MP3 Audio Quality Enhancement

Hi All,
         We are working to develop an Algorithm for Enhancing the
Quality of compressed audio. We are thinking of having High Frequncy
Reconstrucion. We are looking for the communities suggestion or
experience on "High Frequency Reconstrucion of Compressed Audio". Will
it Enhance the quality is the question?
         We also request the community to suggest some other means of
Enhancing the Compressed Audio quality.

Thanks in Advance
-SAGAR

Sagar wrote:
> Hi All,
>          We are working to develop an Algorithm for Enhancing the
> Quality of compressed audio. We are thinking of having High Frequncy
> Reconstrucion.

Fancy word for distortion ...

> We are looking for the communities suggestion or
> experience on "High Frequency Reconstrucion of Compressed Audio". Will
> it Enhance the quality is the question?

That depends on what you kind of reconstruction algorithm you had in
mind. I doubt that much good will come of it, though.

>          We also request the community to suggest some other means of
> Enhancing the Compressed Audio quality.

You can try to mask the compression artefacts (by adding small amounts
of high frequency reverb, for example). However, you can only make up
for so much compression.

Regards,
Andor

kee wrote:

> Hi All,
> We are working to develop an Algorithm for Enhancing the
> Quality of compressed audio.   We are thinking of having High Frequncy
> Reconstrucion. We are looking for the communities suggestion or
> experience on "High Frequency Reconstrucion of Compressed Audio". Will
> it Enhance the quality is the question?
> We also request the community to suggest some other means of
> Enhancing the Compressed Audio quality.

It is not possible to improve the quality. You can apply some audio 
effects like reverberation and adaptive filtering. This makes the sound 
different, and it will be entertaining for the listener for some time.

Vladimir Vassilevsky

DSP and Mixed Signal Design Consultant

http://www.abvolt.com

If you say, you are trying to develop an algorithm to enhance compressed
audio, specifically lossy compression, then it is not possible to get
better quality than the original source. you can run two different
enhancing alforithms and compare the results for 'quality'.However You can
make it sound different than the original source by the methods Vladimir
had suggested.

APS






>Hi All,
>         We are working to develop an Algorithm for Enhancing the
>Quality of compressed audio. We are thinking of having High Frequncy
>Reconstrucion. We are looking for the communities suggestion or
>experience on "High Frequency Reconstrucion of Compressed Audio". Will
>it Enhance the quality is the question?
>         We also request the community to suggest some other means of
>Enhancing the Compressed Audio quality.
>
>Thanks in Advance
>-SAGAR
>
>

Hi All,

   When we go for High frequency reverb, what i find is if we apply
high frequency reverb will it not distort the signal??

With warm regards,
-Prasad B C

Andor wrote:
> Sagar wrote:
> > Hi All,
> >          We are working to develop an Algorithm for Enhancing the
> > Quality of compressed audio. We are thinking of having High Frequncy
> > Reconstrucion.
>
> Fancy word for distortion ...
>
> > We are looking for the communities suggestion or
> > experience on "High Frequency Reconstrucion of Compressed Audio". Will
> > it Enhance the quality is the question?
>
> That depends on what you kind of reconstruction algorithm you had in
> mind. I doubt that much good will come of it, though.
>
> >          We also request the community to suggest some other means of
> > Enhancing the Compressed Audio quality.
>
> You can try to mask the compression artefacts (by adding small amounts
> of high frequency reverb, for example). However, you can only make up
> for so much compression.
>
> Regards,
> Andor

Adding high frequency (or in fact any) reverb is a linear and time-
inavariant proces. Depends on how you define "distortion". It
certainly is less obtrusive than "generating" high frequency content
using non-linear processing.

Prassi wrote:
> Hi All,
>
>    When we go for High frequency reverb, what i find is if we apply
> high frequency reverb will it not distort the signal??
>
> With warm regards,
> -Prasad B C
>
>
>
> Andor wrote:
> > Sagar wrote:
> > > Hi All,
> > >          We are working to develop an Algorithm for Enhancing the
> > > Quality of compressed audio. We are thinking of having High Frequncy
> > > Reconstrucion.
>
> > Fancy word for distortion ...
>
> > > We are looking for the communities suggestion or
> > > experience on "High Frequency Reconstrucion of Compressed Audio". Will
> > > it Enhance the quality is the question?
>
> > That depends on what you kind of reconstruction algorithm you had in
> > mind. I doubt that much good will come of it, though.
>
> > >          We also request the community to suggest some other means of
> > > Enhancing the Compressed Audio quality.
>
> > You can try to mask the compression artefacts (by adding small amounts
> > of high frequency reverb, for example). However, you can only make up
> > for so much compression.
>
> > Regards,
> > Andor- Zitierten Text ausblenden -
>
> - Zitierten Text anzeigen -

Hi,

   I am using RBJ Audio cook book for calculation of the shelving
filter co-efficient.
for a low pass shelving filter with cutoff of f0 = 3KHz (means
bandwith is 3KHz) i want to calculate alpha with bandwidth given.
Formula for alpha according to the cookbook is

alpha = sin(w0) * sinh(ln(2)/2*BW*w0/sin(w0)) where w0 = (2*pi*f0)/fs
and fs = 44.1KHz

here in this formula if i take BW = 3KHz and claculate the value in
matlab i am getting  "INF", so please can you help me out how to
calculate "alpha" when bandwidht is given.

Thanks a lot,

Rgds,
-Prasad