[MPlayer-dev-eng] Audio Visualization Plugin

[Ponekker Zoltan]

Hali

Please read DOCS/tech/patches.txt, and resend your patch :)

Pontscho


On Thu, 29 Aug 2002, Anders Johansson wrote:

> Hi Gustavo,
>
> The current audio plugin layer will soon be replaced by a new more
> generic one. Attached to this mail is the current work in progress.
> Warning the attached files "mplayer.c" and "Makefile" brakes mplayer a
> little bit so take appropriate precautions before you use them.
>
> As for where to start:
>
> If you want to do something that works for real (which imho you
> should) then you could use Welch periodogram method to do the
> spectral estimation. This will give you a good spectral estimates
> where the level of each frequency bin represents the actual energy
> level in that frequency band.
>
> To do the required FFT you could use the fftw package (very fast).
>
> If you have access to Matlab (and understands matlab code) you could
> have a look at the source code for the psd() function to get the
> implementation started (search for psd.m in the matlab installation
> directory to find it). I guess you can find something similar in
> Octave. I can also recommend the following two books on the subject:
>
> "Digital spectral analysis with application", S.Lawrence Marple, Jr
> "Statistical Digital Signal Processing and Modeling", Monson H. Hayes
>
> I have some sample code for using fftw if you want it (can't send it
> public so contact me outside list).
>
> To check your results try dumping the estimates to file and read them
> with gnuplot or matlab.
>
> I will be happy to help you with the audio part of the work.
>
> Good luck,
> //Anders
>
>
>