few words about the wavelets

Originally committed as revision 10167 to svn://svn.ffmpeg.org/ffmpeg/trunk

doc/snow.txt

@@ -231,6 +231,15 @@ FIXME
 
 Wavelet Transform:
 ==================
+
+Snow supports 2 wavelet transforms, the symmetric biorthogonal 5/3 integer
+transform and a integer approximation of the symmetric biorthogonal 9/7
+daubechies wavelet.
+
+5/3 Integer IDWT:
+FIXME
+
+snows 9/7 Integer IDWT:
 FIXME
 
 TODO: