Prev: Tridiagonal matrix - repeated solution
Next: moment invariants
From: divya sharma on 31 Mar 2010 09:27
hi
i want to embed a sine wave into a sound signal.
suppose i want to embed at total of n places in sound signal.
how can i generate a sine signal which gives me values at n locations with in same time period. so that i can add the corresponding value of sine wave( n place in sine wave to n places in sound signal) in sound signal.
and how can i retrive the signal from the sine wave at n different location to add in audio signal.

from
divya
From: Wayne King on 31 Mar 2010 09:53
"divya sharma" <dmatlab1(a)gmail.com> wrote in message <hovij8$cm8$1(a)fred.mathworks.com>...
> hi
> i want to embed a sine wave into a sound signal.
> suppose i want to embed at total of n places in sound signal.
> how can i generate a sine signal which gives me values at n locations with in same time period. so that i can add the corresponding value of sine wave( n place in sine wave to n places in sound signal) in sound signal.
> and how can i retrive the signal from the sine wave at n different location to add in audio signal.
>
> from
> divya

Hi, I'm not sure from your description exactly what you are trying to do. For example, I'm not sure what you mean by "n locations with in same time period". But, I'll guess at what you mean:

1.) Create a vector of zeros the same size as your audio signal.
2.) Create the sine wave you wish to embed, sampled at the same frequency as your audio signal. Make the length of your sine wave the duration you want, for example, one second. You will have multiply your sine wave by the proper amplitude factor to make the SNR what you want.
3.) place your sine wave at the appropriate places in your vector of zeros. For example, if you sine wave is 100 samples long and you want it start at index 1000 of your audio signal, then you'd have something like:

YourZeroVector(1000:1000+99)=YourSineWave;
4.) Add the two vectors--your audio and your vector with the embedded sinewave.

Wayne
From: divya sharma on 1 Apr 2010 06:14
hi wayne
thx for ur suggestions
actually i have taken an audio signal and applied the transformation .after this i had selected a thershold value. the values above the thershold will be selected for embedding.& these values above the thershold i called the n values.
i want to add a sine wave to these values.
one idea is to take the n instances in sine wave and add to the n values above thershold(one to one mapping )
i want the code how to do all this.
it will be helpful to me if u suggest some code.
 | 
Pages: 1
Prev: Tridiagonal matrix - repeated solution
Next: moment invariants