first, i want to say that i work with the Series 60 SDKs for Symbian OS v2.0 download on this site

i want to use CMdaAudioInputStream class to record, handle and process audio data.
When i want to use newL, during linking i have this message error :
unresolved external symbol "public: static class CMdaAudioInputStream * __cdecl CMdaAudioInputStream::NewL(class MMdaAudioInputStreamCallback &)" ...

The sdk doesn't seem to know this method.
I have of course add the library mediaclientaudiostream.lib in my mmp file.

I've try to understand and i'v opened the .lib file to look if it knows something about CMdaAudioInputStream class but it seems not.
Furthermore, mediaclientaudiostream.lib filesize is 3ko in my sdk and in an old sdk ( a v20 beta release) his filesize is 18ko and it seems to know more things about CMdaAudioInputStream. I haven't try to compile with this sdk because i wan't to understand why a new version of the sdk don't know implementation about a class supported from 7.0s

If someone who have use this class could help me, or someone who know what's that joke