add notes on 32-bit building

README

@@ -69,6 +69,14 @@ $ make && sudo make install # by default installs to /usr/local/bin/wavegain
 or
 $ make && sudo make install prefix=/usr # to install to /usr/bin/wavegain
 
+Currently, 64-bit binaries build fine but can generate corrupted audio on output
+files, so to prevent this by default it builts a 32-bit executable instead,
+which runs and works fine on 64-bit architectures. However, multi-arch libraries
+and headers might be needed as a pre-requiste for compiling. On Debian/Ubuntu this
+can be installed by:
+
+	sudo apt install gcc-multilib
+
 
 Pre-compiled binaries and old versions
 -------------------------------------------------------------------------------

TODO

@@ -1,3 +1,8 @@
+- Investigate why 64-bit executable corrupt some test files by chopping audio and
+    changing its pitch. Original windows binary was 32 bits, and to prevent this bug
+    so is this build, forcedly by using GCC's -m32 flag. Proof-reading is required to
+    see what triggers the bug in 64-bits binaries and, to hopefully allow for a non-buggy
+    native AMD64 build in the future.
 - Consider generating a 32-bit binary instead of 64 using GCC's `-m32` flag.
     Original binary was 32 bits, the convertion to 64 never had any proof-reading, 
     and this might be the root cause of several bugs.