search for: steganographi

On Thu, Aug 3, 2023 at 2:35?PM Chris Rapier <rapier at psc.edu> wrote: > > Howdy all, > > So, one night over beers I was telling a friend how you could use the > timing between key presses on a type writer to extract information. > Basically, you make some assumptions about the person typing (touch > typing at so many words per second and then fuzzing the parameters

Hi, Jean-Marc Valin wrote: > Well, you could change the order in the encoder as long as you reverse > it in the decoder as well. Ok, I see that in the split_cb_shape_sign_unquant function, that each coefficient is tied to it's position in the nb_subvect exc coefficients. Honestly, I have problems understanding what exactly the codebook search works like. If you have the time to to

Hello kind developers, I am planning on creating a steganographic extension for speex/CELP. Since speex/CELP is lossy, there should be quite many bits that one can use for hiding data. I'm familiar with the principles of CELP (two filter loops, one for pitch, the other for formants, let the raw speech frame run through those filter loops, take residue signa...

Hi, Jean-Marc Valin wrote: >> 1. What is the point in multiplying a codebook index with some number >> ant adding a loop variable to it as done in the exc unquant function. >> for (j=0;j<subvect_size;j++) >> exc[subvect_size*i+j]+=s*0.03125*shape_cb[ind[i]*subvect_size+j]; > > That's just how you represent a 2D array in C: the codebook has

> I am planning on creating a steganographic extension for speex/CELP. > Since speex/CELP is lossy, there should be quite many bits that one > can use for hiding data. Quite the opposite. Speex uses very few bits, so every bit you corrupt is likely to be heard. You would need to use "fractions of bits" at a time. Even then,...

> 1. What is the point in multiplying a codebook index with some number > ant adding a loop variable to it as done in the exc unquant function. > for (j=0;j<subvect_size;j++) > exc[subvect_size*i+j]+=s*0.03125*shape_cb[ind[i]*subvect_size+j]; That's just how you represent a 2D array in C: the codebook has shape_cb_size entries and subvect_size samples per

How about this: the codebook search gives you the N best (in order) combinations of entries for the current sub-frame. You can simply compute a one-bit checksum on all the codebook entries and choose which of the N-best to use based on that and the "message" you have. Of course, there will be cases where all of the N-best match to the same checksum, but that's what error-correcting

Hello, Is it possible to adjust the level of the denoiser ? In an old beta, before you change the aggressiveness of the denoiser, it works very well with the noise of a car, a road etc... but not now. The AEC too works very well in a old beta, but now, I think there is a problem... I have tested it with the same sound card (WB 16000). In any case, your project is the best VOIP library in this

Howdy all, So, one night over beers I was telling a friend how you could use the timing between key presses on a type writer to extract information. Basically, you make some assumptions about the person typing (touch typing at so many words per second and then fuzzing the parameters until words come out). The I found a paper written back in 2001 talked about using the interpacket timing in

Hello, Jean-Marc Valin schrieb: >>I am planning on creating a steganographic extension for speex/CELP. >>Since speex/CELP is lossy, there should be quite many bits that one >>can use for hiding data. > > Quite the opposite. Speex uses very few bits, so every bit you corrupt > is likely to be heard. You would need to use "fractions of bits" a...

Dear OpenSSH team, First of all thanks a lot for your good work on developing such a usable peace of software. Nice job. As you may know, we have some issues using OpenSSH in Iran. Recently the government did some packet filtering on some protocols, including SSH. We don't know what exactly they've done but it appears to be some routing rule that prevents SSH protocol to initiate a