fir2lift.txt

FIR2LIFT is a program to factor a wavelet FIR filter pair into lifting steps.

FIR2LIFT 27091999 README
========================


DISCLAIMER
==========
No claim whatsoever is made to the correctness of FIR2LIFT, or to the fitness
for use of FIR2LIFT for whatever application. FIR2LIFT is provided as is and 
is used at the user's own risk. No responsibility whatsoever for whatever 
possible damage due to the use of FIR2LIFT is accepted. Do not use FIR2LIFT in 
life supporting applications.


COPYRIGHT
=========
The copyright of FIR2LIFT 27091999 is held by Clemens Valens. All other 
trademarks are owned by there respective owners.


LICENSE
=======
License is granted for all non-commercial applications. FIR2LIFT may be 
distributed and copied freely as long as all files are passed on and all 
copyright notices remain intact.


FAQs
====
Q: What is FIR2LIFT ?
A: FIR2LIFT is a program to factor a wavelet FIR filter pair into lifting steps.
   If you do not understand this, then this program is not for you. You should
   first read the tutorials at http://perso.wanadoo.fr/polyvalens/clemens/

Q: What's new in this version ?
A: Everything.

Q: How do I use FIR2LIFT ?
A: For the moment you have to compile it everytime you change the FIRs since
   there is not yet a decent input module. You have to enter the FIRs to factor
   into the code.

Q: Where do I put my FIRs ?
A: Copy a factory provided FIR pair and change the name and coefficients. The 
   first variable of zpoly_add_element() is the filter, the second is the
   power of the filter coefficient and the third is the weight of the filter
   coefficient:

       zpoly_pair my_fir(void)
       {
         zpoly_pair fir = {NULL,NULL};
       
         fir.p1 = zpoly_add_element_to(fir.p1,-2,-0.125);
         fir.p1 = zpoly_add_element_to(fir.p1,-1,0.25);
         fir.p1 = zpoly_add_element_to(fir.p1,0,0.75);
         fir.p1 = zpoly_add_element_to(fir.p1,1,0.25);
         fir.p1 = zpoly_add_element_to(fir.p1,2,-0.125);
       
         fir.p2 = zpoly_add_element_to(fir.p2,-2,0.25);
         fir.p2 = zpoly_add_element_to(fir.p2,-1,-0.5);
         fir.p2 = zpoly_add_element_to(fir.p2,0,0.25);
       
         return fir;
       }
    
   Probably the only limit on filter lenghts is the amount of system memory and
   the time available to wait for and analyse the result. But then again, there 
   might be a bug somewhere.
   
   Then you register your FIR in the main with the command
   
       fir = my_fir();

   and that's it.
   
Q: So how do I compile FIR2LIFT ?
A: Put all files together in one directory and run make. B.T.W. the makefile was
   autogenerated by RHIDE the IDE for DJGPP, the MS-DOS port of the GNU 
   C-compiler ( http://www.delorie.com/ ). FIR2LIFT was originally written for
   MS-DOS with DJGPP.

Q: What is the status of FIR2LIFT ?
A: FIR2LIFT is still in its very early beta stages and it has version number
   27091999. There are probably many bugs and the results may even be 
   incorrect.

Q: I would like to contribute to FIR2LIFT, may I ?
A: Yes you may. Send your contributions to [e-mail] with a clear
   explication of what it is you contribute and how it should be implemented.
   If it is a useful contribution it will be added to FIR2LIFT and you will get
   your name in this FAQ list.

Q: I had some other question but it is not answered here. Can you answer it ?
A: Maybe. Try sending it to [e-mail]

Q: Are this really frequently asked questions or are you just making this up ?
A: ...
   
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