforge.net/format.html
in the bulleted point beginning, "FLAC
specifies a subset of itself as the Subset
format."
...
> Another
2016 Apr 18
5
Channel Mapping Family for Ambisonics
Hello,
We (Google) have been experimenting with configuration and adjustments to
CELT-only Opus that give good results for compressing ambisonic audio
signals [1]. Based on our results so far, we would like to use Opus to
encode spatial audio. We hope to make it easy/possible to use libopus with
other common tools and software modules (ffmpeg/libav in particular).
Based on my reading of the